package webui

import (
	"embed"
	"io/fs"
	"net/http"
	"path"
	"strings"
)

//go:embed dist
var content embed.FS

// Handler 返回嵌入后的前端静态资源处理器。
func Handler() http.Handler {
	dist, err := fs.Sub(content, "dist")
	if err != nil {
		panic(err)
	}
	files := http.FileServer(http.FS(dist))

	return http.HandlerFunc(func(response http.ResponseWriter, request *http.Request) {
		requestPath := request.URL.Path
		if requestPath == "/api" || strings.HasPrefix(requestPath, "/api/") {
			http.NotFound(response, request)
			return
		}

		fileName := strings.TrimPrefix(path.Clean(requestPath), "/")
		if fileName == "." {
			fileName = ""
		}
		if fileName != "" {
			if _, statErr := fs.Stat(dist, fileName); statErr == nil {
				files.ServeHTTP(response, request)
				return
			}
		}

		if request.Method == http.MethodGet && path.Ext(requestPath) == "" {
			indexRequest := request.Clone(request.Context())
			indexRequest.URL.Path = "/"
			files.ServeHTTP(response, indexRequest)
			return
		}

		http.NotFound(response, request)
	})
}