/*
 * Copyright (C) 2013 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#include "web/WebEmbeddedWorkerImpl.h"

#include "bindings/core/v8/SourceLocation.h"
#include "core/dom/Document.h"
#include "core/dom/ExecutionContextTask.h"
#include "core/dom/SecurityContext.h"
#include "core/fetch/SubstituteData.h"
#include "core/frame/csp/ContentSecurityPolicy.h"
#include "core/inspector/ConsoleMessage.h"
#include "core/inspector/InspectorInstrumentation.h"
#include "core/loader/FrameLoadRequest.h"
#include "core/workers/ParentFrameTaskRunners.h"
#include "core/workers/WorkerClients.h"
#include "core/workers/WorkerGlobalScope.h"
#include "core/workers/WorkerInspectorProxy.h"
#include "core/workers/WorkerLoaderProxy.h"
#include "core/workers/WorkerScriptLoader.h"
#include "core/workers/WorkerThreadStartupData.h"
#include "modules/serviceworkers/ServiceWorkerContainerClient.h"
#include "modules/serviceworkers/ServiceWorkerThread.h"
#include "platform/Histogram.h"
#include "platform/SharedBuffer.h"
#include "platform/heap/Handle.h"
#include "platform/network/ContentSecurityPolicyParsers.h"
#include "platform/network/ContentSecurityPolicyResponseHeaders.h"
#include "platform/network/NetworkUtils.h"
#include "platform/weborigin/SecurityOrigin.h"
#include "public/platform/Platform.h"
#include "public/platform/WebURLRequest.h"
#include "public/platform/modules/serviceworker/WebServiceWorkerProvider.h"
#include "public/web/WebConsoleMessage.h"
#include "public/web/WebDevToolsAgent.h"
#include "public/web/WebSettings.h"
#include "public/web/WebView.h"
#include "public/web/WebWorkerContentSettingsClientProxy.h"
#include "public/web/modules/serviceworker/WebServiceWorkerContextClient.h"
#include "public/web/modules/serviceworker/WebServiceWorkerNetworkProvider.h"
#include "web/IndexedDBClientImpl.h"
#include "web/ServiceWorkerGlobalScopeClientImpl.h"
#include "web/ServiceWorkerGlobalScopeProxy.h"
#include "web/WebDataSourceImpl.h"
#include "web/WebLocalFrameImpl.h"
#include "web/WorkerContentSettingsClient.h"
#include "wtf/Functional.h"
#include "wtf/PtrUtil.h"
#include <memory>

namespace blink {

WebEmbeddedWorker* WebEmbeddedWorker::create(
    WebServiceWorkerContextClient* client,
    WebWorkerContentSettingsClientProxy* contentSettingsClient) {
  return new WebEmbeddedWorkerImpl(WTF::wrapUnique(client),
                                   WTF::wrapUnique(contentSettingsClient));
}

static HashSet<WebEmbeddedWorkerImpl*>& runningWorkerInstances() {
  DEFINE_STATIC_LOCAL(HashSet<WebEmbeddedWorkerImpl*>, set, ());
  return set;
}

WebEmbeddedWorkerImpl::WebEmbeddedWorkerImpl(
    std::unique_ptr<WebServiceWorkerContextClient> client,
    std::unique_ptr<WebWorkerContentSettingsClientProxy> contentSettingsClient)
    : m_workerContextClient(std::move(client)),
      m_contentSettingsClient(std::move(contentSettingsClient)),
      m_workerInspectorProxy(WorkerInspectorProxy::create()),
      m_webView(nullptr),
      m_mainFrame(nullptr),
      m_loadingShadowPage(false),
      m_askedToTerminate(false),
      m_pauseAfterDownloadState(DontPauseAfterDownload),
      m_waitingForDebuggerState(NotWaitingForDebugger) {
  runningWorkerInstances().add(this);
}

