radio/libjs/wController/player.js

"use strict";

var Uint64 = require("../wType/uint64");
var Address = require("../wType/address");

var Controller = require("./controller");
var Button = require("./button");
var ImageById = require("./imageById");
var Vocabulary = require("./vocabulary");
var Audio = require("./file/audio");
var Model = require("./localModel");

var Enum = require("../utils/enum");
var StateMachine = require("../utils/stateMachine");

var Player = Controller.inherit({
    className: "Player",
    constructor: function(addr) {
        Controller.fn.constructor.call(this, addr);
        
        this.controls = Object.create(null);
        this.views = Object.create(null);
        this.mode = PlayerMode.straight.playback;
        this.progress = new ProgressModel();
        this._audio = null;
        this._createStateMachine();
        this._createPlayingInfrastructure();
        
        this.addHandler("get");
        this.addHandler("viewsChange");
        this.addHandler("play");
        this.addHandler("pause");
        
        this._playbackInterval = setInterval(this._onInterval.bind(this), 250);
    },
    destructor: function() {
        this._clearInterval(this._playbackInterval);
        this._destroyPlayingInfrastructure();
        this._fsm.destructor();
        this.progress.destructor();
        
        Controller.fn.destructor.call(this);
    },
    _addControl: function(type, address) {
        var t = type.valueOf();
        
        if (this.controls[t] !== undefined) {
            throw new Error("An attempt to add multiple instances of " + ItemType.reversed[t] + " into Player");
        }
        
        if (ItemType.reversed[t] !== undefined) {
            switch (t) {
                case ItemType.straight.playPause:
                case ItemType.straight.prev:
                case ItemType.straight.next:
                    var btn = new Button(address.clone());
                    btn.itemType = t;
                    this.controls[t] = btn;
                    this.addController(btn);
                    this.trigger("newElement", btn, t);
                    break;
                default:
                    this.trigger("serviceMessage", "An attempt to add ItemType " + ItemType.reversed[t] + " to controls of the Player, but it's not qualified to be a control", 1);
            }
        } else {
            this.trigger("serviceMessage", "An unrecgnized item ItemType in Player: " + t, 1);
        }
    },
    _addView: function(type, address) {
        var t = type.valueOf();
        var ctrl;
        var supported = false;
        
        if (this.views[t] !== undefined) {
            throw new Error("An attempt to add multiple instances of " + ItemType.reversed[t] + " into Player");
        }
        
        if (ItemType.reversed[t] !== undefined) {
            switch (t) {
                case ItemType.straight.queue:
                    this.trigger("serviceMessage", "Queue is not supported yet in Player", 1);
                    break;
                case ItemType.straight.currentPlayback:
                    ctrl = new Vocabulary(address.clone());
                    ctrl.on("newElement", this._onNewPlayBackElement, this);
                    ctrl.on("removeElement", this._onNewRemoveBackElement, this);
                    supported = true;
                    break;
                case ItemType.straight.picture:
                    ctrl = new ImageById(null, address.back());
                    ctrl.ItemType = t;
                    this.views[t] = ctrl;
                    
                    this.trigger("newElement", ctrl, t);
                    supported = false;                  //just to avoid adding with addController, since ImageById is not a controller
                    break;
                default:
                    this.trigger("serviceMessage", "An attempt to add ItemType " + ItemType.reversed[t] + " to views of the Player, but it's not qualified to be a view", 1);
            }
        } else {
            this.trigger("serviceMessage", "An unrecognized item ItemType in Player: " + t, 1);
        }
        
        if (supported) {
            ctrl.ItemType = t;
            this.views[t] = ctrl;
            this.addController(ctrl);
            
            this.trigger("newElement", ctrl, t);
        }
    },
    _createPlayingInfrastructure: function() {
        this._ctx = new AudioContext();
        this._decoder = new Mp3Decoder();
        this._currentTime = 0;
        
