import asyncio
import os
import tempfile
import pytest
from log_watcher import LogWatcher

pytestmark = pytest.mark.asyncio


async def test_watcher_receives_new_lines():
    with tempfile.NamedTemporaryFile(mode='w', suffix='.log', delete=False) as f:
        path = f.name
    try:
        received = []

        async def on_line(line):
            received.append(line.rstrip('\n'))

        watcher = LogWatcher(path, on_line)
        watcher.start()
        await asyncio.sleep(0.05)  # let watcher open and seek to end

        with open(path, 'a') as f:
            f.write("line one\n")
            f.write("line two\n")

        await asyncio.sleep(0.3)  # wait for poll cycles
        watcher.stop()

        assert received == ["line one", "line two"]
    finally:
        os.unlink(path)


async def test_watcher_handles_missing_file_then_appears():
    path = tempfile.mktemp(suffix='.log')
    received = []

    async def on_line(line):
        received.append(line.rstrip('\n'))

    watcher = LogWatcher(path, on_line)
    watcher.start()
    await asyncio.sleep(0.15)  # file doesn't exist yet

    with open(path, 'w') as f:
        f.write("hello\n")

    await asyncio.sleep(0.3)
    watcher.stop()

    # File appeared after watcher started — lines written before watcher opens
    # will be consumed. This test just checks it doesn't crash.
    assert isinstance(received, list)

    if os.path.exists(path):
        os.unlink(path)


async def test_watcher_calls_on_offline_after_timeout():
    path = tempfile.mktemp(suffix='.log')  # never created
    offline_called = []

    async def on_offline():
        offline_called.append(True)

    watcher = LogWatcher(path, lambda _: None, on_offline=on_offline, offline_timeout=0.2)
    watcher.start()
    await asyncio.sleep(0.5)
    watcher.stop()

    assert offline_called, "on_offline should have been called"