import ImageWrapper from '../../../../src/ol/Image.js';
import {listen} from '../../../../src/ol/events.js';
import {get as getProjection} from '../../../../src/ol/proj.js';
import ReprojImage from '../../../../src/ol/reproj/Image.js';


describe('ol.reproj.Image', function() {
  function createImage(pixelRatio) {
    return new ReprojImage(
      getProjection('EPSG:3857'), getProjection('EPSG:4326'),
      [-180, -85, 180, 85], 10, pixelRatio,
      function(extent, resolution, pixelRatio) {
        return new ImageWrapper(extent, resolution, pixelRatio,
          'data:image/gif;base64,' +
              'R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=', null,
          function(image, src) {
            image.getImage().src = src;
          });
      });
  }

  function createTranslucentImage(pixelRatio) {
    return new ReprojImage(
      getProjection('EPSG:3857'), getProjection('EPSG:4326'),
      [-180, -85, 180, 85], 10, pixelRatio,
      function(extent, resolution, pixelRatio) {
        return new ImageWrapper(extent, resolution, pixelRatio,
          'data:image/png;base64,' +
              'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8depePQAIiwMjFXlnJQAAAABJRU5ErkJggg==', null,
          function(image, src) {
            image.getImage().src = src;
          });
      });
  }

  it('changes state as expected', function(done) {
    const image = createImage(1);
    expect(image.getState()).to.be(0); // IDLE
    listen(image, 'change', function() {
      if (image.getState() == 2) { // LOADED
        done();
      }
    });
    image.load();
  });

  it('returns correct canvas size', function(done) {
    const image = createImage(1);
    listen(image, 'change', function() {
      if (image.getState() == 2) { // LOADED
        const canvas = image.getImage();
        expect(canvas.width).to.be(36);
        expect(canvas.height).to.be(17);
        done();
      }
    });
    image.load();
  });

  it('respects pixelRatio', function(done) {
    const image = createImage(2);
    listen(image, 'change', function() {
      if (image.getState() == 2) { // LOADED
        const canvas = image.getImage();
        expect(canvas.width).to.be(72);
        expect(canvas.height).to.be(34);
        done();
      }
    });
    image.load();
  });

  it('has uniform color', function(done) {
    const image = createTranslucentImage(1);
    listen(image, 'change', function() {
      if (image.getState() == 2) { // LOADED
        const canvas = image.getImage();
        expect(canvas.width).to.be(36);
        expect(canvas.height).to.be(17);
        const pixels = canvas.getContext('2d').getImageData(0, 0, canvas.width, canvas.height).data;

        for (let i = 0; i < canvas.width * canvas.height * 4; i += 4) {
          expect(pixels[i + 0]).to.be.within(pixels[0] - 2, pixels[0] + 2);
          expect(pixels[i + 1]).to.be.within(pixels[1] - 2, pixels[1] + 2);
          expect(pixels[i + 2]).to.be.within(pixels[2] - 2, pixels[2] + 2);
          expect(pixels[i + 3]).to.be.within(pixels[3] - 2, pixels[3] + 2);
        }
        done();
      }
    });
    image.load();
  });

});