        this._ctx.suspend();
    },
    _destroyPlayingInfrastructure: function() {
        this._ctx.close();
        this._decoder.delete();
    },
    _createStateMachine: function() {
        this._fsm = new StateMachine("initial", graphs[this.mode]);
        this._fsm.on("stateChanged", this._onStateChanged, this);
    },
    _h_get: function(ev) {
        var data = ev.getData();
        
        var controls = data.at("controls");
        var views = data.at("views");
        var mode = data.at("mode").valueOf();
        var size, i, vc;
        
        size = controls.length();
        for (i = 0; i < size; ++i) {
            vc = controls.at(i);
            this._addControl(vc.at("type"), vc.at("address"));
        }
        
        size = views.length();
        for (i = 0; i < size; ++i) {
            vc = views.at(i);
            this._addView(vc.at("type"), vc.at("address"));
        }
        
        if (this.mode !== mode) {
            if (PlayerMode.reversed[mode] === undefined) {
                throw new Error("Unsupported mode of player: " + mode);
            }
            this.mode = mode;
        }
        
        this.initialized = true;
        this.trigger("data");
    },
    _h_pause: function(ev) {
        this._fsm.manipulation("pause");
    },
    _h_play: function(ev) {
        this._fsm.manipulation("play");
    },
    _h_viewsChange: function(ev) {
        var data = ev.getData();
        
        var add = data.at("add");
        var remove = data.at("remove");
        var size, i, vc;
        
        size = remove.length();
        for (i = 0; i < size; ++i) {
            this._removeView(remove.at(i).valueOf());
        }
        
        size = add.length();
        for (i = 0; i < size; ++i) {
            vc = add.at(i);
            this._addView(vc.at("type"), vc.at("address"));
        }
    },
    _onAudioNewSlice: function(frames) {
        var arr = new Uint8Array(frames.valueOf());
        this._decoder.addFragment(arr);
        
        while (this._decoder.hasMore()) {
            var sb = this._decoder.decode(9999);
            if (sb === undefined) {
                break;
            } else {
                var src = this._ctx.createBufferSource();
                src.buffer = sb;
                src.connect(this._ctx.destination);
                src.start(this._currentTime);
                this._currentTime += sb.duration;
            }
        }
        
        this.progress.setLoad(this._currentTime / this._audio.getDuration());
        
        this._fsm.manipulation("newFrames");
        if (this._audio.hasMore()) {
            this._audio.requestSlice(audioPortion);
        } else {
            this._fsm.manipulation("noMoreFrames");
        }
    },
    _onControllerReady: function() {
        this._fsm.manipulation("controllerReady");
    },
    _onInterval: function() {
        if (this._audio && this._audio.initialized) {
            this.progress.setPlayback(this._ctx.currentTime / this._audio.getDuration());
        }
    },
    _onNewPlayBackElement: function(key, element) {
        switch (key) {
            case "image":
                var address = new Address(["images", element.toString()]);
                this._addView(new Uint64(ItemType.straight.picture), address);
                address.destructor();
                break;
            case "audio":
                if (this.mode === PlayerMode.straight.playback) {
                    this._audio = new Audio(new Address(["music", element.toString()]));
                    this.addForeignController("Corax", this._audio);
                    this._audio.on("slice", this._onAudioNewSlice, this);
                    this._audio.on("ready", this._onControllerReady, this);
                    this._fsm.manipulation("controller");
                }
                break;
        }
    },
    _onNewRemoveBackElement: function(key) {
        switch (key) {
            case "image":
                this._removeView(ItemType.straight.picture);
                break;
            case "audio":
                this.removeForeignController(this._audio);
                this._audio.destructor();
                this._audio = null;
        }
    },
    _onStateChanged: function(e) {
        switch (e.newState) {
            case "initial":
                if (e.manipulation === "noController") {
                    
                    this.removeForeignController(this._audio);
                    this._audio.destructor();
                    this._audio = null;
                    this._destroyPlayingInfrastructure();
                    this._createPlayingInfrastructure();
                }
                break;
            case "initialPlaying":
                if (e.manipulation === "noController") {
                    this._ctx.suspend();
                    
