package main

import (
	"bytes"
	"crypto/sha512"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"net/http"
	"path/filepath"

	"git.milar.in/milarin/envvars/v2"
	"github.com/gorilla/mux"
)

var (
	HttpIntf    = envvars.String("HTTP_INTERFACE", "")
	HttpPort    = envvars.Uint16("HTTP_PORT", 80)
	LibraryPath = envvars.String("LIBRARY_PATH", "/music")
)

func main() {
	r := mux.NewRouter()

	r.HandleFunc("/all/", GetAllHandler).Methods("GET")
	r.HandleFunc("/all/hash/", GetAllHashHandler).Methods("GET")
	r.HandleFunc("/playlist/", GetPlaylistsHandler).Methods("GET")
	r.HandleFunc("/playlist/{playlist}/", GetPlaylistHandler).Methods("GET")
	r.HandleFunc("/playlist/{playlist}/song/{song}/", GetSongHandler).Methods("GET")

	fmt.Printf("Starting music server on port %d\n", HttpPort)
	if err := http.ListenAndServe(fmt.Sprintf("%s:%d", HttpIntf, HttpPort), r); err != nil {
		panic(err)
	}
}

func GetAllHashHandler(w http.ResponseWriter, r *http.Request) {
	playlists, err := GetAll()
	if err != nil {
		InternalServerError(w, err)
		return
	}

	b := &bytes.Buffer{}
	if err := json.NewEncoder(b).Encode(playlists); err != nil {
		InternalServerError(w, err)
		return
	}

	hash := sha512.Sum512(b.Bytes())
	if _, err := fmt.Fprint(w, hex.EncodeToString(hash[:])); err != nil {
		InternalServerError(w, err)
		return
	}
}

func GetAllHandler(w http.ResponseWriter, r *http.Request) {
	playlists, err := GetAll()
	if err != nil {
		InternalServerError(w, err)
		return
	}

	w.Header().Add("Content-Type", "application/json")
	if err := json.NewEncoder(w).Encode(playlists); err != nil {
		InternalServerError(w, err)
		return
	}
}

func GetSongHandler(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	playlist := vars["playlist"]
	song := vars["song"]

	http.ServeFile(w, r, filepath.Join(LibraryPath, playlist, song))
}

func GetPlaylistHandler(w http.ResponseWriter, r *http.Request) {
	playlist := mux.Vars(r)["playlist"]

	songs, err := GetSongs(playlist)
	if err != nil {
		InternalServerError(w, err)
		return
	}

	w.Header().Add("Content-Type", "application/json")
	if err := json.NewEncoder(w).Encode(songs); err != nil {
		InternalServerError(w, err)
		return
	}
}

func GetPlaylistsHandler(w http.ResponseWriter, r *http.Request) {
	playlists, err := GetPlaylists()
	if err != nil {
		InternalServerError(w, err)
		return
	}

	w.Header().Add("Content-Type", "application/json")
	if err := json.NewEncoder(w).Encode(playlists); err != nil {
		InternalServerError(w, err)
		return
	}
}