// Copyright 2013 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 "cc/test/test_web_graphics_context_3d.h"

#include <algorithm>
#include <string>

#include "base/bind.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/message_loop/message_loop.h"
#include "cc/test/test_context_support.h"
#include "gpu/GLES2/gl2extchromium.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/khronos/GLES2/gl2ext.h"

namespace cc {

static const GLuint kFramebufferId = 1;
static const GLuint kRenderbufferId = 2;

static unsigned s_context_id = 1;

const GLuint TestWebGraphicsContext3D::kExternalTextureId = 1337;

static base::LazyInstance<base::Lock>::Leaky
    g_shared_namespace_lock = LAZY_INSTANCE_INITIALIZER;

TestWebGraphicsContext3D::Namespace*
    TestWebGraphicsContext3D::shared_namespace_ = NULL;

TestWebGraphicsContext3D::Namespace::Namespace()
    : next_buffer_id(1),
      next_image_id(1),
      next_texture_id(1) {
}

TestWebGraphicsContext3D::Namespace::~Namespace() {
  g_shared_namespace_lock.Get().AssertAcquired();
  if (shared_namespace_ == this)
    shared_namespace_ = NULL;
}

// static
scoped_ptr<TestWebGraphicsContext3D> TestWebGraphicsContext3D::Create() {
  return make_scoped_ptr(new TestWebGraphicsContext3D());
}

TestWebGraphicsContext3D::TestWebGraphicsContext3D()
    : context_id_(s_context_id++),
      times_bind_texture_succeeds_(-1),
      times_end_query_succeeds_(-1),
      context_lost_(false),
      times_map_image_chromium_succeeds_(-1),
      times_map_buffer_chromium_succeeds_(-1),
      current_used_transfer_buffer_usage_bytes_(0),
      max_used_transfer_buffer_usage_bytes_(0),
      next_program_id_(1000),
      next_shader_id_(2000),
      max_texture_size_(2048),
      reshape_called_(false),
      width_(0),
      height_(0),
      scale_factor_(-1.f),
      test_support_(NULL),
      last_update_type_(NoUpdate),
      next_insert_sync_point_(1),
      last_waited_sync_point_(0),
      bound_buffer_(0),
      weak_ptr_factory_(this) {
  CreateNamespace();
}

TestWebGraphicsContext3D::~TestWebGraphicsContext3D() {
  base::AutoLock lock(g_shared_namespace_lock.Get());
  namespace_ = NULL;
}

void TestWebGraphicsContext3D::CreateNamespace() {
  base::AutoLock lock(g_shared_namespace_lock.Get());
  if (shared_namespace_) {
    namespace_ = shared_namespace_;
  } else {
    namespace_ = new Namespace;
    shared_namespace_ = namespace_.get();
  }
}

void TestWebGraphicsContext3D::reshapeWithScaleFactor(
    int width, int height, float scale_factor) {
  reshape_called_ = true;
  width_ = width;
  height_ = height;
  scale_factor_ = scale_factor;
}

bool TestWebGraphicsContext3D::isContextLost() {
  return context_lost_;
}

GLenum TestWebGraphicsContext3D::checkFramebufferStatus(
    GLenum target) {
  if (context_lost_)
    return GL_FRAMEBUFFER_UNDEFINED_OES;
  return GL_FRAMEBUFFER_COMPLETE;
}

GLint TestWebGraphicsContext3D::getUniformLocation(
    GLuint program,
    const GLchar* name) {
  return 0;
}

GLsizeiptr TestWebGraphicsContext3D::getVertexAttribOffset(
    GLuint index,
    GLenum pname) {
  return 0;
}

GLboolean TestWebGraphicsContext3D::isBuffer(
    GLuint buffer) {
  return false;
}

GLboolean TestWebGraphicsContext3D::isEnabled(
    GLenum cap) {
  return false;
}

GLboolean TestWebGraphicsContext3D::isFramebuffer(
    GLuint framebuffer) {
  return false;
}

GLboolean TestWebGraphicsContext3D::isProgram(
    GLuint program) {
  return false;
}

GLboolean TestWebGraphicsContext3D::isRenderbuffer(
    GLuint renderbuffer) {
  return false;
}

GLboolean TestWebGraphicsContext3D::isShader(
    GLuint shader) {
  return false;
}