WebEmbeddedWorkerImpl::~WebEmbeddedWorkerImpl() {
  // Prevent onScriptLoaderFinished from deleting 'this'.
  m_askedToTerminate = true;

  if (m_workerThread)
    m_workerThread->terminateAndWait();

  DCHECK(runningWorkerInstances().contains(this));
  runningWorkerInstances().remove(this);
  DCHECK(m_webView);

  // Detach the client before closing the view to avoid getting called back.
  m_mainFrame->setClient(0);

  if (m_workerGlobalScopeProxy) {
    m_workerGlobalScopeProxy->detach();
    m_workerGlobalScopeProxy.clear();
  }

  m_webView->close();
  m_mainFrame->close();
  if (m_loaderProxy)
    m_loaderProxy->detachProvider(this);
}

void WebEmbeddedWorkerImpl::startWorkerContext(
    const WebEmbeddedWorkerStartData& data) {
  DCHECK(!m_askedToTerminate);
  DCHECK(!m_mainScriptLoader);
  DCHECK_EQ(m_pauseAfterDownloadState, DontPauseAfterDownload);
  m_workerStartData = data;

  // TODO(mkwst): This really needs to be piped through from the requesting
  // document, like we're doing for SharedWorkers. That turns out to be
  // incredibly convoluted, and since ServiceWorkers are locked to the same
  // origin as the page which requested them, the only time it would come
  // into play is a DNS poisoning attack after the page load. It's something
  // we should fix, but we're taking this shortcut for the prototype.
  //
  // https://crbug.com/590714
  KURL scriptURL = m_workerStartData.scriptURL;
  m_workerStartData.addressSpace = WebAddressSpacePublic;
  if (NetworkUtils::isReservedIPAddress(scriptURL.host()))
    m_workerStartData.addressSpace = WebAddressSpacePrivate;
  if (SecurityOrigin::create(scriptURL)->isLocalhost())
    m_workerStartData.addressSpace = WebAddressSpaceLocal;

  if (data.pauseAfterDownloadMode ==
      WebEmbeddedWorkerStartData::PauseAfterDownload)
    m_pauseAfterDownloadState = DoPauseAfterDownload;
  prepareShadowPageForLoader();
}

void WebEmbeddedWorkerImpl::terminateWorkerContext() {
  if (m_askedToTerminate)
    return;
  m_askedToTerminate = true;
  if (m_loadingShadowPage) {
    // This deletes 'this'.
    m_workerContextClient->workerContextFailedToStart();
    return;
  }
  if (m_mainScriptLoader) {
    m_mainScriptLoader->cancel();
    m_mainScriptLoader.clear();
    // This deletes 'this'.
    m_workerContextClient->workerContextFailedToStart();
    return;
  }
  if (!m_workerThread) {
    // The worker thread has not been created yet if the worker is asked to
    // terminate during waiting for debugger or paused after download.
    DCHECK(m_workerStartData.waitForDebuggerMode ==
               WebEmbeddedWorkerStartData::WaitForDebugger ||
           m_pauseAfterDownloadState == IsPausedAfterDownload);
    // This deletes 'this'.
    m_workerContextClient->workerContextFailedToStart();
    return;
  }
  m_workerThread->terminate();
  m_workerInspectorProxy->workerThreadTerminated();
}

void WebEmbeddedWorkerImpl::resumeAfterDownload() {
  DCHECK(!m_askedToTerminate);
  DCHECK_EQ(m_pauseAfterDownloadState, IsPausedAfterDownload);

  m_pauseAfterDownloadState = DontPauseAfterDownload;
  startWorkerThread();
}

void WebEmbeddedWorkerImpl::attachDevTools(const WebString& hostId,
                                           int sessionId) {
  WebDevToolsAgent* devtoolsAgent = m_mainFrame->devToolsAgent();
  if (devtoolsAgent)
    devtoolsAgent->attach(hostId, sessionId);
}

void WebEmbeddedWorkerImpl::reattachDevTools(const WebString& hostId,
                                             int sessionId,
                                             const WebString& savedState) {
  WebDevToolsAgent* devtoolsAgent = m_mainFrame->devToolsAgent();
  if (devtoolsAgent)
    devtoolsAgent->reattach(hostId, sessionId, savedState);
  resumeStartup();
}

