Merge pull request 'Statistic Page closes #310' (#417) from feature/statistics into main

Reviewed-on: #417
Reviewed-by: carla <carla@noreply.git.local-it.org>

CODE_GUIDELINES.md

@@ -118,7 +118,8 @@ lib/
 │   ├── mailer.ex          # Email mailer
 │   ├── release.ex         # Release tasks
 │   ├── repo.ex            # Database repository
-│   └── secrets.ex         # Secret management
+│   ├── secrets.ex         # Secret management
+│   └── statistics.ex      # Reporting: member/cycle aggregates (counts, sums by year)
 ├── mv_web/                # Web interface layer
 │   ├── components/        # UI components
 │   │   ├── core_components.ex
@@ -155,6 +156,7 @@ lib/
 │   │   ├── import_export_live.ex    # CSV import/export LiveView (mount/events/glue only)
 │   │   ├── import_export_live/     # Import/Export UI components
 │   │   │   └── components.ex       # custom_fields_notice, template_links, import_form, progress, results
+│   │   ├── statistics_live.ex      # Statistics page (aggregates, year filter, joins/exits by year)
 │   │   └── contribution_type_live/ # Contribution types (mock-up)
 │   ├── auth_overrides.ex  # AshAuthentication overrides
 │   ├── endpoint.ex        # Phoenix endpoint

docs/feature-roadmap.md

@@ -291,10 +291,10 @@
 #### 10. **Reporting & Analytics** 📊
 
 **Current State:**
-- ❌ No reporting features
+- ✅ **Statistics page (MVP)** – `/statistics` with active/inactive member counts, joins/exits by year, cycle totals, open amount (2026-02-10)
 
 **Missing Features:**
-- ❌ Member statistics dashboard
+- ❌ Extended member statistics dashboard
 - ❌ Membership growth charts
 - ❌ Payment reports
 - ❌ Custom report builder

docs/page-permission-route-coverage.md

@@ -26,6 +26,7 @@ This document lists all protected routes, which permission set may access them,
 | `/groups/new` | ✗ | ✗ | ✗ | ✓ |
 | `/groups/:slug` | ✗ | ✓ | ✓ | ✓ |
 | `/groups/:slug/edit` | ✗ | ✗ | ✗ | ✓ |
+| `/statistics` | ✗ | ✓ | ✓ | ✓ |
 | `/admin/roles` | ✗ | ✗ | ✗ | ✓ |
 | `/admin/roles/new` | ✗ | ✗ | ✗ | ✓ |
 | `/admin/roles/:id` | ✗ | ✗ | ✗ | ✓ |

docs/statistics-page-implementation-plan.md

@@ -0,0 +1,163 @@
+# Statistics Page – Implementation Plan
+
+**Project:** Mila – Membership Management System  
+**Feature:** Statistics page at `/statistics`  
+**Scope:** MVP only (no export, no optional extensions)  
+**Last updated:** 2026-02-10
+
+---
+
+## Decisions (from clarification)
+
+| Topic | Decision |
+|-------|----------|
+| Route | `/statistics` |
+| Navigation | Top-level menu (next to Members, Fee Types) |
+| Permission | read_only, normal_user, admin (same as member list) |
+| Charts | HTML/CSS and SVG only (no Contex, no Chart.js) |
+| MVP scope | Minimal: active/inactive, joins/exits per year, contribution sums per year, open amount |
+| Open amount | Total unpaid only (no overdue vs. not-yet-due split in MVP) |
+
+Excluded from this plan: Export (CSV/PDF), caching, month/quarter filters, “members per fee type”, “members per group”, and overdue split.
+
+---
+
+## 1. Statistics module (`Mv.Statistics`)
+
+**Goal:** Central module for all statistics; LiveView only calls this API. Uses Ash reads with actor so policies apply.
+
+**Location:** `lib/mv/statistics.ex` (new).
+
+**Functions to implement:**
+
+| Function | Purpose | Data source |
+|----------|---------|-------------|
+| `active_member_count(opts)` | Count members with `exit_date == nil` | `Member` read with filter |
+| `inactive_member_count(opts)` | Count members with `exit_date != nil` | `Member` read with filter |
+| `joins_by_year(year, opts)` | Count members with `join_date` in given year | `Member` read, filter by year, count |
+| `exits_by_year(year, opts)` | Count members with `exit_date` in given year | `Member` read, filter by year, count |
+| `cycle_totals_by_year(year, opts)` | For cycles with `cycle_start` in year: total sum, and sums/counts by status (paid, unpaid, suspended) | `MembershipFeeCycle` read (filter by year via `cycle_start`), aggregate sum(amount) and count per status in Elixir or via Ash aggregates |
+| `open_amount_total(opts)` | Sum of `amount` for all cycles with `status == :unpaid` | `MembershipFeeCycle` read with filter `status == :unpaid`, sum(amount) |
+
+All functions accept `opts` (keyword list) and pass `actor: opts[:actor]` (and `domain:` where needed) to Ash calls. No new resources; only read actions on existing `Member` and `MembershipFeeCycle`.
+
+**Implementation notes:**
+
+- Use `Ash.Query.filter(Member, expr(...))` for date filters; for “year”, filter `join_date >= first_day_of_year` and `join_date <= last_day_of_year` (same for `exit_date` and for `MembershipFeeCycle.cycle_start`).
+- For `cycle_totals_by_year`: either multiple Ash reads (one per status) with sum aggregate, or one read of cycles in that year and `Enum.group_by(..., :status)` then sum amounts in Elixir.
+- Use `Mv.MembershipFees.CalendarCycles` only if needed for interval (e.g. cycle_end); for “cycle in year” the `cycle_start` year is enough.
+
+**Tests:** Unit tests in `test/mv/statistics_test.exs` for each function (with fixtures: members with join_date/exit_date, cycles with cycle_start/amount/status). Use `Mv.Helpers.SystemActor.get_system_actor()` in tests for Ash read authorization where appropriate.
+
+---
+
+## 2. Route and authorization
+
+**Router** ([lib/mv_web/router.ex](lib/mv_web/router.ex)):
+
+- In the same `ash_authentication_live_session` block where `/members` and `/membership_fee_types` live, add:
+  - `live "/statistics", StatisticsLive, :index`
+
+**PagePaths** ([lib/mv_web/page_paths.ex](lib/mv_web/page_paths.ex)):
+
+- Add module attribute `@statistics "/statistics"`.
+- Add `def statistics, do: @statistics`.
+- No change to `@admin_page_paths` (statistics is top-level).
+
+**Page permission** (route matrix is driven by [lib/mv/authorization/permission_sets.ex](lib/mv/authorization/permission_sets.ex)):
+
+- Add `"/statistics"` to the `pages` list of **read_only** (e.g. after `"/groups/:slug"`) and to the `pages` list of **normal_user** (e.g. after groups entries). **admin** already has `"*"` so no change.
+- **own_data** must not list `/statistics` (so they cannot access it).
+- Update [docs/page-permission-route-coverage.md](docs/page-permission-route-coverage.md): add row for `| /statistics | ✗ | ✓ | ✓ | ✓ |`.
+- Add test in `test/mv_web/plugs/check_page_permission_test.exs`: read_only and normal_user and admin can access `/statistics`; own_data cannot.
+
+---
+
+## 3. Sidebar
+
+**File:** [lib/mv_web/components/layouts/sidebar.ex](lib/mv_web/components/layouts/sidebar.ex).
+
+- In `sidebar_menu`, after the “Fee Types” menu item and before the “Administration” block, add a conditional menu item for Statistics:
+  - `can_access_page?(@current_user, PagePaths.statistics())` → show link.
+  - `href={~p"/statistics"}`, `icon="hero-chart-bar"` (or similar), `label={gettext("Statistics")}`.
+
+---
+
+## 4. Statistics LiveView
+
+**Module:** `MvWeb.StatisticsLive`  
+**File:** `lib/mv_web/live/statistics_live.ex`  
+**Mount:** `:index` only.
+
+**Behaviour:**
+
+- `on_mount`: use `MvWeb.LiveUserAuth, :live_user_required` and ensure role/permission check (same as other protected LiveViews). In `mount` or `handle_params`, set default selected year to current year (e.g. `Date.utc_today().year`).
+- **Assigns:** `:year` (integer), `:active_count`, `:inactive_count`, `:joins_this_year`, `:exits_this_year`, `:cycle_totals` (map with keys e.g. `:total`, `:paid`, `:unpaid`, `:suspended` for the selected year), `:open_amount_total`, and any extra needed for the bar data (e.g. list of `%{year: y, joins: j, exits: e}` for a small range of years if you show a minimal bar chart).
+- **Year filter:** A single select or dropdown for year (e.g. from “first year with data” to current year). On change, send event (e.g. `"set_year"`) with `%{"year" => year}`; in `handle_event` update `assigns.year` and reload data by calling `Mv.Statistics` again and re-assigning.
+
+**Data loading:**
+
+- In `mount` and whenever year changes, call `Mv.Statistics` with `actor: current_actor(socket)` (and optionally `year: @year` where needed). Assign results to socket. Handle errors (e.g. redirect or flash) if a call fails.
+
+**Layout (sections):**
+
+1. **Page title:** e.g. “Statistics” (gettext).
+2. **Year filter:** One control to select year; applies to “joins/exits” and “contribution sums” for that year.
+3. **Cards (top row):**
+   - Active members (count)
+   - Inactive members (count)
+   - Joins in selected year
+   - Exits in selected year
+   - Open amount total (sum of all unpaid cycles; format with `MvWeb.Helpers.MembershipFeeHelpers.format_currency/1`)
+   - Optionally: “Paid this year” (from `cycle_totals_by_year` for selected year)
+4. **Contributions for selected year:** One section showing for the chosen year: total (Soll), paid, unpaid, suspended (sums and optionally counts). Use simple table or key-value list; no chart required for MVP.
+5. **Joins / Exits by year (simple bar chart):** Data: e.g. last 5 or 10 years. For each year, show joins and exits as horizontal bars (HTML/CSS: e.g. `div` with `width: #{percent}%`). Pure HTML/SVG; no external chart library. Use Tailwind/DaisyUI for layout and cards.
+
+**Accessibility:** Semantic HTML; headings (e.g. `h2`) for each section; ensure year filter has a label; format numbers in a screen-reader-friendly way (e.g. no purely visual abbreviations without aria-label).
+
+**i18n:** All user-visible strings via gettext (e.g. “Statistics”, “Active members”, “Inactive members”, “Joins (year)”, “Exits (year)”, “Open amount”, “Contributions for year”, “Total”, “Paid”, “Unpaid”, “Suspended”). Add keys to `priv/gettext` as needed.
+
+---
+
+## 5. Implementation order (tasks)
+
+Execute in this order so that each step is testable:
+
+1. **Statistics module**
+   - Add `lib/mv/statistics.ex` with the six functions above and `@moduledoc`.
+   - Add `test/mv/statistics_test.exs` with tests for each function (use fixtures for members and cycles; pass actor in opts).
+   - Run tests and fix until green.
+
+2. **Route and permission**
+   - Add `live "/statistics", StatisticsLive, :index` in router.
+   - Add `statistics/0` and `@statistics` in PagePaths.
+   - Add `/statistics` to page permission logic so read_only, normal_user, admin are allowed and own_data is denied.
+   - Update `docs/page-permission-route-coverage.md` and add/update plug tests for `/statistics`.
+
+3. **Sidebar**
+   - Add Statistics link in sidebar (top-level) with `can_access_page?` and `PagePaths.statistics()`.
+
+4. **StatisticsLive**
+   - Create `lib/mv_web/live/statistics_live.ex` with mount, assigns, year param, and data loading from `Mv.Statistics`.
+   - Implement UI: title, year filter, cards, contribution section, simple joins/exits bar (HTML).
+   - Add gettext keys and use them in the template.
+   - Optionally add a simple LiveView test (e.g. authenticated user sees statistics page and key labels).
+
+5. **CI and docs**
+   - Run `just ci-dev` (or project equivalent); fix formatting, Credo, and tests.
+   - In [docs/feature-roadmap.md](docs/feature-roadmap.md), update “Reporting & Analytics” to reflect that a basic statistics page is implemented (MVP).
+   - In [CODE_GUIDELINES.md](CODE_GUIDELINES.md), add a short note under a suitable section (e.g. “Reporting” or “LiveView”) that statistics are provided by `Mv.Statistics` and displayed in `StatisticsLive`, if desired.
+
+---
+
+## 6. Out of scope (not in this plan)
+
+- Export (CSV/PDF).
+- Caching (ETS/GenServer/HTTP).
+- Month or quarter filters.
+- “Members per fee type” or “members per group” statistics.
+- Overdue vs. not-yet-due split for open amount.
+- Contex or Chart.js.
+- New database tables or Ash resources.
+
+These can be added later as separate tasks or follow-up plans.

