// Copyright 2013 The Flutter 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 "flutter/flow/layers/opacity_layer.h"

#include "flutter/flow/testing/layer_test.h"
#include "flutter/flow/testing/mock_layer.h"
#include "flutter/fml/macros.h"
#include "flutter/testing/mock_canvas.h"

namespace flutter {
namespace testing {

using OpacityLayerTest = LayerTest;

#ifndef NDEBUG
TEST_F(OpacityLayerTest, LeafLayer) {
  auto layer =
      std::make_shared<OpacityLayer>(SK_AlphaOPAQUE, SkPoint::Make(0.0f, 0.0f));

  EXPECT_DEATH_IF_SUPPORTED(layer->Preroll(preroll_context(), SkMatrix()),
                            "\\!container->layers\\(\\)\\.empty\\(\\)");
}

TEST_F(OpacityLayerTest, PaintingEmptyLayerDies) {
  auto mock_layer = std::make_shared<MockLayer>(SkPath());
  auto layer =
      std::make_shared<OpacityLayer>(SK_AlphaOPAQUE, SkPoint::Make(0.0f, 0.0f));
  layer->Add(mock_layer);

  layer->Preroll(preroll_context(), SkMatrix());
  EXPECT_EQ(mock_layer->paint_bounds(), SkPath().getBounds());
  EXPECT_EQ(layer->paint_bounds(), mock_layer->paint_bounds());
  EXPECT_FALSE(mock_layer->needs_painting());
  EXPECT_FALSE(layer->needs_painting());

  EXPECT_DEATH_IF_SUPPORTED(layer->Paint(paint_context()),
                            "needs_painting\\(\\)");
}

TEST_F(OpacityLayerTest, PaintBeforePreollDies) {
  SkPath child_path;
  child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
  auto mock_layer = std::make_shared<MockLayer>(child_path);
  auto layer =
      std::make_shared<OpacityLayer>(SK_AlphaOPAQUE, SkPoint::Make(0.0f, 0.0f));
  layer->Add(mock_layer);

  EXPECT_DEATH_IF_SUPPORTED(layer->Paint(paint_context()),
                            "needs_painting\\(\\)");
}
#endif

TEST_F(OpacityLayerTest, FullyOpaque) {
  const SkPath child_path = SkPath().addRect(SkRect::MakeWH(5.0f, 5.0f));
  const SkPoint layer_offset = SkPoint::Make(0.5f, 1.5f);
  const SkMatrix initial_transform = SkMatrix::MakeTrans(0.5f, 0.5f);
  const SkMatrix layer_transform =
      SkMatrix::MakeTrans(layer_offset.fX, layer_offset.fY);
#ifndef SUPPORT_FRACTIONAL_TRANSLATION
  const SkMatrix integral_layer_transform = RasterCache::GetIntegralTransCTM(
      SkMatrix::Concat(initial_transform, layer_transform));
#endif
  const SkPaint child_paint = SkPaint(SkColors::kGreen);
  const SkRect expected_layer_bounds =
      layer_transform.mapRect(child_path.getBounds());
  auto mock_layer = std::make_shared<MockLayer>(child_path, child_paint);
  auto layer = std::make_shared<OpacityLayer>(SK_AlphaOPAQUE, layer_offset);
  layer->Add(mock_layer);

  layer->Preroll(preroll_context(), initial_transform);
  EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
  EXPECT_EQ(layer->paint_bounds(), expected_layer_bounds);
  EXPECT_TRUE(mock_layer->needs_painting());
  EXPECT_TRUE(layer->needs_painting());
  EXPECT_EQ(mock_layer->parent_matrix(),
            SkMatrix::Concat(initial_transform, layer_transform));
  EXPECT_EQ(mock_layer->parent_mutators(),
            std::vector({Mutator(layer_transform), Mutator(SK_AlphaOPAQUE)}));

  const SkPaint opacity_paint = SkPaint(SkColors::kBlack);  // A = 1.0f
  SkRect opacity_bounds;
  expected_layer_bounds.makeOffset(-layer_offset.fX, -layer_offset.fY)
      .roundOut(&opacity_bounds);
  auto expected_draw_calls = std::vector(
      {MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
       MockCanvas::DrawCall{1, MockCanvas::ConcatMatrixData{layer_transform}},
#ifndef SUPPORT_FRACTIONAL_TRANSLATION
       MockCanvas::DrawCall{
           1, MockCanvas::SetMatrixData{integral_layer_transform}},
#endif
       MockCanvas::DrawCall{
           1, MockCanvas::SaveLayerData{opacity_bounds, opacity_paint, nullptr,
                                        2}},
       MockCanvas::DrawCall{2,
                            MockCanvas::DrawPathData{child_path, child_paint}},
       MockCanvas::DrawCall{2, MockCanvas::RestoreData{1}},
       MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}}});
  layer->Paint(paint_context());
  EXPECT_EQ(mock_canvas().draw_calls(), expected_draw_calls);
}