GLboolean TestWebGraphicsContext3D::isTexture(
    GLuint texture) {
  return false;
}

void TestWebGraphicsContext3D::genBuffers(GLsizei count, GLuint* ids) {
  for (int i = 0; i < count; ++i)
    ids[i] = NextBufferId();
}

void TestWebGraphicsContext3D::genFramebuffers(
    GLsizei count, GLuint* ids) {
  for (int i = 0; i < count; ++i)
    ids[i] = kFramebufferId | context_id_ << 16;
}

void TestWebGraphicsContext3D::genRenderbuffers(
    GLsizei count, GLuint* ids) {
  for (int i = 0; i < count; ++i)
    ids[i] = kRenderbufferId | context_id_ << 16;
}

void TestWebGraphicsContext3D::genTextures(GLsizei count, GLuint* ids) {
  for (int i = 0; i < count; ++i) {
    ids[i] = NextTextureId();
    DCHECK_NE(ids[i], kExternalTextureId);
  }
  base::AutoLock lock(namespace_->lock);
  for (int i = 0; i < count; ++i)
    namespace_->textures.Append(ids[i], new TestTexture());
}

void TestWebGraphicsContext3D::deleteBuffers(GLsizei count, GLuint* ids) {
  for (int i = 0; i < count; ++i)
    RetireBufferId(ids[i]);
}

void TestWebGraphicsContext3D::deleteFramebuffers(
    GLsizei count, GLuint* ids) {
  for (int i = 0; i < count; ++i)
    DCHECK_EQ(kFramebufferId | context_id_ << 16, ids[i]);
}

void TestWebGraphicsContext3D::deleteRenderbuffers(
    GLsizei count, GLuint* ids) {
  for (int i = 0; i < count; ++i)
    DCHECK_EQ(kRenderbufferId | context_id_ << 16, ids[i]);
}

void TestWebGraphicsContext3D::deleteTextures(GLsizei count, GLuint* ids) {
  for (int i = 0; i < count; ++i)
    RetireTextureId(ids[i]);
  base::AutoLock lock(namespace_->lock);
  for (int i = 0; i < count; ++i) {
    namespace_->textures.Remove(ids[i]);
    texture_targets_.UnbindTexture(ids[i]);
  }
}

GLuint TestWebGraphicsContext3D::createBuffer() {
  GLuint id;
  genBuffers(1, &id);
  return id;
}

GLuint TestWebGraphicsContext3D::createFramebuffer() {
  GLuint id;
  genFramebuffers(1, &id);
  return id;
}

GLuint TestWebGraphicsContext3D::createRenderbuffer() {
  GLuint id;
  genRenderbuffers(1, &id);
  return id;
}

GLuint TestWebGraphicsContext3D::createTexture() {
  GLuint id;
  genTextures(1, &id);
  return id;
}

void TestWebGraphicsContext3D::deleteBuffer(GLuint id) {
  deleteBuffers(1, &id);
}

void TestWebGraphicsContext3D::deleteFramebuffer(GLuint id) {
  deleteFramebuffers(1, &id);
}

void TestWebGraphicsContext3D::deleteRenderbuffer(GLuint id) {
  deleteRenderbuffers(1, &id);
}

void TestWebGraphicsContext3D::deleteTexture(GLuint id) {
  deleteTextures(1, &id);
}

unsigned TestWebGraphicsContext3D::createProgram() {
  unsigned program = next_program_id_++ | context_id_ << 16;
  program_set_.insert(program);
  return program;
}

GLuint TestWebGraphicsContext3D::createShader(GLenum) {
  unsigned shader = next_shader_id_++ | context_id_ << 16;
  shader_set_.insert(shader);
  return shader;
}

