window["require_setup"](module);

import {audio as naudio} from "teaclient_connection";

namespace audio.player  {
    //FIXME: Native audio initialize handle!

    export interface Device {
        device_id: string;
        name: string;
    }

    interface Navigator {
        mozGetUserMedia(constraints: MediaStreamConstraints, successCallback: NavigatorUserMediaSuccessCallback, errorCallback: NavigatorUserMediaErrorCallback): void;
        webkitGetUserMedia(constraints: MediaStreamConstraints, successCallback: NavigatorUserMediaSuccessCallback, errorCallback: NavigatorUserMediaErrorCallback): void;
    }

    let _initialized_callbacks: (() => any)[] = [];
    export let _initialized = false;
    export let _initializing = false;
    export let _audioContext: AudioContext;
    export let _processor: ScriptProcessorNode;
    export let _output_stream: naudio.playback.OwnedAudioOutputStream;
    export let _current_device: naudio.AudioDevice;

    export function initialized() : boolean {
        return _initialized;
    }


    export function context() : AudioContext {
        if(!_audioContext) throw "Initialize first!";
        return _audioContext;
    }

    export function destination() : AudioNode {
        if(!_initialized)
            throw "Audio player hasn't yet be initialized";
        return _processor || _audioContext.destination;
    }

    export function on_ready(cb: () => any) {
        if(_initialized)
            cb();
        else
            _initialized_callbacks.push(cb);
    }

    export function initialize() {
        if(_initializing) return;
        _initializing = true;

        naudio.initialize(() => {
            _output_stream = naudio.playback.create_stream();
            _output_stream.set_buffer_max_latency(0.4);
            _output_stream.set_buffer_latency(0.02);

            _output_stream.callback_overflow = () => {
                console.warn("Main audio overflow");
                _output_stream.clear();
            };
            _output_stream.callback_underflow = () => {
                console.warn("Main audio underflow");
            };

            _audioContext = new AudioContext();
            _processor = _audioContext.createScriptProcessor(1024 * 8, _output_stream.channels, _output_stream.channels);

            _processor.onaudioprocess = function(event) {
                const buffer = event.inputBuffer;
                //console.log("Received %d channels of %d with a rate of %d", buffer.numberOfChannels, buffer.length, buffer.sampleRate);
                const target_buffer = new Float32Array(buffer.numberOfChannels * buffer.length);

                for(let channel = 0; channel < buffer.numberOfChannels; channel++) {
                    const channel_data = buffer.getChannelData(channel);
                    target_buffer.set(channel_data, channel * buffer.length);
                }
                _output_stream.write_data_rated(target_buffer.buffer, false, buffer.sampleRate);
            };
            _processor.connect(_audioContext.destination);


            _initialized = true;
            for(const callback of _initialized_callbacks)
                callback();
            _initialized_callbacks = [];
        });
        return true;
    }

    export async function available_devices() : Promise<Device[]> {
        return naudio.available_devices().filter(e => e.output_supported || e.output_default);
    }

    export async function set_device(device_id?: string) : Promise<void> {
        const dev = naudio.available_devices().filter(e => e.device_id == device_id);
        if(dev.length == 0) {
            console.warn("Missing audio device with is %s", device_id);
            throw "invalid device id";
        }

        try {
            naudio.playback.set_device(dev[0].device_id);
        } catch(error) {
            if(error instanceof Error)
                throw error.message;
            throw error;
        }
        _current_device = dev[0];
    }

    export function current_device() : Device {
        if(_current_device)
            return _current_device;

        const dev = naudio.available_devices().filter(e => e.output_default);
        if(dev.length > 0)
            return dev[0];
        return {device_id: "default", name: "default"} as Device;
    }

    export function get_master_volume() : number {
        return naudio.playback.get_master_volume();
    }
    export function set_master_volume(volume: number) {
        naudio.playback.set_master_volume(volume);
    }
}

Object.assign(window["audio"] || (window["audio"] = {} as any), audio);