TEST_F(OpacityLayerTest, FullyTransparent) {
  const SkPath child_path = SkPath().addRect(SkRect::MakeWH(5.0f, 5.0f));
  const SkPoint layer_offset = SkPoint::Make(0.5f, 1.5f);
  const SkMatrix initial_transform = SkMatrix::MakeTrans(0.5f, 0.5f);
  const SkMatrix layer_transform =
      SkMatrix::MakeTrans(layer_offset.fX, layer_offset.fY);
#ifndef SUPPORT_FRACTIONAL_TRANSLATION
  const SkMatrix integral_layer_transform = RasterCache::GetIntegralTransCTM(
      SkMatrix::Concat(initial_transform, layer_transform));
#endif
  const SkPaint child_paint = SkPaint(SkColors::kGreen);
  const SkRect expected_layer_bounds =
      layer_transform.mapRect(child_path.getBounds());
  auto mock_layer = std::make_shared<MockLayer>(child_path, child_paint);
  auto layer =
      std::make_shared<OpacityLayer>(SK_AlphaTRANSPARENT, layer_offset);
  layer->Add(mock_layer);

  layer->Preroll(preroll_context(), initial_transform);
  EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
  EXPECT_EQ(layer->paint_bounds(), expected_layer_bounds);
  EXPECT_TRUE(mock_layer->needs_painting());
  EXPECT_TRUE(layer->needs_painting());
  EXPECT_EQ(mock_layer->parent_matrix(),
            SkMatrix::Concat(initial_transform, layer_transform));
  EXPECT_EQ(
      mock_layer->parent_mutators(),
      std::vector({Mutator(layer_transform), Mutator(SK_AlphaTRANSPARENT)}));

  auto expected_draw_calls = std::vector(
      {MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
       MockCanvas::DrawCall{1, MockCanvas::ConcatMatrixData{layer_transform}},
#ifndef SUPPORT_FRACTIONAL_TRANSLATION
       MockCanvas::DrawCall{
           1, MockCanvas::SetMatrixData{integral_layer_transform}},
#endif
       MockCanvas::DrawCall{1, MockCanvas::SaveData{2}},
       MockCanvas::DrawCall{
           2, MockCanvas::ClipRectData{kEmptyRect, SkClipOp::kIntersect,
                                       MockCanvas::kHard_ClipEdgeStyle}},
       MockCanvas::DrawCall{2,
                            MockCanvas::DrawPathData{child_path, child_paint}},
       MockCanvas::DrawCall{2, MockCanvas::RestoreData{1}},
       MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}}});
  layer->Paint(paint_context());
  EXPECT_EQ(mock_canvas().draw_calls(), expected_draw_calls);
}

TEST_F(OpacityLayerTest, HalfTransparent) {
  const SkPath child_path = SkPath().addRect(SkRect::MakeWH(5.0f, 5.0f));
  const SkPoint layer_offset = SkPoint::Make(0.5f, 1.5f);
  const SkMatrix initial_transform = SkMatrix::MakeTrans(0.5f, 0.5f);
  const SkMatrix layer_transform =
      SkMatrix::MakeTrans(layer_offset.fX, layer_offset.fY);
#ifndef SUPPORT_FRACTIONAL_TRANSLATION
  const SkMatrix integral_layer_transform = RasterCache::GetIntegralTransCTM(
      SkMatrix::Concat(initial_transform, layer_transform));
#endif
  const SkPaint child_paint = SkPaint(SkColors::kGreen);
  const SkRect expected_layer_bounds =
      layer_transform.mapRect(child_path.getBounds());
  const SkAlpha alpha_half = 255 / 2;
  auto mock_layer = std::make_shared<MockLayer>(child_path, child_paint);
  auto layer = std::make_shared<OpacityLayer>(alpha_half, layer_offset);
  layer->Add(mock_layer);

  layer->Preroll(preroll_context(), initial_transform);
  EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
  EXPECT_EQ(layer->paint_bounds(), expected_layer_bounds);
  EXPECT_TRUE(mock_layer->needs_painting());
  EXPECT_TRUE(layer->needs_painting());
  EXPECT_EQ(mock_layer->parent_matrix(),
            SkMatrix::Concat(initial_transform, layer_transform));
  EXPECT_EQ(mock_layer->parent_mutators(),
            std::vector({Mutator(layer_transform), Mutator(alpha_half)}));