lib/mv/authorization/permission_sets.ex

@@ -178,7 +178,9 @@ defmodule Mv.Authorization.PermissionSets do
         # Groups overview
         "/groups",
         # Group detail
-        "/groups/:slug"
+        "/groups/:slug",
+        # Statistics
+        "/statistics"
       ]
     }
   end
@@ -243,7 +245,9 @@ defmodule Mv.Authorization.PermissionSets do
         # Group detail
         "/groups/:slug",
         # Edit group
-        "/groups/:slug/edit"
+        "/groups/:slug/edit",
+        # Statistics
+        "/statistics"
       ]
     }
   end

lib/mv/membership_fees/cycle_generator.ex

@@ -87,7 +87,7 @@ defmodule Mv.MembershipFees.CycleGenerator do
   def generate_cycles_for_member(member_or_id, opts \\ [])
 
   def generate_cycles_for_member(member_id, opts) when is_binary(member_id) do
-    case load_member(member_id) do
+    case load_member(member_id, opts) do
       {:ok, member} -> generate_cycles_for_member(member, opts)
       {:error, reason} -> {:error, reason}
     end
@@ -97,25 +97,25 @@ defmodule Mv.MembershipFees.CycleGenerator do
     today = Keyword.get(opts, :today, Date.utc_today())
     skip_lock? = Keyword.get(opts, :skip_lock?, false)
 
-    do_generate_cycles_with_lock(member, today, skip_lock?)
+    do_generate_cycles_with_lock(member, today, skip_lock?, opts)
   end
 
   # Generate cycles with lock handling
   # Returns {:ok, cycles, notifications} - notifications are never sent here,
   # they should be returned to the caller (e.g., via after_action hook)
-  defp do_generate_cycles_with_lock(member, today, true = _skip_lock?) do
-    # Lock already set by caller (e.g., regenerate_cycles_on_type_change)
+  defp do_generate_cycles_with_lock(member, today, true = _skip_lock?, opts) do
+    # Lock already set by caller (e.g., regenerate_cycles_on_type_change or seeds)
     # Just generate cycles without additional locking
-    do_generate_cycles(member, today)
+    do_generate_cycles(member, today, opts)
   end
 
-  defp do_generate_cycles_with_lock(member, today, false) do
+  defp do_generate_cycles_with_lock(member, today, false, opts) do
     lock_key = :erlang.phash2(member.id)
 
     Repo.transaction(fn ->
       Ecto.Adapters.SQL.query!(Repo, "SELECT pg_advisory_xact_lock($1)", [lock_key])
 
-      case do_generate_cycles(member, today) do
+      case do_generate_cycles(member, today, opts) do
         {:ok, cycles, notifications} ->
           # Return cycles and notifications - do NOT send notifications here
           # They will be sent by the caller (e.g., via after_action hook)
@@ -235,25 +235,33 @@ defmodule Mv.MembershipFees.CycleGenerator do
 
   # Private functions
 
-  defp load_member(member_id) do
-    system_actor = SystemActor.get_system_actor()
-    opts = Helpers.ash_actor_opts(system_actor)
+  # Use actor from opts when provided (e.g. seeds pass admin); otherwise system actor
+  defp get_actor(opts) do
+    case Keyword.get(opts, :actor) do
+      nil -> SystemActor.get_system_actor()
+      actor -> actor
+    end
+  end
+
+  defp load_member(member_id, opts) do
+    actor = get_actor(opts)
+    read_opts = Helpers.ash_actor_opts(actor)
 
     query =
       Member
       |> Ash.Query.filter(id == ^member_id)
       |> Ash.Query.load([:membership_fee_type, :membership_fee_cycles])
 
-    case Ash.read_one(query, opts) do
+    case Ash.read_one(query, read_opts) do
       {:ok, nil} -> {:error, :member_not_found}
       {:ok, member} -> {:ok, member}
       {:error, reason} -> {:error, reason}
     end
   end
 
-  defp do_generate_cycles(member, today) do
+  defp do_generate_cycles(member, today, opts) do
     # Reload member with relationships to ensure fresh data
-    case load_member(member.id) do
+    case load_member(member.id, opts) do
       {:ok, member} ->
         cond do
           is_nil(member.membership_fee_type_id) ->
@@ -263,7 +271,7 @@ defmodule Mv.MembershipFees.CycleGenerator do
             {:error, :no_join_date}
 
           true ->
-            generate_missing_cycles(member, today)
+            generate_missing_cycles(member, today, opts)
         end
 
       {:error, reason} ->
@@ -271,7 +279,7 @@ defmodule Mv.MembershipFees.CycleGenerator do
     end
   end
 
-  defp generate_missing_cycles(member, today) do
+  defp generate_missing_cycles(member, today, opts) do
     fee_type = member.membership_fee_type
     interval = fee_type.interval
     amount = fee_type.amount
@@ -287,7 +295,7 @@ defmodule Mv.MembershipFees.CycleGenerator do
     # Only generate if start_date <= end_date
     if start_date && Date.compare(start_date, end_date) != :gt do
       cycle_starts = generate_cycle_starts(start_date, end_date, interval)
-      create_cycles(cycle_starts, member.id, fee_type.id, amount)
+      create_cycles(cycle_starts, member.id, fee_type.id, amount, opts)
     else
       {:ok, [], []}
     end
@@ -382,9 +390,9 @@ defmodule Mv.MembershipFees.CycleGenerator do
     end
   end
 
-  defp create_cycles(cycle_starts, member_id, fee_type_id, amount) do
-    system_actor = SystemActor.get_system_actor()
-    opts = Helpers.ash_actor_opts(system_actor)
+  defp create_cycles(cycle_starts, member_id, fee_type_id, amount, opts) do
+    actor = get_actor(opts)
+    create_opts = Helpers.ash_actor_opts(actor)
 
     # Always use return_notifications?: true to collect notifications
     # Notifications will be returned to the caller, who is responsible for
@@ -400,7 +408,7 @@ defmodule Mv.MembershipFees.CycleGenerator do
         }
 
         handle_cycle_creation_result(
-          Ash.create(MembershipFeeCycle, attrs, [return_notifications?: true] ++ opts),
+          Ash.create(MembershipFeeCycle, attrs, [return_notifications?: true] ++ create_opts),
           cycle_start
         )
       end)

