/* Copyright 2019 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/* eslint no-var: error */

import { PDFFetchStream } from '../../src/display/fetch_stream';

describe('fetch_stream', function() {
  const pdfUrl = new URL('../pdfs/tracemonkey.pdf', window.location).href;
  const pdfLength = 1016315;

  it('read with streaming', function(done) {
    const stream = new PDFFetchStream({
      url: pdfUrl,
      disableStream: false,
      disableRange: true,
    });

    const fullReader = stream.getFullReader();

    let isStreamingSupported, isRangeSupported;
    const promise = fullReader.headersReady.then(function() {
      isStreamingSupported = fullReader.isStreamingSupported;
      isRangeSupported = fullReader.isRangeSupported;
    });

    let len = 0;
    const read = function() {
      return fullReader.read().then(function(result) {
        if (result.done) {
          return undefined;
        }

        len += result.value.byteLength;
        return read();
      });
    };

    const readPromise = Promise.all([read(), promise]);
    readPromise.then(function() {
      expect(len).toEqual(pdfLength);
      expect(isStreamingSupported).toEqual(true);
      expect(isRangeSupported).toEqual(false);
      done();
    }).catch(done.fail);
  });

  it('read ranges with streaming', function(done) {
    const rangeSize = 32768;
    const stream = new PDFFetchStream({
      url: pdfUrl,
      rangeChunkSize: rangeSize,
      disableStream: false,
      disableRange: false,
    });

    const fullReader = stream.getFullReader();

    let isStreamingSupported, isRangeSupported, fullReaderCancelled;
    const promise = fullReader.headersReady.then(function() {
      isStreamingSupported = fullReader.isStreamingSupported;
      isRangeSupported = fullReader.isRangeSupported;
      // We shall be able to close full reader without any issue.
      fullReader.cancel(new Error('Don\'t need full reader'));
      fullReaderCancelled = true;
    });

    const tailSize = (pdfLength % rangeSize) || rangeSize;
    const rangeReader1 = stream.getRangeReader(pdfLength - tailSize - rangeSize,
                                               pdfLength - tailSize);
    const rangeReader2 = stream.getRangeReader(pdfLength - tailSize, pdfLength);

    let result1 = { value: 0, }, result2 = { value: 0, };
    const read = function(reader, lenResult) {
      return reader.read().then(function(result) {
        if (result.done) {
          return undefined;
        }

        lenResult.value += result.value.byteLength;
        return read(reader, lenResult);
      });
    };

    const readPromise = Promise.all([read(rangeReader1, result1),
                                     read(rangeReader2, result2),
                                     promise]);
    readPromise.then(function() {
      expect(isStreamingSupported).toEqual(true);
      expect(isRangeSupported).toEqual(true);
      expect(fullReaderCancelled).toEqual(true);
      expect(result1.value).toEqual(rangeSize);
      expect(result2.value).toEqual(tailSize);
      done();
    }).catch(done.fail);
  });
});