                    this.removeForeignController(this._audio);
                    this.audio.destructor();
                    this._audio = null;
                    this._destroyPlayingInfrastructure();
                    this._createPlayingInfrastructure();
                }
                break;
            case "controllerNotReady":
                break
            case "controllerNotReadyPlaying":
                break
            case "hasController":
                break;
            case "hasControllerPlaying":
                if (this._audio.hasMore()) {
                    this._audio.requestSlice(audioPortion);
                    
                    this._ctx.resume();    //todo temporal
                } else {
                    this._fsm.manipulation("noMoreFrames");
                }
                break;
            case "paused":
                switch (e.oldState) {
                    case "playing":
                        this._ctx.suspend();
                        break;
                }
                break;
            case "pausedAllLoaded":
                switch (e.oldState) {
                    case "playingAllLoaded":
                        this._ctx.suspend();
                        break;
                }
                break;
            case "playing":
                this._ctx.resume();
                break;
            case "playingAllLoaded":
                switch (e.oldState) {
                    case "pausedAllLoaded":
                        this._ctx.resume();
                        break;
                }
                break;
        }
    },
    _removeControl: function(type) {
        var ctrl = this.controls[type];
        if (ctrl !== undefined) {
            this.trigger("removeElement", type);
            this.removeController(ctrl);
            ctrl.destructor();
        }
    },
    _removeView: function(type) {
        var view = this.views[type];
        if (view !== undefined) {
            this.trigger("removeElement", type);
            
            if (type !== ItemType.straight.picture) {
                this.removeController(view);
            }
            if (type === ItemType.straight.currentPlayback) {
                if (this.views[ItemType.straight.picture]) {
                    this._removeView(ItemType.straight.picture);
                }
                this._fsm.manipulation("noController");
            }
            delete this.views[type];
            view.destructor();
        }
    }
});

var ItemType = new Enum("ItemType");
ItemType.add("playPause");
ItemType.add("currentPlayback");
ItemType.add("queue");
ItemType.add("picture");
ItemType.add("prev");
ItemType.add("next");

var PlayerMode = new Enum("PlayerMode");
PlayerMode.add("playback");

Player.ItemType = ItemType;

var graphs = Object.create(null);
graphs[PlayerMode.straight.playback] = {
    "initial": {
        controller: "controllerNotReady",
        play: "initialPlaying"
    },
    "initialPlaying": {
        pause: "initial",
        controller: "controllerNotReadyPlaying"
    },
    "controllerNotReady": {
        play: "controllerNotReadyPlaying",
        controllerReady: "hasController"
    },
    "controllerNotReadyPlaying": {
        pause: "controllerNotReady",
        controllerReady: "hasControllerPlaying"
    },
    "hasController": {
        newFrames: "paused",
        play: "hasControllerPlaying",
        noController: "initial"
    },
    "hasControllerPlaying": {
        newFrames: "playing",
        pause: "hasController",
        noController: "initialPlaying"
    },
    "paused": {
        play: "playing",
        noController: "initial",
        noMoreFrames: "pausedAllLoaded"
    },
    "pausedAllLoaded": {
        play: "playingAllLoaded",
        noController: "initial"
    },
    "playing": {
        pause: "paused",
        noMoreFrames: "playingAllLoaded",
        noController: "initialPlaying"
    },
    "playingAllLoaded": {
        pause: "pausedAllLoaded",
        noController: "initialPlaying"
    }
}

var audioPortion = 1024 * 50;

var ProgressModel = Model.inherit({
    className: "ProgressModel",
    constructor: function(properties) {
        Model.fn.constructor.call(this, properties);
        
        this.load = 0;
        this.playback = 0;
        this.initialized = true;
    },
    setLoad: function(l) {
        if (l !== this.load) {
            this.load = l;
            this.trigger("load", l);
        }
    },
    setPlayback: function(p) {
        if (p !== this.playback) {
            this.playback = p;
            this.trigger("playback", p);
        }
    }
});

module.exports = Player;