lib/mv/statistics.ex

@@ -0,0 +1,237 @@
+defmodule Mv.Statistics do
+  @moduledoc """
+  Aggregated statistics for members and membership fee cycles.
+
+  Used by the statistics LiveView to display counts and sums. All functions
+  accept an `opts` keyword list and pass `:actor` (and `:domain` where needed)
+  to Ash reads so that policies are enforced.
+  """
+
+  require Ash.Query
+  import Ash.Expr
+
+  require Logger
+
+  alias Mv.Membership.Member
+  alias Mv.MembershipFees
+  alias Mv.MembershipFees.MembershipFeeCycle
+
+  @doc """
+  Returns the earliest year in which any member has a join_date.
+
+  Used to determine the start of the "relevant" year range for statistics
+  (from first membership to current year). Returns `nil` if no member has
+  a join_date.
+  """
+  @spec first_join_year(keyword()) :: non_neg_integer() | nil
+  def first_join_year(opts) do
+    query =
+      Member
+      |> Ash.Query.filter(expr(not is_nil(join_date)))
+      |> Ash.Query.sort(join_date: :asc)
+      |> Ash.Query.limit(1)
+
+    case Ash.read_one(query, opts) do
+      {:ok, nil} ->
+        nil
+
+      {:ok, member} ->
+        member.join_date.year
+
+      {:error, reason} ->
+        Logger.warning("Statistics.first_join_year failed: #{inspect(reason)}")
+        nil
+    end
+  end
+
+  @doc """
+  Returns the count of active members (exit_date is nil).
+  """
+  @spec active_member_count(keyword()) :: non_neg_integer()
+  def active_member_count(opts) do
+    query =
+      Member
+      |> Ash.Query.filter(expr(is_nil(exit_date)))
+
+    case Ash.count(query, opts) do
+      {:ok, count} ->
+        count
+
+      {:error, reason} ->
+        Logger.warning("Statistics.active_member_count failed: #{inspect(reason)}")
+        0
+    end
+  end
+
+  @doc """
+  Returns the count of inactive members (exit_date is not nil).
+  """
+  @spec inactive_member_count(keyword()) :: non_neg_integer()
+  def inactive_member_count(opts) do
+    query =
+      Member
+      |> Ash.Query.filter(expr(not is_nil(exit_date)))
+
+    case Ash.count(query, opts) do
+      {:ok, count} ->
+        count
+
+      {:error, reason} ->
+        Logger.warning("Statistics.inactive_member_count failed: #{inspect(reason)}")
+        0
+    end
+  end
+
+  @doc """
+  Returns the count of members who joined in the given year (join_date in that year).
+  """
+  @spec joins_by_year(integer(), keyword()) :: non_neg_integer()
+  def joins_by_year(year, opts) do
+    first_day = Date.new!(year, 1, 1)
+    last_day = Date.new!(year, 12, 31)
+
+    query =
+      Member
+      |> Ash.Query.filter(expr(join_date >= ^first_day and join_date <= ^last_day))
+
+    case Ash.count(query, opts) do
+      {:ok, count} ->
+        count
+
+      {:error, reason} ->
+        Logger.warning("Statistics.joins_by_year failed: #{inspect(reason)}")
+        0
+    end
+  end
+
+  @doc """
+  Returns the count of members who exited in the given year (exit_date in that year).
+  """
+  @spec exits_by_year(integer(), keyword()) :: non_neg_integer()
+  def exits_by_year(year, opts) do
+    first_day = Date.new!(year, 1, 1)
+    last_day = Date.new!(year, 12, 31)
+
+    query =
+      Member
+      |> Ash.Query.filter(expr(exit_date >= ^first_day and exit_date <= ^last_day))
+
+    case Ash.count(query, opts) do
+      {:ok, count} ->
+        count
+
+      {:error, reason} ->
+        Logger.warning("Statistics.exits_by_year failed: #{inspect(reason)}")
+        0
+    end
+  end
+
+  @doc """
+  Returns totals for membership fee cycles whose cycle_start falls in the given year.
+
+  Returns a map with keys: `:total`, `:paid`, `:unpaid`, `:suspended` (each a Decimal sum).
+  """
+  @spec cycle_totals_by_year(integer(), keyword()) :: %{
+          total: Decimal.t(),
+          paid: Decimal.t(),
+          unpaid: Decimal.t(),
+          suspended: Decimal.t()
+        }
+  def cycle_totals_by_year(year, opts) do
+    first_day = Date.new!(year, 1, 1)
+    last_day = Date.new!(year, 12, 31)
+
+    query =
+      MembershipFeeCycle
+      |> Ash.Query.filter(expr(cycle_start >= ^first_day and cycle_start <= ^last_day))
+
+    query = maybe_filter_by_fee_type(query, opts)
+    # Only pass actor and domain to Ash.read; fee_type_id is only for our filter above
+    opts_for_read =
+      opts
+      |> Keyword.drop([:fee_type_id])
+      |> Keyword.put(:domain, MembershipFees)
+
+    case Ash.read(query, opts_for_read) do
+      {:ok, cycles} ->
+        cycle_totals_from_cycles(cycles)
+
+      {:error, reason} ->
+        Logger.warning("Statistics.cycle_totals_by_year failed: #{inspect(reason)}")
+        zero_cycle_totals()
+    end
+  end
+
+  defp cycle_totals_from_cycles(cycles) do
+    by_status = Enum.group_by(cycles, & &1.status)
+    sum = fn status -> sum_amounts(by_status[status] || []) end
+
+    total =
+      [:paid, :unpaid, :suspended]
+      |> Enum.map(&sum.(&1))
+      |> Enum.reduce(Decimal.new(0), &Decimal.add/2)
+
+    %{
+      total: total,
+      paid: sum.(:paid),
+      unpaid: sum.(:unpaid),
+      suspended: sum.(:suspended)
+    }
+  end
+
+  defp sum_amounts(cycles),
+    do: Enum.reduce(cycles, Decimal.new(0), fn c, acc -> Decimal.add(acc, c.amount) end)
+
+  defp zero_cycle_totals do
+    %{
+      total: Decimal.new(0),
+      paid: Decimal.new(0),
+      unpaid: Decimal.new(0),
+      suspended: Decimal.new(0)
+    }
+  end
+
+  defp maybe_filter_by_fee_type(query, opts) do
+    case Keyword.get(opts, :fee_type_id) do
+      nil ->
+        query
+
+      id when is_binary(id) ->
+        # Only apply filter for valid UUID strings (e.g. from form/URL)
+        if Ecto.UUID.cast(id) != :error do
+          Ash.Query.filter(query, expr(membership_fee_type_id == ^id))
+        else
+          query
+        end
+
+      id ->
+        Ash.Query.filter(query, expr(membership_fee_type_id == ^id))
+    end
+  end
+
+  @doc """
+  Returns the sum of amount for all cycles with status :unpaid.
+  """
+  @spec open_amount_total(keyword()) :: Decimal.t()
+  def open_amount_total(opts) do
+    query =
+      MembershipFeeCycle
+      |> Ash.Query.filter(expr(status == :unpaid))
+
+    query = maybe_filter_by_fee_type(query, opts)
+
+    opts_for_read =
+      opts
+      |> Keyword.drop([:fee_type_id])
+      |> Keyword.put(:domain, MembershipFees)
+
+    case Ash.read(query, opts_for_read) do
+      {:ok, cycles} ->
+        Enum.reduce(cycles, Decimal.new(0), fn c, acc -> Decimal.add(acc, c.amount) end)
+
+      {:error, reason} ->
+        Logger.warning("Statistics.open_amount_total failed: #{inspect(reason)}")
+        Decimal.new(0)
+    end
+  end
+end

lib/mv_web/components/layouts/sidebar.ex

@@ -88,6 +88,14 @@ defmodule MvWeb.Layouts.Sidebar do
         />
       <% end %>
 
+      <%= if can_access_page?(@current_user, PagePaths.statistics()) do %>
+        <.menu_item
+          href={~p"/statistics"}
+          icon="hero-chart-bar"
+          label={gettext("Statistics")}
+        />
+      <% end %>
+
       <%= if admin_menu_visible?(@current_user) do %>
         <.menu_group
           icon="hero-cog-6-tooth"

