//
// app.go
// Copyright (C) 2024 veypi <i@veypi.com>
// 2024-10-22 15:42
// Distributed under terms of the GPL license.
//

package fs

import (
	"net/http"
	"oa/cfg"
	"oa/errs"
	"oa/libs/auth"
	"oa/libs/webdav"
	"os"
	"strings"

	"github.com/veypi/utils"
	"github.com/veypi/utils/logv"
)

func NewAppFs(prefix string) func(http.ResponseWriter, *http.Request) {
	if strings.HasSuffix(prefix, "/") {
		prefix = prefix[:len(prefix)-1]
	}
	tmp := utils.PathJoin(cfg.Config.FsPath, "app")
	if !utils.FileExists(tmp) {
		logv.AssertError(os.MkdirAll(tmp, 0744))
	}

	client := webdav.NewWebdav(tmp)
	client.Prefix = prefix
	client.GenSubPathFunc = func(r *http.Request) (string, error) {
		// /:aid/*p
		dir := strings.TrimPrefix(r.URL.Path, prefix)
		dirs := strings.Split(dir[1:], "/")
		aid := ""
		root := "/"
		if len(dirs) > 0 {
			aid = dirs[0]
		}
		if len(dirs) > 1 {
			root = "/" + strings.Join(dirs[1:], "/")
		}
		if root == "/" {
			// if !utils.FileExists(tmp + "/" + aid) {
			// 	os.MkdirAll(tmp+"/"+aid, 0744)
			// }
		}
		if aid == "" {
			return "", errs.AuthNoPerm
		}
		if root == "/pub" || strings.HasPrefix(root, "/pub/") {
			switch r.Method {
			case "OPTIONS", "GET", "HEAD", "POST":
				return "", nil
			default:
			}
		}
		// appfs权限等于app权限
		// TODO: 存在空文件覆盖重要文件的风险
		handlerLevle := auth.Do
		switch r.Method {
		case "PUT", "MKCOL", "COPY", "MOVE":
			handlerLevle = auth.DoCreate
		case "DELETE":
			handlerLevle = auth.DoDelete
		default:
			handlerLevle = auth.DoRead
		}

		payload, err := getToken(r)
		if err != nil {
			return "", err
		}
		if payload.Access.Check("app", aid, handlerLevle) {
			return "", nil
		}
		return "", errs.AuthNoPerm
	}
	return client.ServeHTTP
}