// Copyright 2014 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 "base/bind.h"
#include "base/message_loop/message_loop.h"
#include "base/run_loop.h"
#include "base/strings/string_split.h"
#include "base/synchronization/waitable_event.h"
#include "base/threading/platform_thread.h"
#include "base/trace_event/trace_event.h"
#include "mojo/application/application_runner_chromium.h"
#include "mojo/application/content_handler_factory.h"
#include "mojo/common/tracing_impl.h"
#include "mojo/dart/embedder/dart_controller.h"
#include "mojo/public/c/system/main.h"
#include "mojo/public/cpp/application/application_delegate.h"
#include "mojo/public/cpp/application/application_impl.h"
#include "mojo/public/cpp/bindings/binding.h"
#include "mojo/public/cpp/bindings/interface_request.h"
#include "mojo/services/tracing/interfaces/tracing.mojom.h"
#include "mojo/services/url_response_disk_cache/interfaces/url_response_disk_cache.mojom.h"
#include "services/dart/content_handler_app_service_connector.h"
#include "services/dart/dart_app.h"
#include "services/dart/dart_tracing.h"
#include "url/gurl.h"

namespace dart {

// Flags for the content handler:
const char kDartTimeline[] = "--dart-timeline";
const char kDisableObservatory[] = "--disable-observatory";
const char kEnableStrictMode[] = "--enable-strict-mode";
const char kRunOnMessageLoop[] = "--run-on-message-loop";
const char kTraceStartup[] = "--trace-startup";
// Flags forwarded to the Dart VM:
const char kCompleteTimeline[] = "--complete-timeline";
const char kPauseIsolatesOnStart[] = "--pause-isolates-on-start";
const char kPauseIsolatesOnExit[] = "--pause-isolates-on-exit";

static bool IsDartZip(std::string url) {
  // If the url doesn't end with ".dart" we assume it is a zipped up
  // dart application.
  return !base::EndsWith(url, ".dart", base::CompareCase::INSENSITIVE_ASCII);
}

// Returns true if |requestedUrl| has a boolean query parameter named |param|.
static bool HasBoolQueryParam(const std::string& requestedUrl,
                              const std::string& param) {
  std::string param_true = param + "=true";
  std::string param_false = param + "=false";

  GURL url(requestedUrl);
  if (url.has_query()) {
    std::vector<std::string> query_parameters = base::SplitString(
        url.query(), "&", base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
    bool has_true =
        std::find(query_parameters.begin(),
                  query_parameters.end(),
                  param_true) != query_parameters.end();
    bool has_false =
        std::find(query_parameters.begin(),
                  query_parameters.end(),
                  param_false) != query_parameters.end();
    return has_true || has_false;
  }
  return false;
}

// Returns the value of the boolean query parameter named |param|, or
// |default_value| if it |param| is not present.
static bool BoolQueryParamValue(const std::string& requestedUrl,
                                const std::string& param,
                                bool default_value) {
  if (!HasBoolQueryParam(requestedUrl, param)) {
    return default_value;
  }
  std::string param_true = param + "=true";
  std::string param_false = param + "=false";
  GURL url(requestedUrl);
  DCHECK(url.has_query());
  std::vector<std::string> query_parameters = base::SplitString(
      url.query(), "&", base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
  bool has_true =
      std::find(query_parameters.begin(),
                query_parameters.end(),
                param_true) != query_parameters.end();
  bool has_false =
      std::find(query_parameters.begin(),
                query_parameters.end(),
                param_false) != query_parameters.end();
  if (has_true) {
    return has_true;
  }
  if (has_false) {
    return false;
  }
  return default_value;
}

static bool HasStrictQueryParam(const std::string& requestedUrl) {
  return BoolQueryParamValue(requestedUrl, "strict", false);
}

class DartContentHandlerApp;

class DartContentHandler : public mojo::ContentHandlerFactory::ManagedDelegate {
 public:
  DartContentHandler(DartContentHandlerApp* app, bool strict)
      : app_(app), strict_(strict) {
  }

  void set_handler_task_runner(
      scoped_refptr<base::SingleThreadTaskRunner> handler_task_runner) {
    handler_task_runner_ = handler_task_runner;
  }

 private:
  // Overridden from ContentHandlerFactory::ManagedDelegate:
  scoped_ptr<mojo::ContentHandlerFactory::HandledApplicationHolder>
  CreateApplication(
      mojo::InterfaceRequest<mojo::Application> application_request,
      mojo::URLResponsePtr response) override;

