"""Cloudflare tunnel management for Docker instances."""

import logging
import os
import re
import signal
import subprocess
import time
from typing import Any

logger = logging.getLogger(__name__)


def start_cloudflared_tunnel(
    container_name: str, port: int, timeout: int = 30
) -> dict[str, str]:
    """Start a temporary Cloudflare tunnel for a container.

    Uses 'cloudflared tunnel --url' to create a temporary tunnel
    with a random trycloudflare.com URL.

    Args:
        container_name: Name of the Docker container to tunnel to
        port: Port number the container listens on
        timeout: Maximum seconds to wait for tunnel URL

    Returns:
        Dict with 'url' (the public tunnel URL) and 'pid' (process ID)
    """
    import select as sel

    # First verify the container is accessible
    logger.info("Checking connectivity to %s:%d...", container_name, port)
    for attempt in range(10):
        check = subprocess.run(
            ["curl", "-s", "-o", "/dev/null", "-w", "%{http_code}",
             f"http://{container_name}:{port}"],
            capture_output=True,
            text=True,
            timeout=5,
        )
        logger.info("Connectivity check %d: http_code=%s", attempt + 1, check.stdout.strip())
        if check.returncode == 0:
            break
        time.sleep(1)
    else:
        logger.warning("Container %s:%d not responding to curl checks", container_name, port)

    # Run cloudflared in background, capture output
    logger.info("Starting cloudflared tunnel to http://%s:%d", container_name, port)
    proc = subprocess.Popen(
        ["cloudflared", "tunnel", "--url", f"http://{container_name}:{port}"],
        stdout=subprocess.PIPE,
        stderr=subprocess.STDOUT,
        text=True,
    )

    # Wait for the URL to appear in output
    url_pattern = re.compile(r"https://[a-z0-9-]+\.trycloudflare\.com")
    start_time = time.time()
    url = None

    while time.time() - start_time < timeout:
        # Read available output
        readable, _, _ = sel.select([proc.stdout], [], [], 1.0)
        if readable:
            line = proc.stdout.readline()
            if line:
                match = url_pattern.search(line)
                if match:
                    url = match.group(0)
                    break

    if not url:
        proc.terminate()
        proc.wait(timeout=5)
        raise RuntimeError(
            f"Failed to get tunnel URL within {timeout}s. "
            f"cloudflared output may contain errors."
        )

    return {"url": url, "pid": str(proc.pid)}


def stop_cloudflared_tunnel(pid: str) -> None:
    """Stop a cloudflared tunnel process.

    Args:
        pid: Process ID of the cloudflared tunnel
    """
    try:
        os.kill(int(pid), signal.SIGTERM)
    except ProcessLookupError:
        pass  # Already stopped


def recreate_tunnel(
    container_name: str, port: int, old_pid: str | None = None
) -> dict[str, str]:
    """Recreate a temporary Cloudflare tunnel.

    Stops the old tunnel (if pid provided) and starts a new one.

    Args:
        container_name: Name of the Docker container to tunnel to
        port: Port number the container listens on
        old_pid: Optional PID of the old tunnel process to stop

    Returns:
        Dict with 'url' and 'pid' for the new tunnel
    """
    if old_pid:
        stop_cloudflared_tunnel(old_pid)

    return start_cloudflared_tunnel(container_name, port)


def check_tunnel_health(url: str, timeout: int = 10) -> dict[str, Any]:
    """Check if a tunnel URL is healthy.

    Args:
        url: The tunnel URL to check
        timeout: Request timeout in seconds

    Returns:
        Dict with 'healthy' (bool) and 'status_code' (int or None)
    """
    try:
        result = subprocess.run(
            ["curl", "-s", "-o", "/dev/null", "-w", "%{http_code}",
             "--max-time", str(timeout), url],
            capture_output=True,
            text=True,
            timeout=timeout + 5,
        )
        status_code = int(result.stdout.strip())
        return {
            "healthy": 200 <= status_code < 400,
            "status_code": status_code,
        }
    except (ValueError, subprocess.TimeoutExpired, Exception) as e:
        return {
            "healthy": False,
            "status_code": None,
            "error": str(e),
        }