// Copyright 2023 The Chromium Authors
// 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/platform/fonts/shaping/ng_shape_cache.h"

#include "base/test/task_environment.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/blink/renderer/platform/fonts/font.h"
#include "third_party/blink/renderer/platform/fonts/font_performance.h"
#include "third_party/blink/renderer/platform/testing/font_test_base.h"
#include "third_party/blink/renderer/platform/testing/font_test_helpers.h"
#include "third_party/blink/renderer/platform/text/text_direction.h"

namespace blink {

class NGShapeCacheTest : public FontTestBase {
 protected:
  void SetUp() override {
    Font* font = test::CreateAhemFont(100);
    cache = MakeGarbageCollected<NGShapeCache>(font->PrimaryFont());
  }
  Persistent<NGShapeCache> cache;
};

TEST_F(NGShapeCacheTest, AddEntriesAndCacheHits) {
  auto ShapeResultFunc = []() -> ShaperResult {
    // For the purposes of this test the actual internals of the shape result
    // doesn't matter.
    return {MakeGarbageCollected<ShapeResult>(0, 0, TextDirection::kLtr),
            /*can_cache=*/true};
  };

  auto CreateKey = [](const String& text,
                      TextDirection direction) -> ShapeCacheKey {
    return ShapeCacheKey(text, 0, text.length(), g_null_atom, {}, direction);
  };

  // Adding an entry is successful.
  const auto* entry_A_LTR =
      cache->GetOrCreate(CreateKey("A", TextDirection::kLtr), ShapeResultFunc);
  ASSERT_TRUE(entry_A_LTR);

  // Adding the same entry again hits cache.
  EXPECT_EQ(
      cache->GetOrCreate(CreateKey("A", TextDirection::kLtr), ShapeResultFunc),
      entry_A_LTR);

  // Adding the an entry with different text does not hit cache.
  const auto* entry_B_LTR =
      cache->GetOrCreate(CreateKey("B", TextDirection::kLtr), ShapeResultFunc);
  ASSERT_TRUE(entry_B_LTR);
  EXPECT_NE(entry_B_LTR, entry_A_LTR);

  // Adding the same entry again hits cache.
  EXPECT_EQ(
      cache->GetOrCreate(CreateKey("B", TextDirection::kLtr), ShapeResultFunc),
      entry_B_LTR);

  // Adding the an entry with different direction does not hit cache.
  const auto* entry_A_RTL =
      cache->GetOrCreate(CreateKey("A", TextDirection::kRtl), ShapeResultFunc);
  ASSERT_TRUE(entry_A_RTL);
  EXPECT_NE(entry_A_RTL, entry_A_LTR);
  EXPECT_NE(entry_A_RTL, entry_B_LTR);

  // Adding the same entry again hits cache.
  EXPECT_EQ(
      cache->GetOrCreate(CreateKey("A", TextDirection::kRtl), ShapeResultFunc),
      entry_A_RTL);
}

TEST_F(NGShapeCacheTest, FontPerformanceMetrics) {
  FontPerformance::Reset();

  auto ShapeResultFunc = []() -> ShaperResult {
    return {MakeGarbageCollected<ShapeResult>(0, 0, TextDirection::kLtr),
            /*can_cache=*/true};
  };

  auto CreateKey = [](const String& text) -> ShapeCacheKey {
    return ShapeCacheKey(text, 0, text.length(), g_null_atom, {},
                         TextDirection::kLtr);
  };

  // First access: Miss
  cache->GetOrCreate(CreateKey("A"), ShapeResultFunc);
  EXPECT_EQ(FontPerformance::ShapeCacheHitCount(), 0u);
  EXPECT_EQ(FontPerformance::ShapeCacheMissCount(), 1u);

  // Second access: Hit
  cache->GetOrCreate(CreateKey("A"), ShapeResultFunc);
  EXPECT_EQ(FontPerformance::ShapeCacheHitCount(), 1u);
  EXPECT_EQ(FontPerformance::ShapeCacheMissCount(), 1u);

  // Access with different key: Miss
  cache->GetOrCreate(CreateKey("B"), ShapeResultFunc);
  EXPECT_EQ(FontPerformance::ShapeCacheHitCount(), 1u);
  EXPECT_EQ(FontPerformance::ShapeCacheMissCount(), 2u);
}

}  // namespace blink