// 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 "mojo/shell/context.h"

#include <vector>

#include "base/bind.h"
#include "base/command_line.h"
#include "base/files/file_path.h"
#include "base/lazy_instance.h"
#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/scoped_vector.h"
#include "base/strings/string_split.h"
#include "build/build_config.h"
#include "mojo/application_manager/application_loader.h"
#include "mojo/application_manager/application_manager.h"
#include "mojo/application_manager/background_shell_application_loader.h"
#include "mojo/edk/embedder/embedder.h"
#include "mojo/edk/embedder/simple_platform_support.h"
#include "mojo/public/cpp/application/application_connection.h"
#include "mojo/public/cpp/application/application_delegate.h"
#include "mojo/public/cpp/application/application_impl.h"
#include "mojo/shell/dynamic_application_loader.h"
#include "mojo/shell/external_application_listener.h"
#include "mojo/shell/in_process_dynamic_service_runner.h"
#include "mojo/shell/out_of_process_dynamic_service_runner.h"
#include "mojo/shell/switches.h"
#include "mojo/shell/ui_application_loader_android.h"
#include "mojo/spy/spy.h"

#if defined(OS_ANDROID)
#include "mojo/services/gles2/gpu_impl.h"
#include "mojo/services/native_viewport/native_viewport_impl.h"
#include "mojo/shell/android/android_handler_loader.h"
#include "mojo/shell/network_application_loader.h"
#endif  // defined(OS_ANDROID)

namespace mojo {
namespace shell {
namespace {

// These mojo: URLs are loaded directly from the local filesystem. They
// correspond to shared libraries bundled alongside the mojo_shell.
const char* kLocalMojoURLs[] = {
    "mojo:network_service",
};

// Used to ensure we only init once.
class Setup {
 public:
  Setup() {
    embedder::Init(scoped_ptr<mojo::embedder::PlatformSupport>(
        new mojo::embedder::SimplePlatformSupport()));
  }

  ~Setup() {
  }

 private:
  DISALLOW_COPY_AND_ASSIGN(Setup);
};

static base::LazyInstance<Setup>::Leaky setup = LAZY_INSTANCE_INITIALIZER;

void InitContentHandlers(DynamicApplicationLoader* loader,
                         base::CommandLine* command_line) {
  // Default content handlers.
  loader->RegisterContentHandler("application/pdf", GURL("mojo:pdf_viewer"));
  loader->RegisterContentHandler("image/png", GURL("mojo:png_viewer"));
  loader->RegisterContentHandler("text/html", GURL("mojo:html_viewer"));

  // Command-line-specified content handlers.
  std::string handlers_spec = command_line->GetSwitchValueASCII(
      switches::kContentHandlers);
  if (handlers_spec.empty())
    return;

  std::vector<std::string> parts;
  base::SplitString(handlers_spec, ',', &parts);
  if (parts.size() % 2 != 0) {
    LOG(ERROR) << "Invalid value for switch " << switches::kContentHandlers
               << ": must be a comma-separated list of mimetype/url pairs.";
    return;
  }

  for (size_t i = 0; i < parts.size(); i += 2) {
    GURL url(parts[i + 1]);
    if (!url.is_valid()) {
      LOG(ERROR) << "Invalid value for switch " << switches::kContentHandlers
                 << ": '" << parts[i + 1] << "' is not a valid URL.";
      return;
    }
    loader->RegisterContentHandler(parts[i], url);
  }
}

class EmptyServiceProvider : public InterfaceImpl<ServiceProvider> {
 private:
  void ConnectToService(const mojo::String& service_name,
                        ScopedMessagePipeHandle client_handle) override {}
};

bool ConfigureURLMappings(const std::string& mappings,
                          mojo::shell::MojoURLResolver* resolver) {
  base::StringPairs pairs;
  if (!base::SplitStringIntoKeyValuePairs(mappings, '=', ',', &pairs))
    return false;
  using StringPair = std::pair<std::string, std::string>;
  for (const StringPair& pair : pairs) {
    const GURL from(pair.first);
    const GURL to(pair.second);
    if (!from.is_valid() || !to.is_valid())
      return false;
    resolver->AddCustomMapping(from, to);
  }
  return true;
}

}  // namespace

#if defined(OS_ANDROID)
class Context::NativeViewportApplicationLoader
    : public ApplicationLoader,
      public ApplicationDelegate,
      public InterfaceFactory<NativeViewport>,
      public InterfaceFactory<Gpu> {
 public:
  NativeViewportApplicationLoader() : gpu_state_(new GpuImpl::State) {}
  virtual ~NativeViewportApplicationLoader() {}

 private:
  // ApplicationLoader implementation.
  virtual void Load(ApplicationManager* manager,
                    const GURL& url,
                    ScopedMessagePipeHandle shell_handle,
                    LoadCallback callback) override {
    DCHECK(shell_handle.is_valid());
    app_.reset(new ApplicationImpl(this, shell_handle.Pass()));
  }

  virtual void OnApplicationError(ApplicationManager* manager,
                                  const GURL& url) override {}

  // ApplicationDelegate implementation.
  virtual bool ConfigureIncomingConnection(
      mojo::ApplicationConnection* connection) override {
    connection->AddService<NativeViewport>(this);
    connection->AddService<Gpu>(this);
    return true;
  }

  // InterfaceFactory<NativeViewport> implementation.
  virtual void Create(ApplicationConnection* connection,
                      InterfaceRequest<NativeViewport> request) override {
    BindToRequest(new NativeViewportImpl(app_.get(), false), &request);
  }

