package main

import (
	"fmt"
	"html/template"
	"net/http"
	"os"
	"path/filepath"
	"strings"

	"github.com/joho/godotenv"
)

// 定义静态文件根目录
var rootPath string

// FileInfo 包含文件的元数据信息
type FileInfo struct {
	Name  string
	Size  string
	IsDir bool
	Href  string
}

func main() {
	err := godotenv.Load()
	if err != nil {
		fmt.Println("Error loading .env file")
		return
	}
	rootPath = os.Getenv("FILE_PATH")

	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		dir := r.URL.Path[1:]

		dir = rootPath + "/" + dir

		dir = strings.Replace(dir, "\\", "/", -1)

		fileInfo, err := os.Stat(dir)

		if err != nil {
			//fmt.Println("File does not exist")
		} else if fileInfo.Mode().IsRegular() {
			file, _ := os.Open(dir)
			defer file.Close()
			http.ServeContent(w, r, fileInfo.Name(), fileInfo.ModTime(), file)
		} else {
			fileInfos, err := listDir(dir)
			if err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}

			tmpl, err := template.ParseFiles("templates/index.html")
			if err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}
			tmpl.Execute(w, fileInfos)
		}

	})

	http.ListenAndServe(":"+os.Getenv("PORT"), nil)
}

func listDir(dir string) ([]FileInfo, error) {
	file, err := os.Open(dir)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	names, err := file.Readdirnames(-1)
	if err != nil {
		return nil, err
	}

	var fileInfos []FileInfo
	for _, name := range names {
		fileInfo, err := os.Stat(filepath.Join(dir, name))
		if err != nil {
			return nil, err
		}

		Href := filepath.Join(dir, name)
		//Href = strings.Replace(Href, filepath.Join(rootPath), "", -1)

		size := fileInfo.Size()
		formattedSize := formatFileSize(size)

		fileInfos = append(fileInfos, FileInfo{
			Name:  name,
			Size:  formattedSize,
			IsDir: fileInfo.IsDir(),
			Href:  Href,
		})
	}
	return fileInfos, nil
}

func formatFileSize(size int64) string {
	units := []string{"B", "KB", "MB", "GB"}
	var unitIndex int
	var fileSize float64
	for size > 1024 && unitIndex < len(units)-1 {
		fileSize = float64(size) / 1024
		size = size / 1024
		unitIndex++
	}
	fileSize = float64(size)
	return fmt.Sprintf("%.2f %s", fileSize, units[unitIndex])
}