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)
    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, and opts" do
      chunk_rows_with_lines = [{2, %{"email" => "john@example.com"}}]
      column_map = %{email: 0}
      opts = []

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

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

      assert {:ok, chunk_result} =
               MemberCSV.process_chunk(chunk_rows_with_lines, column_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 {:error, reason} on failure" do
      chunk_rows_with_lines = []
      column_map = %{}
      opts = []

      # This might return {:ok, _} with zero counts or {:error, _}
      result = MemberCSV.process_chunk(chunk_rows_with_lines, column_map, opts)
      assert match?({:ok, _}, result) or match?({:error, _}, result)
    end

    test "function has documentation" do
      # Check that @doc exists by reading the module
      assert function_exported?(MemberCSV, :process_chunk, 3)
    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