void WebEmbeddedWorkerImpl::detachDevTools() {
  WebDevToolsAgent* devtoolsAgent = m_mainFrame->devToolsAgent();
  if (devtoolsAgent)
    devtoolsAgent->detach();
}

void WebEmbeddedWorkerImpl::dispatchDevToolsMessage(int sessionId,
                                                    int callId,
                                                    const WebString& method,
                                                    const WebString& message) {
  if (m_askedToTerminate)
    return;
  WebDevToolsAgent* devtoolsAgent = m_mainFrame->devToolsAgent();
  if (devtoolsAgent)
    devtoolsAgent->dispatchOnInspectorBackend(sessionId, callId, method,
                                              message);
}

void WebEmbeddedWorkerImpl::addMessageToConsole(
    const WebConsoleMessage& message) {
  MessageLevel webCoreMessageLevel;
  switch (message.level) {
    case WebConsoleMessage::LevelDebug:
      webCoreMessageLevel = DebugMessageLevel;
      break;
    case WebConsoleMessage::LevelLog:
      webCoreMessageLevel = LogMessageLevel;
      break;
    case WebConsoleMessage::LevelWarning:
      webCoreMessageLevel = WarningMessageLevel;
      break;
    case WebConsoleMessage::LevelError:
      webCoreMessageLevel = ErrorMessageLevel;
      break;
    default:
      NOTREACHED();
      return;
  }

  m_mainFrame->frame()->document()->addConsoleMessage(ConsoleMessage::create(
      OtherMessageSource, webCoreMessageLevel, message.text,
      SourceLocation::create(message.url, message.lineNumber,
                             message.columnNumber, nullptr)));
}

void WebEmbeddedWorkerImpl::postMessageToPageInspector(const String& message) {
  m_workerInspectorProxy->dispatchMessageFromWorker(message);
}

void WebEmbeddedWorkerImpl::postTaskToLoader(
    const WebTraceLocation& location,
    std::unique_ptr<ExecutionContextTask> task) {
  // TODO(hiroshige,yuryu): Make this not use ExecutionContextTask and
  // consider using m_mainThreadTaskRunners->get(TaskType::Networking)
  // instead.
  m_mainFrame->frame()->document()->postTask(location, std::move(task));
}

void WebEmbeddedWorkerImpl::postTaskToWorkerGlobalScope(
    const WebTraceLocation& location,
    std::unique_ptr<ExecutionContextTask> task) {
  if (m_askedToTerminate || !m_workerThread)
    return;
  m_workerThread->postTask(location, std::move(task));
}

void WebEmbeddedWorkerImpl::prepareShadowPageForLoader() {
  // Create 'shadow page', which is never displayed and is used mainly to
  // provide a context for loading on the main thread.
  //
  // FIXME: This does mostly same as WebSharedWorkerImpl::initializeLoader.
  // This code, and probably most of the code in this class should be shared
  // with SharedWorker.
  DCHECK(!m_webView);
  m_webView = WebView::create(nullptr, WebPageVisibilityStateVisible);
  WebSettings* settings = m_webView->settings();
  // FIXME: http://crbug.com/363843. This needs to find a better way to
  // not create graphics layers.
  settings->setAcceleratedCompositingEnabled(false);
  // Currently we block all mixed-content requests from a ServiceWorker.
  // FIXME: When we support FetchEvent.default(), we should relax this
  // restriction.
  settings->setStrictMixedContentChecking(true);
  settings->setAllowRunningOfInsecureContent(false);
  settings->setDataSaverEnabled(m_workerStartData.dataSaverEnabled);
  m_mainFrame = toWebLocalFrameImpl(
      WebLocalFrame::create(WebTreeScopeType::Document, this));
  m_webView->setMainFrame(m_mainFrame.get());
  m_mainFrame->setDevToolsAgentClient(this);

