defmodule MessageServer.StorageTest do
  use ExUnit.Case
  import ExUnit.CaptureLog

  @test_server_id "test_server"
  @test_storage_dir "storage/server_#{@test_server_id}"

  setup do
    # clean up any existing test storage
    File.rm_rf!(@test_storage_dir)

    # start the Storage GenServer for testing
    {:ok, pid} = MessageServer.Storage.start_link(@test_server_id)

    on_exit(fn ->
      # clean up after test
      if Process.alive?(pid), do: GenServer.stop(pid)
      File.rm_rf!(@test_storage_dir)
    end)

    %{storage_pid: pid}
  end

  test "creates storage directory on startup" do
    assert File.exists?(@test_storage_dir)
    assert File.dir?(@test_storage_dir)
  end

  test "appends message to user file" do
    user_id = "test_server-alice"
    from_user = "test_server-bob"
    message = "Hello Alice!"

    assert :ok = MessageServer.Storage.append_message(user_id, from_user, message)

    file_path = Path.join(@test_storage_dir, "#{user_id}.txt")
    assert File.exists?(file_path)

    content = File.read!(file_path)
    assert content == "#{from_user}: #{message}\n"
  end

  test "appends multiple messages to same user file" do
    user_id = "test_server-alice"

    assert :ok = MessageServer.Storage.append_message(user_id, "test_server-bob", "First message")

    assert :ok =
             MessageServer.Storage.append_message(
               user_id,
               "test_server-charlie",
               "Second message"
             )

    file_path = Path.join(@test_storage_dir, "#{user_id}.txt")
    content = File.read!(file_path)

    expected_content = """
    test_server-bob: First message
    test_server-charlie: Second message
    """

    assert content == expected_content
  end

  test "creates separate files for different users" do
    assert :ok =
             MessageServer.Storage.append_message(
               "test_server-alice",
               "test_server-bob",
               "Hi Alice"
             )

    assert :ok =
             MessageServer.Storage.append_message(
               "test_server-charlie",
               "test_server-bob",
               "Hi Charlie"
             )

    alice_file = Path.join(@test_storage_dir, "test_server-alice.txt")
    charlie_file = Path.join(@test_storage_dir, "test_server-charlie.txt")

    assert File.exists?(alice_file)
    assert File.exists?(charlie_file)

    assert File.read!(alice_file) == "test_server-bob: Hi Alice\n"
    assert File.read!(charlie_file) == "test_server-bob: Hi Charlie\n"
  end

  test "handles messages with special characters" do
    user_id = "test_server-alice"
    from_user = "test_server-bob"
    message = "Hello! 🎉 Special chars: @#$%^&*()"

    assert :ok = MessageServer.Storage.append_message(user_id, from_user, message)

    file_path = Path.join(@test_storage_dir, "#{user_id}.txt")
    content = File.read!(file_path)

    assert content == "#{from_user}: #{message}\n"
  end

  test "logs successful message storage" do
    user_id = "test_server-alice"
    from_user = "test_server-bob"
    message = "Test message"

    log_output =
      capture_log(fn ->
        assert :ok = MessageServer.Storage.append_message(user_id, from_user, message)
      end)

    assert log_output =~ "Message stored for user #{user_id}"
  end
end