package main

import (
	"context"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"io"
	"os"
	"rtu_linux_services/servicelib"
	"strings"
	"time"

	"hnyfkj.com.cn/rtu/linux/utils/ftpclient"
)

func getFtpUpgradeInfo(ctx context.Context, u *servicelib.UpgradeURL, timeout time.Duration) (upgradeInfo, error) {
	localFile, err := ftpclient.DownloadFileFromFtp(ctx, u.Host, u.User, u.Pass, u.Path, timeout)
	if err != nil {
		return upgradeInfo{}, err
	}

	defer os.Remove(localFile)

	data, err := os.ReadFile(localFile)
	if err != nil {
		return upgradeInfo{}, err
	}

	var info upgradeInfo
	if err := json.Unmarshal(data, &info); err != nil {
		return upgradeInfo{}, err
	}

	info.Version = strings.TrimSpace(info.Version)
	info.SHA256 = strings.TrimSpace(info.SHA256)

	if info.Version == "" {
		return upgradeInfo{}, fmt.Errorf("升级版本号不能为空")
	}

	if info.SHA256 == "" {
		return upgradeInfo{}, fmt.Errorf("升级校验值不能为空")
	}

	if len(info.SHA256) != 64 {
		return upgradeInfo{}, fmt.Errorf("升级校验值长度错误")
	}

	if _, err := hex.DecodeString(info.SHA256); err != nil {
		return upgradeInfo{}, fmt.Errorf("升级校验值格式错误")
	}

	return info, nil
}

func downloadFtpUpgradePackage(ctx context.Context, u *servicelib.UpgradeURL, localFile string, timeout time.Duration) error {
	file, err := ftpclient.DownloadFileFromFtp(ctx, u.Host, u.User, u.Pass, u.Path, timeout)
	if err != nil {
		return err
	}

	defer os.Remove(file)

	src, err := os.Open(file)
	if err != nil {
		return err
	}
	defer src.Close()

	dst, err := os.Create(localFile)
	if err != nil {
		return err
	}

	if _, err := io.Copy(dst, src); err != nil {
		dst.Close()
		_ = os.Remove(localFile)
		return err
	}

	if err := dst.Close(); err != nil {
		_ = os.Remove(localFile)
		return err
	}

	return nil
}