// Copyright (c) 2012 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 "gpu/blink/webgraphicscontext3d_impl.h"

#include <stdint.h>

#include "base/atomicops.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/sys_info.h"
#include "gpu/GLES2/gl2extchromium.h"
#include "gpu/command_buffer/client/gles2_implementation.h"
#include "gpu/command_buffer/client/gles2_lib.h"
#include "gpu/command_buffer/common/gles2_cmd_utils.h"
#include "gpu/command_buffer/common/sync_token.h"

#include "third_party/khronos/GLES2/gl2.h"
#ifndef GL_GLEXT_PROTOTYPES
#define GL_GLEXT_PROTOTYPES 1
#endif
#include "third_party/khronos/GLES2/gl2ext.h"

using blink::WGC3Dbitfield;
using blink::WGC3Dboolean;
using blink::WGC3Dbyte;
using blink::WGC3Dchar;
using blink::WGC3Dclampf;
using blink::WGC3Denum;
using blink::WGC3Dfloat;
using blink::WGC3Dint;
using blink::WGC3Dintptr;
using blink::WGC3Dsizei;
using blink::WGC3Dsizeiptr;
using blink::WGC3Dint64;
using blink::WGC3Duint64;
using blink::WGC3Duint;
using blink::WebGLId;

namespace gpu_blink {

class WebGraphicsContext3DErrorMessageCallback
    : public ::gpu::gles2::GLES2ImplementationErrorMessageCallback {
 public:
  WebGraphicsContext3DErrorMessageCallback(
      WebGraphicsContext3DImpl* context)
      : graphics_context_(context) {
  }

  void OnErrorMessage(const char* msg, int id) override;

 private:
  WebGraphicsContext3DImpl* graphics_context_;

  DISALLOW_COPY_AND_ASSIGN(WebGraphicsContext3DErrorMessageCallback);
};

void WebGraphicsContext3DErrorMessageCallback::OnErrorMessage(
    const char* msg, int id) {
  graphics_context_->OnErrorMessage(msg, id);
}

WebGraphicsContext3DImpl::WebGraphicsContext3DImpl()
    : initialized_(false),
      initialize_failed_(false),
      context_lost_callback_(0),
      error_message_callback_(0),
      gl_(NULL) {}

WebGraphicsContext3DImpl::~WebGraphicsContext3DImpl() {

}

blink::WebString WebGraphicsContext3DImpl::
    getRequestableExtensionsCHROMIUM() {
  return blink::WebString::fromUTF8(
      gl_->GetRequestableExtensionsCHROMIUM());
}

bool WebGraphicsContext3DImpl::getActiveAttrib(
    WebGLId program, WGC3Duint index, ActiveInfo& info) {
  GLint max_name_length = -1;
  gl_->GetProgramiv(
      program, GL_ACTIVE_ATTRIBUTE_MAX_LENGTH, &max_name_length);
  // The caller already checked that there is some active attribute.
  DCHECK_GT(max_name_length, 0);
  scoped_ptr<GLchar[]> name(new GLchar[max_name_length]);
  GLsizei length = 0;
  GLint size = -1;
  GLenum type = 0;
  gl_->GetActiveAttrib(
      program, index, max_name_length, &length, &size, &type, name.get());
  if (size < 0) {
    return false;
  }
  info.name = blink::WebString::fromUTF8(name.get(), length);
  info.type = type;
  info.size = size;
  return true;
}

bool WebGraphicsContext3DImpl::getActiveUniform(
    WebGLId program, WGC3Duint index, ActiveInfo& info) {
  GLint max_name_length = -1;
  gl_->GetProgramiv(
      program, GL_ACTIVE_UNIFORM_MAX_LENGTH, &max_name_length);
  // The caller already checked that there is some active uniform.
  DCHECK_GT(max_name_length, 0);
  scoped_ptr<GLchar[]> name(new GLchar[max_name_length]);
  GLsizei length = 0;
  GLint size = -1;
  GLenum type = 0;
  gl_->GetActiveUniform(
      program, index, max_name_length, &length, &size, &type, name.get());
  if (size < 0) {
    return false;
  }
  info.name = blink::WebString::fromUTF8(name.get(), length);
  info.type = type;
  info.size = size;
  return true;
}

blink::WebString WebGraphicsContext3DImpl::getProgramInfoLog(
    WebGLId program) {
  GLint logLength = 0;
  gl_->GetProgramiv(program, GL_INFO_LOG_LENGTH, &logLength);
  if (!logLength)
    return blink::WebString();
  scoped_ptr<GLchar[]> log(new GLchar[logLength]);
  if (!log)
    return blink::WebString();
  GLsizei returnedLogLength = 0;
  gl_->GetProgramInfoLog(
      program, logLength, &returnedLogLength, log.get());
  DCHECK_EQ(logLength, returnedLogLength + 1);
  blink::WebString res =
      blink::WebString::fromUTF8(log.get(), returnedLogLength);
  return res;
}

blink::WebString WebGraphicsContext3DImpl::getShaderInfoLog(
    WebGLId shader) {
  GLint logLength = 0;
  gl_->GetShaderiv(shader, GL_INFO_LOG_LENGTH, &logLength);
  if (!logLength)
    return blink::WebString();
  scoped_ptr<GLchar[]> log(new GLchar[logLength]);
  if (!log)
    return blink::WebString();
  GLsizei returnedLogLength = 0;
  gl_->GetShaderInfoLog(
      shader, logLength, &returnedLogLength, log.get());
  DCHECK_EQ(logLength, returnedLogLength + 1);
  blink::WebString res =
      blink::WebString::fromUTF8(log.get(), returnedLogLength);
  return res;
}

