"""Tests for the server module."""

import asyncio
import contextlib
from unittest.mock import AsyncMock, MagicMock, patch

import pytest

from mudlib import server
from mudlib.world.terrain import World


def test_port_constant():
    assert server.PORT == 6789
    assert isinstance(server.PORT, int)


def test_shell_exists():
    assert callable(server.shell)
    assert asyncio.iscoroutinefunction(server.shell)


def test_run_server_exists():
    assert callable(server.run_server)
    assert asyncio.iscoroutinefunction(server.run_server)


def test_find_passable_start():
    world = World(seed=42, width=100, height=100)
    x, y = server.find_passable_start(world, 50, 50)
    assert isinstance(x, int)
    assert isinstance(y, int)
    assert world.is_passable(x, y)


@pytest.mark.asyncio
async def test_shell_greets_and_accepts_commands():
    server._world = World(seed=42, width=100, height=100)

    reader = AsyncMock()
    writer = MagicMock()
    writer.is_closing.side_effect = [False, False, False, True]
    writer.drain = AsyncMock()
    writer.close = MagicMock()

    readline = "mudlib.server.readline2"
    with patch(readline, new_callable=AsyncMock) as mock_readline:
        mock_readline.side_effect = ["TestPlayer", "look", "quit"]
        await server.shell(reader, writer)

    calls = [str(call) for call in writer.write.call_args_list]
    assert any("Welcome" in call for call in calls)
    assert any("TestPlayer" in call for call in calls)
    writer.close.assert_called()


@pytest.mark.asyncio
async def test_shell_handles_eof():
    server._world = World(seed=42, width=100, height=100)

    reader = AsyncMock()
    writer = MagicMock()
    writer.is_closing.return_value = False
    writer.drain = AsyncMock()
    writer.close = MagicMock()

    readline = "mudlib.server.readline2"
    with patch(readline, new_callable=AsyncMock) as mock_readline:
        mock_readline.return_value = None
        await server.shell(reader, writer)

    writer.close.assert_called_once()


@pytest.mark.asyncio
async def test_shell_handles_quit():
    server._world = World(seed=42, width=100, height=100)

    reader = AsyncMock()
    writer = MagicMock()
    writer.is_closing.side_effect = [False, False, True]
    writer.drain = AsyncMock()
    writer.close = MagicMock()

    readline = "mudlib.server.readline2"
    with patch(readline, new_callable=AsyncMock) as mock_readline:
        mock_readline.side_effect = ["TestPlayer", "quit"]
        await server.shell(reader, writer)

    calls = [str(call) for call in writer.write.call_args_list]
    assert any("Goodbye" in call for call in calls)
    writer.close.assert_called()


def test_load_world_config():
    """Config loader returns expected values from worlds/earth/config.toml."""
    config = server.load_world_config()
    assert config["world"]["seed"] == 42
    assert config["world"]["width"] == 1000
    assert config["world"]["height"] == 1000


def test_load_world_config_missing():
    """Config loader raises FileNotFoundError for nonexistent world."""
    with pytest.raises(FileNotFoundError):
        server.load_world_config("nonexistent")


def test_tick_constants():
    """Tick rate and interval are configured correctly."""
    assert server.TICK_RATE == 10
    assert pytest.approx(0.1) == server.TICK_INTERVAL


def test_game_loop_exists():
    """Game loop is an async callable."""
    assert callable(server.game_loop)
    assert asyncio.iscoroutinefunction(server.game_loop)


@pytest.mark.asyncio
async def test_game_loop_calls_clear_expired():
    """Game loop calls clear_expired each tick."""
    with patch("mudlib.server.clear_expired") as mock_clear:
        task = asyncio.create_task(server.game_loop())
        await asyncio.sleep(0.25)
        task.cancel()
        with contextlib.suppress(asyncio.CancelledError):
            await task

        assert mock_clear.call_count >= 1