import { LZMA } from './lzma'

export class LZMAHelper {
    static decoder: LZMA = new LZMA()
    static decoderAsync: Worker = new Worker('LZMAWorker.min.js')
    static callback: Function
    static ENCODE: number = 1
    static DECODE: number = 2

    static init(): void {
        var command = 0
        LZMAHelper.decoderAsync.onmessage = function(e) {
            if (command == 0) {
                command = e.data
            } else if (command == LZMAHelper.ENCODE) {
                command = 0 //encode not implemented
            } else if (command == LZMAHelper.DECODE) {
                command = 0
                LZMAHelper.callback(e.data)
                LZMAHelper.callback = null
            }
        }
    }

    static encode(data: ArrayBuffer): ArrayBuffer {
        return null
    }
    static decode(data: ArrayBuffer): ArrayBuffer {
        return LZMAHelper.decoder.decode(new Uint8Array(data)).buffer
    }
    static encodeAsync(data: ArrayBuffer, _callback: Function): void {}
    static decodeAsync(data: ArrayBuffer, _callback: Function): void {
        if (LZMAHelper.callback == null) {
            LZMAHelper.callback = _callback
            LZMAHelper.decoderAsync.postMessage(LZMAHelper.DECODE)
            LZMAHelper.decoderAsync.postMessage(data, [data])
        } else {
            console.log('Warning! Another LZMA decoding is running...')
        }
    }
}

LZMAHelper.init()