defmodule Mv.Membership do
  @moduledoc """
  Ash Domain for membership management.

  ## Resources
  - `Member` - Club members with personal information and custom field values
  - `CustomFieldValue` - Dynamic custom field values attached to members
  - `CustomField` - Schema definitions for custom fields
  - `Setting` - Global application settings (singleton)

  ## Public API
  The domain exposes these main actions:
  - Member CRUD: `create_member/1`, `list_members/0`, `update_member/2`, `destroy_member/1`
  - Custom field value management: `create_custom_field_value/1`, `list_custom_field_values/0`, etc.
  - Custom field management: `create_custom_field/1`, `list_custom_fields/0`, etc.
  - Settings management: `get_settings/0`, `update_settings/2`

  ## Admin Interface
  The domain is configured with AshAdmin for management UI.
  """
  use Ash.Domain,
    extensions: [AshAdmin.Domain, AshPhoenix]

  admin do
    show? true
  end

  resources do
    resource Mv.Membership.Member do
      define :create_member, action: :create_member
      define :list_members, action: :read
      define :update_member, action: :update_member
      define :destroy_member, action: :destroy
    end

    resource Mv.Membership.CustomFieldValue do
      define :create_custom_field_value, action: :create
      define :list_custom_field_values, action: :read
      define :update_custom_field_value, action: :update
      define :destroy_custom_field_value, action: :destroy
    end

    resource Mv.Membership.CustomField do
      define :create_custom_field, action: :create
      define :list_custom_fields, action: :read
      define :update_custom_field, action: :update
      define :destroy_custom_field, action: :destroy_with_values
      define :prepare_custom_field_deletion, action: :prepare_deletion, args: [:id]
    end

    resource Mv.Membership.Setting do
      # Note: create action exists but is not exposed via code interface
      # It's only used internally as fallback in get_settings/0
      # Settings should be created via seed script
      define :update_settings, action: :update
      define :update_member_field_visibility, action: :update_member_field_visibility
    end
  end

  # Singleton pattern: Get the single settings record
  @doc """
  Gets the global settings.

  Settings should normally be created via the seed script (`priv/repo/seeds.exs`).
  If no settings exist, this function will create them as a fallback using the
  `ASSOCIATION_NAME` environment variable or "Club Name" as default.

  ## Returns

    - `{:ok, settings}` - The settings record
    - `{:ok, nil}` - No settings exist (should not happen if seeds were run)
    - `{:error, error}` - Error reading settings

  ## Examples

      iex> {:ok, settings} = Mv.Membership.get_settings()
      iex> settings.club_name
      "My Club"

  """
  def get_settings do
    # Try to get the first (and only) settings record
    case Ash.read_one(Mv.Membership.Setting, domain: __MODULE__) do
      {:ok, nil} ->
        # No settings exist - create as fallback (should normally be created via seed script)
        default_club_name = System.get_env("ASSOCIATION_NAME") || "Club Name"

        Mv.Membership.Setting
        |> Ash.Changeset.for_create(:create, %{club_name: default_club_name})
        |> Ash.create!(domain: __MODULE__)
        |> then(fn settings -> {:ok, settings} end)

      {:ok, settings} ->
        {:ok, settings}

      {:error, error} ->
        {:error, error}
    end
  end

  @doc """
  Updates the global settings.

  ## Parameters

    - `settings` - The settings record to update
    - `attrs` - A map of attributes to update (e.g., `%{club_name: "New Name"}`)

  ## Returns

    - `{:ok, updated_settings}` - Successfully updated settings
    - `{:error, error}` - Validation or update error

  ## Examples

      iex> {:ok, settings} = Mv.Membership.get_settings()
      iex> {:ok, updated} = Mv.Membership.update_settings(settings, %{club_name: "New Club"})
      iex> updated.club_name
      "New Club"

  """
  def update_settings(settings, attrs) do
    settings
    |> Ash.Changeset.for_update(:update, attrs)
    |> Ash.update(domain: __MODULE__)
  end

  @doc """
  Updates the member field visibility configuration.

  This is a specialized action for updating only the member field visibility settings.
  It validates that all keys are valid member fields and all values are booleans.

  ## Parameters

    - `settings` - The settings record to update
    - `visibility_config` - A map of member field names (strings) to boolean visibility values
      (e.g., `%{"street" => false, "house_number" => false}`)

  ## Returns

    - `{:ok, updated_settings}` - Successfully updated settings
    - `{:error, error}` - Validation or update error

  ## Examples

      iex> {:ok, settings} = Mv.Membership.get_settings()
      iex> {:ok, updated} = Mv.Membership.update_member_field_visibility(settings, %{"street" => false, "house_number" => false})
      iex> updated.member_field_visibility
      %{"street" => false, "house_number" => false}

  """
  def update_member_field_visibility(settings, visibility_config) do
    settings
    |> Ash.Changeset.for_update(:update_member_field_visibility, %{
      member_field_visibility: visibility_config
    })
    |> Ash.update(domain: __MODULE__)
  end
end