// Copyright 2018 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 "third_party/blink/renderer/core/paint/text_paint_timing_detector.h"
#include "third_party/blink/renderer/core/paint/paint_timing_detector.h"
#include "third_party/blink/renderer/core/testing/core_unit_test_helper.h"
#include "third_party/blink/renderer/platform/runtime_enabled_features.h"
#include "third_party/blink/renderer/platform/testing/runtime_enabled_features_test_helpers.h"

namespace blink {

class TextPaintTimingDetectorTest
    : public RenderingTest,
      private ScopedFirstContentfulPaintPlusPlusForTest {
 public:
  TextPaintTimingDetectorTest()
      : ScopedFirstContentfulPaintPlusPlusForTest(true) {}
  void SetUp() override { RenderingTest::SetUp(); }

 protected:
  LocalFrameView& GetFrameView() { return *GetFrame().View(); }
  PaintTimingDetector& GetPaintTimingDetector() {
    return GetFrameView().GetPaintTimingDetector();
  }

  TimeTicks LargestPaintStoredResult() {
    return GetPaintTimingDetector()
        .GetTextPaintTimingDetector()
        .largest_text_paint_;
  }

  TimeTicks LastPaintStoredResult() {
    return GetPaintTimingDetector()
        .GetTextPaintTimingDetector()
        .last_text_paint_;
  }

  void UpdateAllLifecyclePhasesAndSimulateSwapTime() {
    GetFrameView().UpdateAllLifecyclePhases(
        DocumentLifecycle::LifecycleUpdateReason::kTest);
    TextPaintTimingDetector& detector =
        GetPaintTimingDetector().GetTextPaintTimingDetector();
    if (detector.texts_to_record_swap_time_.size() > 0) {
      detector.ReportSwapTime(WebLayerTreeView::SwapResult::kDidSwap,
                              CurrentTimeTicks());
    }
  }

  void SimulateAnalyze() {
    GetPaintTimingDetector().GetTextPaintTimingDetector().Analyze();
  }
};

TEST_F(TextPaintTimingDetectorTest, LargestTextPaint_NoText) {
  SetBodyInnerHTML(R"HTML(
    <div></div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLargestPaintCandidate();
  EXPECT_FALSE(record);
}

TEST_F(TextPaintTimingDetectorTest, LargestTextPaint_OneText) {
  SetBodyInnerHTML(R"HTML(
    <div>The only text</div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLargestPaintCandidate();
  EXPECT_TRUE(record);
  EXPECT_EQ(record->text, "The only text");
}

TEST_F(TextPaintTimingDetectorTest, LargestTextPaint_LargestText) {
  SetBodyInnerHTML(R"HTML(
    <div>medium text</div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  Text* larger_text = GetDocument().createTextNode("a long-long-long text");
  GetDocument().body()->AppendChild(larger_text);
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  Text* tiny_text = GetDocument().createTextNode("small");
  GetDocument().body()->AppendChild(tiny_text);
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLargestPaintCandidate();
  EXPECT_EQ(record->text, "a long-long-long text");
}

TEST_F(TextPaintTimingDetectorTest, UpdateResultWhenCandidateChanged) {
  TimeTicks time1 = CurrentTimeTicks();
  SetBodyInnerHTML(R"HTML(
    <div>small text</div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  SimulateAnalyze();
  TimeTicks time2 = CurrentTimeTicks();
  TimeTicks first_largest = LargestPaintStoredResult();
  TimeTicks first_last = LastPaintStoredResult();
  EXPECT_GE(first_largest, time1);
  EXPECT_GE(time2, first_largest);
  EXPECT_GE(first_last, time1);
  EXPECT_GE(time2, first_last);

  Text* larger_text = GetDocument().createTextNode("a long-long-long text");
  GetDocument().body()->AppendChild(larger_text);
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  SimulateAnalyze();
  TimeTicks time3 = CurrentTimeTicks();
  TimeTicks second_largest = LargestPaintStoredResult();
  TimeTicks second_last = LastPaintStoredResult();
  EXPECT_GE(second_largest, time2);
  EXPECT_GE(time3, second_largest);
  EXPECT_GE(second_last, time2);
  EXPECT_GE(time3, second_last);
}