lib/mv_web/live/statistics_live.ex

@@ -0,0 +1,628 @@
+defmodule MvWeb.StatisticsLive do
+  @moduledoc """
+  LiveView for the statistics page at /statistics.
+
+  Displays aggregated member and membership fee cycle statistics.
+  """
+  use MvWeb, :live_view
+
+  require Logger
+
+  import MvWeb.LiveHelpers, only: [current_actor: 1]
+  alias Mv.Statistics
+  alias Mv.MembershipFees.MembershipFeeType
+  alias MvWeb.Helpers.MembershipFeeHelpers
+
+  @impl true
+  def mount(_params, _session, socket) do
+    # Only static assigns and fee types here; load_statistics runs once in handle_params
+    socket =
+      socket
+      |> assign(:page_title, gettext("Statistics"))
+      |> assign(:selected_fee_type_id, nil)
+      |> load_fee_types()
+
+    {:ok, socket}
+  end
+
+  @impl true
+  def handle_params(params, uri, socket) do
+    # Query params: after push_patch, params may not include query string in some cases;
+    # always derive from URI as well so fee_type_id is reliable.
+    uri_query = if uri, do: URI.decode_query(URI.parse(uri).query || ""), else: %{}
+    fee_type_id = params["fee_type_id"] || uri_query["fee_type_id"]
+    fee_type_id = normalize_fee_type_id(fee_type_id)
+
+    socket =
+      socket
+      |> assign(:selected_fee_type_id, fee_type_id)
+      |> load_statistics()
+
+    {:noreply, socket}
+  end
+
+  defp normalize_fee_type_id(nil), do: nil
+  defp normalize_fee_type_id(""), do: nil
+
+  defp normalize_fee_type_id(id) when is_binary(id) do
+    case String.trim(id) do
+      "" -> nil
+      trimmed -> trimmed
+    end
+  end
+
+  defp normalize_fee_type_id(_), do: nil
+
+  @impl true
+  def render(assigns) do
+    ~H"""
+    <Layouts.app flash={@flash} current_user={@current_user}>
+      <.header>
+        {gettext("Statistics")}
+        <:subtitle>{gettext("Overview from first membership to today")}</:subtitle>
+      </.header>
+
+      <section class="mb-8" aria-labelledby="members-heading">
+        <h2 id="members-heading" class="text-xl font-semibold mb-4">{gettext("Members")}</h2>
+        <div class="grid grid-cols-1 sm:grid-cols-2 gap-4 mb-6">
+          <div class="card bg-base-200 shadow-md border border-base-300">
+            <div class="card-body p-5">
+              <h3 class="card-title text-sm font-medium text-base-content/80">
+                {gettext("Active members")}
+              </h3>
+              <p
+                class="text-3xl font-bold tabular-nums"
+                aria-label={gettext("Active members") <> ": " <> to_string(@active_count)}
+              >
+                {@active_count}
+              </p>
+            </div>
+          </div>
+          <div class="card bg-base-200 shadow-md border border-base-300">
+            <div class="card-body p-5">
+              <h3 class="card-title text-sm font-medium text-base-content/80">
+                {gettext("Inactive members")}
+              </h3>
+              <p
+                class="text-3xl font-bold tabular-nums"
+                aria-label={gettext("Inactive members") <> ": " <> to_string(@inactive_count)}
+              >
+                {@inactive_count}
+              </p>
+            </div>
+          </div>
+        </div>
+        <div class="card bg-base-200 shadow-md border border-base-300">
+          <div class="card-body">
+            <h3 class="card-title text-lg mb-4">{gettext("Member numbers by year")}</h3>
+            <p class="text-sm text-base-content/70 mb-4">
+              {gettext("From %{first} to %{last} (relevant years with membership data)",
+                first: @years |> List.last() |> to_string(),
+                last: @years |> List.first() |> to_string()
+              )}
+            </p>
+            <.member_numbers_table joins_exits_by_year={@joins_exits_by_year} />
+          </div>
+        </div>
+      </section>
+
+      <section class="mb-8" aria-labelledby="contributions-heading">
+        <h2 id="contributions-heading" class="text-xl font-semibold mb-4">
+          {gettext("Contributions")}
+        </h2>
+        <div class="flex flex-wrap items-end gap-4 mb-6">
+          <div class="flex items-center gap-2">
+            <form id="fee-type-form" phx-change="change_fee_type" class="flex items-center gap-2">
+              <label for="fee-type-filter" class="text-sm font-medium text-base-content/80">
+                {gettext("Fee type")}:
+              </label>
+              <select
+                id="fee-type-filter"
+                name="fee_type_id"
+                class="select select-bordered select-sm min-w-[10rem]"
+              >
+                <option value="" selected={@selected_fee_type_id in [nil, ""]}>
+                  {gettext("All")}
+                </option>
+                <%= for ft <- @membership_fee_types do %>
+                  <option
+                    value={ft.id}
+                    selected={to_string(@selected_fee_type_id) == to_string(ft.id)}
+                  >
+                    {ft.name}
+                  </option>
+                <% end %>
+              </select>
+            </form>
+          </div>
+        </div>
+        <div class="card bg-base-200 shadow-md border border-base-300">
+          <div class="card-body">
+            <h3 class="card-title text-lg mb-4">{gettext("Contributions by year")}</h3>
+            <div class="flex flex-col gap-8 items-start">
+              <div class="w-full">
+                <.contributions_bars_by_year
+                  contributions_by_year={@contributions_by_year}
+                  totals_over_all_years={@totals_over_all_years}
+                />
+              </div>
+              <div class="w-full flex flex-col items-center pt-6 mt-2 border-t border-base-300">
+                <h4 class="text-sm font-semibold mb-3">{gettext("All years combined (pie)")}</h4>
+                <.contributions_pie cycle_totals={@totals_over_all_years} />
+                <p class="text-xs text-base-content/70 mt-2">
+                  <span class="inline-block w-2 h-2 rounded-full bg-success align-middle mr-1"></span>
+                  {gettext("Paid")}
+                  <span class="inline-block w-2 h-2 rounded-full bg-warning align-middle mx-2 mr-1">
+                  </span>
+                  {gettext("Unpaid")}
+                  <span class="inline-block w-2 h-2 rounded-full bg-base-content/20 align-middle mx-2 mr-1">
+                  </span>
+                  {gettext("Suspended")}
+                </p>
+              </div>
+            </div>
+          </div>
+        </div>
+      </section>
+    </Layouts.app>
+    """
+  end
+
+  @impl true
+  def handle_event("change_fee_type", %{"fee_type_id" => ""}, socket) do
+    {:noreply, push_patch(socket, to: ~p"/statistics")}
+  end
+
+  def handle_event("change_fee_type", %{"fee_type_id" => id}, socket) when is_binary(id) do
+    trimmed = String.trim(id)
+
+    to =
+      if trimmed == "",
+        do: ~p"/statistics",
+        else: ~p"/statistics" <> "?" <> URI.encode_query(%{"fee_type_id" => trimmed})
+
+    {:noreply, push_patch(socket, to: to)}
+  end
+
+  attr :joins_exits_by_year, :list, required: true
+
+  defp member_numbers_table(assigns) do
+    rows = assigns.joins_exits_by_year
+    total_activity = Enum.map(rows, fn r -> r.joins + r.exits end)
+    max_total = (total_activity != [] && Enum.max(total_activity)) || 1
+
+    rows_with_pct =
+      Enum.map(rows, fn row ->
+        sum = row.joins + row.exits
+
+        bar_pct =
+          if max_total > 0 and sum > 0 do
+            min(100.0, Float.round(sum / max_total * 100, 1))
+          else
+            0
+          end
+
+        seg_scale = max(sum, 1)
+        joins_pct = min(100.0, row.joins / seg_scale * 100)
+        exits_pct = min(100.0, row.exits / seg_scale * 100)
+
+        %{
+          year: row.year,
+          joins: row.joins,
+          exits: row.exits,
+          bar_pct: bar_pct,
+          joins_pct: Float.round(joins_pct, 1),
+          exits_pct: Float.round(exits_pct, 1)
+        }
+      end)
+
+    assigns = assign(assigns, :rows, rows_with_pct)
+
+    ~H"""
+    <div
+      class="overflow-x-auto"
+      role="img"
+      aria-label={gettext("Member numbers by year as table with bars")}
+    >
+      <table class="table table-sm w-full">
+        <thead class="bg-base-300">
+          <tr>
+            <th scope="col" class="text-base-content font-semibold w-20">{gettext("Year")}</th>
+            <th scope="col" class="text-base-content font-semibold">{gettext("Joins")}</th>
+            <th scope="col" class="text-base-content font-semibold">{gettext("Exits")}</th>
+          </tr>
+        </thead>
+        <tbody>
+          <%= for row <- @rows do %>
+            <tr>
+              <td
+                rowspan="2"
+                class="font-mono align-middle border-b-0"
+              >
+                {row.year}
+              </td>
+              <td colspan="2" class="align-top p-1 pb-0 border-b-0">
+                <div class="h-6 rounded overflow-hidden bg-base-300 relative min-w-[4rem]">
+                  <div
+                    class="flex h-full absolute left-0 top-0 bottom-0 min-w-0 rounded"
+                    style={"width: #{max(0, row.bar_pct)}%"}
+                  >
+                    <div
+                      class="h-full bg-success min-w-0 rounded-l"
+                      style={"width: #{row.joins_pct}%"}
+                      title={gettext("Joins")}
+                    >
+                    </div>
+                    <div
+                      class="h-full bg-error min-w-0 rounded-r"
+                      style={"width: #{row.exits_pct}%"}
+                      title={gettext("Exits")}
+                    >
+                    </div>
+                  </div>
+                </div>
+              </td>
+            </tr>
+            <tr>
+              <td class="align-middle text-xs font-mono text-base-content whitespace-nowrap pt-0">
+                <span class="inline-flex items-center gap-1.5">
+                  {row.joins}
+                  <span
+                    class="inline-block w-2 h-2 rounded-full bg-success shrink-0"
+                    aria-hidden="true"
+                    title={gettext("Joins")}
+                  >
+                  </span>
+                </span>
+              </td>
+              <td class="align-middle text-xs font-mono text-base-content whitespace-nowrap pt-0">
+                <span class="inline-flex items-center gap-1.5">
+                  {row.exits}
+                  <span
+                    class="inline-block w-2 h-2 rounded-full bg-error shrink-0"
+                    aria-hidden="true"
+                    title={gettext("Exits")}
+                  >
+                  </span>
+                </span>
+              </td>
+            </tr>
+          <% end %>
+        </tbody>
+      </table>
+    </div>
+    """
+  end
+
+  attr :contributions_by_year, :list, required: true
+  attr :totals_over_all_years, :map, required: true
+
+  defp contributions_bars_by_year(assigns) do
+    rows = assigns.contributions_by_year
+    totals = assigns.totals_over_all_years
+
+    all_rows_with_decimals =
+      Enum.map(rows, fn row ->
+        %{
+          year: row.year,
+          summary: false,
+          total: row.total,
+          paid: row.paid,
+          unpaid: row.unpaid,
+          suspended: row.suspended
+        }
+      end) ++
