// 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/browser/browser_about_handler.h"

#include <string>
#include <vector>

#include "app/l10n_util.h"
#include "app/resource_bundle.h"
#include "base/file_version_info.h"
#include "base/histogram.h"
#include "base/i18n/number_formatting.h"
#include "base/path_service.h"
#include "base/platform_thread.h"
#include "base/stats_table.h"
#include "base/string_piece.h"
#include "base/string_util.h"
#include "base/thread.h"
#include "base/tracked_objects.h"
#include "chrome/browser/browser.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/chrome_thread.h"
#include "chrome/browser/dom_ui/chrome_url_data_manager.h"
#include "chrome/browser/google_service_auth_error.h"
#include "chrome/browser/memory_details.h"
#include "chrome/browser/net/dns_global.h"
#include "chrome/browser/profile.h"
#include "chrome/browser/profile_manager.h"
#include "chrome/browser/renderer_host/render_process_host.h"
#include "chrome/browser/renderer_host/render_view_host.h"
#include "chrome/browser/sync/profile_sync_service.h"
#include "chrome/common/chrome_paths.h"
#include "chrome/common/histogram_synchronizer.h"
#include "chrome/common/jstemplate_builder.h"
#include "chrome/common/platform_util.h"
#include "chrome/common/pref_names.h"
#include "chrome/common/pref_service.h"
#include "chrome/common/render_messages.h"
#include "chrome/common/url_constants.h"
#include "chrome/renderer/about_handler.h"
#include "googleurl/src/gurl.h"
#include "grit/browser_resources.h"
#include "grit/chromium_strings.h"
#include "grit/generated_resources.h"
#include "grit/locale_settings.h"
#include "webkit/glue/webkit_glue.h"
#ifdef CHROME_V8
#include "v8/include/v8.h"
#endif

#if defined(OS_WIN)
#include "chrome/browser/views/about_ipc_dialog.h"
#include "chrome/browser/views/about_network_dialog.h"
#elif defined(OS_CHROMEOS)
#include "chrome/browser/chromeos/version_loader.h"
#elif defined(OS_MACOSX)
#include "chrome/browser/cocoa/about_ipc_dialog.h"
#endif

#if defined(USE_TCMALLOC)
#include "third_party/tcmalloc/chromium/src/google/malloc_extension.h"
#endif

using sync_api::SyncManager;

using base::Time;
using base::TimeDelta;

#if defined(USE_TCMALLOC)
// Glue between the callback task and the method in the singleton.
void AboutTcmallocRendererCallback(base::ProcessId pid, std::string output) {
  Singleton<AboutTcmallocOutputs>::get()->RendererCallback(pid, output);
}
#endif

namespace {

// The paths used for the about pages.
const char kDnsPath[] = "dns";
const char kHistogramsPath[] = "histograms";
const char kObjectsPath[] = "objects";
const char kMemoryRedirectPath[] = "memory-redirect";
const char kMemoryPath[] = "memory";
const char kTcmallocPath[] = "tcmalloc";
const char kPluginsPath[] = "plugins";
const char kStatsPath[] = "stats";
const char kVersionPath[] = "version";
const char kCreditsPath[] = "credits";
const char kTermsPath[] = "terms";
const char kSyncPath[] = "sync";

#if defined(OS_CHROMEOS)
const char kOSCreditsPath[] = "os-credits";
#endif

// Points to the singleton AboutSource object, if any.
ChromeURLDataManager::DataSource* about_source = NULL;

// When you type about:memory, it actually loads an intermediate URL that
// redirects you to the final page. This avoids the problem where typing
// "about:memory" on the new tab page or any other page where a process
// transition would occur to the about URL will cause some confusion.
//
// The problem is that during the processing of the memory page, there are two
// processes active, the original and the destination one. This can create the
// impression that we're using more resources than we actually are. This
// redirect solves the problem by eliminating the process transition during the
// time that about memory is being computed.
std::string GetAboutMemoryRedirectResponse() {
  return "<meta http-equiv=\"refresh\" "
      "content=\"0;chrome://about/memory\">";
}

class AboutSource : public ChromeURLDataManager::DataSource {
 public:
  // Creates our datasource.
  AboutSource();

  // Called when the network layer has requested a resource underneath
  // the path we registered.
  virtual void StartDataRequest(const std::string& path,
                                bool is_off_the_record,
                                int request_id);

  virtual std::string GetMimeType(const std::string&) const {
    return "text/html";
  }

  // Send the response data.
  void FinishDataRequest(const std::string& html, int request_id);

 private:
  virtual ~AboutSource();

