// 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 "mojo/application_manager/application_manager.h"

#include <stdio.h>

#include "base/bind.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/stl_util.h"
#include "mojo/application_manager/application_loader.h"
#include "mojo/common/common_type_converters.h"
#include "mojo/public/cpp/application/connect.h"
#include "mojo/public/cpp/bindings/binding.h"
#include "mojo/public/cpp/bindings/error_handler.h"
#include "mojo/public/interfaces/application/application.mojom.h"
#include "mojo/public/interfaces/application/shell.mojom.h"
#include "mojo/services/public/interfaces/content_handler/content_handler.mojom.h"

namespace mojo {

namespace {
// Used by TestAPI.
bool has_created_instance = false;

class StubServiceProvider : public InterfaceImpl<ServiceProvider> {
 public:
  ServiceProvider* GetRemoteServiceProvider() { return client(); }

 private:
  void ConnectToService(const String& service_name,
                        ScopedMessagePipeHandle client_handle) override {}
};

}  // namespace


ApplicationManager::Delegate::~Delegate() {
}

void ApplicationManager::Delegate::OnApplicationError(const GURL& url) {
  LOG(ERROR) << "Communication error with application: " << url.spec();
}

GURL ApplicationManager::Delegate::ResolveURL(const GURL& url) {
  return url;
}


class ApplicationManager::LoadCallbacksImpl
    : public ApplicationLoader::LoadCallbacks {
 public:
  LoadCallbacksImpl(base::WeakPtr<ApplicationManager> manager,
                    const GURL& requested_url,
                    const GURL& resolved_url,
                    const GURL& requestor_url,
                    ServiceProviderPtr service_provider)
      : manager_(manager),
        requested_url_(requested_url),
        resolved_url_(resolved_url),
        requestor_url_(requestor_url),
        service_provider_(service_provider.Pass()) {}

 private:
  ~LoadCallbacksImpl() override {}

  // LoadCallbacks implementation
  ScopedMessagePipeHandle RegisterApplication() override {
    ScopedMessagePipeHandle shell_handle;
    if (manager_) {
      manager_->RegisterLoadedApplication(requested_url_,
                                          resolved_url_,
                                          requestor_url_,
                                          service_provider_.Pass(),
                                          &shell_handle);
    }
    return shell_handle.Pass();
  }

  void LoadWithContentHandler(const GURL& content_handler_url,
                              URLResponsePtr url_response) override {
    if (manager_) {
      manager_->LoadWithContentHandler(requested_url_,
                                       resolved_url_,
                                       requestor_url_,
                                       content_handler_url,
                                       url_response.Pass(),
                                       service_provider_.Pass());
    }
  }

  base::WeakPtr<ApplicationManager> manager_;
  GURL requested_url_;
  GURL resolved_url_;
  GURL requestor_url_;
  ServiceProviderPtr service_provider_;
};

class ApplicationManager::ShellImpl : public Shell, public ErrorHandler {
 public:
  ShellImpl(ScopedMessagePipeHandle handle,
            ApplicationManager* manager,
            const GURL& requested_url,
            const GURL& url)
      : ShellImpl(manager, requested_url, url) {
    binding_.Bind(handle.Pass());
  }

  ShellImpl(ShellPtr* ptr,
            ApplicationManager* manager,
            const GURL& requested_url,
            const GURL& url)
      : ShellImpl(manager, requested_url, url) {
    binding_.Bind(ptr);
  }

  ~ShellImpl() override {}

  void ConnectToClient(const GURL& requestor_url,
                       ServiceProviderPtr service_provider) {
    client()->AcceptConnection(String::From(requestor_url),
                               service_provider.Pass());
  }

  Application* client() { return binding_.client(); }
  const GURL& url() const { return url_; }
  const GURL& requested_url() const { return requested_url_; }

 private:
  ShellImpl(ApplicationManager* manager,
            const GURL& requested_url,
            const GURL& url)
      : manager_(manager),
        requested_url_(requested_url),
        url_(url),
        binding_(this) {
    binding_.set_error_handler(this);
  }

  // Shell implementation:
  void ConnectToApplication(
      const String& app_url,
      InterfaceRequest<ServiceProvider> in_service_provider) override {
    ServiceProviderPtr out_service_provider;
    out_service_provider.Bind(in_service_provider.PassMessagePipe());
    manager_->ConnectToApplication(
        app_url.To<GURL>(), url_, out_service_provider.Pass());
  }

  // ErrorHandler implementation:
  void OnConnectionError() override { manager_->OnShellImplError(this); }

  ApplicationManager* const manager_;
  const GURL requested_url_;
  const GURL url_;
  Binding<Shell> binding_;

  DISALLOW_COPY_AND_ASSIGN(ShellImpl);
};

class ApplicationManager::ContentHandlerConnection : public ErrorHandler {
 public:
  ContentHandlerConnection(ApplicationManager* manager,
                           const GURL& content_handler_url)
      : manager_(manager), content_handler_url_(content_handler_url) {
    ServiceProviderPtr service_provider;
    StubServiceProvider* service_provider_impl =
        BindToProxy(new StubServiceProvider, &service_provider);
    manager->ConnectToApplication(
        content_handler_url, GURL(), service_provider.Pass());
    mojo::ConnectToService(service_provider_impl->client(), &content_handler_);
    content_handler_.set_error_handler(this);
  }

