// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "core/dom/Document.h"
#include "core/dom/FrameRequestCallback.h"
#include "core/html/HTMLIFrameElement.h"
#include "core/layout/api/LayoutViewItem.h"
#include "core/paint/PaintLayer.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "web/tests/sim/SimCompositor.h"
#include "web/tests/sim/SimDisplayItemList.h"
#include "web/tests/sim/SimRequest.h"
#include "web/tests/sim/SimTest.h"

namespace blink {

using namespace HTMLNames;

class DocumentLoadingRenderingTest : public SimTest {};

TEST_F(DocumentLoadingRenderingTest,
       ShouldResumeCommitsAfterBodyParsedWithoutSheets) {
  SimRequest mainResource("https://example.com/test.html", "text/html");

  loadURL("https://example.com/test.html");

  mainResource.start();

  // Still in the head, should not resume commits.
  mainResource.write("<!DOCTYPE html>");
  EXPECT_TRUE(compositor().deferCommits());
  mainResource.write("<title>Test</title><style>div { color red; }</style>");
  EXPECT_TRUE(compositor().deferCommits());

  // Implicitly inserts the body. Since there's no loading stylesheets we
  // should resume commits.
  mainResource.write("<p>Hello World</p>");
  EXPECT_FALSE(compositor().deferCommits());

  // Finish the load, should stay resumed.
  mainResource.finish();
  EXPECT_FALSE(compositor().deferCommits());
}

TEST_F(DocumentLoadingRenderingTest,
       ShouldResumeCommitsAfterBodyIfSheetsLoaded) {
  SimRequest mainResource("https://example.com/test.html", "text/html");
  SimRequest cssResource("https://example.com/test.css", "text/css");

  loadURL("https://example.com/test.html");

  mainResource.start();

  // Still in the head, should not resume commits.
  mainResource.write("<!DOCTYPE html><link rel=stylesheet href=test.css>");
  EXPECT_TRUE(compositor().deferCommits());

  // Sheet is streaming in, but not ready yet.
  cssResource.start();
  cssResource.write("a { color: red; }");
  EXPECT_TRUE(compositor().deferCommits());

  // Sheet finished, but no body yet, so don't resume.
  cssResource.finish();
  EXPECT_TRUE(compositor().deferCommits());

  // Body inserted and sheet is loaded so resume commits.
  mainResource.write("<body>");
  EXPECT_FALSE(compositor().deferCommits());

  // Finish the load, should stay resumed.
  mainResource.finish();
  EXPECT_FALSE(compositor().deferCommits());
}

TEST_F(DocumentLoadingRenderingTest, ShouldResumeCommitsAfterSheetsLoaded) {
  SimRequest mainResource("https://example.com/test.html", "text/html");
  SimRequest cssResource("https://example.com/test.css", "text/css");

  loadURL("https://example.com/test.html");

  mainResource.start();

  // Still in the head, should not resume commits.
  mainResource.write("<!DOCTYPE html><link rel=stylesheet href=test.css>");
  EXPECT_TRUE(compositor().deferCommits());

  // Sheet is streaming in, but not ready yet.
  cssResource.start();
  cssResource.write("a { color: red; }");
  EXPECT_TRUE(compositor().deferCommits());

  // Body inserted, but sheet is still loading so don't resume.
  mainResource.write("<body>");
  EXPECT_TRUE(compositor().deferCommits());

  // Sheet finished and there's a body so resume.
  cssResource.finish();
  EXPECT_FALSE(compositor().deferCommits());

  // Finish the load, should stay resumed.
  mainResource.finish();
  EXPECT_FALSE(compositor().deferCommits());
}

TEST_F(DocumentLoadingRenderingTest,
       ShouldResumeCommitsAfterDocumentElementWithNoSheets) {
  SimRequest mainResource("https://example.com/test.svg", "image/svg+xml");
  SimRequest cssResource("https://example.com/test.css", "text/css");

  loadURL("https://example.com/test.svg");

  mainResource.start();

  // Sheet loading and no documentElement, so don't resume.
  mainResource.write("<?xml-stylesheet type='text/css' href='test.css'?>");
  EXPECT_TRUE(compositor().deferCommits());

  // Sheet finishes loading, but no documentElement yet so don't resume.
  cssResource.complete("a { color: red; }");
  EXPECT_TRUE(compositor().deferCommits());

  // Root inserted so resume.
  mainResource.write("<svg xmlns='http://www.w3.org/2000/svg'></svg>");
  EXPECT_FALSE(compositor().deferCommits());

  // Finish the load, should stay resumed.
  mainResource.finish();
  EXPECT_FALSE(compositor().deferCommits());
}

TEST_F(DocumentLoadingRenderingTest, ShouldResumeCommitsAfterSheetsLoadForXml) {
  SimRequest mainResource("https://example.com/test.svg", "image/svg+xml");
  SimRequest cssResource("https://example.com/test.css", "text/css");

  loadURL("https://example.com/test.svg");

  mainResource.start();