  DISALLOW_COPY_AND_ASSIGN(AboutSource);
};

// Handling about:memory is complicated enough to encapsulate its related
// methods into a single class. The user should create it (on the heap) and call
// its |StartFetch()| method.
class AboutMemoryHandler : public MemoryDetails {
 public:
  AboutMemoryHandler(AboutSource* source, int request_id)
    : source_(source), request_id_(request_id) {}


  virtual void OnDetailsAvailable();

 private:
  ~AboutMemoryHandler() {}

  void BindProcessMetrics(DictionaryValue* data,
                          ProcessMemoryInformation* info);
  void AppendProcess(ListValue* child_data, ProcessMemoryInformation* info);

  scoped_refptr<AboutSource> source_;
  int request_id_;

  DISALLOW_COPY_AND_ASSIGN(AboutMemoryHandler);
};

#if defined(OS_CHROMEOS)
// ChromeOSAboutVersionHandler is responsible for loading the Chrome OS
// version.
// ChromeOSAboutVersionHandler handles deleting itself once the version has
// been obtained and AboutSource notified.
class ChromeOSAboutVersionHandler {
 public:
  ChromeOSAboutVersionHandler(AboutSource* source, int request_id);

  // Callback from chromeos::VersionLoader giving the version.
  void OnVersion(chromeos::VersionLoader::Handle handle,
                 std::string version);

 private:
  // Where the results are fed to.
  scoped_refptr<AboutSource> source_;

  // ID identifying the request.
  int request_id_;

  // Handles asynchronously loading the version.
  chromeos::VersionLoader loader_;

  // Used to request the version.
  CancelableRequestConsumer consumer_;

  DISALLOW_COPY_AND_ASSIGN(ChromeOSAboutVersionHandler);
};
#endif

// Individual about handlers ---------------------------------------------------

std::string AboutCredits() {
  static const std::string credits_html =
      ResourceBundle::GetSharedInstance().GetDataResource(
          IDR_CREDITS_HTML);

  return credits_html;
}

#if defined(OS_CHROMEOS)
std::string AboutOSCredits() {
  static const std::string os_credits_html =
      ResourceBundle::GetSharedInstance().GetDataResource(
          IDR_OS_CREDITS_HTML);

  return os_credits_html;
}
#endif

// AboutDnsHandler bounces the request back to the IO thread to collect
// the DNS information.
class AboutDnsHandler : public base::RefCountedThreadSafe<AboutDnsHandler> {
 public:
  static void Start(AboutSource* source, int request_id) {
    scoped_refptr<AboutDnsHandler> handler =
        new AboutDnsHandler(source, request_id);
    handler->StartOnUIThread();
  }

 private:
  AboutDnsHandler(AboutSource* source, int request_id)
      : source_(source),
        request_id_(request_id) {
    DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
  }

  // Calls FinishOnUIThread() on completion.
  void StartOnUIThread() {
    DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
    ChromeThread::PostTask(
        ChromeThread::IO, FROM_HERE,
        NewRunnableMethod(this, &AboutDnsHandler::StartOnIOThread));
  }

  void StartOnIOThread() {
    DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));

    std::string data;
    chrome_browser_net::DnsPrefetchGetHtmlInfo(&data);

    ChromeThread::PostTask(
        ChromeThread::UI, FROM_HERE,
        NewRunnableMethod(this, &AboutDnsHandler::FinishOnUIThread, data));
  }

  void FinishOnUIThread(const std::string& data) {
    DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
    source_->FinishDataRequest(data, request_id_);
  }

  // Where the results are fed to.
  scoped_refptr<AboutSource> source_;

  // ID identifying the request.
  int request_id_;

  DISALLOW_COPY_AND_ASSIGN(AboutDnsHandler);
};

#if defined(USE_TCMALLOC)
std::string AboutTcmalloc(const std::string& query) {
  std::string data;
  AboutTcmallocOutputsType* outputs =
      Singleton<AboutTcmallocOutputs>::get()->outputs();

  // Display any stats for which we sent off requests the last time.
  data.append("<html><head><title>About tcmalloc</title></head><body>\n");
  data.append("<p>Stats as of last page load;");
  data.append("reload to get stats as of this page load.</p>\n");
  data.append("<table width=\"100%\">\n");
  for (AboutTcmallocOutputsType::const_iterator oit = outputs->begin();
       oit != outputs->end();
       oit++) {
    data.append("<tr><td bgcolor=\"yellow\">");
    data.append(oit->first);
    data.append("</td></tr>\n");
    data.append("<tr><td><pre>\n");
    data.append(oit->second);
    data.append("</pre></td></tr>\n");
  }
  data.append("</table>\n");
  data.append("</body></html>\n");

