const EventEmitter = require('events');

const AudioBuffer = require('./AudioBuffer.js');

class Player extends EventEmitter {

    constructor() {
        super();
        this.events = [];
    }

    async prepare(stream, settings) {
        logger.debug('preparing audio player...');
        this.#reset();
        this.audiobuffer = new AudioBuffer(stream, settings);
        this.audiobuffer.on(constants.THRESHOLD, () => {
            this.#setState(constants.READY);
        });
        this.audiobuffer.on('close', () => {
            this.#setState(constants.STOPPED);
        });
        this.audiobuffer.on('play', () => {
            this.#setState(constants.PLAYING);
        });
        this.audiobuffer.on('pause', () => {
            this.#setState(constants.PAUSED);
        })
    }

    play() {
        this.audiobuffer.resume();
    }

    pause() {
        this.audiobuffer.pause();
    }

    async stop() {
        this.audiobuffer.stop();
        this.#reset();
        this.#setState(constants.STOPPED);
    }

    isReady() {
        return this.state === constants.READY;
    }

    isPlaying() {
        return this.state === constants.PLAYING;
    }

    isPaused() {
        return this.state === constants.PAUSED;
    }

    isFinished() {
        return this.state === constants.STOPPED;
    }

    hasError() {
        return this.state === constants.ERROR;
    }

    getProgress() {
        return this.audiobuffer?.getProgress();
    }

    #setState(state, data) {
        if (this.state === state) {
            return;
        }
        this.state = state;
        logger.debug('setting state of audio player to \'' + state + '\'...');
        if (this.events.includes(state)) {
            return;
        }
        logger.debug('emitting state \'' + state + '\' of audio player...');
        this.emit(this.state, { data: data });
        this.emit(constants.STATECHANGE, { state: this.state, progress: this.getProgress() });
        this.events.push(state);
    }

    #reset() {
        this.events = [];
    }

}

module.exports = Player;