package main

import (
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"net/http"
	"os"
	"strings"
	"sync"
	"time"

	"github.com/kardianos/osext"
)

// 配置文件
type configuration struct {
	Proxy string
}

var G_config configuration

func readConfig() {
	folderPath, err := osext.ExecutableFolder()
	if err != nil {
		log.Fatal(err)
	}
	// 打开文件
	file, err := os.Open(folderPath + "/config.json")
	if err != nil {
		return
	}
	// 关闭文件
	defer file.Close()
	//NewDecoder创建一个从file读取并解码json对象的*Decoder，解码器有自己的缓冲，并可能超前读取部分json数据。
	decoder := json.NewDecoder(file)
	G_config = configuration{}
	//Decode从输入流读取下一个json编码值并保存在v指向的值里
	err = decoder.Decode(&G_config)
	if err != nil {
		fmt.Println("Error:", err)
	}
	// fmt.Println("proxy:" + G_config.Proxy)
}

// 下载
type people struct {
	Tag_name string `json:"tag_name"` //Tag_name 小写变成私有
}

func api_get_version(project string) string {
	git_api := "https://api.github.com/repos/" + project + "/releases/latest"

	// 目标URL
	url := git_api

	// 发送HTTP GET请求
	resp, err := http.Get(url)
	if err != nil {
		panic(err)
	}
	defer resp.Body.Close()

	// 读取响应体
	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		panic(err)
	}

	// 解析JSON数据
	responseData := people{}
	if err := json.Unmarshal(body, &responseData); err != nil {
		panic(err)
	}

	// 打印解析后的数据
	// fmt.Println("tag_name:" + responseData.Tag_name)
	// latest_version = responseData.tag_name
	return responseData.Tag_name
}

type Downloader struct {
	io.Reader
	Total   int64
	Current int64
}

func printProgressBar(progress int64, total int64) {
	// bar := ""
	// numSlashes := progress * 100 / total / 5
	// for i := 0; i < numSlashes; i++ {
	// 	bar += "\u2588" // 这是一个完整的块字符
	// }
	// fmt.Printf("下载进度: [%-21s] %.2f%%\r", bar, float64(progress*100.0/total))
	fmt.Printf("  正在下载：%d / %d bytes (%.2f%%)\r", progress, total, float32(progress*10000/total)/100)
}

func (d *Downloader) Read(p []byte) (n int, err error) {
	n, err = d.Reader.Read(p)
	d.Current += int64(n)

	printProgressBar(d.Current, d.Total)
	return
}

func downloadFile(item int, url string, filePath string) {
	defer wg.Done()
	fmt.Printf("%d.下载%s\n", item, filePath)
	resp, err := http.Get(url)
	if err != nil {
		log.Fatalln(err)
	}
	defer func() {
		_ = resp.Body.Close()
	}()
	file, err := os.Create(filePath)
	if err != nil {
		fmt.Println("文件创建失败：", err)
		// 其他处理
	}

	defer func() {
		_ = file.Close()
	}()
	downloader := &Downloader{
		Reader: resp.Body,
		Total:  resp.ContentLength,
	}
	if _, err := io.Copy(file, downloader); err != nil {
		log.Fatalln(err)
	}
	fmt.Println() // 新的一行以清除进度条打印
}

var wg sync.WaitGroup

func http_down(project string, down_list string, proxy string) {
	// fmt.Println(project, down_list, proxy)

	// 获取最新版本
	latest_version := api_get_version(project)

	// 创建文件夹
	folderPath := latest_version
	err := os.MkdirAll(folderPath, os.ModePerm)
	if err != nil {
		fmt.Printf("创建文件夹错误: %v\n", err)
		return
	}

	// 分割下载列表
	git_down_url := proxy + project + "/releases/download/" + latest_version + "/"
	parts := strings.Split(down_list, ",")
	task := make(map[string]string)
	for i := 0; i < len(parts); i++ {
		// 替换
		version_str := strings.ReplaceAll(latest_version, "v", "")
		version_str = strings.ReplaceAll(version_str, "V", "")
		filename := strings.ReplaceAll(parts[i], "[version]", version_str)
		// 存入
		task[git_down_url+filename] = folderPath + "/" + filename
	}

	item := 1
	for k, v := range task {
		wg.Add(1)
		downloadFile(item, k, v)
		item += 1
	}
	wg.Wait()

	fmt.Println("下载完成")
	time.Sleep(1 * time.Second)
}

func main() {
	// parser := argparse.NewParser("GitAutoupdater", "这是git最新版本的更新工具")
	// name := parser.String("n", "name", &argparse.Options{Required: false, Help: "项目，譬如 fatedier/frp", Default: "fatedier/frp"})
	// list := parser.String("l", "list", &argparse.Options{Required: false, Help: "下载列表(1.[version]可替换最新版本 2.用,分割多个文件)，譬如 frp_[version]_windows_amd64.zip", Default: "frp_[version]_windows_amd64.zip"})
	// proxy := parser.String("p", "proxy", &argparse.Options{Required: false, Help: "代理，譬如 https://ghproxy.com/https://github.com/", Default: "https://github.com/"})
	// err := parser.Parse(os.Args)
	// if err != nil {
	// 	fmt.Print(parser.Usage(err)) // 帮助 -h or --help
	// 	return
	// }

	name := ""
	list := ""
	proxy := "https://github.com/"
	for i, num := range os.Args[1:] {
		switch i {
		case 0:
			name = num
		case 1:
			list = num
		case 2:
			proxy = num
		default:
			fmt.Println(`未知参数:`, num)
		}
	}
	// 优先级：命令>配置>默认
	readConfig()
	if proxy == "https://github.com/" && G_config.Proxy != "" {
		proxy = G_config.Proxy
	}

	fmt.Println("proxy:", proxy)
	http_down(name, list, proxy)
}