// 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 "build/build_config.h"

// Need to include this before most other files because it defines
// IPC_MESSAGE_LOG_ENABLED. We need to use it to define
// IPC_MESSAGE_MACROS_LOG_ENABLED so render_messages.h will generate the
// ViewMsgLog et al. functions.
#include "ipc/ipc_buildflags.h"

// On Windows, the about:ipc dialog shows IPCs; on POSIX, we hook up a
// logger in this file.  (We implement about:ipc on Mac but implement
// the loggers here anyway).  We need to do this real early to be sure
// IPC_MESSAGE_MACROS_LOG_ENABLED doesn't get undefined.
#if defined(OS_POSIX) && BUILDFLAG(IPC_MESSAGE_LOG_ENABLED)
#define IPC_MESSAGE_MACROS_LOG_ENABLED
#include "content/public/common/content_ipc_logging.h"
#define IPC_LOG_TABLE_ADD_ENTRY(msg_id, logger) \
    content::RegisterIPCLogger(msg_id, logger)
#include "chrome/common/all_messages.h"
#endif

#if defined(OS_WIN)
#include <windows.h>
#endif

#include "chrome/common/logging_chrome.h"

#include <fstream>  // NOLINT
#include <memory>  // NOLINT
#include <string>  // NOLINT

#include "base/base_switches.h"
#include "base/bind.h"
#include "base/command_line.h"
#include "base/compiler_specific.h"
#include "base/debug/debugger.h"
#include "base/debug/dump_without_crashing.h"
#include "base/environment.h"
#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/metrics/statistics_recorder.h"
#include "base/path_service.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/strings/utf_string_conversions.h"
#include "chrome/common/chrome_constants.h"
#include "chrome/common/chrome_paths.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/env_vars.h"
#include "content/public/common/content_switches.h"
#include "ipc/ipc_logging.h"

#if defined(OS_CHROMEOS)
#include "chromeos/chromeos_switches.h"
#endif

#if defined(OS_WIN)
#include <initguid.h>
#include "base/logging_win.h"
#include "base/syslog_logging.h"
#include "chrome/common/win/eventlog_messages.h"
#include "chrome/install_static/install_details.h"
#endif

namespace logging {
namespace {

// When true, this means that error dialogs should not be shown.
bool dialogs_are_suppressed_ = false;
ScopedLogAssertHandler* assert_handler_ = nullptr;

// This should be true for exactly the period between the end of
// InitChromeLogging() and the beginning of CleanupChromeLogging().
bool chrome_logging_initialized_ = false;

// Set if we called InitChromeLogging() but failed to initialize.
bool chrome_logging_failed_ = false;

// This should be true for exactly the period between the end of
// InitChromeLogging() and the beginning of CleanupChromeLogging().
bool chrome_logging_redirected_ = false;

#if defined(OS_WIN)
// {7FE69228-633E-4f06-80C1-527FEA23E3A7}
const GUID kChromeTraceProviderName = {
    0x7fe69228, 0x633e, 0x4f06,
        { 0x80, 0xc1, 0x52, 0x7f, 0xea, 0x23, 0xe3, 0xa7 } };
#endif

// Assertion handler for logging errors that occur when dialogs are
// silenced.  To record a new error, pass the log string associated
// with that error in the str parameter.
NOINLINE void SilentRuntimeAssertHandler(const char* file,
                                         int line,
                                         const base::StringPiece message,
                                         const base::StringPiece stack_trace) {
  base::debug::BreakDebugger();
}

// Suppresses error/assertion dialogs and enables the logging of
// those errors into silenced_errors_.
void SuppressDialogs() {
  if (dialogs_are_suppressed_)
    return;

  assert_handler_ =
      new ScopedLogAssertHandler(base::Bind(SilentRuntimeAssertHandler));

#if defined(OS_WIN)
  UINT new_flags = SEM_FAILCRITICALERRORS |
                   SEM_NOGPFAULTERRORBOX |
                   SEM_NOOPENFILEERRORBOX;

  // Preserve existing error mode, as discussed at http://t/dmea
  UINT existing_flags = SetErrorMode(new_flags);
  SetErrorMode(existing_flags | new_flags);
#endif

  dialogs_are_suppressed_ = true;
}

}  // anonymous namespace

LoggingDestination DetermineLoggingDestination(
    const base::CommandLine& command_line) {
// only use OutputDebugString in debug mode
#ifdef NDEBUG
  bool enable_logging = false;
  const char *kInvertLoggingSwitch = switches::kEnableLogging;
  const LoggingDestination kDefaultLoggingMode = LOG_TO_FILE;
#else
  bool enable_logging = true;
  const char *kInvertLoggingSwitch = switches::kDisableLogging;
  const LoggingDestination kDefaultLoggingMode = LOG_TO_ALL;
#endif

  if (command_line.HasSwitch(kInvertLoggingSwitch))
    enable_logging = !enable_logging;

  LoggingDestination log_mode;
  if (enable_logging) {
    // Let --enable-logging=stderr force only stderr, particularly useful for
    // non-debug builds where otherwise you can't get logs to stderr at all.
    if (command_line.GetSwitchValueASCII(switches::kEnableLogging) == "stderr")
      log_mode = LOG_TO_SYSTEM_DEBUG_LOG;
    else
      log_mode = kDefaultLoggingMode;
  } else {
    log_mode = LOG_NONE;
  }
  return log_mode;
}

