// 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/shell/platform/linux/public/flutter_linux/fl_texture_registrar.h"
#include "flutter/shell/platform/linux/fl_texture_registrar_private.h"
#include "flutter/shell/platform/linux/public/flutter_linux/fl_pixel_buffer_texture.h"
#include "flutter/shell/platform/linux/public/flutter_linux/fl_texture_gl.h"
#include "flutter/shell/platform/linux/testing/fl_test.h"
#include "flutter/shell/platform/linux/testing/mock_texture_registrar.h"
#include "gtest/gtest.h"

#include <epoxy/gl.h>

#include <gmodule.h>
#include <pthread.h>

static constexpr uint32_t kBufferWidth = 4u;
static constexpr uint32_t kBufferHeight = 4u;
static constexpr uint32_t kRealBufferWidth = 2u;
static constexpr uint32_t kRealBufferHeight = 2u;
static constexpr uint64_t kThreadCount = 16u;

G_DECLARE_FINAL_TYPE(FlTestRegistrarTexture,
                     fl_test_registrar_texture,
                     FL,
                     TEST_REGISTRAR_TEXTURE,
                     FlTextureGL)

/// A simple texture.
struct _FlTestRegistrarTexture {
  FlTextureGL parent_instance;
};

G_DEFINE_TYPE(FlTestRegistrarTexture,
              fl_test_registrar_texture,
              fl_texture_gl_get_type())

static gboolean fl_test_registrar_texture_populate(FlTextureGL* texture,
                                                   uint32_t* target,
                                                   uint32_t* format,
                                                   uint32_t* width,
                                                   uint32_t* height,
                                                   GError** error) {
  EXPECT_TRUE(FL_IS_TEST_REGISTRAR_TEXTURE(texture));

  EXPECT_EQ(*width, kBufferWidth);
  EXPECT_EQ(*height, kBufferHeight);
  *target = GL_TEXTURE_2D;
  *format = GL_R8;
  *width = kRealBufferWidth;
  *height = kRealBufferHeight;

  return TRUE;
}

static void fl_test_registrar_texture_class_init(
    FlTestRegistrarTextureClass* klass) {
  FL_TEXTURE_GL_CLASS(klass)->populate = fl_test_registrar_texture_populate;
}

static void fl_test_registrar_texture_init(FlTestRegistrarTexture* self) {}

static FlTestRegistrarTexture* fl_test_registrar_texture_new() {
  return FL_TEST_REGISTRAR_TEXTURE(
      g_object_new(fl_test_registrar_texture_get_type(), nullptr));
}

static void* add_mock_texture_to_registrar(void* pointer) {
  g_return_val_if_fail(FL_TEXTURE_REGISTRAR(pointer), ((void*)NULL));
  FlTextureRegistrar* registrar = FL_TEXTURE_REGISTRAR(pointer);
  g_autoptr(FlTexture) texture = FL_TEXTURE(fl_test_registrar_texture_new());
  fl_texture_registrar_register_texture(registrar, texture);
  int64_t* id = static_cast<int64_t*>(malloc(sizeof(int64_t)));
  id[0] = fl_texture_get_id(texture);
  pthread_exit(id);
}

// Checks can make a mock registrar.
TEST(FlTextureRegistrarTest, MockRegistrar) {
  g_autoptr(FlTexture) texture = FL_TEXTURE(fl_test_registrar_texture_new());
  g_autoptr(FlMockTextureRegistrar) registrar = fl_mock_texture_registrar_new();
  EXPECT_TRUE(FL_IS_MOCK_TEXTURE_REGISTRAR(registrar));

  EXPECT_TRUE(fl_texture_registrar_register_texture(
      FL_TEXTURE_REGISTRAR(registrar), texture));
  EXPECT_EQ(fl_mock_texture_registrar_get_texture(registrar), texture);
  EXPECT_TRUE(fl_texture_registrar_mark_texture_frame_available(
      FL_TEXTURE_REGISTRAR(registrar), texture));
  EXPECT_TRUE(fl_mock_texture_registrar_get_frame_available(registrar));
  EXPECT_TRUE(fl_texture_registrar_unregister_texture(
      FL_TEXTURE_REGISTRAR(registrar), texture));
  EXPECT_EQ(fl_mock_texture_registrar_get_texture(registrar), nullptr);
}

// Test that registering a texture works.
TEST(FlTextureRegistrarTest, RegisterTexture) {
  g_autoptr(FlEngine) engine = make_mock_engine();
  g_autoptr(FlTextureRegistrar) registrar = fl_texture_registrar_new(engine);
  g_autoptr(FlTexture) texture = FL_TEXTURE(fl_test_registrar_texture_new());

  EXPECT_FALSE(fl_texture_registrar_unregister_texture(registrar, texture));
  EXPECT_TRUE(fl_texture_registrar_register_texture(registrar, texture));
  EXPECT_TRUE(fl_texture_registrar_unregister_texture(registrar, texture));
}

// Test that marking a texture frame available works.
TEST(FlTextureRegistrarTest, MarkTextureFrameAvailable) {
  g_autoptr(FlEngine) engine = make_mock_engine();
  g_autoptr(FlTextureRegistrar) registrar = fl_texture_registrar_new(engine);
  g_autoptr(FlTexture) texture = FL_TEXTURE(fl_test_registrar_texture_new());

  EXPECT_FALSE(
      fl_texture_registrar_mark_texture_frame_available(registrar, texture));
  EXPECT_TRUE(fl_texture_registrar_register_texture(registrar, texture));
  EXPECT_TRUE(
      fl_texture_registrar_mark_texture_frame_available(registrar, texture));
}

// Test the textures can be accessed via multiple threads without
// synchronization issues.
TEST(FlTextureRegistrarTest, RegistrarRegisterTextureInMultipleThreads) {
  g_autoptr(FlEngine) engine = make_mock_engine();
  g_autoptr(FlTextureRegistrar) registrar = fl_texture_registrar_new(engine);
  pthread_t threads[kThreadCount];
  int64_t ids[kThreadCount];

  for (uint64_t t = 0; t < kThreadCount; t++) {
    EXPECT_EQ(pthread_create(&threads[t], NULL, add_mock_texture_to_registrar,
                             (void*)registrar),
              0);
  }
  for (uint64_t t = 0; t < kThreadCount; t++) {
    void* id;
    pthread_join(threads[t], &id);
    ids[t] = static_cast<int64_t*>(id)[0];
    free(id);
  };
  // Check all the textures were created.
  for (uint64_t t = 0; t < kThreadCount; t++) {
    EXPECT_TRUE(fl_texture_registrar_lookup_texture(registrar, ids[t]) != NULL);
  };
}