import os
import signal
import time
import pytest
from datetime import datetime, timezone
from click.testing import CliRunner
from autossh_mgr.cli import cli
from autossh_mgr.config import save_tunnels, TunnelConfig, ensure_dirs
from autossh_mgr.process import read_pid_file, is_process_alive, write_pid_file


@pytest.fixture
def fake_autossh(tmp_path, monkeypatch):
    """Replace autossh with a long-running dummy process."""
    fake = tmp_path / "autossh"
    fake.write_text("#!/bin/sh\nexec sleep 60\n")
    fake.chmod(0o755)
    monkeypatch.setenv("PATH", f"{tmp_path}:{os.environ['PATH']}")
    return fake


@pytest.fixture
def config_dir(tmp_path):
    ensure_dirs(tmp_path)
    return tmp_path


@pytest.fixture(autouse=True)
def set_config_dir(config_dir, monkeypatch):
    monkeypatch.setenv("AUTOSSH_MGR_CONFIG_DIR", str(config_dir))


@pytest.fixture(autouse=True)
def cleanup_processes(config_dir):
    """Kill any processes recorded in PID files after each test."""
    yield
    pids_dir = config_dir / "pids"
    if not pids_dir.exists():
        return
    for pid_file in pids_dir.glob("*.pid"):
        try:
            lines = pid_file.read_text().splitlines()
            if lines:
                os.kill(int(lines[0]), signal.SIGKILL)
        except (ValueError, OSError, ProcessLookupError):
            pass


@pytest.fixture
def tunnel(config_dir):
    t = TunnelConfig(
        name="test-tunnel",
        host="relay.example.com",
        user="deploy",
        local_port=19999,
        remote_port=29999,
    )
    save_tunnels(config_dir, [t])
    return t


@pytest.fixture
def runner():
    return CliRunner()


def test_start_writes_pid_file(runner, config_dir, tunnel, fake_autossh):
    result = runner.invoke(cli, ["start", "test-tunnel"])
    assert result.exit_code == 0, result.output
    pid_data = read_pid_file(config_dir, "test-tunnel")
    assert pid_data is not None
    pid, _ = pid_data
    assert is_process_alive(pid)


def test_stop_kills_process(runner, config_dir, tunnel, fake_autossh):
    runner.invoke(cli, ["start", "test-tunnel"])
    pid_data = read_pid_file(config_dir, "test-tunnel")
    assert pid_data is not None
    pid = pid_data[0]
    assert is_process_alive(pid)

    result = runner.invoke(cli, ["stop", "test-tunnel"])
    assert result.exit_code == 0
    time.sleep(0.2)
    assert not is_process_alive(pid)
    assert read_pid_file(config_dir, "test-tunnel") is None


def test_status_shows_running(runner, config_dir, tunnel, fake_autossh):
    runner.invoke(cli, ["start", "test-tunnel"])
    result = runner.invoke(cli, ["status", "test-tunnel"])
    assert result.exit_code == 0
    assert "running" in result.output


def test_stale_pid_cleaned_on_start(runner, config_dir, tunnel, fake_autossh):
    write_pid_file(config_dir, "test-tunnel", 9999999, datetime.now(timezone.utc))

    result = runner.invoke(cli, ["start", "test-tunnel"])
    assert result.exit_code == 0, result.output
    assert "stale" in result.output.lower()

    pid_data = read_pid_file(config_dir, "test-tunnel")
    assert pid_data is not None
    assert pid_data[0] != 9999999


def test_restart(runner, config_dir, tunnel, fake_autossh):
    runner.invoke(cli, ["start", "test-tunnel"])
    first_pid = read_pid_file(config_dir, "test-tunnel")[0]

    result = runner.invoke(cli, ["restart", "test-tunnel"])
    assert result.exit_code == 0, result.output

    second_pid = read_pid_file(config_dir, "test-tunnel")[0]
    assert second_pid != first_pid
    assert is_process_alive(second_pid)
    assert not is_process_alive(first_pid)


def test_idempotent_start(runner, config_dir, tunnel, fake_autossh):
    runner.invoke(cli, ["start", "test-tunnel"])
    first_pid = read_pid_file(config_dir, "test-tunnel")[0]

    result = runner.invoke(cli, ["start", "test-tunnel"])
    assert result.exit_code == 0
    assert "already running" in result.output
    assert read_pid_file(config_dir, "test-tunnel")[0] == first_pid


def test_idempotent_stop(runner, tunnel):
    result = runner.invoke(cli, ["stop", "test-tunnel"])
    assert result.exit_code == 0
    assert "not running" in result.output