// 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/transform_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 TransformLayerTest = LayerTest;

#ifndef NDEBUG
TEST_F(TransformLayerTest, PaintingEmptyLayerDies) {
  auto layer = std::make_shared<TransformLayer>(SkMatrix());  // identity

  layer->Preroll(preroll_context(), SkMatrix());
  EXPECT_EQ(layer->paint_bounds(), SkRect::MakeEmpty());
  EXPECT_FALSE(layer->needs_painting());

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

TEST_F(TransformLayerTest, PaintBeforePreollDies) {
  SkPath child_path;
  child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
  auto mock_layer = std::make_shared<MockLayer>(child_path, SkPaint());
  auto layer = std::make_shared<TransformLayer>(SkMatrix());  // identity
  layer->Add(mock_layer);

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

TEST_F(TransformLayerTest, Identity) {
  SkPath child_path;
  child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
  SkRect cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
  auto mock_layer = std::make_shared<MockLayer>(child_path, SkPaint());
  auto layer = std::make_shared<TransformLayer>(SkMatrix());  // identity
  layer->Add(mock_layer);

  preroll_context()->cull_rect = cull_rect;
  layer->Preroll(preroll_context(), SkMatrix());
  EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
  EXPECT_EQ(layer->paint_bounds(), mock_layer->paint_bounds());
  EXPECT_TRUE(mock_layer->needs_painting());
  EXPECT_TRUE(layer->needs_painting());
  EXPECT_EQ(mock_layer->parent_matrix(), SkMatrix());  // identity
  EXPECT_EQ(mock_layer->parent_cull_rect(), cull_rect);
  EXPECT_EQ(mock_layer->parent_mutators(), std::vector({Mutator(SkMatrix())}));

  layer->Paint(paint_context());
  EXPECT_EQ(mock_canvas().draw_calls(),
            std::vector({MockCanvas::DrawCall{
                0, MockCanvas::DrawPathData{child_path, SkPaint()}}}));
}

TEST_F(TransformLayerTest, Simple) {
  SkPath child_path;
  child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
  SkRect cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
  SkMatrix initial_transform = SkMatrix::MakeTrans(-0.5f, -0.5f);
  SkMatrix layer_transform = SkMatrix::MakeTrans(2.5f, 2.5f);
  SkMatrix inverse_layer_transform;
  EXPECT_TRUE(layer_transform.invert(&inverse_layer_transform));

  auto mock_layer = std::make_shared<MockLayer>(child_path, SkPaint());
  auto layer = std::make_shared<TransformLayer>(layer_transform);
  layer->Add(mock_layer);

  preroll_context()->cull_rect = cull_rect;
  layer->Preroll(preroll_context(), initial_transform);
  EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
  EXPECT_EQ(layer->paint_bounds(),
            layer_transform.mapRect(mock_layer->paint_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_cull_rect(),
            inverse_layer_transform.mapRect(cull_rect));
  EXPECT_EQ(mock_layer->parent_mutators(),
            std::vector({Mutator(layer_transform)}));

  layer->Paint(paint_context());
  EXPECT_EQ(
      mock_canvas().draw_calls(),
      std::vector({MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
                   MockCanvas::DrawCall{
                       1, MockCanvas::ConcatMatrixData{layer_transform}},
                   MockCanvas::DrawCall{
                       1, MockCanvas::DrawPathData{child_path, SkPaint()}},
                   MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}}}));
}

TEST_F(TransformLayerTest, Nested) {
  SkPath child_path;
  child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
  SkRect cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
  SkMatrix initial_transform = SkMatrix::MakeTrans(-0.5f, -0.5f);
  SkMatrix layer1_transform = SkMatrix::MakeTrans(2.5f, 2.5f);
  SkMatrix layer2_transform = SkMatrix::MakeTrans(2.5f, 2.5f);
  SkMatrix inverse_layer1_transform, inverse_layer2_transform;
  EXPECT_TRUE(layer1_transform.invert(&inverse_layer1_transform));
  EXPECT_TRUE(layer2_transform.invert(&inverse_layer2_transform));

  auto mock_layer = std::make_shared<MockLayer>(child_path, SkPaint());
  auto layer1 = std::make_shared<TransformLayer>(layer1_transform);
  auto layer2 = std::make_shared<TransformLayer>(layer2_transform);
  layer1->Add(layer2);
  layer2->Add(mock_layer);

  preroll_context()->cull_rect = cull_rect;
  layer1->Preroll(preroll_context(), initial_transform);
  EXPECT_EQ(mock_layer->paint_bounds(), child_path.getBounds());
  EXPECT_EQ(layer2->paint_bounds(),
            layer2_transform.mapRect(mock_layer->paint_bounds()));
  EXPECT_EQ(layer1->paint_bounds(),
            layer1_transform.mapRect(layer2->paint_bounds()));
  EXPECT_TRUE(mock_layer->needs_painting());
  EXPECT_TRUE(layer2->needs_painting());
  EXPECT_TRUE(layer1->needs_painting());
  EXPECT_EQ(
      mock_layer->parent_matrix(),
      SkMatrix::Concat(SkMatrix::Concat(initial_transform, layer1_transform),
                       layer2_transform));
  EXPECT_EQ(mock_layer->parent_cull_rect(),
            inverse_layer2_transform.mapRect(
                inverse_layer1_transform.mapRect(cull_rect)));
  EXPECT_EQ(
      mock_layer->parent_mutators(),
      std::vector({Mutator(layer2_transform), Mutator(layer1_transform)}));

