defmodule Mv.Membership.Import.MemberCSVTest do
  use Mv.DataCase, async: false

  alias Mv.Membership.Import.MemberCSV

  describe "Error struct" do
    test "Error struct exists with required fields" do
      # This will fail at runtime if the struct doesn't exist
      # We use struct/2 to create the struct at runtime
      error =
        struct(MemberCSV.Error, %{
          csv_line_number: 5,
          field: :email,
          message: "is not a valid email"
        })

      assert error.csv_line_number == 5
      assert error.field == :email
      assert error.message == "is not a valid email"
    end

    test "Error struct allows nil field" do
      # This will fail at runtime if the struct doesn't exist
      error =
        struct(MemberCSV.Error, %{
          csv_line_number: 10,
          field: nil,
          message: "Row is empty"
        })

      assert error.csv_line_number == 10
      assert error.field == nil
      assert error.message == "Row is empty"
    end
  end

  describe "prepare/2" do
    test "function exists and accepts file_content and opts" do
      file_content = "email\njohn@example.com"
      opts = []

      # This will fail until the function is implemented
      result = MemberCSV.prepare(file_content, opts)
      assert match?({:ok, _}, result) or match?({:error, _}, result)
    end

    test "returns {:ok, import_state} on success" do
      file_content = "email\njohn@example.com"
      opts = []

      assert {:ok, import_state} = MemberCSV.prepare(file_content, opts)

      # Check that import_state contains expected fields
      assert Map.has_key?(import_state, :chunks)
      assert Map.has_key?(import_state, :column_map)
      assert Map.has_key?(import_state, :custom_field_map)
      assert Map.has_key?(import_state, :warnings)
      assert import_state.column_map[:email] == 0
      assert import_state.chunks != []
    end

    test "returns {:error, reason} on failure" do
      file_content = ""
      opts = []

      assert {:error, _reason} = MemberCSV.prepare(file_content, opts)
    end

    test "function has documentation" do
      # Check that @doc exists by reading the module
      assert function_exported?(MemberCSV, :prepare, 2)
    end
  end

  describe "process_chunk/3" do
    test "function exists and accepts chunk_rows_with_lines, column_map, custom_field_map, and opts" do
      chunk_rows_with_lines = [{2, %{member: %{email: "john@example.com"}, custom: %{}}}]
      column_map = %{email: 0}
      custom_field_map = %{}
      opts = []

      # This will fail until the function is implemented
      result = MemberCSV.process_chunk(chunk_rows_with_lines, column_map, custom_field_map, opts)
      assert match?({:ok, _}, result) or match?({:error, _}, result)
    end

    test "creates member successfully with valid data" do
      chunk_rows_with_lines = [
        {2, %{member: %{email: "john@example.com", first_name: "John"}, custom: %{}}}
      ]

      column_map = %{email: 0, first_name: 1}
      custom_field_map = %{}
      opts = []

      assert {:ok, chunk_result} =
               MemberCSV.process_chunk(chunk_rows_with_lines, column_map, custom_field_map, opts)

      assert chunk_result.inserted == 1
      assert chunk_result.failed == 0
      assert chunk_result.errors == []

      # Verify member was created
      members = Mv.Membership.list_members!()
      assert Enum.any?(members, &(&1.email == "john@example.com"))
    end

    test "returns error for invalid email" do
      chunk_rows_with_lines = [
        {2, %{member: %{email: "invalid-email"}, custom: %{}}}
      ]

      column_map = %{email: 0}
      custom_field_map = %{}
      opts = []

      assert {:ok, chunk_result} =
               MemberCSV.process_chunk(chunk_rows_with_lines, column_map, custom_field_map, opts)

      assert chunk_result.inserted == 0
      assert chunk_result.failed == 1
      assert length(chunk_result.errors) == 1

      error = List.first(chunk_result.errors)
      assert error.csv_line_number == 2
      assert error.field == :email
      assert error.message =~ "email"
    end

    test "returns error for duplicate email" do
      # Create existing member first
      {:ok, _existing} =
        Mv.Membership.create_member(%{email: "duplicate@example.com", first_name: "Existing"})

      chunk_rows_with_lines = [
        {2, %{member: %{email: "duplicate@example.com", first_name: "New"}, custom: %{}}}
      ]

      column_map = %{email: 0, first_name: 1}
      custom_field_map = %{}
      opts = []

      assert {:ok, chunk_result} =
               MemberCSV.process_chunk(chunk_rows_with_lines, column_map, custom_field_map, opts)

      assert chunk_result.inserted == 0
      assert chunk_result.failed == 1
      assert length(chunk_result.errors) == 1