  // Reset our collector singleton.
  outputs->clear();

  // Populate the collector with stats from the local browser process
  // and send off requests to all the renderer processes.
  char buffer[1024 * 32];
  MallocExtension::instance()->GetStats(buffer, sizeof(buffer));
  std::string browser("Browser");
  Singleton<AboutTcmallocOutputs>::get()->SetOutput(browser, buffer);
  RenderProcessHost::iterator it(RenderProcessHost::AllHostsIterator());
  while (!it.IsAtEnd()) {
    it.GetCurrentValue()->Send(new ViewMsg_GetRendererTcmalloc);
    it.Advance();
  }

  return data;
}
#endif

std::string AboutHistograms(const std::string& query) {
  TimeDelta wait_time = TimeDelta::FromMilliseconds(10000);

  HistogramSynchronizer* current_synchronizer =
      HistogramSynchronizer::CurrentSynchronizer();
  DCHECK(current_synchronizer != NULL);
  current_synchronizer->FetchRendererHistogramsSynchronously(wait_time);

  std::string data;
  StatisticsRecorder::WriteHTMLGraph(query, &data);
  return data;
}

void AboutMemory(AboutSource* source, int request_id) {
  // The AboutMemoryHandler cleans itself up, but |StartFetch()| will want the
  // refcount to be greater than 0.
  scoped_refptr<AboutMemoryHandler>
      handler(new AboutMemoryHandler(source, request_id));
  handler->StartFetch();
}

std::string AboutObjects(const std::string& query) {
  std::string data;
  tracked_objects::ThreadData::WriteHTML(query, &data);
  return data;
}

std::string AboutPlugins() {
  // Strings used in the JsTemplate file.
  DictionaryValue localized_strings;
  localized_strings.SetString(L"title",
      l10n_util::GetString(IDS_ABOUT_PLUGINS_TITLE));
  localized_strings.SetString(L"headingPlugs",
      l10n_util::GetString(IDS_ABOUT_PLUGINS_HEADING_PLUGS));
  localized_strings.SetString(L"headingNoPlugs",
      l10n_util::GetString(IDS_ABOUT_PLUGINS_HEADING_NOPLUGS));
  localized_strings.SetString(L"filename",
      l10n_util::GetString(IDS_ABOUT_PLUGINS_FILENAME_LABEL));
  localized_strings.SetString(L"mimetype",
      l10n_util::GetString(IDS_ABOUT_PLUGINS_MIMETYPE_LABEL));
  localized_strings.SetString(L"description",
      l10n_util::GetString(IDS_ABOUT_PLUGINS_DESCRIPTION_LABEL));
  localized_strings.SetString(L"suffixes",
      l10n_util::GetString(IDS_ABOUT_PLUGINS_SUFFIX_LABEL));
  localized_strings.SetString(L"enabled",
      l10n_util::GetString(IDS_ABOUT_PLUGINS_ENABLED_LABEL));
  localized_strings.SetString(L"enabled_yes",
      l10n_util::GetString(IDS_ABOUT_PLUGINS_ENABLED_YES));
  localized_strings.SetString(L"enabled_no",
      l10n_util::GetString(IDS_ABOUT_PLUGINS_ENABLED_NO));

  static const base::StringPiece plugins_html(
      ResourceBundle::GetSharedInstance().GetRawDataResource(
          IDR_ABOUT_PLUGINS_HTML));

  return jstemplate_builder::GetTemplateHtml(
      plugins_html, &localized_strings, "t" /* template root node id */);
}

std::string AboutStats() {
  // We keep the DictionaryValue tree live so that we can do delta
  // stats computations across runs.
  static DictionaryValue root;

  StatsTable* table = StatsTable::current();
  if (!table)
    return std::string();

  // We maintain two lists - one for counters and one for timers.
  // Timers actually get stored on both lists.
  ListValue* counters;
  if (!root.GetList(L"counters", &counters)) {
    counters = new ListValue();
    root.Set(L"counters", counters);
  }

  ListValue* timers;
  if (!root.GetList(L"timers", &timers)) {
    timers = new ListValue();
    root.Set(L"timers", timers);
  }

