package common

import (
	"fmt"
	"github.com/go-resty/resty/v2"
	"io"
	"io/ioutil"
	"net/http"
	"os"
	"path"
	"regexp"
	"strings"
)

// NewHttpClient 新建一个 resty 的对象
func NewHttpClient(_reqParam ...ReqParam) *resty.Client {
	//const defUserAgent = "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_8; en-us) AppleWebKit/534.50 (KHTML, like Gecko) Version/5.1 Safari/534.50"
	const defUserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.77 Safari/537.36 Edg/91.0.864.41"

	var reqParam ReqParam
	var HttpProxy, UserAgent, Referer string

	if len(_reqParam) > 0 {
		reqParam = _reqParam[0]
	}
	if len(reqParam.HttpProxy) > 0 {
		HttpProxy = reqParam.HttpProxy
	}
	if len(reqParam.UserAgent) > 0 {
		UserAgent = reqParam.UserAgent
	} else {
		UserAgent = defUserAgent
	}
	if len(reqParam.Referer) > 0 {
		Referer = reqParam.Referer
	}

	httpClient := resty.New()
	httpClient.SetTimeout(HTMLTimeOut)
	if HttpProxy != "" {
		httpClient.SetProxy(HttpProxy)
	}

	httpClient.SetHeaders(map[string]string{
		"Content-Type": "application/json",
		"User-Agent": UserAgent,
	})
	if len(Referer) > 0 {
		httpClient.SetHeader("Referer", Referer)
	}

	return httpClient
}

// DownFile 从指定的 url 下载文件
func DownFile(urlStr string, _reqParam ...ReqParam) ([]byte, string, error)  {
	var reqParam ReqParam
	if len(_reqParam) > 0 {
		reqParam = _reqParam[0]
	}
	httpClient := NewHttpClient(reqParam)
	resp, err := httpClient.R().Get(urlStr)
	if err != nil {
		return nil, "", err
	}
	filename := GetFileName(resp.RawResponse)
	return resp.Body(), filename, nil
}

// GetFileName 获取下载文件的文件名
func GetFileName(resp *http.Response) string {
	contentDisposition := resp.Header.Get("Content-Disposition")
	if len(contentDisposition) == 0 {
		return ""
	}
	re := regexp.MustCompile(`filename=["]*([^"]+)["]*`)
	matched := re.FindStringSubmatch(contentDisposition)
	if matched == nil || len(matched) == 0 || len(matched[0]) == 0 {
		//fmt.Println("######")
		return ""
	}
	return matched[1]
}

// AddBaseUrl 判断驶入的 url 是否需要拼接 baseUrl
func AddBaseUrl(baseUrl, url string) string {
	if strings.Contains(url, "://") {
		return url
	}
	return fmt.Sprintf("%s%s", baseUrl, url)
}

func GetDebugFolder() (string, error) {
	if defDebugFolder == "" {
		nowProcessRoot, _ := os.Getwd()
		nowProcessRoot = path.Join(nowProcessRoot, DebugFolder)
		err := os.MkdirAll(nowProcessRoot, os.ModePerm)
		if err != nil {
			return "", err
		}
		defDebugFolder = nowProcessRoot
		return nowProcessRoot, err
	}
	return defDebugFolder, nil
}

func GetTmpFolder() (string, error) {
	if defTmpFolder == "" {
		nowProcessRoot, _ := os.Getwd()
		nowProcessRoot = path.Join(nowProcessRoot, TmpFolder)
		err := os.MkdirAll(nowProcessRoot, os.ModePerm)
		if err != nil {
			return "", err
		}
		defTmpFolder = nowProcessRoot
		return nowProcessRoot, err
	}
	return defTmpFolder, nil
}

func ClearTmpFolder() error {
	nowTmpFolder, err := GetTmpFolder()
	if err != nil {
		return err
	}

	pathSep := string(os.PathSeparator)
	files, err := ioutil.ReadDir(nowTmpFolder)
	if err != nil {
		return err
	}
	for _, curFile := range files {
		fullPath := nowTmpFolder + pathSep + curFile.Name()
		if curFile.IsDir() {
			err = os.RemoveAll(fullPath)
			if err != nil {
				return err
			}
		} else {
			// 这里就是文件了
			err = os.Remove(fullPath)
			if err != nil {
				return err
			}
		}
	}

	return nil
}

func CopyFile(dstName, srcName string) (written int64, err error) {
	src, err := os.Open(srcName)
	if err != nil {
		return
	}
	defer src.Close()

	dst, err := os.OpenFile(dstName, os.O_WRONLY|os.O_CREATE, 0644)
	if err != nil {
		return
	}
	defer dst.Close()
	return io.Copy(dst, src)
}

var (
	defDebugFolder = ""
	defTmpFolder = ""
)

// ReqParam 可选择传入的参数
type ReqParam struct {
	UserExtList []string	// 用户确认的视频后缀名支持列表
	DebugMode bool			// 调试标志位
	HttpProxy string		// HttpClient 相关
	UserAgent string		// HttpClient 相关
	Referer   string		// HttpClient 相关
	MediaType string		// HttpClient 相关
	Charset   string		// HttpClient 相关
	Topic	  int			// 搜索结果的时候，返回 Topic N 以内的
}