// Copyright (c) 2006-2008 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 <windows.h>
#include "chrome/plugin/plugin_process.h"

#include "base/basictypes.h"
#include "base/scoped_handle.h"
#include "chrome/common/ipc_channel.h"
#include "chrome/common/ipc_message_utils.h"
#include "chrome/common/plugin_messages.h"
#include "chrome/common/render_messages.h"
#include "webkit/glue/webkit_glue.h"

// Custom factory to allow us to pass additional ctor arguments.
class PluginProcessFactory : public ChildProcessFactoryInterface {
 public:
  explicit PluginProcessFactory(const std::wstring& plugin_path)
      : plugin_path_(plugin_path) {
  }

  virtual ChildProcess* Create(const std::wstring& channel_name) {
    return new PluginProcess(channel_name, plugin_path_);
  }

  const std::wstring& plugin_path_;
};

// How long to wait after there are no more plugin instances before killing the
// process.
static const int kProcessShutdownDelayMs = 10 * 1000;

// No AddRef required when using PluginProcess with RunnableMethod.  This is
// okay since the lifetime of the PluginProcess is always greater than the
// lifetime of PluginThread because it's a member variable.
template <> struct RunnableMethodTraits<PluginProcess> {
  static void RetainCallee(PluginProcess*) {}
  static void ReleaseCallee(PluginProcess*) {}
};

PluginProcess::PluginProcess(const std::wstring& channel_name,
                             const std::wstring& plugin_path) :
    plugin_path_(plugin_path),
#pragma warning(suppress: 4355)  // Okay to pass "this" here.
    plugin_thread_(this, channel_name) {
}

PluginProcess::~PluginProcess() {
}

bool PluginProcess::GlobalInit(const std::wstring &channel_name,
                               const std::wstring &plugin_path) {
  PluginProcessFactory factory(plugin_path);
  return ChildProcess::GlobalInit(channel_name, &factory);
}


// Note: may be called on any thread
void PluginProcess::OnFinalRelease() {
  // We override this to have the process linger for a few seconds to
  // better accomdate back/forth navigation. This avoids shutting down and
  // immediately starting a new plugin process. If a new channel is
  // opened in the interim, the current process will not be shutdown.
  main_thread_loop_->PostDelayedTask(FROM_HERE, NewRunnableMethod(
          this, &PluginProcess::OnProcessShutdownTimeout),
      kProcessShutdownDelayMs);
}

void PluginProcess::OnProcessShutdownTimeout() {
  if (ProcessRefCountIsZero()) {
    // The plugin process shutdown sequence is a request response based
    // mechanism, where we send out an initial feeler request to the plugin
    // process host instance in the browser to verify if it is ok to shutdown
    // the plugin process. The browser then sends back a response indicating
    // whether it is ok to shutdown.
    plugin_thread_.Send(new PluginProcessHostMsg_ShutdownRequest);
  }
}

// static
void PluginProcess::ShutdownProcessResponse(bool ok_to_shutdown) {
  if (ok_to_shutdown) {
    PluginProcess* plugin_process =
        static_cast<PluginProcess*>(child_process_);
    DCHECK(plugin_process);
    plugin_process->Shutdown();
  }
}

void PluginProcess::BrowserShutdown() {
  ShutdownProcessResponse(true);
}

void PluginProcess::Shutdown() {
  ChildProcess::OnFinalRelease();
}