  // NOTE: Counters start at index 1.
  for (int index = 1; index <= table->GetMaxCounters(); index++) {
    // Get the counter's full name
    std::string full_name = table->GetRowName(index);
    if (full_name.length() == 0)
      break;
    DCHECK(full_name[1] == ':');
    char counter_type = full_name[0];
    std::string name = full_name.substr(2);

    // JSON doesn't allow '.' in names.
    size_t pos;
    while ((pos = name.find(".")) != std::string::npos)
      name.replace(pos, 1, ":");

    // Try to see if this name already exists.
    DictionaryValue* counter = NULL;
    for (size_t scan_index = 0;
         scan_index < counters->GetSize(); scan_index++) {
      DictionaryValue* dictionary;
      if (counters->GetDictionary(scan_index, &dictionary)) {
        std::wstring scan_name;
        if (dictionary->GetString(L"name", &scan_name) &&
            WideToASCII(scan_name) == name) {
          counter = dictionary;
        }
      } else {
        NOTREACHED();  // Should always be there
      }
    }

    if (counter == NULL) {
      counter = new DictionaryValue();
      counter->SetString(L"name", ASCIIToWide(name));
      counters->Append(counter);
    }

    switch (counter_type) {
      case 'c':
        {
          int new_value = table->GetRowValue(index);
          int prior_value = 0;
          int delta = 0;
          if (counter->GetInteger(L"value", &prior_value)) {
            delta = new_value - prior_value;
          }
          counter->SetInteger(L"value", new_value);
          counter->SetInteger(L"delta", delta);
        }
        break;
      case 'm':
        {
          // TODO(mbelshe): implement me.
        }
        break;
      case 't':
        {
          int time = table->GetRowValue(index);
          counter->SetInteger(L"time", time);

          // Store this on the timers list as well.
          timers->Append(counter);
        }
        break;
      default:
        NOTREACHED();
    }
  }

  // Get about_stats.html
  static const base::StringPiece stats_html(
      ResourceBundle::GetSharedInstance().GetRawDataResource(
          IDR_ABOUT_STATS_HTML));

  // Create jstemplate and return.
  std::string data = jstemplate_builder::GetTemplateHtml(
      stats_html, &root, "t" /* template root node id */);

  // Clear the timer list since we stored the data in the timers list as well.
  for (int index = static_cast<int>(timers->GetSize())-1; index >= 0;
       index--) {
    Value* value;
    timers->Remove(index, &value);
    // We don't care about the value pointer; it's still tracked
    // on the counters list.
  }

  return data;
}

std::string AboutTerms() {
  static const std::string terms_html =
      ResourceBundle::GetSharedInstance().GetDataResource(
          IDR_TERMS_HTML);

  return terms_html;
}

std::string AboutVersion(DictionaryValue* localized_strings) {
  localized_strings->SetString(L"title",
      l10n_util::GetString(IDS_ABOUT_VERSION_TITLE));
  scoped_ptr<FileVersionInfo> version_info(
      FileVersionInfo::CreateFileVersionInfoForCurrentModule());
  if (version_info == NULL) {
    DLOG(ERROR) << "Unable to create FileVersionInfo object";
    return std::string();
  }

  std::wstring webkit_version = UTF8ToWide(webkit_glue::GetWebKitVersion());
#ifdef CHROME_V8
  const char* v8_vers = v8::V8::GetVersion();
  std::wstring js_version = UTF8ToWide(v8_vers);
  std::wstring js_engine = L"V8";
#else
  std::wstring js_version = webkit_version;
  std::wstring js_engine = L"JavaScriptCore";
#endif

  localized_strings->SetString(L"name",
      l10n_util::GetString(IDS_PRODUCT_NAME));
  localized_strings->SetString(L"version", version_info->file_version());
  std::wstring mod = UTF16ToWide(platform_util::GetVersionStringModifier());
  localized_strings->SetString(L"version_modifier", mod);
  localized_strings->SetString(L"js_engine", js_engine);
  localized_strings->SetString(L"js_version", js_version);
  localized_strings->SetString(L"webkit_version", webkit_version);
  localized_strings->SetString(L"company",
      l10n_util::GetString(IDS_ABOUT_VERSION_COMPANY_NAME));
  localized_strings->SetString(L"copyright",
      l10n_util::GetString(IDS_ABOUT_VERSION_COPYRIGHT));
  localized_strings->SetString(L"cl", version_info->last_change());
  if (version_info->is_official_build()) {
    localized_strings->SetString(L"official",
      l10n_util::GetString(IDS_ABOUT_VERSION_OFFICIAL));
  } else {
    localized_strings->SetString(L"official",
      l10n_util::GetString(IDS_ABOUT_VERSION_UNOFFICIAL));
  }
  localized_strings->SetString(L"useragent",
      UTF8ToWide(webkit_glue::GetUserAgent(GURL())));