      error = List.first(chunk_result.errors)
      assert error.csv_line_number == 2
      assert error.field == :email
      assert error.message =~ "email" or error.message =~ "duplicate" or error.message =~ "unique"
    end

    test "creates member with custom field values" do
      # Create custom field first
      {:ok, custom_field} =
        Mv.Membership.CustomField
        |> Ash.Changeset.for_create(:create, %{
          name: "Phone",
          value_type: :string
        })
        |> Ash.create()

      chunk_rows_with_lines = [
        {2,
         %{
           member: %{email: "withcustom@example.com"},
           custom: %{to_string(custom_field.id) => "123-456-7890"}
         }}
      ]

      column_map = %{email: 0}
      custom_field_map = %{to_string(custom_field.id) => 1}
      opts = []

      assert {:ok, chunk_result} =
               MemberCSV.process_chunk(chunk_rows_with_lines, column_map, custom_field_map, opts)

      assert chunk_result.inserted == 1
      assert chunk_result.failed == 0

      # Verify member and custom field value were created
      members = Mv.Membership.list_members!()
      member = Enum.find(members, &(&1.email == "withcustom@example.com"))
      assert member != nil

      {:ok, member_with_cf} = Ash.load(member, :custom_field_values)
      assert length(member_with_cf.custom_field_values) == 1
      cfv = List.first(member_with_cf.custom_field_values)
      assert cfv.custom_field_id == custom_field.id
      assert cfv.value.value == "123-456-7890"
    end

    test "handles multiple rows with mixed success and failure" do
      chunk_rows_with_lines = [
        {2, %{member: %{email: "valid1@example.com"}, custom: %{}}},
        {3, %{member: %{email: "invalid-email"}, custom: %{}}},
        {4, %{member: %{email: "valid2@example.com"}, custom: %{}}}
      ]

      column_map = %{email: 0}
      custom_field_map = %{}
      opts = []

      assert {:ok, chunk_result} =
               MemberCSV.process_chunk(chunk_rows_with_lines, column_map, custom_field_map, opts)

      assert chunk_result.inserted == 2
      assert chunk_result.failed == 1
      assert length(chunk_result.errors) == 1

      error = List.first(chunk_result.errors)
      assert error.csv_line_number == 3
    end

    test "preserves CSV line numbers in errors" do
      chunk_rows_with_lines = [
        {5, %{member: %{email: "invalid"}, custom: %{}}},
        {10, %{member: %{email: "also-invalid"}, custom: %{}}}
      ]

      column_map = %{email: 0}
      custom_field_map = %{}
      opts = []

      assert {:ok, chunk_result} =
               MemberCSV.process_chunk(chunk_rows_with_lines, column_map, custom_field_map, opts)

      assert chunk_result.failed == 2
      assert length(chunk_result.errors) == 2

      line_numbers = Enum.map(chunk_result.errors, & &1.csv_line_number)
      assert 5 in line_numbers
      assert 10 in line_numbers
    end

    test "returns {:ok, chunk_result} on success" do
      chunk_rows_with_lines = [{2, %{member: %{email: "test@example.com"}, custom: %{}}}]
      column_map = %{email: 0}
      custom_field_map = %{}
      opts = []

      assert {:ok, chunk_result} =
               MemberCSV.process_chunk(chunk_rows_with_lines, column_map, custom_field_map, opts)

      # Check that chunk_result contains expected fields
      assert Map.has_key?(chunk_result, :inserted)
      assert Map.has_key?(chunk_result, :failed)
      assert Map.has_key?(chunk_result, :errors)
      assert is_integer(chunk_result.inserted)
      assert is_integer(chunk_result.failed)
      assert is_list(chunk_result.errors)
    end

    test "returns {:ok, _} with zero counts for empty chunk" do
      chunk_rows_with_lines = []
      column_map = %{}
      custom_field_map = %{}
      opts = []

      assert {:ok, chunk_result} =
               MemberCSV.process_chunk(chunk_rows_with_lines, column_map, custom_field_map, opts)

      assert chunk_result.inserted == 0
      assert chunk_result.failed == 0
      assert chunk_result.errors == []
    end

    test "function has documentation" do
      # Check that @doc exists by reading the module
      assert function_exported?(MemberCSV, :process_chunk, 4)
    end
  end

  describe "module documentation" do
    test "module has @moduledoc" do
      # Check that the module exists and has documentation
      assert Code.ensure_loaded?(MemberCSV)

      # Try to get the module documentation
      {:docs_v1, _, _, _, %{"en" => moduledoc}, _, _} = Code.fetch_docs(MemberCSV)
      assert is_binary(moduledoc)
      assert String.length(moduledoc) > 0
    end
  end
end