hds-audio/handlers.go

package main

import (
	"encoding/json"
	"log"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"github.com/gabriel-vasile/mimetype"
)

type Status struct {
	Playing         bool    //If the device is playing
	Loop            bool    //If playback as loop
	PlayingFileName string  //The playing filename
	PlayingURL      string  //The playing URL
	Gain            float64 //The volume currently is playing at, in percentage
	Mute            bool    //If the playback should be muted
	Status          string  //Status of the device, support {downloading, converting, playing, paused, ready}
}

type Endpoint struct {
	Name       string
	RelPath    string
	Desc       string
	Type       string
	AllowRead  bool
	AllowWrite bool
	Min        int
	Max        int
	Steps      float64
	Regex      string
}

type SongData struct {
	Filename string
	Filesize int64
	Ext      string
}

func handleIndex(w http.ResponseWriter, r *http.Request) {
	//Serve the index
	sendOK(w)
}

func handleStatus(w http.ResponseWriter, r *http.Request) {
	//Send out the current device status
	js, _ := json.Marshal(deviceStatus)
	sendJSONResponse(w, string(js))
}

func handleEndpoints(w http.ResponseWriter, r *http.Request) {
	endpoints := []Endpoint{}
	endpoints = append(endpoints, Endpoint{
		Name:    "Play",
		RelPath: "play",
		Desc:    "Toggle player to play or pause",
		Type:    "none",
	})

	endpoints = append(endpoints, Endpoint{
		Name:    "Stop",
		RelPath: "stop",
		Desc:    "Stop and flush the buffer of the playing song",
		Type:    "none",
	})

	endpoints = append(endpoints, Endpoint{
		Name:    "PlayingURL",
		RelPath: "load",
		Desc:    "Load a network resources to play",
		Type:    "string",
	})

	endpoints = append(endpoints, Endpoint{
		Name:    "Loop",
		RelPath: "loop",
		Desc:    "Playback in normal or loop mode",
		Type:    "bool",
	})

	endpoints = append(endpoints, Endpoint{
		Name:    "Mute",
		RelPath: "mute",
		Desc:    "Mute the playback",
		Type:    "bool",
	})

	endpoints = append(endpoints, Endpoint{
		Name:    "FileData",
		RelPath: "name",
		Desc:    "Set the file data of the playing song",
		Type:    "string",
	})

	endpoints = append(endpoints, Endpoint{
		Name:    "Gain",
		RelPath: "gain",
		Desc:    "Set the gain of the device playback, 0 means default",
		Type:    "integer",
		Max:     2,
		Min:     -6,
		Steps:   0.1,
	})

	js, _ := json.Marshal(endpoints)
	sendJSONResponse(w, string(js))

}

func handlePlayToggle(w http.ResponseWriter, r *http.Request) {
	deviceStatus.Playing = !deviceStatus.Playing
	if deviceStatus.Playing == true {
		deviceStatus.Status = "playing"
	} else {
		deviceStatus.Status = "paused"
	}
	sendOK(w)
}

func handleStop(w http.ResponseWriter, r *http.Request) {
	globalStopFlag = true
}

func handleMute(w http.ResponseWriter, r *http.Request) {
	value, err := mv(r, "value", true)
	if err != nil {
		sendErrorResponse(w, "Invalid value given")
		return
	}

	if value == "true" {
		deviceStatus.Mute = true
	} else {
		deviceStatus.Mute = false
	}
}

func handleLoad(w http.ResponseWriter, r *http.Request) {
	_, err := mv(r, "value", false)
	if err != nil {
		//Nothing is passed in
		sendErrorResponse(w, "Invalid value given")
		return
	}

	//There is something here. But for full request purposes, use raw input and split it
	urlChunks := strings.Split(r.RequestURI, "?value=")
	finalResourcesEndpoing := strings.Join(urlChunks[1:], "?value=")

	//Download the file
	deviceStatus.Status = "downloading"
	tmpFilename := strconv.Itoa(int(time.Now().Unix()))
	downloadedFile := filepath.Join("./tmp", tmpFilename)

	os.Mkdir("./tmp", 0775)
	log.Println("Downlaod audio file from: ", finalResourcesEndpoing)
	err = DownloadFile(downloadedFile, finalResourcesEndpoing)
	if err != nil {
		log.Println(err.Error())
		sendErrorResponse(w, err.Error())
		return
	}