  static const std::string version_html(
      ResourceBundle::GetSharedInstance().GetDataResource(
          IDR_ABOUT_VERSION_HTML));

  std::string output = version_html;
  jstemplate_builder::AppendJsonHtml(localized_strings, &output);
  jstemplate_builder::AppendI18nTemplateSourceHtml(&output);
  jstemplate_builder::AppendI18nTemplateProcessHtml(&output);
  jstemplate_builder::AppendJsTemplateSourceHtml(&output);
  jstemplate_builder::AppendJsTemplateProcessHtml("t", &output);
  return output;
}

static void AddBoolSyncDetail(ListValue* details, const std::wstring& stat_name,
                              bool stat_value) {
  DictionaryValue* val = new DictionaryValue;
  val->SetString(L"stat_name", stat_name);
  val->SetBoolean(L"stat_value", stat_value);
  details->Append(val);
}

static void AddIntSyncDetail(ListValue* details, const std::wstring& stat_name,
                             int64 stat_value) {
  DictionaryValue* val = new DictionaryValue;
  val->SetString(L"stat_name", stat_name);
  val->SetString(L"stat_value", UTF16ToWide(base::FormatNumber(stat_value)));
  details->Append(val);
}

static std::wstring MakeSyncAuthErrorText(
    const GoogleServiceAuthError::State& state) {
  switch (state) {
    case GoogleServiceAuthError::INVALID_GAIA_CREDENTIALS:
      return L"INVALID_GAIA_CREDENTIALS";
    case GoogleServiceAuthError::USER_NOT_SIGNED_UP:
      return L"USER_NOT_SIGNED_UP";
    case GoogleServiceAuthError::CONNECTION_FAILED:
      return L"CONNECTION_FAILED";
    default:
      return std::wstring();
  }
}

std::string AboutSync() {
  FilePath user_data_dir;
  if (!PathService::Get(chrome::DIR_USER_DATA, &user_data_dir))
    return std::string();
  ProfileManager* profile_manager = g_browser_process->profile_manager();
  Profile* profile = profile_manager->GetDefaultProfile(user_data_dir);
  ProfileSyncService* service = profile->GetProfileSyncService();

  DictionaryValue strings;
  if (!service || !service->HasSyncSetupCompleted()) {
    strings.SetString(L"summary", L"SYNC DISABLED");
  } else {
    SyncManager::Status full_status(service->QueryDetailedSyncStatus());

    strings.SetString(L"summary",
        ProfileSyncService::BuildSyncStatusSummaryText(
            full_status.summary));

    strings.Set(L"authenticated",
        new FundamentalValue(full_status.authenticated));
    strings.SetString(L"auth_problem",
        MakeSyncAuthErrorText(service->GetAuthError().state()));

    strings.SetString(L"time_since_sync", service->GetLastSyncedTimeString());

    ListValue* details = new ListValue();
    strings.Set(L"details", details);
    AddBoolSyncDetail(details, L"Server Up", full_status.server_up);
    AddBoolSyncDetail(details, L"Server Reachable",
                      full_status.server_reachable);
    AddBoolSyncDetail(details, L"Server Broken", full_status.server_broken);
    AddBoolSyncDetail(details, L"Notifications Enabled",
                      full_status.notifications_enabled);
    AddIntSyncDetail(details, L"Notifications Received",
                     full_status.notifications_received);
    AddIntSyncDetail(details, L"Notifications Sent",
                     full_status.notifications_sent);
    AddIntSyncDetail(details, L"Unsynced Count", full_status.unsynced_count);
    AddIntSyncDetail(details, L"Conflicting Count",
                     full_status.conflicting_count);
    AddBoolSyncDetail(details, L"Syncing", full_status.syncing);
    AddBoolSyncDetail(details, L"Initial Sync Ended",
                      full_status.initial_sync_ended);
    AddBoolSyncDetail(details, L"Syncer Stuck", full_status.syncer_stuck);
    AddIntSyncDetail(details, L"Updates Available",
                     full_status.updates_available);
    AddIntSyncDetail(details, L"Updates Received",
                     full_status.updates_received);
    AddBoolSyncDetail(details, L"Disk Full", full_status.disk_full);
    AddBoolSyncDetail(details, L"Invalid Store", full_status.invalid_store);
    AddIntSyncDetail(details, L"Max Consecutive Errors",
                     full_status.max_consecutive_errors);
  }

  static const base::StringPiece sync_html(
      ResourceBundle::GetSharedInstance().GetRawDataResource(
      IDR_ABOUT_SYNC_HTML));

  return jstemplate_builder::GetTemplateHtml(
      sync_html, &strings , "t" /* template root node id */);
}