GLuint TestWebGraphicsContext3D::createExternalTexture() {
  base::AutoLock lock(namespace_->lock);
  namespace_->textures.Append(kExternalTextureId, new TestTexture());
  return kExternalTextureId;
}

void TestWebGraphicsContext3D::deleteProgram(GLuint id) {
  if (!program_set_.count(id))
    ADD_FAILURE() << "deleteProgram called on unknown program " << id;
  program_set_.erase(id);
}

void TestWebGraphicsContext3D::deleteShader(GLuint id) {
  if (!shader_set_.count(id))
    ADD_FAILURE() << "deleteShader called on unknown shader " << id;
  shader_set_.erase(id);
}

void TestWebGraphicsContext3D::attachShader(GLuint program, GLuint shader) {
  if (!program_set_.count(program))
    ADD_FAILURE() << "attachShader called with unknown program " << program;
  if (!shader_set_.count(shader))
    ADD_FAILURE() << "attachShader called with unknown shader " << shader;
}

void TestWebGraphicsContext3D::useProgram(GLuint program) {
  if (!program)
    return;
  if (!program_set_.count(program))
    ADD_FAILURE() << "useProgram called on unknown program " << program;
}

void TestWebGraphicsContext3D::bindFramebuffer(
    GLenum target, GLuint framebuffer) {
  if (!framebuffer)
    return;
  DCHECK_EQ(kFramebufferId | context_id_ << 16, framebuffer);
}

void TestWebGraphicsContext3D::bindRenderbuffer(
      GLenum target, GLuint renderbuffer) {
  if (!renderbuffer)
    return;
  DCHECK_EQ(kRenderbufferId | context_id_ << 16, renderbuffer);
}

void TestWebGraphicsContext3D::bindTexture(
    GLenum target, GLuint texture_id) {
  if (times_bind_texture_succeeds_ >= 0) {
    if (!times_bind_texture_succeeds_) {
      loseContextCHROMIUM(GL_GUILTY_CONTEXT_RESET_ARB,
                          GL_INNOCENT_CONTEXT_RESET_ARB);
    }
    --times_bind_texture_succeeds_;
  }

  if (!texture_id)
    return;
  base::AutoLock lock(namespace_->lock);
  DCHECK(namespace_->textures.ContainsId(texture_id));
  texture_targets_.BindTexture(target, texture_id);
  used_textures_.insert(texture_id);
}

GLuint TestWebGraphicsContext3D::BoundTextureId(
    GLenum target) {
  return texture_targets_.BoundTexture(target);
}

scoped_refptr<TestTexture> TestWebGraphicsContext3D::BoundTexture(
    GLenum target) {
  // The caller is expected to lock the namespace for texture access.
  namespace_->lock.AssertAcquired();
  return namespace_->textures.TextureForId(BoundTextureId(target));
}

void TestWebGraphicsContext3D::CheckTextureIsBound(GLenum target) {
  DCHECK(BoundTextureId(target));
}

GLuint TestWebGraphicsContext3D::createQueryEXT() { return 1u; }

void TestWebGraphicsContext3D::endQueryEXT(GLenum target) {
  if (times_end_query_succeeds_ >= 0) {
    if (!times_end_query_succeeds_) {
      loseContextCHROMIUM(GL_GUILTY_CONTEXT_RESET_ARB,
                          GL_INNOCENT_CONTEXT_RESET_ARB);
    }
    --times_end_query_succeeds_;
  }
}

void TestWebGraphicsContext3D::getQueryObjectuivEXT(
    GLuint query,
    GLenum pname,
    GLuint* params) {
  // If the context is lost, behave as if result is available.
  if (pname == GL_QUERY_RESULT_AVAILABLE_EXT)
    *params = 1;
}

void TestWebGraphicsContext3D::getIntegerv(
    GLenum pname,
    GLint* value) {
  if (pname == GL_MAX_TEXTURE_SIZE)
    *value = max_texture_size_;
  else if (pname == GL_ACTIVE_TEXTURE)
    *value = GL_TEXTURE0;
}

void TestWebGraphicsContext3D::getProgramiv(GLuint program,
                                            GLenum pname,
                                            GLint* value) {
  if (pname == GL_LINK_STATUS)
    *value = 1;
}

void TestWebGraphicsContext3D::getShaderiv(GLuint shader,
                                           GLenum pname,
                                           GLint* value) {
  if (pname == GL_COMPILE_STATUS)
    *value = 1;
}