TEST_F(TextPaintTimingDetectorTest, LargestTextPaint_ReportFirstPaintTime) {
  TimeTicks time1 = CurrentTimeTicks();
  SetBodyInnerHTML(R"HTML(
    <div>
      <div id='b'>size-changing block</div>
      <div>a long-long-long-long moving text</div>
    </div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  TimeTicks time2 = CurrentTimeTicks();
  GetDocument().getElementById("b")->setAttribute(html_names::kStyleAttr,
                                                  AtomicString("height:50px"));
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  GetDocument().getElementById("b")->setAttribute(html_names::kStyleAttr,
                                                  AtomicString("height:100px"));
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLargestPaintCandidate();
  EXPECT_EQ(record->text, "a long-long-long-long moving text");
  TimeTicks firing_time = record->first_paint_time;
  EXPECT_GE(firing_time, time1);
  EXPECT_GE(time2, firing_time);
}

TEST_F(TextPaintTimingDetectorTest,
       LargestTextPaint_IgnoreTextOutsideViewport) {
  SetBodyInnerHTML(R"HTML(
    <style>
      div.out {
        position: fixed;
        top: -100px;
      }
    </style>
    <div class='out'>text outside of viewport</div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  EXPECT_FALSE(GetPaintTimingDetector()
                   .GetTextPaintTimingDetector()
                   .FindLargestPaintCandidate());
  EXPECT_FALSE(GetPaintTimingDetector()
                   .GetTextPaintTimingDetector()
                   .FindLastPaintCandidate());
}

TEST_F(TextPaintTimingDetectorTest, LargestTextPaint_IgnoreRemovedText) {
  SetBodyInnerHTML(R"HTML(
    <div id='parent'>
      <div id='earlyLargeText'>(large text)(large text)(large text)(large text)(large text)(large text)</div>
      <div>small text</div>
    </div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLargestPaintCandidate();
  EXPECT_TRUE(record);
  EXPECT_EQ(record->text,
            "(large text)(large text)(large text)(large text)(large "
            "text)(large text)");

  GetDocument().getElementById("parent")->RemoveChild(
      GetDocument().getElementById("earlyLargeText"));
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  record = GetPaintTimingDetector()
               .GetTextPaintTimingDetector()
               .FindLargestPaintCandidate();
  EXPECT_EQ(record->text, "small text");
}

TEST_F(TextPaintTimingDetectorTest, LargestTextPaint_ReportLastNullCandidate) {
  SetBodyInnerHTML(R"HTML(
    <div id='parent'>
      <div id='remove'>text</div>
    </div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  SimulateAnalyze();
  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLargestPaintCandidate();
  EXPECT_TRUE(record);
  EXPECT_EQ(record->text, "text");
  EXPECT_NE(LargestPaintStoredResult(), base::TimeTicks());

  GetDocument().getElementById("parent")->RemoveChild(
      GetDocument().getElementById("remove"));
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  SimulateAnalyze();
  record = GetPaintTimingDetector()
               .GetTextPaintTimingDetector()
               .FindLargestPaintCandidate();
  EXPECT_FALSE(record);
  EXPECT_EQ(LargestPaintStoredResult(), base::TimeTicks());
}

TEST_F(TextPaintTimingDetectorTest,
       LargestTextPaint_CompareVisualSizeNotActualSize) {
  SetBodyInnerHTML(R"HTML(
    <div>
      <div>short</div>
      <div style="position:fixed;left:-10px">a long text</div>
    </div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLargestPaintCandidate();
  EXPECT_EQ(record->text, "short");
}

TEST_F(TextPaintTimingDetectorTest, LargestTextPaint_CompareSizesAtFirstPaint) {
  SetBodyInnerHTML(R"HTML(
    <div>
      <div id="shorteningText">large-to-small text</div>
      <div>a medium text</div>
    </div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  // The visual size becomes smaller when less portion intersecting with
  // viewport.
  GetDocument()
      .getElementById("shorteningText")
      ->setAttribute(html_names::kStyleAttr,
                     AtomicString("position:fixed;left:-10px"));
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLargestPaintCandidate();
  EXPECT_EQ(record->text, "large-to-small text");
}

TEST_F(TextPaintTimingDetectorTest, LastTextPaint_NoText) {
  SetBodyInnerHTML(R"HTML(
    <div></div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLastPaintCandidate();
  EXPECT_FALSE(record);
}

TEST_F(TextPaintTimingDetectorTest, LastTextPaint_OneText) {
  SetBodyInnerHTML(R"HTML(
    <div>The only text</div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLastPaintCandidate();
  EXPECT_EQ(record->text, "The only text");
}