  // If we were asked to wait for debugger then it is the good time to do that.
  m_workerContextClient->workerReadyForInspection();
  if (m_workerStartData.waitForDebuggerMode ==
      WebEmbeddedWorkerStartData::WaitForDebugger) {
    m_waitingForDebuggerState = WaitingForDebugger;
    return;
  }

  loadShadowPage();
}

void WebEmbeddedWorkerImpl::loadShadowPage() {
  // Construct substitute data source for the 'shadow page'. We only need it
  // to have same origin as the worker so the loading checks work correctly.
  CString content("");
  RefPtr<SharedBuffer> buffer(
      SharedBuffer::create(content.data(), content.length()));
  m_loadingShadowPage = true;
  m_mainFrame->frame()->loader().load(
      FrameLoadRequest(0, ResourceRequest(m_workerStartData.scriptURL),
                       SubstituteData(buffer, "text/html", "UTF-8", KURL())));
}

void WebEmbeddedWorkerImpl::willSendRequest(WebLocalFrame* frame,
                                            WebURLRequest& request) {
  if (m_networkProvider)
    m_networkProvider->willSendRequest(frame->dataSource(), request);
}

void WebEmbeddedWorkerImpl::didFinishDocumentLoad(WebLocalFrame* frame) {
  DCHECK(!m_mainScriptLoader);
  DCHECK(!m_networkProvider);
  DCHECK(m_mainFrame);
  DCHECK(m_workerContextClient);
  DCHECK(m_loadingShadowPage);
  DCHECK(!m_askedToTerminate);
  m_loadingShadowPage = false;
  m_networkProvider =
      WTF::wrapUnique(m_workerContextClient->createServiceWorkerNetworkProvider(
          frame->dataSource()));
  m_mainScriptLoader = WorkerScriptLoader::create();
  m_mainScriptLoader->setRequestContext(
      WebURLRequest::RequestContextServiceWorker);
  m_mainScriptLoader->loadAsynchronously(
      *m_mainFrame->frame()->document(), m_workerStartData.scriptURL,
      DenyCrossOriginRequests, m_workerStartData.addressSpace, nullptr,
      bind(&WebEmbeddedWorkerImpl::onScriptLoaderFinished,
           WTF::unretained(this)));
  // Do nothing here since onScriptLoaderFinished() might have been already
  // invoked and |this| might have been deleted at this point.
}

void WebEmbeddedWorkerImpl::sendProtocolMessage(int sessionId,
                                                int callId,
                                                const WebString& message,
                                                const WebString& state) {
  m_workerContextClient->sendDevToolsMessage(sessionId, callId, message, state);
}

void WebEmbeddedWorkerImpl::resumeStartup() {
  bool wasWaiting = (m_waitingForDebuggerState == WaitingForDebugger);
  m_waitingForDebuggerState = NotWaitingForDebugger;
  if (wasWaiting)
    loadShadowPage();
}

WebDevToolsAgentClient::WebKitClientMessageLoop*
WebEmbeddedWorkerImpl::createClientMessageLoop() {
  return m_workerContextClient->createDevToolsMessageLoop();
}

void WebEmbeddedWorkerImpl::onScriptLoaderFinished() {
  DCHECK(m_mainScriptLoader);
  if (m_askedToTerminate)
    return;

  // The browser is expected to associate a registration and then load the
  // script. If there's no associated registration, the browser could not
  // successfully handle the SetHostedVersionID IPC, and the script load came
  // through the normal network stack rather than through service worker
  // loading code.
  if (!m_workerContextClient->hasAssociatedRegistration() ||
      m_mainScriptLoader->failed()) {
    m_mainScriptLoader.clear();
    // This deletes 'this'.
    m_workerContextClient->workerContextFailedToStart();
    return;
  }
  m_workerContextClient->workerScriptLoaded();