  const SkPaint opacity_paint =
      SkPaint(SkColor4f::FromColor(SkColorSetA(SK_ColorBLACK, alpha_half)));
  SkRect opacity_bounds;
  expected_layer_bounds.makeOffset(-layer_offset.fX, -layer_offset.fY)
      .roundOut(&opacity_bounds);
  auto expected_draw_calls = std::vector(
      {MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
       MockCanvas::DrawCall{1, MockCanvas::ConcatMatrixData{layer_transform}},
#ifndef SUPPORT_FRACTIONAL_TRANSLATION
       MockCanvas::DrawCall{
           1, MockCanvas::SetMatrixData{integral_layer_transform}},
#endif
       MockCanvas::DrawCall{
           1, MockCanvas::SaveLayerData{opacity_bounds, opacity_paint, nullptr,
                                        2}},
       MockCanvas::DrawCall{2,
                            MockCanvas::DrawPathData{child_path, child_paint}},
       MockCanvas::DrawCall{2, MockCanvas::RestoreData{1}},
       MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}}});
  layer->Paint(paint_context());
  EXPECT_EQ(mock_canvas().draw_calls(), expected_draw_calls);
}

TEST_F(OpacityLayerTest, Nested) {
  const SkPath child1_path = SkPath().addRect(SkRect::MakeWH(5.0f, 6.0f));
  const SkPath child2_path = SkPath().addRect(SkRect::MakeWH(2.0f, 7.0f));
  const SkPath child3_path = SkPath().addRect(SkRect::MakeWH(6.0f, 6.0f));
  const SkPoint layer1_offset = SkPoint::Make(0.5f, 1.5f);
  const SkPoint layer2_offset = SkPoint::Make(2.5f, 0.5f);
  const SkMatrix initial_transform = SkMatrix::MakeTrans(0.5f, 0.5f);
  const SkMatrix layer1_transform =
      SkMatrix::MakeTrans(layer1_offset.fX, layer1_offset.fY);
  const SkMatrix layer2_transform =
      SkMatrix::MakeTrans(layer2_offset.fX, layer2_offset.fY);
#ifndef SUPPORT_FRACTIONAL_TRANSLATION
  const SkMatrix integral_layer1_transform = RasterCache::GetIntegralTransCTM(
      SkMatrix::Concat(initial_transform, layer1_transform));
  const SkMatrix integral_layer2_transform = RasterCache::GetIntegralTransCTM(
      SkMatrix::Concat(SkMatrix::Concat(initial_transform, layer1_transform),
                       layer2_transform));
#endif
  const SkPaint child1_paint = SkPaint(SkColors::kRed);
  const SkPaint child2_paint = SkPaint(SkColors::kBlue);
  const SkPaint child3_paint = SkPaint(SkColors::kGreen);
  const SkAlpha alpha1 = 155;
  const SkAlpha alpha2 = 224;
  auto mock_layer1 = std::make_shared<MockLayer>(child1_path, child1_paint);
  auto mock_layer2 = std::make_shared<MockLayer>(child2_path, child2_paint);
  auto mock_layer3 = std::make_shared<MockLayer>(child3_path, child3_paint);
  auto layer1 = std::make_shared<OpacityLayer>(alpha1, layer1_offset);
  auto layer2 = std::make_shared<OpacityLayer>(alpha2, layer2_offset);
  layer2->Add(mock_layer2);
  layer1->Add(mock_layer1);
  layer1->Add(layer2);
  layer1->Add(mock_layer3);  // Ensure something is processed after recursion