TEST_F(TextPaintTimingDetectorTest, LastTextPaint_LastText) {
  SetBodyInnerHTML(R"HTML(
    <div>1st text</div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  Text* larger_text = GetDocument().createTextNode("2nd text");
  GetDocument().body()->AppendChild(larger_text);
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  Text* tiny_text = GetDocument().createTextNode("3rd text");
  GetDocument().body()->AppendChild(tiny_text);
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLastPaintCandidate();
  EXPECT_EQ(record->text, "3rd text");
}

TEST_F(TextPaintTimingDetectorTest, LastTextPaint_ReportFirstPaintTime) {
  SetBodyInnerHTML(R"HTML(
    <div>
      <div id='b'>size-changing block</div>
    </div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  TimeTicks time1 = CurrentTimeTicks();
  Text* tiny_text = GetDocument().createTextNode("latest text");
  GetDocument().body()->AppendChild(tiny_text);
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  TimeTicks time2 = CurrentTimeTicks();
  GetDocument().getElementById("b")->setAttribute(html_names::kStyleAttr,
                                                  AtomicString("height:50px"));
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  GetDocument().getElementById("b")->setAttribute(html_names::kStyleAttr,
                                                  AtomicString("height:100px"));
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLastPaintCandidate();
  EXPECT_EQ(record->text, "latest text");
  TimeTicks firing_time = record->first_paint_time;
  EXPECT_GE(firing_time, time1);
  EXPECT_GE(time2, firing_time);
}

TEST_F(TextPaintTimingDetectorTest, LastTextPaint_IgnoreRemovedText) {
  SetBodyInnerHTML(R"HTML(
    <body>
      <div>earliest text</div>
    </body>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  Text* tiny_text = GetDocument().createTextNode("latest text");
  GetDocument().body()->AppendChild(tiny_text);
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  GetDocument().body()->RemoveChild(GetDocument().body()->lastChild());
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLastPaintCandidate();
  EXPECT_EQ(record->text, "earliest text");
}

TEST_F(TextPaintTimingDetectorTest, LastTextPaint_StopRecordingOverNodeLimit) {
  SetBodyInnerHTML(R"HTML(
    <body>
    </body>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  for (int i = 1; i <= 4999; i++) {
    Element* div = GetDocument().CreateRawElement(html_names::kDivTag);
    div->appendChild(GetDocument().createTextNode(WTF::String::Number(i)));
    div->setAttribute(html_names::kStyleAttr,
                      AtomicString("position:fixed;left:0px"));
    GetDocument().body()->AppendChild(div);
  }
  UpdateAllLifecyclePhasesAndSimulateSwapTime();

  TextRecord* record;
  Text* text;

  text = GetDocument().createTextNode(WTF::String::Number(5000));
  GetDocument().body()->AppendChild(text);
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  record = GetPaintTimingDetector()
               .GetTextPaintTimingDetector()
               .FindLastPaintCandidate();
  EXPECT_EQ(record->text, "5000");

  text = GetDocument().createTextNode(WTF::String::Number(5001));
  GetDocument().body()->AppendChild(text);
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  record = GetPaintTimingDetector()
               .GetTextPaintTimingDetector()
               .FindLastPaintCandidate();
  EXPECT_EQ(record->text, "5000");
}

TEST_F(TextPaintTimingDetectorTest, LastTextPaint_ReportLastNullCandidate) {
  SetBodyInnerHTML(R"HTML(
    <div id='parent'>
      <div id='remove'>text</div>
    </div>
  )HTML");
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  SimulateAnalyze();
  TextRecord* record = GetPaintTimingDetector()
                           .GetTextPaintTimingDetector()
                           .FindLargestPaintCandidate();
  EXPECT_TRUE(record);
  EXPECT_EQ(record->text, "text");
  EXPECT_NE(LastPaintStoredResult(), base::TimeTicks());

  GetDocument().getElementById("parent")->RemoveChild(
      GetDocument().getElementById("remove"));
  UpdateAllLifecyclePhasesAndSimulateSwapTime();
  SimulateAnalyze();
  record = GetPaintTimingDetector()
               .GetTextPaintTimingDetector()
               .FindLargestPaintCandidate();
  EXPECT_FALSE(record);
  EXPECT_EQ(LastPaintStoredResult(), base::TimeTicks());
}

}  // namespace blink