// AboutSource -----------------------------------------------------------------

AboutSource::AboutSource()
    : DataSource(chrome::kAboutScheme, MessageLoop::current()) {
  // This should be a singleton.
  DCHECK(!about_source);
  about_source = this;

  // Add us to the global URL handler on the IO thread.
  ChromeThread::PostTask(
      ChromeThread::IO, FROM_HERE,
      NewRunnableMethod(
          Singleton<ChromeURLDataManager>::get(),
          &ChromeURLDataManager::AddDataSource,
          make_scoped_refptr(this)));
}

AboutSource::~AboutSource() {
  about_source = NULL;
}

void AboutSource::StartDataRequest(const std::string& path_raw,
    bool is_off_the_record, int request_id) {
  std::string path = path_raw;
  std::string info;
  if (path.find("/") != std::string::npos) {
    size_t pos = path.find("/");
    info = path.substr(pos + 1, path.length() - (pos + 1));
    path = path.substr(0, pos);
  }
  path = StringToLowerASCII(path);

  std::string response;
  if (path == kDnsPath) {
    AboutDnsHandler::Start(this, request_id);
    return;
  } else if (path == kHistogramsPath) {
    response = AboutHistograms(info);
  } else if (path == kMemoryPath) {
    AboutMemory(this, request_id);
    return;
  } else if (path == kMemoryRedirectPath) {
    response = GetAboutMemoryRedirectResponse();
  } else if (path == kObjectsPath) {
    response = AboutObjects(info);
  } else if (path == kPluginsPath) {
    response = AboutPlugins();
  } else if (path == kStatsPath) {
    response = AboutStats();
#if defined(USE_TCMALLOC)
  } else if (path == kTcmallocPath) {
    response = AboutTcmalloc(info);
#endif
  } else if (path == kVersionPath || path.empty()) {
#if defined(OS_CHROMEOS)
    new ChromeOSAboutVersionHandler(this, request_id);
    return;
#else
    DictionaryValue value;
    response = AboutVersion(&value);
#endif
  } else if (path == kCreditsPath) {
    response = AboutCredits();
#if defined(OS_CHROMEOS)
  } else if (path == kOSCreditsPath) {
    response = AboutOSCredits();
#endif
  } else if (path == kTermsPath) {
    response = AboutTerms();
  } else if (path == kSyncPath) {
    response = AboutSync();
  }

  FinishDataRequest(response, request_id);
}

void AboutSource::FinishDataRequest(const std::string& response,
                                    int request_id) {
  scoped_refptr<RefCountedBytes> html_bytes(new RefCountedBytes);
  html_bytes->data.resize(response.size());
  std::copy(response.begin(), response.end(), html_bytes->data.begin());
  SendResponse(request_id, html_bytes);
}

// AboutMemoryHandler ----------------------------------------------------------

// Helper for AboutMemory to bind results from a ProcessMetrics object
// to a DictionaryValue. Fills ws_usage and comm_usage so that the objects
// can be used in caller's scope (e.g for appending to a net total).
void AboutMemoryHandler::BindProcessMetrics(DictionaryValue* data,
                                            ProcessMemoryInformation* info) {
  DCHECK(data && info);

  // Bind metrics to dictionary.
  data->SetInteger(L"ws_priv", static_cast<int>(info->working_set.priv));
  data->SetInteger(L"ws_shareable",
    static_cast<int>(info->working_set.shareable));
  data->SetInteger(L"ws_shared", static_cast<int>(info->working_set.shared));
  data->SetInteger(L"comm_priv", static_cast<int>(info->committed.priv));
  data->SetInteger(L"comm_map", static_cast<int>(info->committed.mapped));
  data->SetInteger(L"comm_image", static_cast<int>(info->committed.image));
  data->SetInteger(L"pid", info->pid);
  data->SetString(L"version", info->version);
  data->SetInteger(L"processes", info->num_processes);
}

// Helper for AboutMemory to append memory usage information for all
// sub-processes (i.e. renderers, plugins) used by Chrome.
void AboutMemoryHandler::AppendProcess(ListValue* child_data,
                                       ProcessMemoryInformation* info) {
  DCHECK(child_data && info);