  // Not done parsing.
  mainResource.write("<?xml-stylesheet type='text/css' href='test.css'?>");
  EXPECT_TRUE(compositor().deferCommits());

  // Sheet is streaming in, but not ready yet.
  cssResource.start();
  cssResource.write("a { color: red; }");
  EXPECT_TRUE(compositor().deferCommits());

  // Root inserted, but sheet is still loading so don't resume.
  mainResource.write("<svg xmlns='http://www.w3.org/2000/svg'></svg>");
  EXPECT_TRUE(compositor().deferCommits());

  // Finish the load, but sheets still loading so don't resume.
  mainResource.finish();
  EXPECT_TRUE(compositor().deferCommits());

  // Sheet finished, so resume commits.
  cssResource.finish();
  EXPECT_FALSE(compositor().deferCommits());
}

TEST_F(DocumentLoadingRenderingTest, ShouldResumeCommitsAfterFinishParsingXml) {
  SimRequest mainResource("https://example.com/test.svg", "image/svg+xml");

  loadURL("https://example.com/test.svg");

  mainResource.start();

  // Finish parsing, no sheets loading so resume.
  mainResource.finish();
  EXPECT_FALSE(compositor().deferCommits());
}

TEST_F(DocumentLoadingRenderingTest, ShouldResumeImmediatelyForImageDocuments) {
  SimRequest mainResource("https://example.com/test.png", "image/png");

  loadURL("https://example.com/test.png");

  mainResource.start();
  EXPECT_TRUE(compositor().deferCommits());

  // Not really a valid image but enough for the test. ImageDocuments should
  // resume painting as soon as the first bytes arrive.
  mainResource.write("image data");
  EXPECT_FALSE(compositor().deferCommits());

  mainResource.finish();
  EXPECT_FALSE(compositor().deferCommits());
}

TEST_F(DocumentLoadingRenderingTest, ShouldScheduleFrameAfterSheetsLoaded) {
  SimRequest mainResource("https://example.com/test.html", "text/html");
  SimRequest firstCssResource("https://example.com/first.css", "text/css");
  SimRequest secondCssResource("https://example.com/second.css", "text/css");

  loadURL("https://example.com/test.html");

  mainResource.start();

  // Load a stylesheet.
  mainResource.write(
      "<!DOCTYPE html><link id=link rel=stylesheet href=first.css>");
  EXPECT_TRUE(compositor().deferCommits());

  firstCssResource.start();
  firstCssResource.write("body { color: red; }");
  mainResource.write("<body>");
  firstCssResource.finish();

  // Sheet finished and there's a body so resume.
  EXPECT_FALSE(compositor().deferCommits());

  mainResource.finish();
  compositor().beginFrame();

  // Replace the stylesheet by changing href.
  auto* element = document().getElementById("link");
  EXPECT_NE(nullptr, element);
  element->setAttribute(hrefAttr, "second.css");
  EXPECT_FALSE(compositor().needsBeginFrame());

  secondCssResource.complete("body { color: red; }");
  EXPECT_TRUE(compositor().needsBeginFrame());
}

TEST_F(DocumentLoadingRenderingTest,
       ShouldNotPaintIframeContentWithPendingSheets) {
  SimRequest mainResource("https://example.com/test.html", "text/html");
  SimRequest frameResource("https://example.com/frame.html", "text/html");
  SimRequest cssResource("https://example.com/test.css", "text/css");

  loadURL("https://example.com/test.html");

  webView().resize(WebSize(800, 600));

  mainResource.complete(
      "<!DOCTYPE html>"
      "<body style='background: red'>"
      "<iframe id=frame src=frame.html style='border: none'></iframe>"
      "<p style='transform: translateZ(0)'>Hello World</p>");

  // Main page is ready to begin painting as there's no pending sheets.
  // The frame is not yet loaded, so we only paint the top level page.
  auto frame1 = compositor().beginFrame();
  EXPECT_TRUE(frame1.contains(SimCanvas::Text));

  frameResource.complete(
      "<!DOCTYPE html>"
      "<style>html { background: pink }</style>"
      "<link rel=stylesheet href=test.css>"
      "<p style='background: yellow;'>Hello World</p>"
      "<div style='transform: translateZ(0); background: green;'>"
      "    <p style='background: blue;'>Hello Layer</p>"
      "    <div style='position: relative; background: red;'>Hello World</div>"
      "</div>");

  // Trigger a layout with pending sheets. For example a page could trigger
  // this by doing offsetTop in a setTimeout, or by a parent frame executing
  // script that touched offsetTop in the child frame.
  auto* childFrame = toHTMLIFrameElement(document().getElementById("frame"));
  childFrame->contentDocument()->updateStyleAndLayoutIgnorePendingStylesheets();

  auto frame2 = compositor().beginFrame();

