/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "LogModulePrefWatcher.h"

#include "mozilla/Logging.h"

#include "mozilla/Preferences.h"

#include "nsMemory.h"

#include "nsString.h"

#include "nsXULAppAPI.h"

#include "base/process_util.h"

static const char kLoggingPrefPrefix[] = "logging.";

static const char kLoggingConfigPrefPrefix[] = "logging.config";

static const int  kLoggingConfigPrefixLen = sizeof(kLoggingConfigPrefPrefix) - 1;

static const char kLoggingPrefClearOnStartup[] = "logging.config.clear_on_startup";

static const char kLoggingPrefLogFile[] = "logging.config.LOG_FILE";

static const char kLoggingPrefAddTimestamp[] = "logging.config.add_timestamp";

static const char kLoggingPrefSync[] = "logging.config.sync";

namespace mozilla {

NS_IMPL_ISUPPORTS(LogModulePrefWatcher, nsIObserver)

/**

 * Resets all the preferences in the logging. branch

 * This is needed because we may crash while logging, and this would cause us

 * to log after restarting as well.

 *

 * If logging after restart is desired, set the logging.config.clear_on_startup

 * pref to false, or use the MOZ_LOG_FILE and MOZ_LOG_MODULES env vars.

 */

void ResetExistingPrefs()

{

  uint32_t count;

  char** names;

  nsresult rv = Preferences::GetRootBranch()->

      GetChildList(kLoggingPrefPrefix, &count, &names);

  if (NS_SUCCEEDED(rv) && count) {

    for (size_t i = 0; i < count; i++) {

      // Clearing the pref will cause it to reload, thus resetting the log level

      Preferences::ClearUser(names[i]);

    }

    NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(count, names);

  }

}

/**

 * Loads the log level from the given pref and updates the corresponding

 * LogModule.

 */

static void

LoadPrefValue(const char* aName)

{

  LogLevel logLevel = LogLevel::Disabled;

  nsresult rv;

  int32_t prefLevel = 0;

  nsAutoCString prefValue;

  if (strncmp(aName, kLoggingConfigPrefPrefix, kLoggingConfigPrefixLen) == 0) {

    nsAutoCString prefName(aName);

    if (prefName.EqualsLiteral(kLoggingPrefLogFile)) {

      rv = Preferences::GetCString(aName, prefValue);

      // The pref was reset. Clear the user file.

      if (NS_FAILED(rv) || prefValue.IsEmpty()) {

        LogModule::SetLogFile(nullptr);

        return;

      }

      // If the pref value doesn't have a PID placeholder, append it to the end.

      if (!strstr(prefValue.get(), "%PID")) {

        prefValue.AppendLiteral("%PID");

      }

      LogModule::SetLogFile(prefValue.BeginReading());

    } else if (prefName.EqualsLiteral(kLoggingPrefAddTimestamp)) {

      bool addTimestamp = Preferences::GetBool(aName, false);

      LogModule::SetAddTimestamp(addTimestamp);

    } else if (prefName.EqualsLiteral(kLoggingPrefSync)) {

      bool sync = Preferences::GetBool(aName, false);

      LogModule::SetIsSync(sync);

    }

    return;

  }

  if (Preferences::GetInt(aName, &prefLevel) == NS_OK) {

    logLevel = ToLogLevel(prefLevel);

  } else if (Preferences::GetCString(aName, prefValue) == NS_OK) {

    if (prefValue.LowerCaseEqualsLiteral("error")) {

      logLevel = LogLevel::Error;

    } else if (prefValue.LowerCaseEqualsLiteral("warning")) {

      logLevel = LogLevel::Warning;

    } else if (prefValue.LowerCaseEqualsLiteral("info")) {

      logLevel = LogLevel::Info;

    } else if (prefValue.LowerCaseEqualsLiteral("debug")) {

      logLevel = LogLevel::Debug;

    } else if (prefValue.LowerCaseEqualsLiteral("verbose")) {

      logLevel = LogLevel::Verbose;

    }

  }

  const char* moduleName = aName + strlen(kLoggingPrefPrefix);

  LogModule::Get(moduleName)->SetLevel(logLevel);

}

void

LoadExistingPrefs()

{

  nsIPrefBranch* root = Preferences::GetRootBranch();

  if (!root) {

    return;

  }

  uint32_t count;

  char** names;

  nsresult rv = root->GetChildList(kLoggingPrefPrefix, &count, &names);

  if (NS_SUCCEEDED(rv) && count) {

    for (size_t i = 0; i < count; i++) {

      LoadPrefValue(names[i]);

    }

    NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(count, names);

  }

}

LogModulePrefWatcher::LogModulePrefWatcher()

{

}

void

LogModulePrefWatcher::RegisterPrefWatcher()

{

  RefPtr<LogModulePrefWatcher> prefWatcher = new LogModulePrefWatcher();

  Preferences::AddStrongObserver(prefWatcher, kLoggingPrefPrefix);

  nsCOMPtr<nsIObserverService> observerService =

    mozilla::services::GetObserverService();

  if (observerService && XRE_IsParentProcess()) {

    observerService->AddObserver(prefWatcher, "browser-delayed-startup-finished", false);

  }

  LoadExistingPrefs();

}

NS_IMETHODIMP

LogModulePrefWatcher::Observe(nsISupports* aSubject, const char* aTopic,

                              const char16_t* aData)

{

  if (strcmp(NS_PREFBRANCH_PREFCHANGE_TOPIC_ID, aTopic) == 0) {

    NS_LossyConvertUTF16toASCII prefName(aData);

    LoadPrefValue(prefName.get());

  } else if (strcmp("browser-delayed-startup-finished", aTopic) == 0) {

    bool clear = Preferences::GetBool(kLoggingPrefClearOnStartup, true);

    if (clear) {

      ResetExistingPrefs();

    }

    nsCOMPtr<nsIObserverService> observerService =

      mozilla::services::GetObserverService();

    if (observerService) {

      observerService->RemoveObserver(this, "browser-delayed-startup-finished");

    }

  }

  return NS_OK;

}

} // namespace mozilla