defmodule Mv.Membership.MemberExport.BuildTest do
  @moduledoc """
  Tests for MemberExport.Build module.

  Tests verify that the module correctly:
  - Loads and filters members based on query/selected_ids
  - Builds column specifications (without labels)
  - Generates row data as cell strings
  - Handles member fields, custom fields, and computed fields
  - Applies sorting and filtering consistently
  """
  use Mv.DataCase, async: true

  alias Mv.Fixtures
  alias Mv.Membership.{CustomField, Member, MemberExport.Build}
  alias Mv.Constants

  @custom_field_prefix Constants.custom_field_prefix()

  setup do
    system_actor = Mv.Helpers.SystemActor.get_system_actor()

    # Create test members
    member1 =
      Fixtures.member_fixture(%{
        first_name: "Alice",
        last_name: "Anderson",
        email: "alice@example.com"
      })

    member2 =
      Fixtures.member_fixture(%{
        first_name: "Bob",
        last_name: "Brown",
        email: "bob@example.com"
      })

    %{actor: system_actor, member1: member1, member2: member2}
  end

  describe "build/3 - standard member fields" do
    test "returns columns and rows for standard member fields", %{
      actor: actor,
      member1: m1,
      member2: m2
    } do
      parsed = %{
        selected_ids: [m1.id, m2.id],
        member_fields: ["first_name", "last_name", "email"],
        selectable_member_fields: ["first_name", "last_name", "email"],
        computed_fields: [],
        custom_field_ids: [],
        query: nil,
        sort_field: nil,
        sort_order: nil,
        show_current_cycle: false
      }

      result = Build.build(actor, parsed, fn _key -> "Label" end)

      assert {:ok, data} = result
      assert %{columns: columns, rows: rows, meta: meta} = data

      # Check columns structure
      assert length(columns) == 3
      first_name_col = Enum.find(columns, &(&1.key == "first_name" && &1.kind == :member_field))
      assert first_name_col
      assert first_name_col.label == "Label"
      assert Enum.find(columns, &(&1.key == "last_name" && &1.kind == :member_field))
      assert Enum.find(columns, &(&1.key == "email" && &1.kind == :member_field))

      # Check rows - should have 2 members
      assert length(rows) == 2

      # Check first row (member1)
      row1 = Enum.at(rows, 0)
      assert length(row1) == 3
      assert "Alice" in row1
      assert "Anderson" in row1
      assert "alice@example.com" in row1

      # Check meta
      assert %{generated_at: _timestamp, member_count: 2} = meta
      assert is_binary(meta.generated_at)
    end

    test "filters members by selected_ids", %{actor: actor, member1: m1, member2: _m2} do
      parsed = %{
        selected_ids: [m1.id],
        member_fields: ["first_name"],
        selectable_member_fields: ["first_name"],
        computed_fields: [],
        custom_field_ids: [],
        query: nil,
        sort_field: nil,
        sort_order: nil,
        show_current_cycle: false
      }

      {:ok, data} = Build.build(actor, parsed, fn _key -> "Label" end)

      assert length(data.rows) == 1
      row = hd(data.rows)
      assert "Alice" in row
      assert data.meta.member_count == 1
    end

    test "applies search query when selected_ids is empty", %{
      actor: actor,
      member1: m1,
      member2: _m2
    } do
      parsed = %{
        selected_ids: [],
        member_fields: ["first_name", "last_name"],
        selectable_member_fields: ["first_name", "last_name"],
        computed_fields: [],
        custom_field_ids: [],
        query: "Alice",
        sort_field: nil,
        sort_order: nil,
        show_current_cycle: false
      }

      {:ok, data} = Build.build(actor, parsed, fn _key -> "Label" end)

      assert length(data.rows) == 1
      row = hd(data.rows)
      assert "Alice" in row
    end
  end

  describe "build/3 - custom fields" do
    test "includes custom field columns and values", %{
      actor: actor,
      member1: m1
    } do
      # Create custom field
      {:ok, custom_field} =
        CustomField
        |> Ash.Changeset.for_create(:create, %{
          name: "Membership Number",
          value_type: :string
        })
        |> Ash.create(actor: actor)

      # Create custom field value for member
      {:ok, _cfv} =
        Mv.Membership.CustomFieldValue
        |> Ash.Changeset.for_create(:create, %{
          member_id: m1.id,
          custom_field_id: custom_field.id,
          value: "M12345"
        })
        |> Ash.create(actor: actor)

      parsed = %{
        selected_ids: [m1.id],
        member_fields: ["first_name"],
        selectable_member_fields: ["first_name"],
        computed_fields: [],
        custom_field_ids: [custom_field.id],
        query: nil,
        sort_field: nil,
        sort_order: nil,
        show_current_cycle: false
      }

      {:ok, data} = Build.build(actor, parsed, fn _key -> "Label" end)

      # Should have 2 columns: first_name + custom field
      assert length(data.columns) == 2

      custom_col =
        Enum.find(
          data.columns,
          &(&1.kind == :custom_field && &1.key == to_string(custom_field.id))
        )

      assert custom_col
      assert custom_col.custom_field.id == custom_field.id
      assert custom_col.label == "Label"

