"""
Tests for app.apply_schedule().

The function rewrites the crontab file and reloads crond via SIGHUP, falling
back to spawning a fresh crond when the recorded pid is dead or absent. These
tests cover the six meaningful state combinations of (schedule, crontab present,
pid file present, pid alive).
"""

import os
import signal
import sys
from unittest.mock import MagicMock

import pytest

# Make the app module importable without installing it.
sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

import app as app_module  # noqa: E402


@pytest.fixture
def patched(monkeypatch, tmp_path):
    """Redirect crontab/pid paths to tmp and swap os.kill + subprocess.Popen with mocks."""
    crontab = tmp_path / "crontabs" / "root"
    pid_file = tmp_path / "crond.pid"
    monkeypatch.setattr(app_module, "CRONTAB_FILE", str(crontab))
    monkeypatch.setattr(app_module, "CROND_PID_FILE", str(pid_file))

    mock_kill = MagicMock()
    monkeypatch.setattr(app_module.os, "kill", mock_kill)

    mock_popen = MagicMock()
    mock_popen.return_value = MagicMock(pid=9999)
    monkeypatch.setattr(app_module.subprocess, "Popen", mock_popen)

    return {
        "crontab": crontab,
        "pid_file": pid_file,
        "kill": mock_kill,
        "popen": mock_popen,
    }


def test_manual_with_existing_crontab_and_live_pid(patched):
    patched["crontab"].parent.mkdir(parents=True)
    patched["crontab"].write_text("0 2 * * * /app/sync.sh\n")
    patched["pid_file"].write_text("1234")

    app_module.apply_schedule("manual")

    assert not patched["crontab"].exists()
    patched["kill"].assert_called_once_with(1234, signal.SIGHUP)
    patched["popen"].assert_not_called()


def test_manual_with_no_crontab_and_no_pid_file(patched):
    assert not patched["crontab"].exists()
    assert not patched["pid_file"].exists()

    app_module.apply_schedule("manual")  # should not raise

    assert not patched["crontab"].exists()
    patched["kill"].assert_not_called()
    patched["popen"].assert_not_called()


def test_real_schedule_with_live_pid(patched):
    patched["pid_file"].write_text("4321")

    app_module.apply_schedule("0 4 * * *")

    expected_line = "0 4 * * * /app/sync.sh >> /var/log/youtube-sync.log 2>&1\n"
    assert patched["crontab"].read_text() == expected_line
    patched["kill"].assert_called_once_with(4321, signal.SIGHUP)
    patched["popen"].assert_not_called()


def test_real_schedule_with_dead_pid(patched):
    patched["pid_file"].write_text("4321")
    patched["kill"].side_effect = ProcessLookupError()

    app_module.apply_schedule("0 4 * * *")

    expected_line = "0 4 * * * /app/sync.sh >> /var/log/youtube-sync.log 2>&1\n"
    assert patched["crontab"].read_text() == expected_line
    patched["kill"].assert_called_once_with(4321, signal.SIGHUP)
    patched["popen"].assert_called_once_with(
        ["crond", "-f", "-l", "2"],
        stdout=app_module.subprocess.DEVNULL,
        stderr=app_module.subprocess.DEVNULL,
    )
    assert patched["pid_file"].read_text() == "9999"


def test_real_schedule_with_no_pid_file(patched):
    assert not patched["pid_file"].exists()

    app_module.apply_schedule("0 4 * * *")

    expected_line = "0 4 * * * /app/sync.sh >> /var/log/youtube-sync.log 2>&1\n"
    assert patched["crontab"].read_text() == expected_line
    patched["kill"].assert_not_called()
    patched["popen"].assert_called_once()
    assert patched["pid_file"].read_text() == "9999"


def test_real_schedule_with_garbage_pid_file(patched):
    patched["pid_file"].write_text("not-a-number")

    app_module.apply_schedule("0 4 * * *")

    expected_line = "0 4 * * * /app/sync.sh >> /var/log/youtube-sync.log 2>&1\n"
    assert patched["crontab"].read_text() == expected_line
    patched["kill"].assert_not_called()
    patched["popen"].assert_called_once()
    assert patched["pid_file"].read_text() == "9999"