  ContentHandler* content_handler() { return content_handler_.get(); }

  GURL content_handler_url() { return content_handler_url_; }

 private:
  // ErrorHandler implementation:
  void OnConnectionError() override { manager_->OnContentHandlerError(this); }

  ApplicationManager* manager_;
  GURL content_handler_url_;
  ContentHandlerPtr content_handler_;

  DISALLOW_COPY_AND_ASSIGN(ContentHandlerConnection);
};

// static
ApplicationManager::TestAPI::TestAPI(ApplicationManager* manager)
    : manager_(manager) {
}

ApplicationManager::TestAPI::~TestAPI() {
}

bool ApplicationManager::TestAPI::HasCreatedInstance() {
  return has_created_instance;
}

bool ApplicationManager::TestAPI::HasFactoryForURL(const GURL& url) const {
  return manager_->url_to_shell_impl_.find(url) !=
         manager_->url_to_shell_impl_.end();
}

ApplicationManager::ApplicationManager(Delegate* delegate)
    : delegate_(delegate),
      interceptor_(NULL),
      weak_ptr_factory_(this) {
}

ApplicationManager::~ApplicationManager() {
  STLDeleteValues(&url_to_content_handler_);
  TerminateShellConnections();
  STLDeleteValues(&url_to_loader_);
  STLDeleteValues(&scheme_to_loader_);
}

void ApplicationManager::TerminateShellConnections() {
  STLDeleteValues(&url_to_shell_impl_);
  STLDeleteElements(&content_shell_impls_);
}

void ApplicationManager::ConnectToApplication(
    const GURL& requested_url,
    const GURL& requestor_url,
    ServiceProviderPtr service_provider) {
  ApplicationLoader* loader = GetLoaderForURL(requested_url,
                                              DONT_INCLUDE_DEFAULT_LOADER);
  if (loader) {
    ConnectToApplicationImpl(requested_url, requested_url, requestor_url,
                             service_provider.Pass(), loader);
    return;
  }

  GURL resolved_url = delegate_->ResolveURL(requested_url);
  loader = GetLoaderForURL(resolved_url, INCLUDE_DEFAULT_LOADER);
  if (loader) {
    ConnectToApplicationImpl(requested_url, resolved_url, requestor_url,
                             service_provider.Pass(), loader);
    return;
  }

  LOG(WARNING) << "Could not find loader to load application: "
               << requested_url.spec();
}

void ApplicationManager::ConnectToApplicationImpl(
    const GURL& requested_url, const GURL& resolved_url,
    const GURL& requestor_url, ServiceProviderPtr service_provider,
    ApplicationLoader* loader) {
  URLToShellImplMap::const_iterator shell_it =
      url_to_shell_impl_.find(resolved_url);
  if (shell_it != url_to_shell_impl_.end()) {
    ConnectToClient(shell_it->second, resolved_url, requestor_url,
                    service_provider.Pass());
    return;
  }

  scoped_refptr<LoadCallbacksImpl> callbacks(
      new LoadCallbacksImpl(weak_ptr_factory_.GetWeakPtr(),
                            requested_url,
                            resolved_url,
                            requestor_url,
                            service_provider.Pass()));
  loader->Load(this, resolved_url, callbacks);
}

void ApplicationManager::ConnectToClient(ShellImpl* shell_impl,
                                         const GURL& url,
                                         const GURL& requestor_url,
                                         ServiceProviderPtr service_provider) {
  if (interceptor_) {
    shell_impl->ConnectToClient(
        requestor_url,
        interceptor_->OnConnectToClient(url, service_provider.Pass()));
  } else {
    shell_impl->ConnectToClient(requestor_url, service_provider.Pass());
  }
}

void ApplicationManager::RegisterExternalApplication(
    const GURL& url,
    ScopedMessagePipeHandle shell_handle) {
  ShellImpl* shell_impl = new ShellImpl(shell_handle.Pass(), this, url, url);
  url_to_shell_impl_[url] = shell_impl;

  URLToArgsMap::const_iterator args_it = url_to_args_.find(url);
  Array<String> args;
  if (args_it != url_to_args_.end())
    args = Array<String>::From(args_it->second);
  shell_impl->client()->Initialize(args.Pass());
}

void ApplicationManager::RegisterLoadedApplication(
    const GURL& requested_url,
    const GURL& resolved_url,
    const GURL& requestor_url,
    ServiceProviderPtr service_provider,
    ScopedMessagePipeHandle* shell_handle) {
  ShellImpl* shell_impl = NULL;
  URLToShellImplMap::iterator iter = url_to_shell_impl_.find(resolved_url);
  if (iter != url_to_shell_impl_.end()) {
    // This can happen because services are loaded asynchronously. So if we get
    // two requests for the same service close to each other, we might get here
    // and find that we already have it.
    shell_impl = iter->second;
  } else {
    MessagePipe pipe;
    shell_impl =
        new ShellImpl(pipe.handle1.Pass(), this, requested_url, resolved_url);
    url_to_shell_impl_[resolved_url] = shell_impl;
    *shell_handle = pipe.handle0.Pass();
    shell_impl->client()->Initialize(GetArgsForURL(requested_url));
  }

