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 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._audio = null;
        this._sound = new window.Audio();
        this._ctx = new AudioContext();
        this._currentTime = 0;
        this._createStateMachine();
        this._proxySchedule = this._schedule.bind(this);
        
        this.addHandler("get");
        this.addHandler("viewsChange");
        this.addHandler("play");
        this.addHandler("pause");
    },
    destructor: function() {
        this._fsm.destructor();
        this._sound.pause();
        this._ctx.close();
        
        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:
                    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");
            }
        } else {
            this.trigger("serviceMessage", "An unrecgnized item ItemType in Player: " + t);
        }
    },
    _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");
                    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");
            }
        } else {
            this.trigger("serviceMessage", "An unrecgnized item ItemType in Player: " + t);
        }
        
        if (supported) {
            ctrl.ItemType = t;
            this.views[t] = ctrl;
            this.addController(ctrl);
            
            this.trigger("newElement", ctrl, t);
        }
    },
    _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("plause");
    },
    _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));
        }
        
        size = add.length();
        for (i = 0; i < size; ++i) {
            vc = add.at(i);
            this._addView(vc.at("type"), vc.at("address"));
        }
    },
    _onAudioNewFrames: function(frames) {
        this._ctx.decodeAudioData(frames.valueOf(), this._proxySchedule);
        this._fsm.manipulation("newFrames");
        if (this._audio.hasMore()) {
            this._audio.requestMore();
        } else {
            this._fsm.manipulation("noMoreFrames");
        }
    },
    _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("newFrames", this._onAudioNewFrames, this);
                    this._fsm.manipulation("controller");
                }
                break;
        }
    },
    _onNewRemoveBackElement: function(key) {
        switch (key) {
            case "image":
                this._removeView(new Uint64(ItemType.straight.picture));
                break;
            case "audio":
                this.removeForeignController(this._audio);
                this._audio.destructor();
                this._audio = null;
        }
    },
    _onStateChanged: function(e) {
        switch (e.newState) {
            case "initial":
                break;
            case "initialPlaying":
                break;
            case "hasController":
                break;
            case "hasControllerPlaying":
                if (this._audio.hasMore()) {
                    this._audio.requestMore();
                } else {
                    this._fsm.manipulation("noMoreFrames");
                }
                break;
            case "paused":
                switch (e.oldState) {
                    case "playing":
                        this._sound.pause();
                        break;
                }
                break;
            case "pausedAllLoaded":
                switch (e.oldState) {
                    case "playingAllLoaded":
                        this._sound.pause();
                        break;
                }
                break;
            case "playing":
                this._sound.play();
                break;
            case "playingAllLoaded":
                switch (e.oldState) {
                    case "pausedAllLoaded":
                        this._sound.play();
                        break;
                }
                break;
        }
    },
    _removeControl: function(type) {
        //TODO
    },
    _removeView: function(type) {
        //TODO
    },
    _schedule: function(buffer) {
        var source = this._ctx.createBufferSource();
        source.buffer = buffer;
        source.connect(this._ctx.destination);
        
        source.start(this._currentTime);
        this._currentTime += buffer.duration;
    }
});

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

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

Player.ItemType = ItemType;

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

module.exports = Player;