+        [
+          %{
+            year: nil,
+            summary: true,
+            total: totals.total,
+            paid: totals.paid,
+            unpaid: totals.unpaid,
+            suspended: totals.suspended
+          }
+        ]
+
+    max_total = max_decimal(all_rows_with_decimals, :total)
+
+    rows_with_pct =
+      Enum.map(all_rows_with_decimals, fn row ->
+        bar_pct = bar_pct(row.total, max_total)
+
+        sum_positive =
+          Decimal.add(Decimal.add(row.paid, row.unpaid), row.suspended)
+
+        seg_scale =
+          if Decimal.compare(sum_positive, 0) == :gt, do: sum_positive, else: Decimal.new(1)
+
+        paid_pct =
+          row.paid
+          |> Decimal.div(seg_scale)
+          |> Decimal.mult(100)
+          |> Decimal.to_float()
+          |> min(100.0)
+
+        unpaid_pct =
+          row.unpaid
+          |> Decimal.div(seg_scale)
+          |> Decimal.mult(100)
+          |> Decimal.to_float()
+          |> min(100.0)
+
+        suspended_pct =
+          row.suspended
+          |> Decimal.div(seg_scale)
+          |> Decimal.mult(100)
+          |> Decimal.to_float()
+          |> min(100.0)
+
+        %{
+          year: row.year,
+          summary: row.summary,
+          total_formatted: MembershipFeeHelpers.format_currency(row.total),
+          paid_formatted: MembershipFeeHelpers.format_currency(row.paid),
+          unpaid_formatted: MembershipFeeHelpers.format_currency(row.unpaid),
+          suspended_formatted: MembershipFeeHelpers.format_currency(row.suspended),
+          bar_pct: bar_pct,
+          paid_pct: paid_pct,
+          unpaid_pct: unpaid_pct,
+          suspended_pct: suspended_pct
+        }
+      end)
+
+    assigns = assign(assigns, :rows, rows_with_pct)
+
+    ~H"""
+    <div
+      class="overflow-x-auto"
+      role="img"
+      aria-label={gettext("Contributions by year as table with stacked bars")}
+    >
+      <table class="table table-sm w-full">
+        <thead class="bg-base-300">
+          <tr>
+            <th scope="col" class="text-base-content font-semibold w-20">{gettext("Year")}</th>
+            <th scope="col" class="text-base-content font-semibold">{gettext("Paid")}</th>
+            <th scope="col" class="text-base-content font-semibold">{gettext("Unpaid")}</th>
+            <th scope="col" class="text-base-content font-semibold">{gettext("Suspended")}</th>
+            <th scope="col" class="text-base-content font-semibold">{gettext("Total")}</th>
+          </tr>
+        </thead>
+        <tbody>
+          <%= for row <- @rows do %>
+            <tr class={row.summary && "border-t-2 border-base-300 bg-base-300/30"}>
+              <td
+                rowspan="2"
+                class={"font-mono align-middle border-b-0 #{if row.summary, do: "font-semibold", else: ""}"}
+              >
+                <%= if row.summary do %>
+                  {gettext("Total")}
+                <% else %>
+                  {row.year}
+                <% end %>
+              </td>
+              <td colspan="4" class="align-top p-1 pb-0 border-b-0">
+                <div class="h-6 rounded overflow-hidden bg-base-300 relative min-w-[4rem]">
+                  <div
+                    class="flex h-full absolute left-0 top-0 bottom-0 min-w-0 rounded"
+                    style={"width: #{max(0, Float.round(row.bar_pct, 1))}%"}
+                  >
+                    <div
+                      class="h-full bg-success min-w-0 rounded-l"
+                      style={"width: #{Float.round(row.paid_pct, 1)}%"}
+                      title={gettext("Paid")}
+                    >
+                    </div>
+                    <div
+                      class="h-full bg-warning min-w-0"
+                      style={"width: #{Float.round(row.unpaid_pct, 1)}%"}
+                      title={gettext("Unpaid")}
+                    >
+                    </div>
+                    <div
+                      class="h-full bg-base-content/20 min-w-0 rounded-r"
+                      style={"width: #{Float.round(row.suspended_pct, 1)}%"}
+                      title={gettext("Suspended")}
+                    >
+                    </div>
+                  </div>
+                </div>
+              </td>
+            </tr>
+            <tr class={row.summary && "bg-base-300/30"}>
+              <td class="align-middle text-xs font-mono text-base-content whitespace-nowrap pt-0">
+                <span class="inline-flex items-center gap-1.5">
+                  {row.paid_formatted}
+                  <span
+                    class="inline-block w-2 h-2 rounded-full bg-success shrink-0"
+                    aria-hidden="true"
+                    title={gettext("Paid")}
+                  >
+                  </span>
+                </span>
+              </td>
+              <td class="align-middle text-xs font-mono text-base-content whitespace-nowrap pt-0">
+                <span class="inline-flex items-center gap-1.5">
+                  {row.unpaid_formatted}
+                  <span
+                    class="inline-block w-2 h-2 rounded-full bg-warning shrink-0"
+                    aria-hidden="true"
+                    title={gettext("Unpaid")}
+                  >
+                  </span>
+                </span>
+              </td>
+              <td class="align-middle text-xs font-mono text-base-content whitespace-nowrap pt-0">
+                <span class="inline-flex items-center gap-1.5">
+                  {row.suspended_formatted}
+                  <span
+                    class="inline-block w-2 h-2 rounded-full bg-base-content/20 shrink-0"
+                    aria-hidden="true"
+                    title={gettext("Suspended")}
+                  >
+                  </span>
+                </span>
+              </td>
+              <td class="align-middle text-xs font-mono text-base-content whitespace-nowrap pt-0">
+                {row.total_formatted}
+              </td>
+            </tr>
+          <% end %>
+        </tbody>
+      </table>
+    </div>
+    """
+  end
+
+  defp max_decimal(rows, key) do
+    Enum.reduce(rows, Decimal.new(0), fn row, acc ->
+      val = Map.get(row, key)
+      if Decimal.compare(val, acc) == :gt, do: val, else: acc
+    end)
+  end
+
+  defp bar_pct(value, max) do
+    scale = if Decimal.compare(max, 0) == :gt, do: max, else: Decimal.new(1)
+    pct = value |> Decimal.div(scale) |> Decimal.mult(100) |> Decimal.to_float()
+    min(100.0, pct)
+  end
+
+  attr :cycle_totals, :map, required: true
+
+  defp contributions_pie(assigns) do
+    paid = assigns.cycle_totals.paid
+    unpaid = assigns.cycle_totals.unpaid
+    suspended = assigns.cycle_totals.suspended
+
+    sum_positive = Decimal.add(Decimal.add(paid, unpaid), suspended)
+    scale = if Decimal.compare(sum_positive, 0) == :gt, do: sum_positive, else: Decimal.new(1)
+
+    paid_pct = Decimal.div(paid, scale) |> Decimal.mult(100) |> Decimal.to_float()
+    unpaid_pct = Decimal.div(unpaid, scale) |> Decimal.mult(100) |> Decimal.to_float()
+    suspended_pct = Decimal.div(suspended, scale) |> Decimal.mult(100) |> Decimal.to_float()
+
+    # Conic gradient: 0deg = top, clockwise. Success (paid), warning (unpaid), base-300 (suspended)
+    # Use theme CSS variables (--color-*) so the pie renders in all themes
+    paid_deg = paid_pct * 3.6
+    unpaid_deg = unpaid_pct * 3.6
+
+    gradient_stops =
+      "var(--color-success) 0deg, var(--color-success) #{paid_deg}deg, var(--color-warning) #{paid_deg}deg, var(--color-warning) #{paid_deg + unpaid_deg}deg, var(--color-base-300) #{paid_deg + unpaid_deg}deg, var(--color-base-300) 360deg"
+
+    assigns =
+      assigns
+      |> assign(:paid_pct, paid_pct)
+      |> assign(:unpaid_pct, unpaid_pct)
+      |> assign(:suspended_pct, suspended_pct)
+      |> assign(:gradient_stops, gradient_stops)
+
+    ~H"""
+    <div
+      class="w-40 h-40 min-h-[10rem] rounded-full shrink-0 border-2 border-base-300 bg-base-300"
+      style={"background: conic-gradient(#{@gradient_stops});"}
+      role="img"
+      aria-label={
+        gettext(
+          "Contributions pie: paid %{paid}%%, unpaid %{unpaid}%%, suspended %{suspended}%%",
+          paid: Float.round(@paid_pct, 1),
+          unpaid: Float.round(@unpaid_pct, 1),
+          suspended: Float.round(@suspended_pct, 1)
+        )
+      }
+      title={"#{gettext("Paid")}: #{Float.round(@paid_pct, 1)}%, #{gettext("Unpaid")}: #{Float.round(@unpaid_pct, 1)}%, #{gettext("Suspended")}: #{Float.round(@suspended_pct, 1)}%"}
+    >
+    </div>
+    """
+  end
+
+  defp load_fee_types(socket) do
+    actor = current_actor(socket)
+
+    case MembershipFeeType
+         |> Ash.Query.sort(name: :asc)
+         |> Ash.read(domain: Mv.MembershipFees, actor: actor) do
+      {:ok, fee_types} ->
+        assign(socket, :membership_fee_types, fee_types)
+
+      {:error, reason} ->
+        Logger.warning("StatisticsLive: failed to load fee types: #{inspect(reason)}")
+
+        socket
+        |> put_flash(:error, gettext("Fee types could not be loaded."))
+        |> assign(:membership_fee_types, [])
+    end
+  end
+
+  defp load_statistics(socket) do
+    actor = current_actor(socket)
+    fee_type_id = socket.assigns[:selected_fee_type_id]
+    # Member stats must never depend on fee type (only contributions do)
+    opts_member = [actor: actor]
+
+    opts_contributions =
+      [actor: actor] ++ if fee_type_id, do: [fee_type_id: fee_type_id], else: []
+
+    current_year = Date.utc_today().year
+    first_year = Statistics.first_join_year(opts_member) || current_year
+    years = first_year..current_year |> Enum.to_list() |> Enum.reverse()
+
+    active_count = Statistics.active_member_count(opts_member)
+    inactive_count = Statistics.inactive_member_count(opts_member)
+    joins_exits_by_year = build_joins_exits_by_year(years, opts_member)
+    contributions_by_year = build_contributions_by_year(years, opts_contributions)
+    totals_over_all_years = sum_cycle_totals(contributions_by_year)
+
+    assign(socket,
+      years: years,
+      active_count: active_count,
+      inactive_count: inactive_count,
+      joins_exits_by_year: joins_exits_by_year,
+      contributions_by_year: contributions_by_year,
+      totals_over_all_years: totals_over_all_years
+    )
+  end
+
+  defp build_joins_exits_by_year(years, opts) do
+    Enum.map(years, fn y ->
+      %{
+        year: y,
+        joins: Statistics.joins_by_year(y, opts),
+        exits: Statistics.exits_by_year(y, opts)
+      }
+    end)
+  end
+
+  defp build_contributions_by_year(years, opts) do
+    Enum.map(years, fn y ->
+      totals = Statistics.cycle_totals_by_year(y, opts)
+
+      %{
+        year: y,
+        total: totals.total,
+        paid: totals.paid,
+        unpaid: totals.unpaid,
+        suspended: totals.suspended
+      }
+    end)
+  end
+
+  defp sum_cycle_totals(contributions_by_year) do
+    Enum.reduce(
+      contributions_by_year,
+      %{
+        total: Decimal.new(0),
+        paid: Decimal.new(0),
+        unpaid: Decimal.new(0),
+        suspended: Decimal.new(0)
+      },
+      fn row, acc ->
+        %{
+          total: Decimal.add(acc.total, row.total),
+          paid: Decimal.add(acc.paid, row.paid),
+          unpaid: Decimal.add(acc.unpaid, row.unpaid),
+          suspended: Decimal.add(acc.suspended, row.suspended)
+        }
+      end
+    )
+  end
+end

