package tray

import (
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"sync"
)

var (
	panelMu   sync.Mutex
	panelProc *os.Process
)

// launchPanel starts the syncwarden-panel subprocess if not already running.
func launchPanel(baseURL string) {
	panelMu.Lock()
	defer panelMu.Unlock()

	// Check if already running
	if panelProc != nil {
		// Check if process is still alive
		if err := panelProc.Signal(os.Signal(nil)); err == nil {
			log.Println("panel already running")
			return
		}
		panelProc = nil
	}

	panelBin := panelBinaryPath()
	if panelBin == "" {
		log.Println("syncwarden-panel binary not found")
		return
	}

	cmd := exec.Command(panelBin, "-addr", baseURL)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	if err := cmd.Start(); err != nil {
		log.Printf("failed to start panel: %v", err)
		return
	}
	panelProc = cmd.Process
	log.Printf("panel started (pid %d)", cmd.Process.Pid)

	// Wait for process to exit in background
	go func() {
		_ = cmd.Wait()
		panelMu.Lock()
		panelProc = nil
		panelMu.Unlock()
		log.Println("panel exited")
	}()
}

// panelBinaryPath finds the syncwarden-panel binary next to the main binary.
func panelBinaryPath() string {
	exe, err := os.Executable()
	if err != nil {
		return ""
	}
	dir := filepath.Dir(exe)

	name := "syncwarden-panel"
	if runtime.GOOS == "windows" {
		name = "syncwarden-panel.exe"
	}

	p := filepath.Join(dir, name)
	if _, err := os.Stat(p); err == nil {
		return p
	}
	return ""
}