	//Check if this is a valid audio file
	mime, err := mimetype.DetectFile(downloadedFile)
	if err != nil {
		log.Println(err.Error())
		sendErrorResponse(w, err.Error())
		return
	}

	if strings.Contains(mime.String(), "audio/") {
		log.Println("Download file is " + mime.String() + ". Starting Convertsion...")
	} else {
		log.Println("Not supported media type")
		sendErrorResponse(w, "Not supported media type")
		return
	}

	//Set the correct extension for the file
	var fileMime = strings.Split(mime.String(), "/")[1]
	var needConv = true
	var finalFilename = ""
	if fileMime == "mpeg" {
		//mp3 file
		os.Rename(downloadedFile, downloadedFile+".mp3")
		finalFilename = downloadedFile + ".mp3"
	} else if fileMime == "flac" {
		//flac
		os.Rename(downloadedFile, downloadedFile+".flac")
		finalFilename = downloadedFile + ".flac"
	} else if fileMime == "wav" {
		//wav file
		os.Rename(downloadedFile, downloadedFile+".wav")
		finalFilename = downloadedFile + ".wav"
		needConv = false
	} else {
		//Unknown. Just append the mime to it
		os.Rename(downloadedFile, downloadedFile+"."+fileMime)
		finalFilename = downloadedFile + "." + fileMime
	}

	//Start the conversion process (As we need to force the device only playback wav for compeitbility purposes)
	playReadyFile := filepath.Join("./tmp", strings.TrimSuffix(filepath.Base(downloadedFile), filepath.Ext(filepath.Base(downloadedFile)))+".wav")

	if needConv {
		log.Println("Conversion started")
		deviceStatus.Status = "converting"

		cmd := exec.Command("ffmpeg", "-i", finalFilename, playReadyFile)
		out, err := cmd.CombinedOutput()
		if err != nil {
			log.Println("Conversion failed: ", string(out))
			sendErrorResponse(w, err.Error())
			return
		}
		log.Println(string(out))
	}

	//Start playing the file
	log.Println("Conversion finished. Playing audio file.")
	deviceStatus.Status = "playing"                  //Set status text to playing
	deviceStatus.Playing = true                      //Unpause the playback
	deviceStatus.PlayingURL = finalResourcesEndpoing //Set the playing URL to target url

	playFile(playReadyFile)
}

func handleVol(w http.ResponseWriter, r *http.Request) {
	val, err := mv(r, "value", false)
	if err != nil {
		sendErrorResponse(w, "Invalid gain set")
		return
	}

	//Parse the string to float
	if s, err := strconv.ParseFloat(val, 64); err == nil {
		if s > 2 || s < -6 {
			sendErrorResponse(w, "Invalid ranged gain value")
			return
		}

		//Update the new volume gain
		deviceStatus.Gain = s
	} else {
		sendErrorResponse(w, "Unable to parse new value")
		return
	}

	sendOK(w)

}

//Handle set name of the playing file. No logical purpose, just for display only
//Require struct matching. See the SongInfo struct
//Remember to pass it in as encodedURL string
func handleSetName(w http.ResponseWriter, r *http.Request) {
	//Get the song data
	value, err := mv(r, "value", true)
	if err != nil {
		sendErrorResponse(w, "value invalid")
		return
	}

	//Parse the song data
	thisSongdata := SongData{}
	err = json.Unmarshal([]byte(value), &thisSongdata)
	if err != nil {
		sendErrorResponse(w, "Failed to parse song data.")
		return
	}
	deviceStatus.PlayingFileName = thisSongdata.Filename
	playingSongData = thisSongdata

	sendOK(w)
}

func handleLoop(w http.ResponseWriter, r *http.Request) {
	value, err := mv(r, "value", true)
	if err != nil {
		sendErrorResponse(w, "value invalid")
		return
	}

	if value == "true" {
		deviceStatus.Loop = true
	} else {
		deviceStatus.Loop = false
	}
}