  layer1->Paint(paint_context());
  EXPECT_EQ(
      mock_canvas().draw_calls(),
      std::vector({MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
                   MockCanvas::DrawCall{
                       1, MockCanvas::ConcatMatrixData{layer1_transform}},
                   MockCanvas::DrawCall{1, MockCanvas::SaveData{2}},
                   MockCanvas::DrawCall{
                       2, MockCanvas::ConcatMatrixData{layer2_transform}},
                   MockCanvas::DrawCall{
                       2, MockCanvas::DrawPathData{child_path, SkPaint()}},
                   MockCanvas::DrawCall{2, MockCanvas::RestoreData{1}},
                   MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}}}));
}

TEST_F(TransformLayerTest, NestedSeparated) {
  SkPath child_path;
  child_path.addRect(5.0f, 6.0f, 20.5f, 21.5f);
  SkRect cull_rect = SkRect::MakeXYWH(2.0f, 2.0f, 14.0f, 14.0f);
  SkMatrix initial_transform = SkMatrix::MakeTrans(-0.5f, -0.5f);
  SkMatrix layer1_transform = SkMatrix::MakeTrans(2.5f, 2.5f);
  SkMatrix layer2_transform = SkMatrix::MakeTrans(2.5f, 2.5f);
  SkMatrix inverse_layer1_transform, inverse_layer2_transform;
  EXPECT_TRUE(layer1_transform.invert(&inverse_layer1_transform));
  EXPECT_TRUE(layer2_transform.invert(&inverse_layer2_transform));

  auto mock_layer1 =
      std::make_shared<MockLayer>(child_path, SkPaint(SkColors::kBlue));
  auto mock_layer2 =
      std::make_shared<MockLayer>(child_path, SkPaint(SkColors::kGreen));
  auto layer1 = std::make_shared<TransformLayer>(layer1_transform);
  auto layer2 = std::make_shared<TransformLayer>(layer2_transform);
  layer1->Add(mock_layer1);
  layer1->Add(layer2);
  layer2->Add(mock_layer2);

  preroll_context()->cull_rect = cull_rect;
  layer1->Preroll(preroll_context(), initial_transform);
  SkRect expected_layer1_bounds = layer2->paint_bounds();
  expected_layer1_bounds.join(mock_layer1->paint_bounds());
  layer1_transform.mapRect(&expected_layer1_bounds);
  EXPECT_EQ(mock_layer2->paint_bounds(), child_path.getBounds());
  EXPECT_EQ(layer2->paint_bounds(),
            layer2_transform.mapRect(mock_layer2->paint_bounds()));
  EXPECT_EQ(mock_layer1->paint_bounds(), child_path.getBounds());
  EXPECT_EQ(layer1->paint_bounds(), expected_layer1_bounds);
  EXPECT_TRUE(mock_layer2->needs_painting());
  EXPECT_TRUE(layer2->needs_painting());
  EXPECT_TRUE(mock_layer1->needs_painting());
  EXPECT_TRUE(layer1->needs_painting());
  EXPECT_EQ(mock_layer1->parent_matrix(),
            SkMatrix::Concat(initial_transform, layer1_transform));
  EXPECT_EQ(
      mock_layer2->parent_matrix(),
      SkMatrix::Concat(SkMatrix::Concat(initial_transform, layer1_transform),
                       layer2_transform));
  EXPECT_EQ(mock_layer1->parent_cull_rect(),
            inverse_layer1_transform.mapRect(cull_rect));
  EXPECT_EQ(mock_layer2->parent_cull_rect(),
            inverse_layer2_transform.mapRect(
                inverse_layer1_transform.mapRect(cull_rect)));
  EXPECT_EQ(mock_layer1->parent_mutators(),
            std::vector({Mutator(layer1_transform)}));
  EXPECT_EQ(
      mock_layer2->parent_mutators(),
      std::vector({Mutator(layer2_transform), Mutator(layer1_transform)}));

  layer1->Paint(paint_context());
  EXPECT_EQ(
      mock_canvas().draw_calls(),
      std::vector({MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
                   MockCanvas::DrawCall{
                       1, MockCanvas::ConcatMatrixData{layer1_transform}},
                   MockCanvas::DrawCall{
                       1, MockCanvas::DrawPathData{child_path,
                                                   SkPaint(SkColors::kBlue)}},
                   MockCanvas::DrawCall{1, MockCanvas::SaveData{2}},
                   MockCanvas::DrawCall{
                       2, MockCanvas::ConcatMatrixData{layer2_transform}},
                   MockCanvas::DrawCall{
                       2, MockCanvas::DrawPathData{child_path,
                                                   SkPaint(SkColors::kGreen)}},
                   MockCanvas::DrawCall{2, MockCanvas::RestoreData{1}},
                   MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}}}));
}

}  // namespace testing
}  // namespace flutter