lib/mv_web/page_paths.ex

@@ -9,6 +9,7 @@ defmodule MvWeb.PagePaths do
   # Sidebar top-level menu paths
   @members "/members"
   @membership_fee_types "/membership_fee_types"
+  @statistics "/statistics"
 
   # Administration submenu paths (all must match router)
   @users "/users"
@@ -31,6 +32,9 @@ defmodule MvWeb.PagePaths do
   @doc "Path for Membership Fee Types index (sidebar and page permission check)."
   def membership_fee_types, do: @membership_fee_types
 
+  @doc "Path for Statistics page (sidebar and page permission check)."
+  def statistics, do: @statistics
+
   @doc "Paths for Administration menu; show group if user can access any of these."
   def admin_menu_paths, do: @admin_page_paths
 

lib/mv_web/router.ex

@@ -73,6 +73,9 @@ defmodule MvWeb.Router do
 
       # Membership Fee Types Management
       live "/membership_fee_types", MembershipFeeTypeLive.Index, :index
+
+      # Statistics
+      live "/statistics", StatisticsLive, :index
       live "/membership_fee_types/new", MembershipFeeTypeLive.Form, :new
       live "/membership_fee_types/:id/edit", MembershipFeeTypeLive.Form, :edit
 

priv/gettext/de/LC_MESSAGES/default.po

@@ -153,6 +153,7 @@ msgstr "Notizen"
 #: lib/mv_web/live/components/member_filter_component.ex
 #: lib/mv_web/live/member_live/show.ex
 #: lib/mv_web/live/member_live/show/membership_fees_component.ex
+#: lib/mv_web/live/statistics_live.ex
 #: lib/mv_web/member_live/index/membership_fee_status.ex
 #, elixir-autogen, elixir-format
 msgid "Paid"
@@ -318,6 +319,7 @@ msgstr "Benutzer*innen auflisten"
 #: lib/mv_web/live/member_live/index.ex
 #: lib/mv_web/live/member_live/index.html.heex
 #: lib/mv_web/live/membership_fee_type_live/index.ex
+#: lib/mv_web/live/statistics_live.ex
 #, elixir-autogen, elixir-format
 msgid "Members"
 msgstr "Mitglieder"
@@ -762,6 +764,7 @@ msgstr "Dieses Feld darf nicht leer bleiben"
 
 #: lib/mv_web/components/core_components.ex
 #: lib/mv_web/live/components/member_filter_component.ex
+#: lib/mv_web/live/statistics_live.ex
 #, elixir-autogen, elixir-format
 msgid "All"
 msgstr "Alle"
@@ -931,6 +934,7 @@ msgstr "Status"
 
 #: lib/mv_web/live/member_live/show.ex
 #: lib/mv_web/live/member_live/show/membership_fees_component.ex
+#: lib/mv_web/live/statistics_live.ex
 #: lib/mv_web/member_live/index/membership_fee_status.ex
 #, elixir-autogen, elixir-format
 msgid "Suspended"
@@ -939,6 +943,7 @@ msgstr "Pausiert"
 #: lib/mv_web/live/components/member_filter_component.ex
 #: lib/mv_web/live/member_live/show.ex
 #: lib/mv_web/live/member_live/show/membership_fees_component.ex
+#: lib/mv_web/live/statistics_live.ex
 #: lib/mv_web/member_live/index/membership_fee_status.ex
 #, elixir-autogen, elixir-format
 msgid "Unpaid"
@@ -2468,22 +2473,93 @@ msgstr "Pausiert"
 msgid "unpaid"
 msgstr "Unbezahlt"
 
-#~ #: lib/mv_web/live/global_settings_live.ex
-#~ #, elixir-autogen, elixir-format, fuzzy
-#~ msgid "Custom Fields in CSV Import"
-#~ msgstr "Benutzerdefinierte Felder"
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Active members"
+msgstr "Aktive Mitglieder"
 
-#~ #: lib/mv_web/live/global_settings_live.ex
-#~ #, elixir-autogen, elixir-format
-#~ msgid "Failed to prepare CSV import: %{error}"
-#~ msgstr "Das Vorbereiten des CSV Imports ist gescheitert: %{error}"
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Exits"
+msgstr "Austritte"
 
-#~ #: lib/mv_web/live/global_settings_live.ex
-#~ #, elixir-autogen, elixir-format, fuzzy
-#~ msgid "Individual data fields must be created in Mila before importing. Use the field name as the CSV column header. Unknown custom field columns will be ignored with a warning."
-#~ msgstr "Individuelle Datenfelder müssen in Mila erstellt werden, bevor sie importiert werden können. Verwende den Namen des Datenfeldes als CSV-Spaltenüberschrift. Unbekannte Spaltenüberschriften werden mit einer Warnung ignoriert."
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Inactive members"
+msgstr "Inaktive Mitglieder"
 
-#~ #: lib/mv_web/live/member_live/show/membership_fees_component.ex
-#~ #, elixir-autogen, elixir-format
-#~ msgid "Only administrators can regenerate cycles"
-#~ msgstr "Nur Administrator*innen können Zyklen regenerieren"
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Joins"
+msgstr "Eintritte"
+
+#: lib/mv_web/components/layouts/sidebar.ex
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Statistics"
+msgstr "Statistik"
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Total"
+msgstr "Gesamt"
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Year"
+msgstr "Jahr"
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Contributions pie: paid %{paid}%%, unpaid %{unpaid}%%, suspended %{suspended}%%"
+msgstr "Beiträge Kreis: bezahlt %{paid}%, unbezahlt %{unpaid}%, pausiert %{suspended}%"
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "All years combined (pie)"
+msgstr "Alle Jahre zusammengefasst (Kreis)"
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Contributions by year"
+msgstr "Beiträge nach Jahr"
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Overview from first membership to today"
+msgstr "Übersicht vom ersten Eintritt bis heute"
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Contributions by year as table with stacked bars"
+msgstr "Beiträge nach Jahr als Tabelle mit gestapelten Balken"
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format, fuzzy
+msgid "Contributions"
+msgstr "Beiträge"
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Fee type"
+msgstr "Beitragsart"
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Member numbers by year"
+msgstr "Mitgliederzahlen nach Jahr"
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "From %{first} to %{last} (relevant years with membership data)"
+msgstr "Von %{first} bis %{last} (Jahre mit Mitgliederdaten)"
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Member numbers by year as table with bars"
+msgstr "Mitgliederzahlen nach Jahr als Tabelle mit Balken"
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Fee types could not be loaded."
+msgstr "Beitragsarten konnten nicht geladen werden."

priv/gettext/default.pot

@@ -154,6 +154,7 @@ msgstr ""
 #: lib/mv_web/live/components/member_filter_component.ex
 #: lib/mv_web/live/member_live/show.ex
 #: lib/mv_web/live/member_live/show/membership_fees_component.ex
+#: lib/mv_web/live/statistics_live.ex
 #: lib/mv_web/member_live/index/membership_fee_status.ex
 #, elixir-autogen, elixir-format
 msgid "Paid"
@@ -319,6 +320,7 @@ msgstr ""
 #: lib/mv_web/live/member_live/index.ex
 #: lib/mv_web/live/member_live/index.html.heex
 #: lib/mv_web/live/membership_fee_type_live/index.ex
+#: lib/mv_web/live/statistics_live.ex
 #, elixir-autogen, elixir-format
 msgid "Members"
 msgstr ""
@@ -763,6 +765,7 @@ msgstr ""
 
 #: lib/mv_web/components/core_components.ex
 #: lib/mv_web/live/components/member_filter_component.ex
+#: lib/mv_web/live/statistics_live.ex
 #, elixir-autogen, elixir-format
 msgid "All"
 msgstr ""
@@ -932,6 +935,7 @@ msgstr ""
 
 #: lib/mv_web/live/member_live/show.ex
 #: lib/mv_web/live/member_live/show/membership_fees_component.ex
+#: lib/mv_web/live/statistics_live.ex
 #: lib/mv_web/member_live/index/membership_fee_status.ex
 #, elixir-autogen, elixir-format
 msgid "Suspended"
@@ -940,6 +944,7 @@ msgstr ""
 #: lib/mv_web/live/components/member_filter_component.ex
 #: lib/mv_web/live/member_live/show.ex
 #: lib/mv_web/live/member_live/show/membership_fees_component.ex
+#: lib/mv_web/live/statistics_live.ex
 #: lib/mv_web/member_live/index/membership_fee_status.ex
 #, elixir-autogen, elixir-format
 msgid "Unpaid"
@@ -2468,3 +2473,94 @@ msgstr ""
 #, elixir-autogen, elixir-format
 msgid "unpaid"
 msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Active members"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Exits"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Inactive members"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Joins"
+msgstr ""
+
+#: lib/mv_web/components/layouts/sidebar.ex
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Statistics"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Total"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Year"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Contributions pie: paid %{paid}%%, unpaid %{unpaid}%%, suspended %{suspended}%%"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "All years combined (pie)"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Contributions by year"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Overview from first membership to today"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Contributions by year as table with stacked bars"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Contributions"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Fee type"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Member numbers by year"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "From %{first} to %{last} (relevant years with membership data)"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Member numbers by year as table with bars"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Fee types could not be loaded."
+msgstr ""

priv/gettext/en/LC_MESSAGES/default.po

@@ -153,6 +153,7 @@ msgstr ""
 #: lib/mv_web/live/components/member_filter_component.ex
 #: lib/mv_web/live/member_live/show.ex
 #: lib/mv_web/live/member_live/show/membership_fees_component.ex
+#: lib/mv_web/live/statistics_live.ex
 #: lib/mv_web/member_live/index/membership_fee_status.ex
 #, elixir-autogen, elixir-format
 msgid "Paid"
@@ -318,6 +319,7 @@ msgstr ""
 #: lib/mv_web/live/member_live/index.ex
 #: lib/mv_web/live/member_live/index.html.heex
 #: lib/mv_web/live/membership_fee_type_live/index.ex
+#: lib/mv_web/live/statistics_live.ex
 #, elixir-autogen, elixir-format
 msgid "Members"
 msgstr ""
@@ -761,6 +763,7 @@ msgstr ""
 
 #: lib/mv_web/components/core_components.ex
 #: lib/mv_web/live/components/member_filter_component.ex
+#: lib/mv_web/live/statistics_live.ex
 #, elixir-autogen, elixir-format
 msgid "All"
 msgstr ""
@@ -930,6 +933,7 @@ msgstr ""
 
 #: lib/mv_web/live/member_live/show.ex
 #: lib/mv_web/live/member_live/show/membership_fees_component.ex
+#: lib/mv_web/live/statistics_live.ex
 #: lib/mv_web/member_live/index/membership_fee_status.ex
 #, elixir-autogen, elixir-format
 msgid "Suspended"
@@ -938,6 +942,7 @@ msgstr ""
 #: lib/mv_web/live/components/member_filter_component.ex
 #: lib/mv_web/live/member_live/show.ex
 #: lib/mv_web/live/member_live/show/membership_fees_component.ex
+#: lib/mv_web/live/statistics_live.ex
 #: lib/mv_web/member_live/index/membership_fee_status.ex
 #, elixir-autogen, elixir-format
 msgid "Unpaid"
@@ -2407,22 +2412,93 @@ msgstr ""
 msgid "unpaid"
 msgstr ""
 
