"""Tests for the DM notification channel."""

from pathlib import Path

import pytest

from storied import notifications


@pytest.fixture
def world(tmp_path: Path) -> str:
    """Return the world_id with world directory created under the
    autouse-isolated data home."""
    world_dir = tmp_path / "worlds" / "test-world"
    world_dir.mkdir(parents=True)
    return "test-world"


class TestAppendAndDrain:
    def test_drain_empty(self, world: str):
        assert notifications.drain(world) == []

    def test_append_then_drain(self, world: str):
        notifications.append(world, "Something happened")

        messages = notifications.drain(world)
        assert messages == ["Something happened"]

    def test_drain_clears(self, world: str):
        notifications.append(world, "First")

        notifications.drain(world)
        assert notifications.drain(world) == []

    def test_multiple_messages(self, world: str):
        notifications.append(world, "First thing")
        notifications.append(world, "Second thing")
        notifications.append(world, "Third thing")

        messages = notifications.drain(world)
        assert messages == ["First thing", "Second thing", "Third thing"]

    def test_file_removed_after_drain(self, world: str, tmp_path: Path):
        notifications.append(world, "Temporary")

        notifications.drain(world)
        path = tmp_path / "worlds" / "test-world" / "dm_notifications.md"
        assert not path.exists()

    def test_creates_world_dir_if_missing(self):
        notifications.append("new-world", "Hello")

        messages = notifications.drain("new-world")
        assert messages == ["Hello"]

    def test_drain_empty_existing_file_returns_empty(
        self,
        world: str,
        tmp_path: Path,
    ):
        """An existing notifications file with only whitespace drains
        as empty and is removed."""
        path = tmp_path / "worlds" / "test-world" / "dm_notifications.md"
        path.write_text("   \n  \n")

        assert notifications.drain(world) == []
        assert not path.exists()