class FLYSocket {
    constructor(ws,
        callbackData = this.callbackDummy,
        callbackRaw = this.callbackDummy) {
        this.ws = new WebSocket(ws);
        this.pointer = 0;
        
        this.callbackData = callbackData;
        this.callbackRaw = callbackRaw;

        this.ws.onmessage = this.onMessage.bind(this);
    }

    onMessage(e) {
        new Response(event.data).arrayBuffer().then(
            function(buff) {
                let data = new DataView(buff);
                this.callbackRaw(data);
                
                if (this.callbackData != this.callbackDummy || true) { // DEBUG
                    this.callbackData( this.parse(data) );
                }
            }.bind(this)
        );
    }

    parse(data) {
        window.data = data; // DEBUG
        let packets = [];
        this.pointer = 0;

        while (this.pointer < data.byteLength) {
            let packetID = data.getInt8(this.pointer++);
            packets.push({
                    packetID: packetID,
                    value: (this["handle_packet" + packetID] || this.handle_packetInvalid)(data)
                });
        }

        return packets;
    }

    handle_packet0(data) {
        // BxI
        // B: Length
        // I: FlightUUID
        let ret = [];
        let length = data.getUint8(this.pointer++);
        for (let i = 0; i < length; i++) {
            ret.push( data.getUint32(this.pointer) );
            this.pointer += 4;
        }
        return ret;
    }

    handle_packet1(data) {
        // ?
        // ?: Subscribed to changes
        return data.getUint8(this.pointer++) != 0;
    }

    handle_packet2(data) {
        // I?
        // I: FlightUUID
        // ?: Subscribed to flight data
        let ret = [];
        ret.push( data.getUint32(this.pointer) ); this.pointer += 4;
        ret.push( data.getUint8(this.pointer++) != 0 );
        return ret;
    }

    handle_packet3(data) { // TODO: implement (Whole data / history)
        // xs
        // s: DataStream
        let ret = {};
        ret["uuid"] = data.getUint32(this.pointer); this.pointer += 4;
        ret["maxFuel"] = data.getFloat32(this.pointer); this.pointer += 4;
        ret["model"] = data.getUint16(this.pointer); this.pointer += 2;
        let playernameLength = data.getUint8(this.pointer++);
        let playername = "";
        for (let i = 0; i < playernameLength; i++)
            playername += String.fromCharCode( data.getUint8(this.pointer++) );
        ret["playername"] = playername;

        let timeline = [];
        while (this.pointer < data.byteLength)
            timeline.push( this.parseFrame(data) );
        ret["timeline"] = timeline;
        return ret;
    }

    handle_packet4(data) {
        // I?
        // I: FlightUUID
        // ?: Flight active
        let ret = [];
        ret.push( data.getUint32(this.pointer) ); this.pointer += 4;
        ret.push( data.getUint8(this.pointer++) != 0 );
        return ret;
    }

    handle_packet5(data) {
        // Ixs
        // I: FlightUUID
        // s: DataStream
        let ret = [];
        ret.push( data.getUint32(this.pointer) ); this.pointer += 4;
        ret.push( this.parseFrame(data) );
        return ret;
    }

    handle_packet255(data) {
        // Hxs
        // H: Length
        // s: ErrorMessage
        let ret = "";
        let length = data.getUint16(this.pointer); this.pointer += 2;
        for (let i = 0; i < length; i++) {
            ret += String.fromCharCode( data.getUint8(this.pointer++) );
        }
        return ret;
    }

    handle_packetInvalid(data) {
        throw TypeError(`Invalid DATA: ${Array.from( this.buffer2HexArray(data, --this.pointer) ).join(" ")}`);
    }

    parseFrame(data) {
        // IBxs
        // I: Timestamp
        // B: Flag
        // s: FrameStream
        let ret = {};
        ret["timestamp"] = data.getUint32(this.pointer); this.pointer += 4;
        let flags = data.getUint8(this.pointer++);
        if (flags & (1<<0)) {
            let statusFlag = data.getUint8(this.pointer++);
            ret["paused"] = !!( statusFlag & (1<<0) );
            ret["engine"] = !!( statusFlag & (1<<1) );
        }
        if (flags & (1<<1)) {
            ret["satisfaction"] = data.getUint8(this.pointer++);
        }
        if (flags & (1<<2)) {
            ret["speed"] = data.getUint16(this.pointer); this.pointer += 2;
        }
        if (flags & (1<<3)) {
            ret["altitude"] = data.getInt16(this.pointer); this.pointer += 2;
        }
        if (flags & (1<<4)) {
            ret["health"] = data.getUint16(this.pointer); this.pointer += 2;
        }
        if (flags & (1<<5)) {
            ret["fuel"] = data.getFloat32(this.pointer); this.pointer += 4;
        }
        if (flags & (1<<6)) {
            ret["x"] = data.getFloat32(this.pointer); this.pointer += 4;
        }
        if (flags & (1<<7)) {
            ret["y"] = data.getFloat32(this.pointer); this.pointer += 4;
        }
        return ret;
    }

    *buffer2HexArray(buff, start = 0, end = buff.byteLength) {
        for (let i = start; i < end; i++) {
            yield hex.push( buff.getUint8(i).toString(16) );
        }
    }

    callbackDummy(_) {}
}

console.log("OK") // TODO: please remove...