  // Append a new DictionaryValue for this renderer to our list.
  DictionaryValue* child = new DictionaryValue();
  child_data->Append(child);
  BindProcessMetrics(child, info);

  std::wstring child_label(ChildProcessInfo::GetTypeNameInEnglish(info->type));
  if (info->is_diagnostics)
    child_label.append(L" (diagnostics)");
  child->SetString(L"child_name", child_label);
  ListValue* titles = new ListValue();
  child->Set(L"titles", titles);
  for (size_t i = 0; i < info->titles.size(); ++i)
    titles->Append(new StringValue(info->titles[i]));
}


void AboutMemoryHandler::OnDetailsAvailable() {
  // the root of the JSON hierarchy for about:memory jstemplate
  DictionaryValue root;
  ListValue* browsers = new ListValue();
  root.Set(L"browsers", browsers);

  const std::vector<ProcessData>& browser_processes = processes();

  // Aggregate per-process data into browser summary data.
  std::wstring log_string;
  for (size_t index = 0; index < browser_processes.size(); index++) {
    if (browser_processes[index].processes.size() == 0)
      continue;

    // Sum the information for the processes within this browser.
    ProcessMemoryInformation aggregate;
    ProcessMemoryInformationList::const_iterator iterator;
    iterator = browser_processes[index].processes.begin();
    aggregate.pid = iterator->pid;
    aggregate.version = iterator->version;
    while (iterator != browser_processes[index].processes.end()) {
      if (!iterator->is_diagnostics ||
          browser_processes[index].processes.size() == 1) {
        aggregate.working_set.priv += iterator->working_set.priv;
        aggregate.working_set.shared += iterator->working_set.shared;
        aggregate.working_set.shareable += iterator->working_set.shareable;
        aggregate.committed.priv += iterator->committed.priv;
        aggregate.committed.mapped += iterator->committed.mapped;
        aggregate.committed.image += iterator->committed.image;
        aggregate.num_processes++;
      }
      ++iterator;
    }
    DictionaryValue* browser_data = new DictionaryValue();
    browsers->Append(browser_data);
    browser_data->SetString(L"name", browser_processes[index].name);

    BindProcessMetrics(browser_data, &aggregate);

    // We log memory info as we record it.
    if (log_string.length() > 0)
      log_string.append(L", ");
    log_string.append(browser_processes[index].name);
    log_string.append(L", ");
    log_string.append(Int64ToWString(aggregate.working_set.priv));
    log_string.append(L", ");
    log_string.append(Int64ToWString(aggregate.working_set.shared));
    log_string.append(L", ");
    log_string.append(Int64ToWString(aggregate.working_set.shareable));
  }
  if (log_string.length() > 0)
    LOG(INFO) << "memory: " << log_string;

  // Set the browser & renderer detailed process data.
  DictionaryValue* browser_data = new DictionaryValue();
  root.Set(L"browzr_data", browser_data);
  ListValue* child_data = new ListValue();
  root.Set(L"child_data", child_data);

  ProcessData process = browser_processes[0];  // Chrome is the first browser.
  for (size_t index = 0; index < process.processes.size(); index++) {
    if (process.processes[index].type == ChildProcessInfo::BROWSER_PROCESS)
      BindProcessMetrics(browser_data, &process.processes[index]);
    else
      AppendProcess(child_data, &process.processes[index]);
  }

  // Get about_memory.html
  static const base::StringPiece memory_html(
      ResourceBundle::GetSharedInstance().GetRawDataResource(
          IDR_ABOUT_MEMORY_HTML));

  // Create jstemplate and return.
  std::string template_html = jstemplate_builder::GetTemplateHtml(
      memory_html, &root, "t" /* template root node id */);

  source_->FinishDataRequest(template_html, request_id_);
}

#if defined(OS_CHROMEOS)
// ChromeOSAboutVersionHandler  -----------------------------------------------

ChromeOSAboutVersionHandler::ChromeOSAboutVersionHandler(AboutSource* source,
                                                         int request_id)
    : source_(source),
      request_id_(request_id) {
  loader_.GetVersion(&consumer_,
      NewCallback(this, &ChromeOSAboutVersionHandler::OnVersion));
}

void ChromeOSAboutVersionHandler::OnVersion(
    chromeos::VersionLoader::Handle handle,
    std::string version) {
  DictionaryValue localized_strings;
  localized_strings.SetString(L"os_name",
                              l10n_util::GetString(IDS_PRODUCT_OS_NAME));
  localized_strings.SetString(L"os_version", UTF8ToWide(version));
  localized_strings.SetBoolean(L"is_chrome_os", true);
  source_->FinishDataRequest(AboutVersion(&localized_strings), request_id_);