  const SkRect expected_layer2_bounds =
      layer2_transform.mapRect(child2_path.getBounds());
  SkRect expected_layer1_bounds = expected_layer2_bounds;
  expected_layer1_bounds.join(child1_path.getBounds());
  expected_layer1_bounds.join(child3_path.getBounds());
  expected_layer1_bounds = layer1_transform.mapRect(expected_layer1_bounds);
  layer1->Preroll(preroll_context(), initial_transform);
  EXPECT_EQ(mock_layer1->paint_bounds(), child1_path.getBounds());
  EXPECT_EQ(mock_layer2->paint_bounds(), child2_path.getBounds());
  EXPECT_EQ(mock_layer3->paint_bounds(), child3_path.getBounds());
  EXPECT_EQ(layer1->paint_bounds(), expected_layer1_bounds);
  EXPECT_EQ(layer2->paint_bounds(), expected_layer2_bounds);
  EXPECT_TRUE(mock_layer1->needs_painting());
  EXPECT_TRUE(mock_layer2->needs_painting());
  EXPECT_TRUE(mock_layer3->needs_painting());
  EXPECT_TRUE(layer1->needs_painting());
  EXPECT_TRUE(layer2->needs_painting());
  EXPECT_EQ(mock_layer1->parent_matrix(),
            SkMatrix::Concat(initial_transform, layer1_transform));
  //   EXPECT_EQ(mock_layer1->parent_mutators(),
  //             std::vector({Mutator(layer1_transform), Mutator(alpha1)}));
  EXPECT_EQ(
      mock_layer2->parent_matrix(),
      SkMatrix::Concat(SkMatrix::Concat(initial_transform, layer1_transform),
                       layer2_transform));
  //   EXPECT_EQ(mock_layer2->parent_mutators(),
  //             std::vector({Mutator(layer1_transform), Mutator(alpha1),
  //                          Mutator(layer2_transform), Mutator(alpha2)}));
  EXPECT_EQ(mock_layer3->parent_matrix(),
            SkMatrix::Concat(initial_transform, layer1_transform));
  //   EXPECT_EQ(mock_layer3->parent_mutators(),
  //             std::vector({Mutator(layer1_transform), Mutator(alpha1)}));

  const SkPaint opacity1_paint =
      SkPaint(SkColor4f::FromColor(SkColorSetA(SK_ColorBLACK, alpha1)));
  const SkPaint opacity2_paint =
      SkPaint(SkColor4f::FromColor(SkColorSetA(SK_ColorBLACK, alpha2)));
  SkRect opacity1_bounds, opacity2_bounds;
  expected_layer1_bounds.makeOffset(-layer1_offset.fX, -layer1_offset.fY)
      .roundOut(&opacity1_bounds);
  expected_layer2_bounds.makeOffset(-layer2_offset.fX, -layer2_offset.fY)
      .roundOut(&opacity2_bounds);
  auto expected_draw_calls = std::vector(
      {MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
       MockCanvas::DrawCall{1, MockCanvas::ConcatMatrixData{layer1_transform}},
#ifndef SUPPORT_FRACTIONAL_TRANSLATION
       MockCanvas::DrawCall{
           1, MockCanvas::SetMatrixData{integral_layer1_transform}},
#endif
       MockCanvas::DrawCall{
           1, MockCanvas::SaveLayerData{opacity1_bounds, opacity1_paint,
                                        nullptr, 2}},
       MockCanvas::DrawCall{
           2, MockCanvas::DrawPathData{child1_path, child1_paint}},
       MockCanvas::DrawCall{2, MockCanvas::SaveData{3}},
       MockCanvas::DrawCall{3, MockCanvas::ConcatMatrixData{layer2_transform}},
#ifndef SUPPORT_FRACTIONAL_TRANSLATION
       MockCanvas::DrawCall{
           3, MockCanvas::SetMatrixData{integral_layer2_transform}},
#endif
       MockCanvas::DrawCall{
           3, MockCanvas::SaveLayerData{opacity2_bounds, opacity2_paint,
                                        nullptr, 4}},
       MockCanvas::DrawCall{
           4, MockCanvas::DrawPathData{child2_path, child2_paint}},
       MockCanvas::DrawCall{4, MockCanvas::RestoreData{3}},
       MockCanvas::DrawCall{3, MockCanvas::RestoreData{2}},
       MockCanvas::DrawCall{
           2, MockCanvas::DrawPathData{child3_path, child3_paint}},
       MockCanvas::DrawCall{2, MockCanvas::RestoreData{1}},
       MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}}});
  layer1->Paint(paint_context());
  EXPECT_EQ(mock_canvas().draw_calls(), expected_draw_calls);
}

TEST_F(OpacityLayerTest, Readback) {
  auto initial_transform = SkMatrix();
  auto layer = std::make_shared<OpacityLayer>(kOpaque_SkAlphaType, SkPoint());
  layer->Add(std::make_shared<MockLayer>(SkPath()));

  // OpacityLayer does not read from surface
  preroll_context()->surface_needs_readback = false;
  layer->Preroll(preroll_context(), initial_transform);
  EXPECT_FALSE(preroll_context()->surface_needs_readback);

  // OpacityLayer blocks child with readback
  auto mock_layer =
      std::make_shared<MockLayer>(SkPath(), SkPaint(), false, false, true);
  layer->Add(mock_layer);
  preroll_context()->surface_needs_readback = false;
  layer->Preroll(preroll_context(), initial_transform);
  EXPECT_FALSE(preroll_context()->surface_needs_readback);
}

}  // namespace testing
}  // namespace flutter