/*
 * noVNC: HTML5 VNC client
 * Copyright (C) 2020 The noVNC Authors
 * Licensed under MPL 2.0 (see LICENSE.txt)
 *
 * See README.md for usage and integration instructions.
 */

import { deflateInit, deflate } from '../vendor/pako/lib/zlib/deflate.js';
import { Z_FULL_FLUSH } from '../vendor/pako/lib/zlib/deflate.js';
import ZStream from '../vendor/pako/lib/zlib/zstream.js';

export default class Deflator {
  constructor() {
    this.strm = new ZStream();
    this.chunkSize = 1024 * 10 * 10;
    this.outputBuffer = new Uint8Array(this.chunkSize);
    this.windowBits = 5;

    deflateInit(this.strm, this.windowBits);
  }

  deflate(inData) {
    /* eslint-disable camelcase */
    this.strm.input = inData;
    this.strm.avail_in = this.strm.input.length;
    this.strm.next_in = 0;
    this.strm.output = this.outputBuffer;
    this.strm.avail_out = this.chunkSize;
    this.strm.next_out = 0;
    /* eslint-enable camelcase */

    let lastRet = deflate(this.strm, Z_FULL_FLUSH);
    let outData = new Uint8Array(this.strm.output.buffer, 0, this.strm.next_out);

    if (lastRet < 0) {
      throw new Error('zlib deflate failed');
    }

    if (this.strm.avail_in > 0) {
      // Read chunks until done

      let chunks = [outData];
      let totalLen = outData.length;
      do {
        /* eslint-disable camelcase */
        this.strm.output = new Uint8Array(this.chunkSize);
        this.strm.next_out = 0;
        this.strm.avail_out = this.chunkSize;
        /* eslint-enable camelcase */

        lastRet = deflate(this.strm, Z_FULL_FLUSH);

        if (lastRet < 0) {
          throw new Error('zlib deflate failed');
        }

        let chunk = new Uint8Array(this.strm.output.buffer, 0, this.strm.next_out);
        totalLen += chunk.length;
        chunks.push(chunk);
      } while (this.strm.avail_in > 0);

      // Combine chunks into a single data

      let newData = new Uint8Array(totalLen);
      let offset = 0;

      for (let i = 0; i < chunks.length; i++) {
        newData.set(chunks[i], offset);
        offset += chunks[i].length;
      }

      outData = newData;
    }

    /* eslint-disable camelcase */
    this.strm.input = null;
    this.strm.avail_in = 0;
    this.strm.next_in = 0;
    /* eslint-enable camelcase */

    return outData;
  }
}