  // The child frame still has pending sheets, and the parent frame has no
  // invalid paint so we shouldn't draw any text.
  EXPECT_FALSE(frame2.contains(SimCanvas::Text));

  // 1 for the main frame background (red).
  // TODO(esprehn): If we were super smart we'd notice that the nested iframe is
  // actually composited and not repaint the main frame, but that likely
  // requires doing compositing and paint invalidation bottom up.
  EXPECT_EQ(1, frame2.drawCount());
  EXPECT_TRUE(frame2.contains(SimCanvas::Rect, "red"));

  // Finish loading the sheets in the child frame. After it should issue a
  // paint invalidation for every layer when the frame becomes unthrottled.
  cssResource.complete();

  // First frame where all frames are loaded, should paint the text in the
  // child frame.
  auto frame3 = compositor().beginFrame();
  EXPECT_TRUE(frame3.contains(SimCanvas::Text));
}

namespace {

class CheckRafCallback final : public FrameRequestCallback {
 public:
  void handleEvent(double highResTimeMs) override { m_wasCalled = true; }
  bool wasCalled() const { return m_wasCalled; }

 private:
  bool m_wasCalled = false;
};
};

TEST_F(DocumentLoadingRenderingTest,
       ShouldThrottleIframeLifecycleUntilPendingSheetsLoaded) {
  SimRequest mainResource("https://example.com/main.html", "text/html");
  SimRequest frameResource("https://example.com/frame.html", "text/html");
  SimRequest cssResource("https://example.com/frame.css", "text/css");

  loadURL("https://example.com/main.html");

  webView().resize(WebSize(800, 600));

  mainResource.complete(
      "<!DOCTYPE html>"
      "<body style='background: red'>"
      "<iframe id=frame src=frame.html></iframe>");

  frameResource.complete(
      "<!DOCTYPE html>"
      "<link rel=stylesheet href=frame.css>"
      "<body style='background: blue'>");

  auto* childFrame = toHTMLIFrameElement(document().getElementById("frame"));

  // Frame while the child frame still has pending sheets.
  auto* frame1Callback = new CheckRafCallback();
  childFrame->contentDocument()->requestAnimationFrame(frame1Callback);
  auto frame1 = compositor().beginFrame();
  EXPECT_FALSE(frame1Callback->wasCalled());
  EXPECT_TRUE(frame1.contains(SimCanvas::Rect, "red"));
  EXPECT_FALSE(frame1.contains(SimCanvas::Rect, "blue"));

  // Finish loading the sheets in the child frame. Should enable lifecycle
  // updates and raf callbacks.
  cssResource.complete();

  // Frame with all lifecycle updates enabled.
  auto* frame2Callback = new CheckRafCallback();
  childFrame->contentDocument()->requestAnimationFrame(frame2Callback);
  auto frame2 = compositor().beginFrame();
  EXPECT_TRUE(frame1Callback->wasCalled());
  EXPECT_TRUE(frame2Callback->wasCalled());
  EXPECT_TRUE(frame2.contains(SimCanvas::Rect, "red"));
  EXPECT_TRUE(frame2.contains(SimCanvas::Rect, "blue"));
}

TEST_F(DocumentLoadingRenderingTest,
       ShouldContinuePaintingWhenSheetsStartedAfterBody) {
  SimRequest mainResource("https://example.com/test.html", "text/html");
  SimRequest cssHeadResource("https://example.com/testHead.css", "text/css");
  SimRequest cssBodyResource("https://example.com/testBody.css", "text/css");

  loadURL("https://example.com/test.html");

  mainResource.start();

  // Still in the head, should not paint.
  mainResource.write("<!DOCTYPE html><link rel=stylesheet href=testHead.css>");
  EXPECT_FALSE(document().isRenderingReady());

  // Sheet is streaming in, but not ready yet.
  cssHeadResource.start();
  cssHeadResource.write("a { color: red; }");
  EXPECT_FALSE(document().isRenderingReady());

  // Body inserted but sheet is still pending so don't paint.
  mainResource.write("<body>");
  EXPECT_FALSE(document().isRenderingReady());

  // Sheet finished and body inserted, ok to paint.
  cssHeadResource.finish();
  EXPECT_TRUE(document().isRenderingReady());

  // In the body, should not stop painting.
  mainResource.write("<link rel=stylesheet href=testBody.css>");
  EXPECT_TRUE(document().isRenderingReady());

  // Finish loading the CSS resource (no change to painting).
  cssBodyResource.complete("a { color: red; }");
  EXPECT_TRUE(document().isRenderingReady());

  // Finish the load, painting should stay enabled.
  mainResource.finish();
  EXPECT_TRUE(document().isRenderingReady());
}

}  // namespace blink