  ConnectToClient(shell_impl, resolved_url, requestor_url,
                  service_provider.Pass());
}

void ApplicationManager::LoadWithContentHandler(
    const GURL& requested_url,
    const GURL& resolved_url,
    const GURL& requestor_url,
    const GURL& content_handler_url,
    URLResponsePtr url_response,
    ServiceProviderPtr service_provider) {
  ContentHandlerConnection* connection = NULL;
  URLToContentHandlerMap::iterator iter =
      url_to_content_handler_.find(content_handler_url);
  if (iter != url_to_content_handler_.end()) {
    connection = iter->second;
  } else {
    connection = new ContentHandlerConnection(this, content_handler_url);
    url_to_content_handler_[content_handler_url] = connection;
  }

  ShellPtr shell_proxy;
  ShellImpl* shell_impl =
      new ShellImpl(&shell_proxy, this, requested_url, resolved_url);
  content_shell_impls_.insert(shell_impl);
  shell_impl->client()->Initialize(GetArgsForURL(requested_url));

  connection->content_handler()->StartApplication(shell_proxy.Pass(),
                                                  url_response.Pass());
  ConnectToClient(
      shell_impl, resolved_url, requestor_url, service_provider.Pass());
}

void ApplicationManager::SetLoaderForURL(scoped_ptr<ApplicationLoader> loader,
                                         const GURL& url) {
  URLToLoaderMap::iterator it = url_to_loader_.find(url);
  if (it != url_to_loader_.end())
    delete it->second;
  url_to_loader_[url] = loader.release();
}

void ApplicationManager::SetLoaderForScheme(
    scoped_ptr<ApplicationLoader> loader,
    const std::string& scheme) {
  SchemeToLoaderMap::iterator it = scheme_to_loader_.find(scheme);
  if (it != scheme_to_loader_.end())
    delete it->second;
  scheme_to_loader_[scheme] = loader.release();
}

void ApplicationManager::SetArgsForURL(const std::vector<std::string>& args,
                                       const GURL& url) {
  url_to_args_[url] = args;
}

void ApplicationManager::SetInterceptor(Interceptor* interceptor) {
  interceptor_ = interceptor;
}

ApplicationLoader* ApplicationManager::GetLoaderForURL(
    const GURL& url, IncludeDefaultLoader include_default_loader) {
  auto url_it = url_to_loader_.find(url);
  if (url_it != url_to_loader_.end())
    return url_it->second;
  auto scheme_it = scheme_to_loader_.find(url.scheme());
  if (scheme_it != scheme_to_loader_.end())
    return scheme_it->second;
  if (include_default_loader == INCLUDE_DEFAULT_LOADER)
    return default_loader_.get();
  return NULL;
}

void ApplicationManager::OnShellImplError(ShellImpl* shell_impl) {
  // Called from ~ShellImpl, so we do not need to call Destroy here.
  auto content_shell_it = content_shell_impls_.find(shell_impl);
  if (content_shell_it != content_shell_impls_.end()) {
    delete (*content_shell_it);
    content_shell_impls_.erase(content_shell_it);
    return;
  }
  const GURL url = shell_impl->url();
  const GURL requested_url = shell_impl->requested_url();
  // Remove the shell.
  URLToShellImplMap::iterator it = url_to_shell_impl_.find(url);
  DCHECK(it != url_to_shell_impl_.end());
  delete it->second;
  url_to_shell_impl_.erase(it);
  ApplicationLoader* loader = GetLoaderForURL(requested_url,
                                              INCLUDE_DEFAULT_LOADER);
  if (loader)
    loader->OnApplicationError(this, url);
  delegate_->OnApplicationError(requested_url);
}

void ApplicationManager::OnContentHandlerError(
    ContentHandlerConnection* content_handler) {
  // Remove the mapping to the content handler.
  auto it =
      url_to_content_handler_.find(content_handler->content_handler_url());
  DCHECK(it != url_to_content_handler_.end());
  delete it->second;
  url_to_content_handler_.erase(it);
}

ScopedMessagePipeHandle ApplicationManager::ConnectToServiceByName(
    const GURL& application_url,
    const std::string& interface_name) {
  StubServiceProvider* stub_sp = new StubServiceProvider;
  ServiceProviderPtr spp;
  BindToProxy(stub_sp, &spp);
  ConnectToApplication(application_url, GURL(), spp.Pass());
  MessagePipe pipe;
  stub_sp->GetRemoteServiceProvider()->ConnectToService(interface_name,
                                                        pipe.handle1.Pass());
  return pipe.handle0.Pass();
}

Array<String> ApplicationManager::GetArgsForURL(const GURL& url) {
  URLToArgsMap::const_iterator args_it = url_to_args_.find(url);
  if (args_it != url_to_args_.end())
    return Array<String>::From(args_it->second);
  return Array<String>();
}
}  // namespace mojo