// Copyright (c) 2009 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 "chrome/worker/webworkerclient_proxy.h"

#include "base/command_line.h"
#include "chrome/common/child_process.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/ipc_logging.h"
#include "chrome/common/worker_messages.h"
#include "chrome/renderer/webworker_proxy.h"
#include "chrome/worker/worker_thread.h"
#include "chrome/worker/nativewebworker_impl.h"
#include "webkit/api/public/WebString.h"
#include "webkit/api/public/WebURL.h"
#include "webkit/api/public/WebWorker.h"

using WebKit::WebString;
using WebKit::WebWorker;
using WebKit::WebWorkerClient;

namespace {

// How long to wait for worker to finish after it's been told to terminate.
static const int kMaxTimeForRunawayWorkerMs = 3000;

class KillProcessTask : public Task {
 public:
  KillProcessTask(WebWorkerClientProxy* proxy) : proxy_(proxy) { }
  void Run() {
    // This shuts down the process cleanly from the perspective of the browser
    // process, and avoids the crashed worker infobar from appearing to the new
    // page.
    proxy_->workerContextDestroyed();
  }
 private:
  WebWorkerClientProxy* proxy_;
};

}

static bool UrlIsNativeWorker(const GURL& url) {
  // If the renderer was not passed the switch to enable native workers,
  // then the URL should be treated as a JavaScript worker.
  if (!CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableNativeWebWorkers)) {
    return false;
  }
  // Based on the suffix, decide whether the url should be considered
  // a NativeWebWorker (for .nexe) or a WebWorker (for anything else).
  const std::string kNativeSuffix(".nexe");
  std::string worker_url = url.path();
  // Compute the start index of the suffix.
  std::string::size_type suffix_index =
      worker_url.length() - kNativeSuffix.length();
  std::string::size_type pos = worker_url.find(kNativeSuffix, suffix_index);
  return (suffix_index == pos);
}

WebWorkerClientProxy::WebWorkerClientProxy(const GURL& url, int route_id)
    : url_(url),
      route_id_(route_id) {
  if (UrlIsNativeWorker(url)) {
    // Launch a native worker.
    impl_ = NativeWebWorkerImpl::create(this);
  } else {
    // Launch a JavaScript worker.
    impl_ = WebWorker::create(this);
  }
  WorkerThread::current()->AddRoute(route_id_, this);
  ChildProcess::current()->AddRefProcess();
}

WebWorkerClientProxy::~WebWorkerClientProxy() {
  WorkerThread::current()->RemoveRoute(route_id_);
  ChildProcess::current()->ReleaseProcess();
}

void WebWorkerClientProxy::postMessageToWorkerObject(
    const WebString& message) {
  Send(new WorkerHostMsg_PostMessageToWorkerObject(route_id_, message));
}

void WebWorkerClientProxy::postExceptionToWorkerObject(
    const WebString& error_message,
    int line_number,
    const WebString& source_url) {
  Send(new WorkerHostMsg_PostExceptionToWorkerObject(
      route_id_, error_message, line_number, source_url));
}

void WebWorkerClientProxy::postConsoleMessageToWorkerObject(
    int destination,
    int source,
    int level,
    const WebString& message,
    int line_number,
    const WebString& source_url) {
  Send(new WorkerHostMsg_PostConsoleMessageToWorkerObject(
      route_id_, destination, source, level,message, line_number, source_url));
}

void WebWorkerClientProxy::confirmMessageFromWorkerObject(
    bool has_pending_activity) {
  Send(new WorkerHostMsg_ConfirmMessageFromWorkerObject(
      route_id_, has_pending_activity));
}

void WebWorkerClientProxy::reportPendingActivity(bool has_pending_activity) {
  Send(new WorkerHostMsg_ReportPendingActivity(
      route_id_, has_pending_activity));
}

void WebWorkerClientProxy::workerContextDestroyed() {
  Send(new WorkerHostMsg_WorkerContextDestroyed(route_id_));

  delete this;
}

WebKit::WebWorker* WebWorkerClientProxy::createWorker(
    WebKit::WebWorkerClient* client) {
  return new WebWorkerProxy(client, WorkerThread::current(), 0);
}

bool WebWorkerClientProxy::Send(IPC::Message* message) {
  return WorkerThread::current()->Send(message);
}

void WebWorkerClientProxy::OnMessageReceived(const IPC::Message& message) {
  if (!impl_)
    return;

  IPC_BEGIN_MESSAGE_MAP(WebWorkerClientProxy, message)
    IPC_MESSAGE_FORWARD(WorkerMsg_StartWorkerContext, impl_,
                        WebWorker::startWorkerContext)
    IPC_MESSAGE_HANDLER(WorkerMsg_TerminateWorkerContext,
                        OnTerminateWorkerContext)
    IPC_MESSAGE_FORWARD(WorkerMsg_PostMessageToWorkerContext, impl_,
                        WebWorker::postMessageToWorkerContext)
    IPC_MESSAGE_FORWARD(WorkerMsg_WorkerObjectDestroyed, impl_,
                        WebWorker::workerObjectDestroyed)
  IPC_END_MESSAGE_MAP()
}

void WebWorkerClientProxy::OnTerminateWorkerContext() {
  impl_->terminateWorkerContext();

  // Avoid a worker doing a while(1) from never exiting.
  if (CommandLine::ForCurrentProcess()->HasSwitch(
          switches::kWebWorkerShareProcesses)) {
    // Can't kill the process since there could be workers from other
    // renderer process.
    NOTIMPLEMENTED();
    return;
  }

  MessageLoop::current()->PostDelayedTask(FROM_HERE,
      new KillProcessTask(this), kMaxTimeForRunawayWorkerMs);
}