"""Tests for TunnelManager."""
import os
import signal
from unittest.mock import MagicMock, patch

import pytest

from bridge.models import BridgeState, ReconnectPolicy, TunnelConfig
from bridge.manager import TunnelManager, build_ssh_command


@pytest.fixture
def tunnel_cfg():
    return TunnelConfig(
        name="test-tunnel",
        host="host.local",
        remote_port=18000,
        local_port=8000,
        ssh_user="ubuntu",
        ssh_key="~/.ssh/id_ops",
        actor="operator.bernd",
        reconnect=ReconnectPolicy(max_attempts=3, backoff_initial=1, backoff_max=5),
    )


@pytest.fixture
def state_dir(tmp_path):
    return tmp_path / "bridge"


class TestBuildSshCommand:
    def test_basic_command(self, tunnel_cfg):
        cmd = build_ssh_command(tunnel_cfg)
        assert cmd[0] == "ssh"
        assert "-N" in cmd
        assert "-R" in cmd
        assert "18000:127.0.0.1:8000" in cmd
        assert "-i" in cmd
        assert "ubuntu@host.local" in cmd

    def test_server_alive_options(self, tunnel_cfg):
        cmd = build_ssh_command(tunnel_cfg)
        assert "-o" in cmd
        assert "ServerAliveInterval=10" in cmd
        assert "ExitOnForwardFailure=yes" in cmd

    def test_ssh_key_expanded(self, tunnel_cfg):
        cmd = build_ssh_command(tunnel_cfg)
        key_idx = cmd.index("-i") + 1
        assert not cmd[key_idx].startswith("~")


class TestTunnelManager:
    def test_get_state_initial(self, tunnel_cfg, state_dir):
        mgr = TunnelManager(tunnel_cfg, state_dir=state_dir)
        assert mgr.get_state() == BridgeState.STOPPED

    def test_stop_when_not_running_is_noop(self, tunnel_cfg, state_dir):
        mgr = TunnelManager(tunnel_cfg, state_dir=state_dir)
        # Should not raise
        mgr.stop()
        assert mgr.get_state() == BridgeState.STOPPED

    def test_stop_kills_pid(self, tunnel_cfg, state_dir):
        mgr = TunnelManager(tunnel_cfg, state_dir=state_dir)
        # Write a fake PID of our own process to simulate running
        mgr._state.write_pid(tunnel_cfg.name, os.getpid())
        mgr._state.write_state(tunnel_cfg.name, BridgeState.CONNECTED)

        with patch("os.kill") as mock_kill:
            mgr.stop()

        # Should have sent SIGTERM
        mock_kill.assert_any_call(os.getpid(), signal.SIGTERM)
        assert mgr.get_state() == BridgeState.STOPPED

    def test_backoff_calculation(self, tunnel_cfg, state_dir):
        mgr = TunnelManager(tunnel_cfg, state_dir=state_dir)
        # First backoff = initial
        assert mgr._next_backoff(0) == 1
        # Doubles each time up to max
        assert mgr._next_backoff(1) == 2
        assert mgr._next_backoff(2) == 4
        assert mgr._next_backoff(3) == 5  # capped at max

    def test_start_daemonizes(self, tunnel_cfg, state_dir):
        """Verify start() forks without hanging."""
        mgr = TunnelManager(tunnel_cfg, state_dir=state_dir)

        # We can't actually fork in tests; verify state transitions via mock
        with patch("subprocess.Popen") as mock_popen, \
             patch("os.fork", return_value=1234), \
             patch("os.setsid"), \
             patch("os._exit"):
            mock_proc = MagicMock()
            mock_proc.pid = 9999
            mock_popen.return_value = mock_proc

            # When fork returns non-zero we're the parent — just check PID written
            mgr.start()

        # After start the state should be STARTING (set before fork)
        # and PID file should exist (written in parent branch)

    def test_is_running_false_initially(self, tunnel_cfg, state_dir):
        mgr = TunnelManager(tunnel_cfg, state_dir=state_dir)
        assert not mgr.is_running()