void TestWebGraphicsContext3D::getShaderPrecisionFormat(GLenum shadertype,
                                                        GLenum precisiontype,
                                                        GLint* range,
                                                        GLint* precision) {
  // Return the minimum precision requirements of the GLES2
  // specification.
  switch (precisiontype) {
    case GL_LOW_INT:
      range[0] = 8;
      range[1] = 8;
      *precision = 0;
      break;
    case GL_MEDIUM_INT:
      range[0] = 10;
      range[1] = 10;
      *precision = 0;
      break;
    case GL_HIGH_INT:
      range[0] = 16;
      range[1] = 16;
      *precision = 0;
      break;
    case GL_LOW_FLOAT:
      range[0] = 8;
      range[1] = 8;
      *precision = 8;
      break;
    case GL_MEDIUM_FLOAT:
      range[0] = 14;
      range[1] = 14;
      *precision = 10;
      break;
    case GL_HIGH_FLOAT:
      range[0] = 62;
      range[1] = 62;
      *precision = 16;
      break;
    default:
      NOTREACHED();
      break;
  }
}

void TestWebGraphicsContext3D::genMailboxCHROMIUM(GLbyte* mailbox) {
  static char mailbox_name1 = '1';
  static char mailbox_name2 = '1';
  mailbox[0] = mailbox_name1;
  mailbox[1] = mailbox_name2;
  mailbox[2] = '\0';
  if (++mailbox_name1 == 0) {
    mailbox_name1 = '1';
    ++mailbox_name2;
  }
}

GLuint TestWebGraphicsContext3D::createAndConsumeTextureCHROMIUM(
    GLenum target,
    const GLbyte* mailbox) {
  return createTexture();
}

void TestWebGraphicsContext3D::loseContextCHROMIUM(GLenum current,
                                                   GLenum other) {
  if (context_lost_)
    return;
  context_lost_ = true;
  if (!context_lost_callback_.is_null())
    context_lost_callback_.Run();

  for (size_t i = 0; i < shared_contexts_.size(); ++i)
    shared_contexts_[i]->loseContextCHROMIUM(current, other);
  shared_contexts_.clear();
}

void TestWebGraphicsContext3D::finish() {
  test_support_->CallAllSyncPointCallbacks();
}

void TestWebGraphicsContext3D::flush() {
  test_support_->CallAllSyncPointCallbacks();
}

GLint TestWebGraphicsContext3D::getAttribLocation(GLuint program,
                                                  const GLchar* name) {
  return 0;
}

GLenum TestWebGraphicsContext3D::getError() { return GL_NO_ERROR; }

void TestWebGraphicsContext3D::bindBuffer(GLenum target,
                                          GLuint buffer) {
  bound_buffer_ = buffer;
  if (!bound_buffer_)
    return;
  unsigned context_id = buffer >> 16;
  unsigned buffer_id = buffer & 0xffff;
  base::AutoLock lock(namespace_->lock);
  DCHECK(buffer_id);
  DCHECK_LT(buffer_id, namespace_->next_buffer_id);
  DCHECK_EQ(context_id, context_id_);

  base::ScopedPtrHashMap<unsigned, Buffer>& buffers = namespace_->buffers;
  if (buffers.count(bound_buffer_) == 0)
    buffers.set(bound_buffer_, make_scoped_ptr(new Buffer).Pass());

  buffers.get(bound_buffer_)->target = target;
}

void TestWebGraphicsContext3D::bufferData(GLenum target,
                                          GLsizeiptr size,
                                          const void* data,
                                          GLenum usage) {
  base::AutoLock lock(namespace_->lock);
  base::ScopedPtrHashMap<unsigned, Buffer>& buffers = namespace_->buffers;
  DCHECK_GT(buffers.count(bound_buffer_), 0u);
  DCHECK_EQ(target, buffers.get(bound_buffer_)->target);
  Buffer* buffer = buffers.get(bound_buffer_);
  if (context_lost_) {
    buffer->pixels.reset();
    return;
  }

  size_t old_size = buffer->size;

  buffer->pixels.reset(new uint8[size]);
  buffer->size = size;
  if (data != NULL)
    memcpy(buffer->pixels.get(), data, size);
  if (buffer->target == GL_PIXEL_UNPACK_TRANSFER_BUFFER_CHROMIUM)
    current_used_transfer_buffer_usage_bytes_ += buffer->size - old_size;
  max_used_transfer_buffer_usage_bytes_ =
      std::max(max_used_transfer_buffer_usage_bytes_,
               current_used_transfer_buffer_usage_bytes_);
}

