/* Copyright 2017 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.
 */

import { buildGetDocumentParams, NodeCanvasFactory } from "./test_utils.js";
import { DOMCanvasFactory } from "../../src/display/display_utils.js";
import { getDocument } from "../../src/display/api.js";
import { isNodeJS } from "../../src/shared/is_node.js";

function getTopLeftPixel(canvasContext) {
  const imgData = canvasContext.getImageData(0, 0, 1, 1);
  return {
    r: imgData.data[0],
    g: imgData.data[1],
    b: imgData.data[2],
    a: imgData.data[3],
  };
}

describe("custom canvas rendering", function() {
  const transparentGetDocumentParams = buildGetDocumentParams(
    "transparent.pdf"
  );

  let CanvasFactory;
  let loadingTask;
  let page;

  beforeAll(function(done) {
    if (isNodeJS) {
      CanvasFactory = new NodeCanvasFactory();
    } else {
      CanvasFactory = new DOMCanvasFactory();
    }
    loadingTask = getDocument(transparentGetDocumentParams);
    loadingTask.promise
      .then(function(doc) {
        return doc.getPage(1);
      })
      .then(function(data) {
        page = data;
        done();
      })
      .catch(done.fail);
  });

  afterAll(function(done) {
    CanvasFactory = null;
    page = null;
    loadingTask.destroy().then(done);
  });

  it("renders to canvas with a default white background", function(done) {
    var viewport = page.getViewport({ scale: 1 });
    var canvasAndCtx = CanvasFactory.create(viewport.width, viewport.height);

    const renderTask = page.render({
      canvasContext: canvasAndCtx.context,
      viewport,
    });
    renderTask.promise
      .then(function() {
        expect(getTopLeftPixel(canvasAndCtx.context)).toEqual({
          r: 255,
          g: 255,
          b: 255,
          a: 255,
        });
        CanvasFactory.destroy(canvasAndCtx);
        done();
      })
      .catch(done.fail);
  });

  it("renders to canvas with a custom background", function(done) {
    var viewport = page.getViewport({ scale: 1 });
    var canvasAndCtx = CanvasFactory.create(viewport.width, viewport.height);

    const renderTask = page.render({
      canvasContext: canvasAndCtx.context,
      viewport,
      background: "rgba(255,0,0,1.0)",
    });
    renderTask.promise
      .then(function() {
        expect(getTopLeftPixel(canvasAndCtx.context)).toEqual({
          r: 255,
          g: 0,
          b: 0,
          a: 255,
        });
        CanvasFactory.destroy(canvasAndCtx);
        done();
      })
      .catch(done.fail);
  });
});