  // InterfaceFactory<Gpu> implementation.
  virtual void Create(ApplicationConnection* connection,
                      InterfaceRequest<Gpu> request) override {
    new GpuImpl(request.Pass(), gpu_state_);
  }

  scoped_refptr<GpuImpl::State> gpu_state_;
  scoped_ptr<ApplicationImpl> app_;
  DISALLOW_COPY_AND_ASSIGN(NativeViewportApplicationLoader);
};
#endif

Context::Context() : application_manager_(this) {
  DCHECK(!base::MessageLoop::current());
}

Context::~Context() {
  DCHECK(!base::MessageLoop::current());
}

void Context::EnsureEmbedderIsInitialized() {
  setup.Get();
}

bool Context::Init() {
  EnsureEmbedderIsInitialized();
  task_runners_.reset(
      new TaskRunners(base::MessageLoop::current()->message_loop_proxy()));

  for (size_t i = 0; i < arraysize(kLocalMojoURLs); ++i)
    mojo_url_resolver_.AddLocalFileMapping(GURL(kLocalMojoURLs[i]));

  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();

  if (command_line->HasSwitch(switches::kEnableExternalApplications)) {
    listener_ = ExternalApplicationListener::Create(
        task_runners_->shell_runner(), task_runners_->io_runner());

    base::FilePath socket_path =
        command_line->GetSwitchValuePath(switches::kEnableExternalApplications);
    if (socket_path.empty())
      socket_path = ExternalApplicationListener::ConstructDefaultSocketPath();

    listener_->ListenInBackground(
        socket_path,
        base::Bind(&ApplicationManager::RegisterExternalApplication,
                   base::Unretained(&application_manager_)));
  }
  if (command_line->HasSwitch(switches::kOrigin)) {
    mojo_url_resolver()->SetBaseURL(
        GURL(command_line->GetSwitchValueASCII(switches::kOrigin)));
  }
  if (command_line->HasSwitch(switches::kURLMappings) &&
      !ConfigureURLMappings(
          command_line->GetSwitchValueASCII(switches::kURLMappings),
          mojo_url_resolver())) {
    return false;
  }

  scoped_ptr<DynamicServiceRunnerFactory> runner_factory;
  if (command_line->HasSwitch(switches::kEnableMultiprocess))
    runner_factory.reset(new OutOfProcessDynamicServiceRunnerFactory());
  else
    runner_factory.reset(new InProcessDynamicServiceRunnerFactory());

  DynamicApplicationLoader* dynamic_application_loader =
      new DynamicApplicationLoader(this, runner_factory.Pass());
  InitContentHandlers(dynamic_application_loader, command_line);
  application_manager_.set_default_loader(
      scoped_ptr<ApplicationLoader>(dynamic_application_loader));

  // The native viewport service synchronously waits for certain messages. If we
  // don't run it on its own thread we can easily deadlock. Long term native
  // viewport should run its own process so that this isn't an issue.
#if defined(OS_ANDROID)
  application_manager_.SetLoaderForURL(
      scoped_ptr<ApplicationLoader>(new UIApplicationLoader(
          scoped_ptr<ApplicationLoader>(new NativeViewportApplicationLoader()),
          this)),
      GURL("mojo:native_viewport_service"));
#endif

  if (command_line->HasSwitch(switches::kSpy)) {
    spy_.reset(
        new mojo::Spy(&application_manager_,
                      command_line->GetSwitchValueASCII(switches::kSpy)));
    // TODO(cpu): the spy can snoop, but can't tell anybody until
    // the Spy::WebSocketDelegate is implemented. In the original repo this
    // was implemented by src\mojo\spy\websocket_server.h and .cc.
  }

#if defined(OS_ANDROID)
  // On android, the network service is bundled with the shell because the
  // network stack depends on the android runtime.
  {
    scoped_ptr<BackgroundShellApplicationLoader> loader(
        new BackgroundShellApplicationLoader(
            scoped_ptr<ApplicationLoader>(new NetworkApplicationLoader()),
            "network_service",
            base::MessageLoop::TYPE_IO));
    application_manager_.SetLoaderForURL(loader.Pass(),
                                         GURL("mojo:network_service"));
  }
  {
    scoped_ptr<BackgroundShellApplicationLoader> loader(
        new BackgroundShellApplicationLoader(
            scoped_ptr<ApplicationLoader>(new AndroidHandlerLoader()),
            "android_handler", base::MessageLoop::TYPE_DEFAULT));
    application_manager_.SetLoaderForURL(loader.Pass(),
                                         GURL("mojo:android_handler"));
  }
#endif

  if (listener_)
    listener_->WaitForListening();

  return true;
}

void Context::OnApplicationError(const GURL& url) {
  if (app_urls_.find(url) != app_urls_.end()) {
    app_urls_.erase(url);
    if (app_urls_.empty() && base::MessageLoop::current()->is_running())
      base::MessageLoop::current()->Quit();
  }
}

GURL Context::ResolveURL(const GURL& url) {
  return mojo_url_resolver_.Resolve(url);
}

void Context::Run(const GURL& url) {
  EmptyServiceProvider* sp = new EmptyServiceProvider;
  ServiceProviderPtr spp;
  BindToProxy(sp, &spp);

  app_urls_.insert(url);
  application_manager_.ConnectToApplication(url, GURL(), spp.Pass());
}

ScopedMessagePipeHandle Context::ConnectToServiceByName(
    const GURL& application_url,
    const std::string& service_name) {
  app_urls_.insert(application_url);
  return application_manager_.ConnectToServiceByName(
      application_url, service_name).Pass();
}

}  // namespace shell
}  // namespace mojo