  DEFINE_STATIC_LOCAL(CustomCountHistogram, scriptSizeHistogram,
                      ("ServiceWorker.ScriptSize", 1000, 5000000, 50));
  scriptSizeHistogram.count(m_mainScriptLoader->script().length());
  if (m_mainScriptLoader->cachedMetadata()) {
    DEFINE_STATIC_LOCAL(
        CustomCountHistogram, scriptCachedMetadataSizeHistogram,
        ("ServiceWorker.ScriptCachedMetadataSize", 1000, 50000000, 50));
    scriptCachedMetadataSizeHistogram.count(
        m_mainScriptLoader->cachedMetadata()->size());
  }

  if (m_pauseAfterDownloadState == DoPauseAfterDownload) {
    m_pauseAfterDownloadState = IsPausedAfterDownload;
    return;
  }
  startWorkerThread();
}

void WebEmbeddedWorkerImpl::startWorkerThread() {
  DCHECK_EQ(m_pauseAfterDownloadState, DontPauseAfterDownload);
  DCHECK(!m_askedToTerminate);

  Document* document = m_mainFrame->frame()->document();

  // FIXME: this document's origin is pristine and without any extra privileges.
  // (crbug.com/254993)
  SecurityOrigin* starterOrigin = document->getSecurityOrigin();

  WorkerClients* workerClients = WorkerClients::create();
  provideContentSettingsClientToWorker(workerClients,
                                       std::move(m_contentSettingsClient));
  provideIndexedDBClientToWorker(workerClients, IndexedDBClientImpl::create());
  provideServiceWorkerGlobalScopeClientToWorker(
      workerClients,
      ServiceWorkerGlobalScopeClientImpl::create(*m_workerContextClient));
  provideServiceWorkerContainerClientToWorker(
      workerClients,
      WTF::wrapUnique(m_workerContextClient->createServiceWorkerProvider()));

  // We need to set the CSP to both the shadow page's document and the
  // ServiceWorkerGlobalScope.
  document->initContentSecurityPolicy(
      m_mainScriptLoader->releaseContentSecurityPolicy());
  if (!m_mainScriptLoader->getReferrerPolicy().isNull()) {
    document->parseAndSetReferrerPolicy(
        m_mainScriptLoader->getReferrerPolicy());
  }

  KURL scriptURL = m_mainScriptLoader->url();
  WorkerThreadStartMode startMode =
      m_workerInspectorProxy->workerStartMode(document);
  std::unique_ptr<WorkerSettings> workerSettings =
      WTF::wrapUnique(new WorkerSettings(document->settings()));

  std::unique_ptr<WorkerThreadStartupData> startupData =
      WorkerThreadStartupData::create(
          scriptURL, m_workerStartData.userAgent, m_mainScriptLoader->script(),
          m_mainScriptLoader->releaseCachedMetadata(), startMode,
          document->contentSecurityPolicy()->headers().get(),
          m_mainScriptLoader->getReferrerPolicy(), starterOrigin, workerClients,
          m_mainScriptLoader->responseAddressSpace(),
          m_mainScriptLoader->originTrialTokens(), std::move(workerSettings),
          static_cast<V8CacheOptions>(m_workerStartData.v8CacheOptions));

  m_mainScriptLoader.clear();

  // We have a dummy document here for loading but it doesn't really represent
  // the document/frame of associated document(s) for this worker. Here we
  // populate the task runners with null document not to confuse the frame
  // scheduler (which will end up using the thread's default task runner).
  m_mainThreadTaskRunners = ParentFrameTaskRunners::create(nullptr);

  m_workerGlobalScopeProxy = ServiceWorkerGlobalScopeProxy::create(
      *this, *document, *m_workerContextClient);
  m_loaderProxy = WorkerLoaderProxy::create(this);
  m_workerThread =
      ServiceWorkerThread::create(m_loaderProxy, *m_workerGlobalScopeProxy);
  m_workerThread->start(std::move(startupData));
  m_workerInspectorProxy->workerThreadCreated(document, m_workerThread.get(),
                                              scriptURL);
}

}  // namespace blink