-#~ #: lib/mv_web/live/global_settings_live.ex
-#~ #, elixir-autogen, elixir-format, fuzzy
-#~ msgid "Custom Fields in CSV Import"
-#~ msgstr ""
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format, fuzzy
+msgid "Active members"
+msgstr ""
 
-#~ #: lib/mv_web/live/global_settings_live.ex
-#~ #, elixir-autogen, elixir-format
-#~ msgid "Failed to prepare CSV import: %{error}"
-#~ msgstr ""
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Exits"
+msgstr ""
 
-#~ #: lib/mv_web/live/global_settings_live.ex
-#~ #, elixir-autogen, elixir-format, fuzzy
-#~ msgid "Individual data fields must be created in Mila before importing. Use the field name as the CSV column header. Unknown custom field columns will be ignored with a warning."
-#~ msgstr ""
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Inactive members"
+msgstr ""
 
-#~ #: lib/mv_web/live/member_live/show/membership_fees_component.ex
-#~ #, elixir-autogen, elixir-format
-#~ msgid "Only administrators can regenerate cycles"
-#~ msgstr ""
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Joins"
+msgstr ""
+
+#: lib/mv_web/components/layouts/sidebar.ex
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Statistics"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Total"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format, fuzzy
+msgid "Year"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Contributions pie: paid %{paid}%%, unpaid %{unpaid}%%, suspended %{suspended}%%"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "All years combined (pie)"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format, fuzzy
+msgid "Contributions by year"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Overview from first membership to today"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format, fuzzy
+msgid "Contributions by year as table with stacked bars"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format, fuzzy
+msgid "Contributions"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format, fuzzy
+msgid "Fee type"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Member numbers by year"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "From %{first} to %{last} (relevant years with membership data)"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format, fuzzy
+msgid "Member numbers by year as table with bars"
+msgstr ""
+
+#: lib/mv_web/live/statistics_live.ex
+#, elixir-autogen, elixir-format
+msgid "Fee types could not be loaded."
+msgstr ""

priv/repo/seeds.exs

@@ -379,10 +379,9 @@ Enum.each(member_attrs_list, fn member_attrs ->
 
   # Generate cycles if member has a fee type
   if final_member.membership_fee_type_id do
-    # Load member with cycles to check if they already exist
+    # Load member with cycles to check if they already exist (actor required for auth)
     member_with_cycles =
-      final_member
-      |> Ash.load!(:membership_fee_cycles)
+      Ash.load!(final_member, :membership_fee_cycles, actor: admin_user_with_role)
 
     # Only generate if no cycles exist yet (to avoid duplicates on re-run)
     cycles =
@@ -427,7 +426,7 @@ Enum.each(member_attrs_list, fn member_attrs ->
         if cycle.status != status do
           cycle
           |> Ash.Changeset.for_update(:update, %{status: status})
-          |> Ash.update!(actor: admin_user_with_role)
+          |> Ash.update!(actor: admin_user_with_role, domain: Mv.MembershipFees)
         end
       end)
     end
@@ -542,10 +541,9 @@ Enum.with_index(linked_members)
 
   # Generate cycles for linked members
   if final_member.membership_fee_type_id do
-    # Load member with cycles to check if they already exist
+    # Load member with cycles to check if they already exist (actor required for auth)
     member_with_cycles =
-      final_member
-      |> Ash.load!(:membership_fee_cycles)
+      Ash.load!(final_member, :membership_fee_cycles, actor: admin_user_with_role)
 
     # Only generate if no cycles exist yet (to avoid duplicates on re-run)
     cycles =
@@ -575,7 +573,7 @@ Enum.with_index(linked_members)
       if cycle.status != status do
         cycle
         |> Ash.Changeset.for_update(:update, %{status: status})
-        |> Ash.update!()
+        |> Ash.update!(actor: admin_user_with_role, domain: Mv.MembershipFees)
       end
     end)
   end

test/mv/statistics_test.exs

@@ -0,0 +1,227 @@
+defmodule Mv.StatisticsTest do
+  @moduledoc """
+  Tests for Mv.Statistics module (member and membership fee cycle statistics).
+  """
+  use Mv.DataCase, async: true
+
+  require Ash.Query
+  import Ash.Expr
+
+  alias Mv.Membership.Member
+  alias Mv.Statistics
+  alias Mv.MembershipFees
+  alias Mv.MembershipFees.MembershipFeeCycle
+  alias Mv.MembershipFees.MembershipFeeType
+
+  setup do
+    actor = Mv.Helpers.SystemActor.get_system_actor()
+    %{actor: actor}
+  end
+
+  defp create_fee_type(actor, attrs) do
+    MembershipFeeType
+    |> Ash.Changeset.for_create(
+      :create,
+      Map.merge(
+        %{
+          name: "Test Fee #{System.unique_integer([:positive])}",
+          amount: Decimal.new("50.00"),
+          interval: :yearly
+        },
+        attrs
+      )
+    )
+    |> Ash.create!(actor: actor)
+  end
+
+  describe "first_join_year/1" do
+    test "returns the year of the earliest join_date", %{actor: actor} do
+      Mv.Fixtures.member_fixture(%{join_date: ~D[2019-03-15]})
+      Mv.Fixtures.member_fixture(%{join_date: ~D[2022-01-01]})
+      assert Statistics.first_join_year(actor: actor) == 2019
+    end
+
+    test "returns the only member's join year when one member exists", %{actor: actor} do
+      Mv.Fixtures.member_fixture(%{join_date: ~D[2021-06-01]})
+      assert Statistics.first_join_year(actor: actor) == 2021
+    end
+
+    test "returns nil when no members exist", %{actor: actor} do
+      # Guarantee empty member table so the assertion is deterministic
+      Member
+      |> Ash.read!(actor: actor)
+      |> Enum.each(&Ash.destroy!(&1, actor: actor))
+
+      result = Statistics.first_join_year(actor: actor)
+      assert is_nil(result)
+    end
+  end
+
+  describe "active_member_count/1" do
+    test "returns 0 when there are no members", %{actor: actor} do
+      assert Statistics.active_member_count(actor: actor) == 0
+    end
+
+    test "returns 1 when one member has no exit_date", %{actor: actor} do
+      Mv.Fixtures.member_fixture(%{join_date: ~D[2023-01-15]})
+      assert Statistics.active_member_count(actor: actor) == 1
+    end
+
+    test "returns 0 for that member when exit_date is set", %{actor: actor} do
+      _member =
+        Mv.Fixtures.member_fixture(%{join_date: ~D[2023-01-15], exit_date: ~D[2024-06-01]})
+
+      assert Statistics.active_member_count(actor: actor) == 0
+    end
+
+    test "counts only active members when mix of active and inactive", %{actor: actor} do
+      Mv.Fixtures.member_fixture(%{join_date: ~D[2022-01-01]})
+      Mv.Fixtures.member_fixture(%{join_date: ~D[2023-01-01], exit_date: ~D[2024-01-01]})
+      assert Statistics.active_member_count(actor: actor) == 1
+    end
+  end
+
+  describe "inactive_member_count/1" do
+    test "returns 0 when all members are active", %{actor: actor} do
+      Mv.Fixtures.member_fixture(%{join_date: ~D[2023-01-01]})
+      assert Statistics.inactive_member_count(actor: actor) == 0
+    end
+
+    test "returns 1 when one member has exit_date set", %{actor: actor} do
+      Mv.Fixtures.member_fixture(%{join_date: ~D[2022-01-01], exit_date: ~D[2024-06-01]})
+      assert Statistics.inactive_member_count(actor: actor) == 1
+    end
+  end
+
+  describe "joins_by_year/2" do
+    test "returns 0 for year with no joins", %{actor: actor} do
+      assert Statistics.joins_by_year(1999, actor: actor) == 0
+    end
+
+    test "returns 1 when one member has join_date in that year", %{actor: actor} do
+      Mv.Fixtures.member_fixture(%{join_date: ~D[2023-06-15]})
+      assert Statistics.joins_by_year(2023, actor: actor) == 1
+    end
+
+    test "returns 2 when two members joined in that year", %{actor: actor} do
+      Mv.Fixtures.member_fixture(%{join_date: ~D[2023-01-01]})
+      Mv.Fixtures.member_fixture(%{join_date: ~D[2023-12-31]})
+      assert Statistics.joins_by_year(2023, actor: actor) == 2
+    end
+  end
+
+  describe "exits_by_year/2" do
+    test "returns 0 for year with no exits", %{actor: actor} do
+      assert Statistics.exits_by_year(1999, actor: actor) == 0
+    end
+
+    test "returns 1 when one member has exit_date in that year", %{actor: actor} do
+      Mv.Fixtures.member_fixture(%{join_date: ~D[2020-01-01], exit_date: ~D[2023-06-15]})
+      assert Statistics.exits_by_year(2023, actor: actor) == 1
+    end
+  end
+
+  describe "cycle_totals_by_year/2" do
+    test "returns zero totals for year with no cycles", %{actor: actor} do
+      result = Statistics.cycle_totals_by_year(1999, actor: actor)
+      assert result.total == Decimal.new(0)
+      assert result.paid == Decimal.new(0)
+      assert result.unpaid == Decimal.new(0)
+      assert result.suspended == Decimal.new(0)
+    end
+
+    test "returns totals by status for cycles in that year", %{actor: actor} do
+      fee_type = create_fee_type(actor, %{amount: Decimal.new("50.00")})
+
+      # Creating members with fee type triggers cycle generation (2020..today). We use 2024 cycles.
+      _member1 =
+        Mv.Fixtures.member_fixture(%{
+          join_date: ~D[2020-01-01],
+          membership_fee_type_id: fee_type.id
+        })
+
+      _member2 =
+        Mv.Fixtures.member_fixture(%{
+          join_date: ~D[2020-01-01],
+          membership_fee_type_id: fee_type.id
+        })
+
+      # Get 2024 cycles and set status (each member has one 2024 yearly cycle from generator)
+      cycles_2024 =
+        MembershipFeeCycle
+        |> Ash.Query.filter(
+          expr(cycle_start >= ^~D[2024-01-01] and cycle_start < ^~D[2025-01-01])
+        )
+        |> Ash.read!(actor: actor)
+        |> Enum.sort_by(& &1.member_id)
+
+      [c1, c2] = cycles_2024
+      assert {:ok, _} = Ash.update(c1, %{status: :paid}, domain: MembershipFees, actor: actor)
+
+      assert {:ok, _} =
+               Ash.update(c2, %{status: :suspended}, domain: MembershipFees, actor: actor)
+
+      result = Statistics.cycle_totals_by_year(2024, actor: actor)
+      assert Decimal.equal?(result.total, Decimal.new("100.00"))
+      assert Decimal.equal?(result.paid, Decimal.new("50.00"))
+      assert Decimal.equal?(result.unpaid, Decimal.new(0))
+      assert Decimal.equal?(result.suspended, Decimal.new("50.00"))
+    end
+
+    test "when fee_type_id is passed in opts, returns only cycles of that fee type", %{
+      actor: actor
+    } do
+      fee_type_a = create_fee_type(actor, %{amount: Decimal.new("30.00")})
+      fee_type_b = create_fee_type(actor, %{amount: Decimal.new("70.00")})
+
+      _m1 =
+        Mv.Fixtures.member_fixture(%{
+          join_date: ~D[2020-01-01],
+          membership_fee_type_id: fee_type_a.id
+        })
+
+      _m2 =
+        Mv.Fixtures.member_fixture(%{
+          join_date: ~D[2020-01-01],
+          membership_fee_type_id: fee_type_b.id
+        })
+
+      # Without filter: both fee types' cycles (2024)
+      all_result = Statistics.cycle_totals_by_year(2024, actor: actor)
+      assert Decimal.equal?(all_result.total, Decimal.new("100.00"))
+
+      # With fee_type_id as string (as from form/URL): only that type's cycles
+      opts_a = [actor: actor, fee_type_id: to_string(fee_type_a.id)]
+      result_a = Statistics.cycle_totals_by_year(2024, opts_a)
+      assert Decimal.equal?(result_a.total, Decimal.new("30.00"))
+
+      opts_b = [actor: actor, fee_type_id: to_string(fee_type_b.id)]
+      result_b = Statistics.cycle_totals_by_year(2024, opts_b)
+      assert Decimal.equal?(result_b.total, Decimal.new("70.00"))
+    end
+  end
+
+  describe "open_amount_total/1" do
+    test "returns 0 when there are no unpaid cycles", %{actor: actor} do
+      assert Statistics.open_amount_total(actor: actor) == Decimal.new(0)
+    end
+
+    test "returns sum of amount for all unpaid cycles", %{actor: actor} do
+      fee_type = create_fee_type(actor, %{amount: Decimal.new("50.00")})
+
+      _member =
+        Mv.Fixtures.member_fixture(%{
+          join_date: ~D[2020-01-01],
+          membership_fee_type_id: fee_type.id
+        })
+
+      # Cycle generator creates yearly cycles (2020..today), all unpaid by default
+      unpaid_sum = Statistics.open_amount_total(actor: actor)
+      assert Decimal.compare(unpaid_sum, Decimal.new(0)) == :gt
+      # Should be 50 * number of years from 2020 to current year
+      current_year = Date.utc_today().year
+      expected_count = current_year - 2020 + 1
+      assert Decimal.equal?(unpaid_sum, Decimal.new(50 * expected_count))
+    end
+  end
+end

