package main

import (
	"crypto/sha256"
	"fmt"
	"io"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"sentinel/pkg/log"
	"sentinel/pkg/utils"

	"sentinel/pkg/device"
	"sentinel/pkg/net"
)

func main() {
	deviceID := device.GetDeviceID()
	fmt.Printf("[updater] device id: %s\n", deviceID)

	exeDir, _ := os.Executable()
	target := filepath.Join(filepath.Dir(exeDir), "main_program_binary_name") // TODO: 替换

	if err := RunUpdate(deviceID, target); err != nil {
		log.Fatalf("[updater] update failed: %v", err)
	}
	fmt.Println("[updater] update finished")
}

// RunUpdate 检查更新、下载、替换主程序并启动新程序
func RunUpdate(deviceID string, targetExe string) error {
	info, err := api.CheckUpdate(deviceID)
	if err != nil {
		return err
	}
	// 2. 比对本地版本
	if info.Version <= utils.APP_VERSION {
		fmt.Println("[updater] already latest version:", utils.APP_VERSION)
		return nil
	}
	fmt.Println("[updater] updating to version:", info.Version, "notes:", info.Notes)

	// 3. 下载新版本到临时目录
	tmpFile := filepath.Join(os.TempDir(), "new_program_tmp")
	out, err := os.Create(tmpFile)
	if err != nil {
		return fmt.Errorf("create temp file failed: %w", err)
	}
	defer out.Close()

	resp2, err := http.Get(info.DownloadURL)
	if err != nil {
		return fmt.Errorf("download failed: %w", err)
	}
	defer resp2.Body.Close()

	h := sha256.New()
	mw := io.MultiWriter(out, h)
	if _, err := io.Copy(mw, resp2.Body); err != nil {
		return fmt.Errorf("write temp file failed: %w", err)
	}

	// 4. 替换 targetExe
	backup := targetExe + ".bak"
	_ = os.Remove(backup)
	_ = os.Rename(targetExe, backup) // 备份旧版本
	if err := os.Rename(tmpFile, targetExe); err != nil {
		return fmt.Errorf("replace main program failed: %w", err)
	}
	fmt.Println("[updater] replaced main program")

	// 5. 启动新主程序
	cmd := exec.Command(targetExe)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	if err := cmd.Start(); err != nil {
		return fmt.Errorf("start new program failed: %w", err)
	}

	fmt.Println("[updater] new program started successfully")
	return nil
}