/* Any copyright is dedicated to the Public Domain.
   http://creativecommons.org/publicdomain/zero/1.0/ */

/**
 * Tests that errors are properly handled when trying to compile a
 * defective shader source.
 */

function* ifWebGLSupported() {
  let { target, front } = yield initBackend(SIMPLE_CANVAS_URL);
  front.setup({ reload: true });

  let programActor = yield once(front, "program-linked");
  let vertexShader = yield programActor.getVertexShader();
  let fragmentShader = yield programActor.getFragmentShader();

  let oldVertSource = yield vertexShader.getText();
  let newVertSource = oldVertSource.replace("vec4", "vec3");

  try {
    yield vertexShader.compile(newVertSource);
    ok(false, "Vertex shader was compiled with a defective source!");
  } catch (error) {
    ok(error,
      "The new vertex shader source was compiled with errors.");

    // The implementation has the choice to defer all compile-time errors to link time.
    let infoLog = (error.compile != "") ? error.compile : error.link;

    isnot(infoLog, "",
      "The one of the compile or link info logs should not be empty.");
    is(infoLog.split("ERROR").length - 1, 2,
      "The info log contains two errors.");
    ok(infoLog.includes("ERROR: 0:8: 'constructor'"),
      "A constructor error is contained in the info log.");
    ok(infoLog.includes("ERROR: 0:8: 'assign'"),
      "An assignment error is contained in the info log.");
  }

  yield ensurePixelIs(front, { x: 0, y: 0 }, { r: 255, g: 0, b: 0, a: 255 }, true);
  yield ensurePixelIs(front, { x: 511, y: 511 }, { r: 0, g: 255, b: 0, a: 255 }, true);
  ok(true, "The shader was reverted to the old source.");

  let vertSource = yield vertexShader.getText();
  ok(vertSource.includes("vec4(aVertexPosition, 1.0);"),
    "The previous correct vertex shader source was preserved.");

  let oldFragSource = yield fragmentShader.getText();
  let newFragSource = oldFragSource.replace("vec3", "vec4");

  try {
    yield fragmentShader.compile(newFragSource);
    ok(false, "Fragment shader was compiled with a defective source!");
  } catch (error) {
    ok(error,
      "The new fragment shader source was compiled with errors.");

    // The implementation has the choice to defer all compile-time errors to link time.
    let infoLog = (error.compile != "") ? error.compile : error.link;

    isnot(infoLog, "",
      "The one of the compile or link info logs should not be empty.");
    is(infoLog.split("ERROR").length - 1, 1,
      "The info log contains one error.");
    ok(infoLog.includes("ERROR: 0:6: 'constructor'"),
      "A constructor error is contained in the info log.");
  }

  yield ensurePixelIs(front, { x: 0, y: 0 }, { r: 255, g: 0, b: 0, a: 255 }, true);
  yield ensurePixelIs(front, { x: 511, y: 511 }, { r: 0, g: 255, b: 0, a: 255 }, true);
  ok(true, "The shader was reverted to the old source.");

  let fragSource = yield fragmentShader.getText();
  ok(fragSource.includes("vec3 vFragmentColor;"),
    "The previous correct fragment shader source was preserved.");

  yield programActor.highlight([0, 1, 0, 1]);
  yield ensurePixelIs(front, { x: 0, y: 0 }, { r: 0, g: 0, b: 0, a: 255 }, true);
  yield ensurePixelIs(front, { x: 511, y: 511 }, { r: 0, g: 255, b: 0, a: 255 }, true);
  ok(true, "Highlighting worked after setting a defective fragment source.");

  yield programActor.unhighlight();
  yield ensurePixelIs(front, { x: 0, y: 0 }, { r: 255, g: 0, b: 0, a: 255 }, true);
  yield ensurePixelIs(front, { x: 511, y: 511 }, { r: 0, g: 255, b: 0, a: 255 }, true);
  ok(true, "Unhighlighting worked after setting a defective vertex source.");

  yield removeTab(target.tab);
  finish();
}