// Copyright (c) 2012 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 "content/browser/download/mhtml_generation_manager.h"

#include "base/bind.h"
#include "base/platform_file.h"
#include "content/browser/renderer_host/render_process_host_impl.h"
#include "content/browser/renderer_host/render_view_host_impl.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/notification_service.h"
#include "content/public/browser/web_contents.h"
#include "content/common/view_messages.h"
#include "content/public/browser/notification_types.h"

namespace content {

MHTMLGenerationManager::Job::Job()
    : browser_file(base::kInvalidPlatformFileValue),
      renderer_file(IPC::InvalidPlatformFileForTransit()),
      process_id(-1),
      routing_id(-1) {
}

MHTMLGenerationManager::Job::~Job() {
}

MHTMLGenerationManager* MHTMLGenerationManager::GetInstance() {
  return Singleton<MHTMLGenerationManager>::get();
}

MHTMLGenerationManager::MHTMLGenerationManager() {
}

MHTMLGenerationManager::~MHTMLGenerationManager() {
}

void MHTMLGenerationManager::SaveMHTML(WebContents* web_contents,
                                       const base::FilePath& file,
                                       const GenerateMHTMLCallback& callback) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  int job_id = NewJob(web_contents, callback);

  base::ProcessHandle renderer_process =
      web_contents->GetRenderProcessHost()->GetHandle();
  BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
      base::Bind(&MHTMLGenerationManager::CreateFile, base::Unretained(this),
                 job_id, file, renderer_process));
}

void MHTMLGenerationManager::StreamMHTML(
    WebContents* web_contents,
    const base::PlatformFile browser_file,
    const GenerateMHTMLCallback& callback) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  int job_id = NewJob(web_contents, callback);

  base::ProcessHandle renderer_process =
      web_contents->GetRenderProcessHost()->GetHandle();
  IPC::PlatformFileForTransit renderer_file =
      IPC::GetFileHandleForProcess(browser_file, renderer_process, false);

  FileHandleAvailable(job_id, browser_file, renderer_file);
}


void MHTMLGenerationManager::MHTMLGenerated(int job_id, int64 mhtml_data_size) {
  JobFinished(job_id, mhtml_data_size);
}

void MHTMLGenerationManager::CreateFile(
    int job_id, const base::FilePath& file_path,
    base::ProcessHandle renderer_process) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  base::PlatformFile browser_file = base::CreatePlatformFile(file_path,
      base::PLATFORM_FILE_CREATE_ALWAYS | base::PLATFORM_FILE_WRITE,
      NULL, NULL);
  if (browser_file == base::kInvalidPlatformFileValue) {
    LOG(ERROR) << "Failed to create file to save MHTML at: " <<
        file_path.value();
  }

  IPC::PlatformFileForTransit renderer_file =
      IPC::GetFileHandleForProcess(browser_file, renderer_process, false);

  BrowserThread::PostTask(
      BrowserThread::UI,
      FROM_HERE,
      base::Bind(&MHTMLGenerationManager::FileHandleAvailable,
                 base::Unretained(this),
                 job_id,
                 browser_file,
                 renderer_file));
}

void MHTMLGenerationManager::FileHandleAvailable(int job_id,
    base::PlatformFile browser_file,
    IPC::PlatformFileForTransit renderer_file) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  if (browser_file == base::kInvalidPlatformFileValue) {
    LOG(ERROR) << "Failed to create file";
    JobFinished(job_id, -1);
    return;
  }

  IDToJobMap::iterator iter = id_to_job_.find(job_id);
  if (iter == id_to_job_.end()) {
    NOTREACHED();
    return;
  }

  Job& job = iter->second;
  job.browser_file = browser_file;
  job.renderer_file = renderer_file;

  RenderViewHostImpl* rvh = RenderViewHostImpl::FromID(
      job.process_id, job.routing_id);
  if (!rvh) {
    // The contents went away.
    JobFinished(job_id, -1);
    return;
  }

  rvh->Send(new ViewMsg_SavePageAsMHTML(rvh->GetRoutingID(), job_id,
                                        renderer_file));
}

void MHTMLGenerationManager::JobFinished(int job_id, int64 file_size) {
  IDToJobMap::iterator iter = id_to_job_.find(job_id);
  if (iter == id_to_job_.end()) {
    NOTREACHED();
    return;
  }

  Job& job = iter->second;
  job.callback.Run(file_size);

  BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
      base::Bind(&MHTMLGenerationManager::CloseFile, base::Unretained(this),
                 job.browser_file));

  id_to_job_.erase(job_id);
}

void MHTMLGenerationManager::CloseFile(base::PlatformFile file) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  base::ClosePlatformFile(file);
}

int MHTMLGenerationManager::NewJob(WebContents* web_contents,
                                   const GenerateMHTMLCallback& callback) {
  static int id_counter = 0;
  int job_id = id_counter++;
  Job& job = id_to_job_[job_id];
  job.process_id = web_contents->GetRenderProcessHost()->GetID();
  job.routing_id = web_contents->GetRenderViewHost()->GetRoutingID();
  job.callback = callback;
  if (!registrar_.IsRegistered(
          this,
          NOTIFICATION_RENDERER_PROCESS_TERMINATED,
          Source<RenderProcessHost>(web_contents->GetRenderProcessHost()))) {
    registrar_.Add(
        this,
        NOTIFICATION_RENDERER_PROCESS_TERMINATED,
        Source<RenderProcessHost>(web_contents->GetRenderProcessHost()));
  }
  return job_id;
}

void MHTMLGenerationManager::Observe(int type,
                                     const NotificationSource& source,
                                     const NotificationDetails& details) {
  DCHECK(type == NOTIFICATION_RENDERER_PROCESS_TERMINATED);
  RenderProcessHost* host = Source<RenderProcessHost>(source).ptr();
  registrar_.Remove(
      this,
      NOTIFICATION_RENDERER_PROCESS_TERMINATED,
      source);
  std::set<int> job_to_delete;
  for (IDToJobMap::iterator it = id_to_job_.begin(); it != id_to_job_.end();
       ++it) {
    if (it->second.process_id == host->GetID())
      job_to_delete.insert(it->first);
  }
  for (std::set<int>::iterator it = job_to_delete.begin();
       it != job_to_delete.end();
       ++it) {
    JobFinished(*it, -1);
  }
}

}  // namespace content