test/mv_web/components/sidebar_authorization_test.exs

@@ -25,12 +25,13 @@ defmodule MvWeb.SidebarAuthorizationTest do
   end
 
   describe "sidebar menu with admin user" do
-    test "shows Members, Fee Types and Administration with all subitems" do
+    test "shows Members, Fee Types, Statistics and Administration with all subitems" do
       user = Fixtures.user_with_role_fixture("admin")
       html = render_sidebar(sidebar_assigns(user))
 
       assert html =~ ~s(href="/members")
       assert html =~ ~s(href="/membership_fee_types")
+      assert html =~ ~s(href="/statistics")
       assert html =~ ~s(data-testid="sidebar-administration")
       assert html =~ ~s(href="/users")
       assert html =~ ~s(href="/groups")
@@ -41,11 +42,12 @@ defmodule MvWeb.SidebarAuthorizationTest do
   end
 
   describe "sidebar menu with read_only user (Vorstand/Buchhaltung)" do
-    test "shows Members and Groups (from Administration)" do
+    test "shows Members, Statistics and Groups (from Administration)" do
       user = Fixtures.user_with_role_fixture("read_only")
       html = render_sidebar(sidebar_assigns(user))
 
       assert html =~ ~s(href="/members")
+      assert html =~ ~s(href="/statistics")
       assert html =~ ~s(href="/groups")
     end
 
@@ -61,11 +63,12 @@ defmodule MvWeb.SidebarAuthorizationTest do
   end
 
   describe "sidebar menu with normal_user (Kassenwart)" do
-    test "shows Members and Groups" do
+    test "shows Members, Statistics and Groups" do
       user = Fixtures.user_with_role_fixture("normal_user")
       html = render_sidebar(sidebar_assigns(user))
 
       assert html =~ ~s(href="/members")
+      assert html =~ ~s(href="/statistics")
       assert html =~ ~s(href="/groups")
     end
 
@@ -88,10 +91,11 @@ defmodule MvWeb.SidebarAuthorizationTest do
       refute html =~ ~s(href="/members")
     end
 
-    test "does not show Fee Types or Administration" do
+    test "does not show Statistics, Fee Types or Administration" do
       user = Fixtures.user_with_role_fixture("own_data")
       html = render_sidebar(sidebar_assigns(user))
 
+      refute html =~ ~s(href="/statistics")
       refute html =~ ~s(href="/membership_fee_types")
       refute html =~ ~s(href="/users")
       refute html =~ ~s(data-testid="sidebar-administration")

test/mv_web/live/statistics_live_test.exs

@@ -0,0 +1,78 @@
+defmodule MvWeb.StatisticsLiveTest do
+  @moduledoc """
+  Tests for the Statistics LiveView at /statistics.
+
+  Uses explicit auth: conn is authenticated with a role that has access to
+  the statistics page (read_only by default; override with @tag :role).
+  """
+  use MvWeb.ConnCase, async: true
+
+  import Phoenix.LiveViewTest
+
+  alias Mv.MembershipFees.MembershipFeeType
+
+  describe "statistics page" do
+    @describetag role: :read_only
+    test "renders statistics page with title and key labels for authenticated user with access",
+         %{
+           conn: conn
+         } do
+      {:ok, _view, html} = live(conn, ~p"/statistics")
+
+      assert html =~ "Statistics"
+      assert html =~ "Active members"
+      assert html =~ "Unpaid"
+      assert html =~ "Contributions by year"
+      assert html =~ "Member numbers by year"
+    end
+
+    test "page shows overview of all relevant years without year selector", %{conn: conn} do
+      {:ok, _view, html} = live(conn, ~p"/statistics")
+
+      # No year dropdown: single select for year should not be present as main control
+      assert html =~ "Overview" or html =~ "overview"
+      # table header or legend
+      assert html =~ "Year"
+    end
+
+    test "fee_type_id in URL updates selected filter and contributions", %{conn: conn} do
+      actor = Mv.Helpers.SystemActor.get_system_actor()
+
+      fee_types =
+        MembershipFeeType
+        |> Ash.Query.sort(name: :asc)
+        |> Ash.read!(domain: Mv.MembershipFees, actor: actor)
+
+      fee_type =
+        case List.first(fee_types) do
+          nil ->
+            MembershipFeeType
+            |> Ash.Changeset.for_create(:create, %{
+              name: "Test Fee #{System.unique_integer([:positive])}",
+              amount: Decimal.new("50.00"),
+              interval: :yearly
+            })
+            |> Ash.create!(actor: actor)
+
+          ft ->
+            ft
+        end
+
+      path = ~p"/statistics" <> "?" <> URI.encode_query(%{"fee_type_id" => fee_type.id})
+      {:ok, view, html} = live(conn, path)
+
+      assert view |> element("select#fee-type-filter") |> has_element?()
+      assert html =~ fee_type.name
+      assert html =~ "Contributions by year"
+    end
+  end
+
+  describe "statistics page with own_data role" do
+    @describetag role: :member
+    test "redirects when user has only own_data (no access to statistics page)", %{conn: conn} do
+      # member role uses own_data permission set; /statistics is not in own_data pages
+      conn = get(conn, ~p"/statistics")
+      assert redirected_to(conn) != ~p"/statistics"
+    end
+  end
+end

test/mv_web/plugs/check_page_permission_test.exs

@@ -107,6 +107,37 @@ defmodule MvWeb.Plugs.CheckPagePermissionTest do
     end
   end
 
+  describe "statistics route /statistics" do
+    test "read_only can access /statistics" do
+      user = Fixtures.user_with_role_fixture("read_only")
+      conn = conn_with_user("/statistics", user) |> CheckPagePermission.call([])
+
+      refute conn.halted
+    end
+
+    test "normal_user can access /statistics" do
+      user = Fixtures.user_with_role_fixture("normal_user")
+      conn = conn_with_user("/statistics", user) |> CheckPagePermission.call([])
+
+      refute conn.halted
+    end
+
+    test "admin can access /statistics" do
+      user = Fixtures.user_with_role_fixture("admin")
+      conn = conn_with_user("/statistics", user) |> CheckPagePermission.call([])
+
+      refute conn.halted
+    end
+
+    test "own_data cannot access /statistics" do
+      user = Fixtures.user_with_role_fixture("own_data")
+      conn = conn_with_user("/statistics", user) |> CheckPagePermission.call([])
+
+      assert conn.halted
+      assert redirected_to(conn) == "/users/#{user.id}"
+    end
+  end
+
   describe "read_only and normal_user denied on admin routes" do
     test "read_only cannot access /admin/roles" do
       user = Fixtures.user_with_role_fixture("read_only")