void* TestWebGraphicsContext3D::mapBufferCHROMIUM(GLenum target,
                                                  GLenum access) {
  base::AutoLock lock(namespace_->lock);
  base::ScopedPtrHashMap<unsigned, Buffer>& buffers = namespace_->buffers;
  DCHECK_GT(buffers.count(bound_buffer_), 0u);
  DCHECK_EQ(target, buffers.get(bound_buffer_)->target);
  if (times_map_buffer_chromium_succeeds_ >= 0) {
    if (!times_map_buffer_chromium_succeeds_) {
      return NULL;
    }
    --times_map_buffer_chromium_succeeds_;
  }

  return buffers.get(bound_buffer_)->pixels.get();
}

GLboolean TestWebGraphicsContext3D::unmapBufferCHROMIUM(
    GLenum target) {
  base::AutoLock lock(namespace_->lock);
  base::ScopedPtrHashMap<unsigned, Buffer>& buffers = namespace_->buffers;
  DCHECK_GT(buffers.count(bound_buffer_), 0u);
  DCHECK_EQ(target, buffers.get(bound_buffer_)->target);
  buffers.get(bound_buffer_)->pixels.reset();
  return true;
}

GLuint TestWebGraphicsContext3D::createImageCHROMIUM(GLsizei width,
                                                     GLsizei height,
                                                     GLenum internalformat,
                                                     GLenum usage) {
  DCHECK_EQ(GL_RGBA8_OES, static_cast<int>(internalformat));
  GLuint image_id = NextImageId();
  base::AutoLock lock(namespace_->lock);
  base::ScopedPtrHashMap<unsigned, Image>& images = namespace_->images;
  images.set(image_id, make_scoped_ptr(new Image).Pass());
  images.get(image_id)->pixels.reset(new uint8[width * height * 4]);
  return image_id;
}

void TestWebGraphicsContext3D::destroyImageCHROMIUM(
    GLuint id) {
  RetireImageId(id);
}

void TestWebGraphicsContext3D::getImageParameterivCHROMIUM(
    GLuint image_id,
    GLenum pname,
    GLint* params) {
  base::AutoLock lock(namespace_->lock);
  DCHECK_GT(namespace_->images.count(image_id), 0u);
  DCHECK_EQ(GL_IMAGE_ROWBYTES_CHROMIUM, static_cast<int>(pname));
  *params = 0;
}

void* TestWebGraphicsContext3D::mapImageCHROMIUM(GLuint image_id) {
  base::AutoLock lock(namespace_->lock);
  base::ScopedPtrHashMap<unsigned, Image>& images = namespace_->images;
  DCHECK_GT(images.count(image_id), 0u);
  if (times_map_image_chromium_succeeds_ >= 0) {
    if (!times_map_image_chromium_succeeds_) {
      return NULL;
    }
    --times_map_image_chromium_succeeds_;
  }
  return images.get(image_id)->pixels.get();
}

void TestWebGraphicsContext3D::unmapImageCHROMIUM(
    GLuint image_id) {
  base::AutoLock lock(namespace_->lock);
  DCHECK_GT(namespace_->images.count(image_id), 0u);
}

unsigned TestWebGraphicsContext3D::insertSyncPoint() {
  return next_insert_sync_point_++;
}

void TestWebGraphicsContext3D::waitSyncPoint(unsigned sync_point) {
  if (sync_point)
    last_waited_sync_point_ = sync_point;
}

size_t TestWebGraphicsContext3D::NumTextures() const {
  base::AutoLock lock(namespace_->lock);
  return namespace_->textures.Size();
}

GLuint TestWebGraphicsContext3D::TextureAt(int i) const {
  base::AutoLock lock(namespace_->lock);
  return namespace_->textures.IdAt(i);
}

GLuint TestWebGraphicsContext3D::NextTextureId() {
  base::AutoLock lock(namespace_->lock);
  GLuint texture_id = namespace_->next_texture_id++;
  DCHECK(texture_id < (1 << 16));
  texture_id |= context_id_ << 16;
  return texture_id;
}

void TestWebGraphicsContext3D::RetireTextureId(GLuint id) {
  base::AutoLock lock(namespace_->lock);
  unsigned context_id = id >> 16;
  unsigned texture_id = id & 0xffff;
  DCHECK(texture_id);
  DCHECK_LT(texture_id, namespace_->next_texture_id);
  DCHECK_EQ(context_id, context_id_);
}

