//go:build windows

package main

import (
	"os"
	"os/exec"
	"strconv"
	"strings"
	"syscall"
	"time"
)

const windowsCreateNewProcessGroupForAIServer = 0x00000200

func prepareAIServerCommandForLifecycle(cmd *exec.Cmd) {
	if cmd == nil {
		return
	}
	if cmd.SysProcAttr == nil {
		cmd.SysProcAttr = &syscall.SysProcAttr{}
	}
	cmd.SysProcAttr.CreationFlags |= windowsCreateNewProcessGroupForAIServer
}

func terminateAIServerProcessTree(cmd *exec.Cmd) {
	if cmd == nil || cmd.Process == nil || cmd.Process.Pid <= 0 {
		return
	}

	terminateWindowsPIDTree(cmd.Process.Pid)
	_ = cmd.Process.Kill()
}

func stopStaleAIServerOnPort(port string) error {
	portNumber, err := strconv.Atoi(strings.TrimSpace(port))
	if err != nil || portNumber <= 0 || portNumber > 65535 {
		return nil
	}

	pids, err := windowsPIDsListeningOnPort(portNumber)
	if err != nil {
		return err
	}

	currentPID := os.Getpid()
	for _, pid := range pids {
		if pid <= 0 || pid == currentPID {
			continue
		}
		if !windowsPIDLooksLikeAIServer(pid) {
			appLogf("⚠️ Listener auf AI-Port %d übersprungen, Prozess sieht nicht nach AI Server aus: pid=%d", portNumber, pid)
			continue
		}
		appLogf("🧹 Alter AI Server auf Port %d wird beendet: pid=%d", portNumber, pid)
		terminateWindowsPIDTree(pid)
	}

	if len(pids) > 0 {
		time.Sleep(500 * time.Millisecond)
	}

	return nil
}

func windowsPIDsListeningOnPort(port int) ([]int, error) {
	ps := "Get-NetTCPConnection -LocalPort " + strconv.Itoa(port) + " -State Listen -ErrorAction SilentlyContinue | Select-Object -ExpandProperty OwningProcess -Unique"
	cmd := exec.Command(
		"powershell",
		"-NoProfile",
		"-NonInteractive",
		"-ExecutionPolicy", "Bypass",
		"-Command", ps,
	)
	hideCommandWindow(cmd)

	out, err := cmd.Output()
	if err != nil {
		return nil, err
	}

	pidSet := map[int]struct{}{}
	for _, line := range strings.Split(string(out), "\n") {
		pid, err := strconv.Atoi(strings.TrimSpace(line))
		if err != nil || pid <= 0 {
			continue
		}
		pidSet[pid] = struct{}{}
	}

	pids := make([]int, 0, len(pidSet))
	for pid := range pidSet {
		pids = append(pids, pid)
	}
	return pids, nil
}

func terminateWindowsPIDTree(pid int) {
	if pid <= 0 {
		return
	}

	cmd := exec.Command("taskkill", "/PID", strconv.Itoa(pid), "/T", "/F")
	hideCommandWindow(cmd)
	_ = cmd.Run()
}

func windowsPIDLooksLikeAIServer(pid int) bool {
	ps := "(Get-CimInstance Win32_Process -Filter \"ProcessId = " + strconv.Itoa(pid) + "\" -ErrorAction SilentlyContinue).CommandLine"
	cmd := exec.Command(
		"powershell",
		"-NoProfile",
		"-NonInteractive",
		"-ExecutionPolicy", "Bypass",
		"-Command", ps,
	)
	hideCommandWindow(cmd)

	out, err := cmd.Output()
	if err != nil {
		return false
	}

	cmdline := strings.ToLower(strings.TrimSpace(string(out)))
	return strings.Contains(cmdline, "ai_server:app") ||
		strings.Contains(cmdline, "ai_server.py") ||
		(strings.Contains(cmdline, "uvicorn") && strings.Contains(cmdline, "ai_server"))
}