  DartContentHandlerApp* app_;
  bool strict_;
  scoped_refptr<base::SingleThreadTaskRunner> handler_task_runner_;

  DISALLOW_COPY_AND_ASSIGN(DartContentHandler);
};

class DartContentHandlerApp : public mojo::ApplicationDelegate {
 public:
  DartContentHandlerApp()
      : content_handler_(this, false),
        strict_content_handler_(this, true),
        content_handler_factory_(&content_handler_),
        strict_content_handler_factory_(&strict_content_handler_),
        service_connector_(nullptr),
        default_strict_(false),
        run_on_message_loop_(false) {}

  ~DartContentHandlerApp() override {
    // Shutdown the controller.
    mojo::dart::DartController::Shutdown();
    delete service_connector_;
  }

  void ExtractApplication(base::FilePath* application_dir,
                          mojo::URLResponsePtr response,
                          const base::Closure& callback) {
    url_response_disk_cache_->UpdateAndGetExtracted(
        response.Pass(),
        [application_dir, callback](mojo::Array<uint8_t> application_dir_path,
                                    mojo::Array<uint8_t> cache_path) {
          if (application_dir_path.is_null()) {
            *application_dir = base::FilePath();
          } else {
            *application_dir = base::FilePath(std::string(
                reinterpret_cast<char*>(&application_dir_path.front()),
                application_dir_path.size()));
          }
          callback.Run();
        });
  }

  bool run_on_message_loop() const {
    return run_on_message_loop_;
  }

 private:
  // Overridden from mojo::ApplicationDelegate:
  void Initialize(mojo::ApplicationImpl* app) override {
    // Tracing of content handler and controller.
    tracing_.Initialize(app);
    // Tracing of isolates and VM.
    dart_tracing_.Initialize(app);

    // TODO(qsr): This has no effect for now, as the tracing infrastructure
    // doesn't allow to trace anything before the tracing app connects to the
    // application.
    TRACE_EVENT0("dart_content_handler", "DartContentHandler::Initialize");

    default_strict_ = app->HasArg(kEnableStrictMode);
    content_handler_.set_handler_task_runner(
        base::MessageLoop::current()->task_runner());
    strict_content_handler_.set_handler_task_runner(
        base::MessageLoop::current()->task_runner());
    app->ConnectToService("mojo:url_response_disk_cache",
                          &url_response_disk_cache_);
    service_connector_ = new ContentHandlerAppServiceConnector(app);

    if (app->HasArg(kRunOnMessageLoop)) {
      run_on_message_loop_ = true;
    }

    bool enable_observatory = true;
    if (app->HasArg(kDisableObservatory)) {
      enable_observatory = false;
    }

    bool enable_dart_timeline = false;
    if (app->HasArg(kDartTimeline)) {
      enable_dart_timeline = true;
    }

    std::vector<const char*> extra_args;

    if (app->HasArg(kPauseIsolatesOnStart)) {
      extra_args.push_back(kPauseIsolatesOnStart);
    }

    if (app->HasArg(kPauseIsolatesOnExit)) {
      extra_args.push_back(kPauseIsolatesOnExit);
    }

    if (app->HasArg(kCompleteTimeline)) {
      extra_args.push_back(kCompleteTimeline);
    }

    bool success = mojo::dart::DartController::Initialize(
        service_connector_,
        default_strict_,
        enable_observatory,
        enable_dart_timeline,
        extra_args.data(),
        extra_args.size());

    if (app->HasArg(kTraceStartup)) {
      DartTimelineController::EnableAll();
    }
    if (!success) {
      LOG(ERROR) << "Dart VM Initialization failed";
    }
  }