GLuint TestWebGraphicsContext3D::NextBufferId() {
  base::AutoLock lock(namespace_->lock);
  GLuint buffer_id = namespace_->next_buffer_id++;
  DCHECK(buffer_id < (1 << 16));
  buffer_id |= context_id_ << 16;
  return buffer_id;
}

void TestWebGraphicsContext3D::RetireBufferId(GLuint id) {
  base::AutoLock lock(namespace_->lock);
  unsigned context_id = id >> 16;
  unsigned buffer_id = id & 0xffff;
  DCHECK(buffer_id);
  DCHECK_LT(buffer_id, namespace_->next_buffer_id);
  DCHECK_EQ(context_id, context_id_);
}

GLuint TestWebGraphicsContext3D::NextImageId() {
  base::AutoLock lock(namespace_->lock);
  GLuint image_id = namespace_->next_image_id++;
  DCHECK(image_id < (1 << 16));
  image_id |= context_id_ << 16;
  return image_id;
}

void TestWebGraphicsContext3D::RetireImageId(GLuint id) {
  base::AutoLock lock(namespace_->lock);
  unsigned context_id = id >> 16;
  unsigned image_id = id & 0xffff;
  DCHECK(image_id);
  DCHECK_LT(image_id, namespace_->next_image_id);
  DCHECK_EQ(context_id, context_id_);
}

void TestWebGraphicsContext3D::SetMaxTransferBufferUsageBytes(
    size_t max_transfer_buffer_usage_bytes) {
  test_capabilities_.max_transfer_buffer_usage_bytes =
      max_transfer_buffer_usage_bytes;
}

TestWebGraphicsContext3D::TextureTargets::TextureTargets() {
  // Initialize default bindings.
  bound_textures_[GL_TEXTURE_2D] = 0;
  bound_textures_[GL_TEXTURE_EXTERNAL_OES] = 0;
  bound_textures_[GL_TEXTURE_RECTANGLE_ARB] = 0;
}

TestWebGraphicsContext3D::TextureTargets::~TextureTargets() {}

void TestWebGraphicsContext3D::TextureTargets::BindTexture(
    GLenum target,
    GLuint id) {
  // Make sure this is a supported target by seeing if it was bound to before.
  DCHECK(bound_textures_.find(target) != bound_textures_.end());
  bound_textures_[target] = id;
}

void TestWebGraphicsContext3D::texParameteri(GLenum target,
                                             GLenum pname,
                                             GLint param) {
  CheckTextureIsBound(target);
  base::AutoLock lock_for_texture_access(namespace_->lock);
  scoped_refptr<TestTexture> texture = BoundTexture(target);
  DCHECK(texture->IsValidParameter(pname));
  texture->params[pname] = param;
}

void TestWebGraphicsContext3D::getTexParameteriv(GLenum target,
                                                 GLenum pname,
                                                 GLint* value) {
  CheckTextureIsBound(target);
  base::AutoLock lock_for_texture_access(namespace_->lock);
  scoped_refptr<TestTexture> texture = BoundTexture(target);
  DCHECK(texture->IsValidParameter(pname));
  TestTexture::TextureParametersMap::iterator it = texture->params.find(pname);
  if (it != texture->params.end())
    *value = it->second;
}

void TestWebGraphicsContext3D::TextureTargets::UnbindTexture(
    GLuint id) {
  // Bind zero to any targets that the id is bound to.
  for (TargetTextureMap::iterator it = bound_textures_.begin();
       it != bound_textures_.end();
       it++) {
    if (it->second == id)
      it->second = 0;
  }
}

GLuint TestWebGraphicsContext3D::TextureTargets::BoundTexture(
    GLenum target) {
  DCHECK(bound_textures_.find(target) != bound_textures_.end());
  return bound_textures_[target];
}

TestWebGraphicsContext3D::Buffer::Buffer() : target(0), size(0) {}

TestWebGraphicsContext3D::Buffer::~Buffer() {}

TestWebGraphicsContext3D::Image::Image() {}

TestWebGraphicsContext3D::Image::~Image() {}

}  // namespace cc