api_views.go

package frontend

import (
	"encoding/json"
	// "fmt"
	"io"
	"log"
	"net/http"
	"os"
	"strconv"
	"time"

	"git.autistici.org/ale/djrandom/api"
	"git.autistici.org/ale/djrandom/util"
	db_client "git.autistici.org/ale/djrandom/services/database/client"
	"github.com/gorilla/mux"
)

var (
	numParallelQueries = 20
)

func sendJsonResponse(w http.ResponseWriter, resp interface{}) {
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(resp)
}

// Upload receives files from sync clients, saves them to permanent
// storage and creates new Song objects in the db.
func Upload(w http.ResponseWriter, r *djRequest) {
	// Create a local temporary file, and copy the request body to
	// it. As soon as this is done, return an 'ok' response to the
	// client (and process the file in the background).
	tmpf, err := util.TempFile("djrandom-upload-", "")
	if err != nil {
		log.Printf("Upload(): Error creating temporary file: %s", err)
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
		return
	}

	defer r.Request.Body.Close()

	_, err = io.Copy(tmpf, r.Request.Body)
	if err != nil {
		log.Printf("Upload(): Error saving file to local storage: %s", err)
		os.Remove(tmpf.Name())
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
		return
	}
	tmpf.Close()

	// Run further processing in the background.  AnalyzeAndStore
	// will remove the file when it's done.
	go AnalyzeAndStore(r.Ctx, tmpf.Name())

	sendJsonResponse(w, &api.UploadResponse{Ok: true})
}

// GetSongInfo returns data on a specific song.
func GetSongInfo(w http.ResponseWriter, r *djRequest) {
	vars := mux.Vars(r.Request)
	songId := vars["id"]
	log.Printf("GetSongInfo(%s)", songId)

	song, ok := r.Ctx.Db.GetSong(nil, songId)
	if !ok {
		http.Error(w, "Not Found", http.StatusNotFound)
		return
	}