  // Overridden from ApplicationDelegate:
  bool ConfigureIncomingConnection(
      mojo::ApplicationConnection* connection) override {
    bool strict = HasStrictQueryParam(connection->GetConnectionURL());
    if (default_strict_ || strict) {
      connection->AddService(&strict_content_handler_factory_);
    } else {
      connection->AddService(&content_handler_factory_);
    }
    return true;
  }

  mojo::TracingImpl tracing_;
  DartContentHandler content_handler_;
  DartContentHandler strict_content_handler_;
  mojo::ContentHandlerFactory content_handler_factory_;
  mojo::ContentHandlerFactory strict_content_handler_factory_;
  mojo::URLResponseDiskCachePtr url_response_disk_cache_;
  ContentHandlerAppServiceConnector* service_connector_;
  DartTracingImpl dart_tracing_;
  bool default_strict_;
  bool run_on_message_loop_;

  DISALLOW_COPY_AND_ASSIGN(DartContentHandlerApp);
};

scoped_ptr<mojo::ContentHandlerFactory::HandledApplicationHolder>
DartContentHandler::CreateApplication(
    mojo::InterfaceRequest<mojo::Application> application_request,
    mojo::URLResponsePtr response) {
  base::trace_event::TraceLog::GetInstance()
      ->SetCurrentThreadBlocksMessageLoop();

  TRACE_EVENT1("dart_content_handler", "DartContentHandler::CreateApplication",
               "url", response->url.get());

  const bool run_on_message_loop = app_->run_on_message_loop();
  base::FilePath application_dir;
  std::string url = response->url.get();
  const char* kPauseIsolatesOnStart = "pauseIsolatesOnStart";
  const char* kPauseIsolatesOnExit = "pauseIsolatesOnExit";
  const bool override_pause_isolates_flags =
      HasBoolQueryParam(url, kPauseIsolatesOnStart) ||
      HasBoolQueryParam(url, kPauseIsolatesOnExit);
  const bool pause_isolates_on_start = BoolQueryParamValue(
      url,
      kPauseIsolatesOnStart,
      mojo::dart::DartControllerConfig::kDefaultPauseOnStart);
  const bool pause_isolates_on_exit = BoolQueryParamValue(
      url,
      kPauseIsolatesOnExit,
      mojo::dart::DartControllerConfig::kDefaultPauseOnExit);
  if (IsDartZip(response->url.get())) {
    // Loading a zipped snapshot:
    // 1) Extract the zip file.
    // 2) Launch from temporary directory (|application_dir|).
    handler_task_runner_->PostTask(
        FROM_HERE,
        base::Bind(
            &DartContentHandlerApp::ExtractApplication, base::Unretained(app_),
            base::Unretained(&application_dir), base::Passed(response.Pass()),
            base::Bind(
                base::IgnoreResult(&base::SingleThreadTaskRunner::PostTask),
                base::MessageLoop::current()->task_runner(), FROM_HERE,
                base::MessageLoop::QuitWhenIdleClosure())));
    base::RunLoop().Run();
    return make_scoped_ptr(
        new DartApp(application_request.Pass(),
                    url,
                    application_dir,
                    strict_,
                    run_on_message_loop,
                    override_pause_isolates_flags,
                    pause_isolates_on_start,
                    pause_isolates_on_exit));
  } else {
    // Loading a raw .dart file pointed at by |url|.
    return make_scoped_ptr(
        new DartApp(application_request.Pass(),
                    url,
                    strict_,
                    run_on_message_loop,
                    override_pause_isolates_flags,
                    pause_isolates_on_start,
                    pause_isolates_on_exit));
  }
}

}  // namespace dart

MojoResult MojoMain(MojoHandle application_request) {
  mojo::ApplicationRunnerChromium runner(new dart::DartContentHandlerApp);
  return runner.Run(application_request);
}