package storage

import (
	"encoding/json"
	"errors"
	"io"
	"net/http"
	"os"
	"path/filepath"
)

type Server struct {
	DataDir string
}

func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	mux := http.NewServeMux()
	mux.HandleFunc("GET /", func(w http.ResponseWriter, r *http.Request) {
		path := filepath.Join(s.DataDir, r.URL.Path)
		fi, err := os.Stat(path)
		if errors.Is(err, os.ErrNotExist) {
			return
		}
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		if fi.IsDir() {
			entries, err := os.ReadDir(path)
			if err != nil {
				http.Error(w, err.Error(), http.StatusInternalServerError)
				return
			}
			err = json.NewEncoder(w).Encode(entries)
			if err != nil {
				panic(err)
			}
			return
		}
		f, err := os.Open(path)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		defer f.Close()
		_, err = io.Copy(w, f)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
	})
	mux.HandleFunc("PUT /", func(w http.ResponseWriter, r *http.Request) {
		path := filepath.Join(s.DataDir, r.URL.Path)
		err := os.MkdirAll(filepath.Dir(path), 0755)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		f, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		defer f.Close()
		_, err = io.Copy(f, r.Body)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
	})
	mux.HandleFunc("DELETE /", func(w http.ResponseWriter, r *http.Request) {
		path := filepath.Join(s.DataDir, r.URL.Path)
		err := os.RemoveAll(path)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
	})
	mux.ServeHTTP(w, r)
}