  // CancelableRequestProvider isn't happy when it's deleted and servicing a
  // task, so we delay the deletion.
  MessageLoop::current()->DeleteSoon(FROM_HERE, this);
}

#endif

// Returns true if |url|'s spec starts with |about_specifier|, and is
// terminated by the start of a path.
bool StartsWithAboutSpecifier(const GURL& url, const char* about_specifier) {
  return StartsWithASCII(url.spec(), about_specifier, true) &&
         (url.spec().size() == strlen(about_specifier) ||
          url.spec()[strlen(about_specifier)] == '/');
}

// Transforms a URL of the form "about:foo/XXX" to <url_prefix> + "XXX".
GURL RemapAboutURL(const std::string& url_prefix, const GURL& url) {
  std::string path;
  size_t split = url.spec().find('/');
  if (split != std::string::npos)
    path = url.spec().substr(split + 1);
  return GURL(url_prefix + path);
}

}  // namespace

// -----------------------------------------------------------------------------

bool WillHandleBrowserAboutURL(GURL* url, Profile* profile) {
  // We only handle about: schemes.
  if (!url->SchemeIs(chrome::kAboutScheme))
    return false;

  // about:blank is special. Frames are allowed to access about:blank,
  // but they are not allowed to access other types of about pages.
  // Just ignore the about:blank and let the TAB_CONTENTS_WEB handle it.
  if (LowerCaseEqualsASCII(url->spec(), chrome::kAboutBlankURL))
    return false;

  // Rewrite about:cache/* URLs to chrome://net-internals/view-cache/*
  if (StartsWithAboutSpecifier(*url, chrome::kAboutCacheURL)) {
    *url = RemapAboutURL(chrome::kNetworkViewCacheURL + std::string("/"),
                         *url);
    return true;
  }

  // Rewrite about:net-internals/* URLs to chrome://net-internals/*
  if (StartsWithAboutSpecifier(*url, chrome::kAboutNetInternalsURL)) {
    *url = RemapAboutURL(chrome::kNetworkViewInternalsURL, *url);
    return true;
  }

  // Handle URL to crash the browser process.
  if (LowerCaseEqualsASCII(url->spec(), chrome::kAboutBrowserCrash)) {
    // Induce an intentional crash in the browser process.
    int* bad_pointer = NULL;
    *bad_pointer = 42;
    return true;
  }

  // There are a few about: URLs that we hand over to the renderer. If the
  // renderer wants them, don't do any rewriting.
  if (AboutHandler::WillHandle(*url))
    return false;

  // Anything else requires our special handler, make sure its initialized.
  // We only need to register the AboutSource once and it is kept globally.
  // There is currently no way to remove a data source.
  static bool initialized = false;
  if (!initialized) {
    about_source = new AboutSource();
    initialized = true;
  }

  // Special case about:memory to go through a redirect before ending up on
  // the final page. See GetAboutMemoryRedirectResponse above for why.
  if (LowerCaseEqualsASCII(url->path(), kMemoryPath)) {
    *url = GURL("chrome://about/memory-redirect");
    return true;
  }

  // Rewrite the about URL to use chrome:. WebKit treats all about URLS the
  // same (blank page), so if we want to display content, we need another
  // scheme.
  std::string about_url = "chrome://about/";
  about_url.append(url->path());
  *url = GURL(about_url);
  return true;
}

// This function gets called with the fixed-up chrome: URLs, so we have to
// compare against those instead of "about:blah".
bool HandleNonNavigationAboutURL(const GURL& url) {
  // About:network and IPC and currently buggy, so we disable it for official
  // builds.
#if !defined(OFFICIAL_BUILD)

#if defined(OS_WIN)
  if (LowerCaseEqualsASCII(url.spec(), chrome::kChromeUINetworkURL)) {
    // Run the dialog. This will re-use the existing one if it's already up.
    AboutNetworkDialog::RunDialog();
    return true;
  }
#endif

#if !defined(OS_LINUX) && defined(IPC_MESSAGE_LOG_ENABLED)
  if (LowerCaseEqualsASCII(url.spec(), chrome::kChromeUIIPCURL)) {
    // Run the dialog. This will re-use the existing one if it's already up.
    AboutIPCDialog::RunDialog();
    return true;
  }
#endif

#endif  // OFFICIAL_BUILD

  return false;
}