import os
import signal
import socket
import subprocess
import time

# Read ports from environment variables; use default values if not set
FD_API_PORT = int(os.getenv("FD_API_PORT", 8188))
FD_ENGINE_QUEUE_PORT = int(os.getenv("FD_ENGINE_QUEUE_PORT", 8133))
FD_METRICS_PORT = int(os.getenv("FD_METRICS_PORT", 8233))
FD_CACHE_QUEUE_PORT = int(os.getenv("FD_CACHE_QUEUE_PORT", 8333))

# List of ports to clean before and after tests
PORTS_TO_CLEAN = [FD_API_PORT, FD_ENGINE_QUEUE_PORT, FD_METRICS_PORT, FD_CACHE_QUEUE_PORT]


def is_port_open(host: str, port: int, timeout=1.0):
    """
    Check if a TCP port is open on the given host.
    Returns True if connection succeeds, False otherwise.
    """
    try:
        with socket.create_connection((host, port), timeout):
            return True
    except Exception:
        return False


def kill_process_on_port(port: int):
    """
    Kill processes that are listening on the given port.
    Uses multiple methods to ensure thorough cleanup.
    """
    current_pid = os.getpid()
    parent_pid = os.getppid()

    # Method 1: Use lsof to find processes
    try:
        output = subprocess.check_output(f"lsof -i:{port} -t", shell=True).decode().strip()
        for pid in output.splitlines():
            pid = int(pid)
            if pid in (current_pid, parent_pid):
                print(f"Skip killing current process (pid={pid}) on port {port}")
                continue
            try:
                # First try SIGTERM for graceful shutdown
                os.kill(pid, signal.SIGTERM)
                time.sleep(1)
                # Then SIGKILL if still running
                os.kill(pid, signal.SIGKILL)
                print(f"Killed process on port {port}, pid={pid}")
            except ProcessLookupError:
                pass  # Process already terminated
    except subprocess.CalledProcessError:
        pass

    # Method 2: Use netstat and fuser as backup
    try:
        # Find processes using netstat and awk
        cmd = f"netstat -tulpn 2>/dev/null | grep :{port} | awk '{{print $7}}' | cut -d'/' -f1"
        output = subprocess.check_output(cmd, shell=True).decode().strip()
        for pid in output.splitlines():
            if pid and pid.isdigit():
                pid = int(pid)
                if pid in (current_pid, parent_pid):
                    continue
                try:
                    os.kill(pid, signal.SIGKILL)
                    print(f"Killed process (netstat) on port {port}, pid={pid}")
                except ProcessLookupError:
                    pass
    except (subprocess.CalledProcessError, FileNotFoundError):
        pass

    # Method 3: Use fuser if available
    try:
        subprocess.run(f"fuser -k {port}/tcp", shell=True, timeout=5)
    except (subprocess.TimeoutExpired, subprocess.CalledProcessError, FileNotFoundError):
        pass


def clean_ports():
    """
    Kill all processes occupying the ports listed in PORTS_TO_CLEAN.
    """
    print(f"Cleaning ports: {PORTS_TO_CLEAN}")
    for port in PORTS_TO_CLEAN:
        kill_process_on_port(port)

    # Double check and retry if ports are still in use
    time.sleep(2)
    for port in PORTS_TO_CLEAN:
        if is_port_open("127.0.0.1", port, timeout=0.1):
            print(f"Port {port} still in use, retrying cleanup...")
            kill_process_on_port(port)
            time.sleep(1)