// Copyright 2015 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 "headless/lib/headless_content_main_delegate.h"

#include "base/command_line.h"
#include "base/path_service.h"
#include "base/run_loop.h"
#include "base/trace_event/trace_event.h"
#include "content/public/browser/browser_main_runner.h"
#include "content/public/common/content_switches.h"
#include "headless/lib/browser/headless_browser_impl.h"
#include "headless/lib/browser/headless_content_browser_client.h"
#include "headless/lib/renderer/headless_content_renderer_client.h"
#include "headless/lib/utility/headless_content_utility_client.h"
#include "ui/base/resource/resource_bundle.h"
#include "ui/ozone/public/ozone_switches.h"

namespace headless {
namespace {
// Keep in sync with content/common/content_constants_internal.h.
// TODO(skyostil): Add a tracing test for this.
const int kTraceEventBrowserProcessSortIndex = -6;

HeadlessContentMainDelegate* g_current_headless_content_main_delegate = nullptr;
}  // namespace

HeadlessContentMainDelegate::HeadlessContentMainDelegate(
    scoped_ptr<HeadlessBrowserImpl> browser)
    : content_client_(browser->options()), browser_(std::move(browser)) {
  DCHECK(!g_current_headless_content_main_delegate);
  g_current_headless_content_main_delegate = this;
}

HeadlessContentMainDelegate::~HeadlessContentMainDelegate() {
  DCHECK(g_current_headless_content_main_delegate == this);
  g_current_headless_content_main_delegate = nullptr;
}

bool HeadlessContentMainDelegate::BasicStartupComplete(int* exit_code) {
  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();

  command_line->AppendSwitch(switches::kNoSandbox);
  command_line->AppendSwitch(switches::kSingleProcess);

  // The headless backend is automatically chosen for a headless build, but also
  // adding it here allows us to run in a non-headless build too.
  command_line->AppendSwitchASCII(switches::kOzonePlatform, "headless");

  // TODO(skyostil): Investigate using Mesa/SwiftShader for output.
  command_line->AppendSwitch(switches::kDisableGpu);

  SetContentClient(&content_client_);
  return false;
}

void HeadlessContentMainDelegate::PreSandboxStartup() {
  InitializeResourceBundle();
}

int HeadlessContentMainDelegate::RunProcess(
    const std::string& process_type,
    const content::MainFunctionParams& main_function_params) {
  if (!process_type.empty())
    return -1;

  base::trace_event::TraceLog::GetInstance()->SetProcessName("HeadlessBrowser");
  base::trace_event::TraceLog::GetInstance()->SetProcessSortIndex(
      kTraceEventBrowserProcessSortIndex);

  scoped_ptr<content::BrowserMainRunner> browser_runner(
      content::BrowserMainRunner::Create());

  int exit_code = browser_runner->Initialize(main_function_params);
  DCHECK_LT(exit_code, 0) << "content::BrowserMainRunner::Initialize failed in "
                             "HeadlessContentMainDelegate::RunProcess";

  browser_->RunOnStartCallback();
  browser_runner->Run();
  browser_.reset();
  browser_runner->Shutdown();

  // Return value >=0 here to disable calling content::BrowserMain.
  return 0;
}

void HeadlessContentMainDelegate::ZygoteForked() {
  // TODO(skyostil): Disable the zygote host.
}

// static
HeadlessContentMainDelegate* HeadlessContentMainDelegate::GetInstance() {
  return g_current_headless_content_main_delegate;
}

// static
void HeadlessContentMainDelegate::InitializeResourceBundle() {
  base::FilePath pak_file;
  bool result = PathService::Get(base::DIR_MODULE, &pak_file);
  DCHECK(result);
  pak_file = pak_file.Append(FILE_PATH_LITERAL("headless_lib.pak"));
  ui::ResourceBundle::InitSharedInstanceWithPakPath(pak_file);
}

content::ContentBrowserClient*
HeadlessContentMainDelegate::CreateContentBrowserClient() {
  browser_client_.reset(new HeadlessContentBrowserClient(browser_.get()));
  return browser_client_.get();
}

content::ContentRendererClient*
HeadlessContentMainDelegate::CreateContentRendererClient() {
  renderer_client_.reset(new HeadlessContentRendererClient);
  return renderer_client_.get();
}

content::ContentUtilityClient*
HeadlessContentMainDelegate::CreateContentUtilityClient() {
  utility_client_.reset(new HeadlessContentUtilityClient);
  return utility_client_.get();
}

}  // namespace headless