blink::WebString WebGraphicsContext3DImpl::getShaderSource(
    WebGLId shader) {
  GLint logLength = 0;
  gl_->GetShaderiv(shader, GL_SHADER_SOURCE_LENGTH, &logLength);
  if (!logLength)
    return blink::WebString();
  scoped_ptr<GLchar[]> log(new GLchar[logLength]);
  if (!log)
    return blink::WebString();
  GLsizei returnedLogLength = 0;
  gl_->GetShaderSource(
      shader, logLength, &returnedLogLength, log.get());
  if (!returnedLogLength)
    return blink::WebString();
  DCHECK_EQ(logLength, returnedLogLength + 1);
  blink::WebString res =
      blink::WebString::fromUTF8(log.get(), returnedLogLength);
  return res;
}

blink::WebString WebGraphicsContext3DImpl::
    getTranslatedShaderSourceANGLE(WebGLId shader) {
  GLint logLength = 0;
  gl_->GetShaderiv(
      shader, GL_TRANSLATED_SHADER_SOURCE_LENGTH_ANGLE, &logLength);
  if (!logLength)
    return blink::WebString();
  scoped_ptr<GLchar[]> log(new GLchar[logLength]);
  if (!log)
    return blink::WebString();
  GLsizei returnedLogLength = 0;
  gl_->GetTranslatedShaderSourceANGLE(
      shader, logLength, &returnedLogLength, log.get());
  if (!returnedLogLength)
    return blink::WebString();
  DCHECK_EQ(logLength, returnedLogLength + 1);
  blink::WebString res =
      blink::WebString::fromUTF8(log.get(), returnedLogLength);
  return res;
}

blink::WebString WebGraphicsContext3DImpl::getString(
    WGC3Denum name) {
  return blink::WebString::fromUTF8(
      reinterpret_cast<const char*>(gl_->GetString(name)));
}

void WebGraphicsContext3DImpl::shaderSource(
    WebGLId shader, const WGC3Dchar* string) {
  GLint length = strlen(string);
  gl_->ShaderSource(shader, 1, &string, &length);
}

void WebGraphicsContext3DImpl::setErrorMessageCallback(
    WebGraphicsContext3D::WebGraphicsErrorMessageCallback* cb) {
  error_message_callback_ = cb;
}

void WebGraphicsContext3DImpl::setContextLostCallback(
    WebGraphicsContext3D::WebGraphicsContextLostCallback* cb) {
  context_lost_callback_ = cb;
}

void WebGraphicsContext3DImpl::pushGroupMarkerEXT(
    const WGC3Dchar* marker) {
  gl_->PushGroupMarkerEXT(0, marker);
}

::gpu::gles2::GLES2Interface* WebGraphicsContext3DImpl::getGLES2Interface() {
  return gl_;
}

::gpu::gles2::GLES2ImplementationErrorMessageCallback*
    WebGraphicsContext3DImpl::getErrorMessageCallback() {
  if (!client_error_message_callback_) {
    client_error_message_callback_.reset(
        new WebGraphicsContext3DErrorMessageCallback(this));
  }
  return client_error_message_callback_.get();
}

void WebGraphicsContext3DImpl::OnErrorMessage(
    const std::string& message, int id) {
  if (error_message_callback_) {
    blink::WebString str = blink::WebString::fromUTF8(message.c_str());
    error_message_callback_->onErrorMessage(str, id);
  }
}

// static
void WebGraphicsContext3DImpl::ConvertAttributes(
    const blink::WebGraphicsContext3D::Attributes& attributes,
    ::gpu::gles2::ContextCreationAttribHelper* output_attribs) {
  output_attribs->alpha_size = attributes.alpha ? 8 : 0;
  output_attribs->depth_size = attributes.depth ? 24 : 0;
  // TODO(jinsukkim): Pass RGBA info directly from client by cleaning up
  //   how this is passed to the constructor.
#if defined(OS_ANDROID)
  if (base::SysInfo::IsLowEndDevice() && !attributes.alpha) {
    output_attribs->red_size = 5;
    output_attribs->green_size = 6;
    output_attribs->blue_size = 5;
    output_attribs->depth_size = 16;
  } else {
    output_attribs->red_size = 8;
    output_attribs->green_size = 8;
    output_attribs->blue_size = 8;
  }
#endif
  output_attribs->stencil_size = attributes.stencil ? 8 : 0;
  output_attribs->samples = attributes.antialias ? 4 : 0;
  output_attribs->sample_buffers = attributes.antialias ? 1 : 0;
  output_attribs->fail_if_major_perf_caveat =
      attributes.failIfMajorPerformanceCaveat;
  output_attribs->bind_generates_resource = false;
  switch (attributes.webGLVersion) {
    case 0:
      output_attribs->context_type = ::gpu::gles2::CONTEXT_TYPE_OPENGLES2;
      break;
    case 1:
      output_attribs->context_type = ::gpu::gles2::CONTEXT_TYPE_WEBGL1;
      break;
    case 2:
      output_attribs->context_type = ::gpu::gles2::CONTEXT_TYPE_WEBGL2;
      break;
    default:
      NOTREACHED();
      output_attribs->context_type = ::gpu::gles2::CONTEXT_TYPE_OPENGLES2;
      break;
  }
}

}  // namespace gpu_blink