      # Check row has custom field value
      row = hd(data.rows)
      assert length(row) == 2
      assert "M12345" in row
    end

    test "handles members without custom field values", %{
      actor: actor,
      member1: m1
    } do
      # Create custom field but no value for member
      {:ok, custom_field} =
        CustomField
        |> Ash.Changeset.for_create(:create, %{
          name: "Optional Field",
          value_type: :string
        })
        |> Ash.create(actor: actor)

      parsed = %{
        selected_ids: [m1.id],
        member_fields: ["first_name"],
        selectable_member_fields: ["first_name"],
        computed_fields: [],
        custom_field_ids: [custom_field.id],
        query: nil,
        sort_field: nil,
        sort_order: nil,
        show_current_cycle: false
      }

      {:ok, data} = Build.build(actor, parsed, fn _key -> "Label" end)

      row = hd(data.rows)
      # Custom field value should be empty string
      assert "" in row
    end
  end

  describe "build/3 - computed fields" do
    test "includes computed field columns and values", %{
      actor: actor,
      member1: m1
    } do
      parsed = %{
        selected_ids: [m1.id],
        member_fields: ["first_name", "membership_fee_status"],
        selectable_member_fields: ["first_name"],
        computed_fields: ["membership_fee_status"],
        custom_field_ids: [],
        query: nil,
        sort_field: nil,
        sort_order: nil,
        show_current_cycle: false
      }

      {:ok, data} = Build.build(actor, parsed, fn _key -> "Label" end)

      # Should have 2 columns: first_name + computed field
      assert length(data.columns) == 2

      computed_col =
        Enum.find(data.columns, &(&1.kind == :computed && &1.key == :membership_fee_status))

      assert computed_col
      assert computed_col.label == "Label"

      # Check row has computed field value (may be empty if no cycles)
      row = hd(data.rows)
      assert length(row) == 2
      # membership_fee_status should be present (even if empty)
    end
  end

  describe "build/3 - sorting" do
    test "sorts by member field", %{actor: actor, member1: m1, member2: m2} do
      parsed = %{
        selected_ids: [m1.id, m2.id],
        member_fields: ["first_name"],
        selectable_member_fields: ["first_name"],
        computed_fields: [],
        custom_field_ids: [],
        query: nil,
        sort_field: "first_name",
        sort_order: "asc",
        show_current_cycle: false
      }

      {:ok, data} = Build.build(actor, parsed, fn _key -> "Label" end)

      # Should be sorted: Alice, Bob
      [row1, row2] = data.rows
      assert "Alice" in row1
      assert "Bob" in row2
    end

    test "sorts by custom field", %{actor: actor, member1: m1, member2: m2} do
      # Create custom field
      {:ok, custom_field} =
        CustomField
        |> Ash.Changeset.for_create(:create, %{
          name: "Sort Field",
          value_type: :string
        })
        |> Ash.create(actor: actor)

      # Add values: m1="Zebra", m2="Alpha"
      {:ok, _cfv1} =
        Mv.Membership.CustomFieldValue
        |> Ash.Changeset.for_create(:create, %{
          member_id: m1.id,
          custom_field_id: custom_field.id,
          value: "Zebra"
        })
        |> Ash.create(actor: actor)

      {:ok, _cfv2} =
        Mv.Membership.CustomFieldValue
        |> Ash.Changeset.for_create(:create, %{
          member_id: m2.id,
          custom_field_id: custom_field.id,
          value: "Alpha"
        })
        |> Ash.create(actor: actor)

      sort_field = "#{@custom_field_prefix}#{custom_field.id}"

      parsed = %{
        selected_ids: [m1.id, m2.id],
        member_fields: ["first_name"],
        selectable_member_fields: ["first_name"],
        computed_fields: [],
        custom_field_ids: [custom_field.id],
        query: nil,
        sort_field: sort_field,
        sort_order: "asc",
        show_current_cycle: false
      }

      {:ok, data} = Build.build(actor, parsed, fn _key -> "Label" end)

      # Should be sorted by custom field: Alpha (Bob), Zebra (Alice)
      [row1, row2] = data.rows
      # Alpha
      assert "Bob" in row1
      # Zebra
      assert "Alice" in row2
    end
  end

  describe "build/3 - error handling" do
    test "returns error when actor lacks permission", %{member1: m1} do
      # Create a user with limited permissions
      user = Fixtures.password_user_with_role_fixture(%{permission_set_name: "own_data"})

      parsed = %{
        selected_ids: [m1.id],
        member_fields: ["first_name"],
        selectable_member_fields: ["first_name"],
        computed_fields: [],
        custom_field_ids: [],
        query: nil,
        sort_field: nil,
        sort_order: nil,
        show_current_cycle: false
      }

      result = Build.build(user, parsed, fn _key -> "Label" end)

      assert {:error, :forbidden} = result
    end
  end
end