#if defined(OS_CHROMEOS)
base::FilePath SetUpSymlinkIfNeeded(const base::FilePath& symlink_path,
                                    bool new_log) {
  DCHECK(!symlink_path.empty());
  // For backward compatibility, set up a .../chrome symlink to
  // .../chrome.LATEST as needed.  This code needs to run only
  // after the migration (i.e. the addition of chrome.LATEST).
  if (symlink_path.Extension() == ".LATEST") {
    base::FilePath extensionless_path = symlink_path.ReplaceExtension("");
    base::FilePath target_path;
    bool extensionless_symlink_exists =
        base::ReadSymbolicLink(extensionless_path, &target_path);

    if (target_path != symlink_path) {
      // No link, or wrong link.  Clean up.  This should happen only once in
      // each log directory after the OS version update, but some of those
      // directories may not be accessed for a long time, so this code needs to
      // stay in forever :/
      if (extensionless_symlink_exists &&
          !base::DeleteFile(extensionless_path, false)) {
        DPLOG(WARNING) << "Cannot delete " << extensionless_path.value();
      }
      // After cleaning up, create the symlink.
      if (!base::CreateSymbolicLink(symlink_path, extensionless_path)) {
        DPLOG(ERROR) << "Cannot create " << extensionless_path.value();
      }
    }
  }

  // If not starting a new log, then just log through the existing symlink, but
  // if the symlink doesn't exist, create it.
  //
  // If starting a new log, then rename the old symlink as
  // symlink_path.PREVIOUS and make a new symlink to a fresh log file.

  // Check for existence of the symlink.
  base::FilePath target_path;
  bool symlink_exists = base::ReadSymbolicLink(symlink_path, &target_path);

  if (symlink_exists && !new_log)
    return target_path;

  // Remove any extension before time-stamping.
  target_path = GenerateTimestampedName(symlink_path.RemoveExtension(),
                                        base::Time::Now());

  if (symlink_exists) {
    base::FilePath previous_symlink_path =
        symlink_path.ReplaceExtension(".PREVIOUS");
    // Rename symlink to .PREVIOUS.  This nukes an existing symlink just like
    // the rename(2) syscall does.
    if (!base::ReplaceFile(symlink_path, previous_symlink_path, nullptr)) {
      DPLOG(WARNING) << "Cannot rename " << symlink_path.value() << " to "
                     << previous_symlink_path.value();
    }
  }
  // If all went well, the symlink no longer exists.  Recreate it.
  if (!base::CreateSymbolicLink(target_path, symlink_path)) {
    DPLOG(ERROR) << "Unable to create symlink " << symlink_path.value()
                 << " pointing at " << target_path.value();
  }
  return target_path;
}

void RemoveSymlinkAndLog(const base::FilePath& link_path,
                         const base::FilePath& target_path) {
  if (::unlink(link_path.value().c_str()) == -1)
    DPLOG(WARNING) << "Unable to unlink symlink " << link_path.value();
  if (::unlink(target_path.value().c_str()) == -1)
    DPLOG(WARNING) << "Unable to unlink log file " << target_path.value();
}

base::FilePath GetSessionLogDir(const base::CommandLine& command_line) {
  base::FilePath log_dir;
  std::string log_dir_str;
  std::unique_ptr<base::Environment> env(base::Environment::Create());
  if (env->GetVar(env_vars::kSessionLogDir, &log_dir_str) &&
      !log_dir_str.empty()) {
    log_dir = base::FilePath(log_dir_str);
  } else if (command_line.HasSwitch(chromeos::switches::kLoginProfile)) {
    base::PathService::Get(chrome::DIR_USER_DATA, &log_dir);
    base::FilePath profile_dir;
    std::string login_profile_value =
        command_line.GetSwitchValueASCII(chromeos::switches::kLoginProfile);
    if (login_profile_value == chrome::kLegacyProfileDir ||
        login_profile_value == chrome::kTestUserProfileDir) {
      profile_dir = base::FilePath(login_profile_value);
    } else {
      // We could not use g_browser_process > profile_helper() here.
      std::string profile_dir_str = chrome::kProfileDirPrefix;
      profile_dir_str.append(login_profile_value);
      profile_dir = base::FilePath(profile_dir_str);
    }
    log_dir = log_dir.Append(profile_dir);
  }
  return log_dir;
}

base::FilePath GetSessionLogFile(const base::CommandLine& command_line) {
  return GetSessionLogDir(command_line)
      .Append(GetLogFileName(command_line).BaseName());
}

#endif  // defined(OS_CHROMEOS)

void InitChromeLogging(const base::CommandLine& command_line,
                       OldFileDeletionState delete_old_log_file) {
  DCHECK(!chrome_logging_initialized_) <<
    "Attempted to initialize logging when it was already initialized.";
  LoggingDestination logging_dest = DetermineLoggingDestination(command_line);
  LogLockingState log_locking_state = LOCK_LOG_FILE;
  base::FilePath log_path;
#if defined(OS_CHROMEOS)
  base::FilePath target_path;
#endif

  // Don't resolve the log path unless we need to. Otherwise we leave an open
  // ALPC handle after sandbox lockdown on Windows.
  if ((logging_dest & LOG_TO_FILE) != 0) {
    log_path = GetLogFileName(command_line);

#if defined(OS_CHROMEOS)
    // For BWSI (Incognito) logins, we want to put the logs in the user
    // profile directory that is created for the temporary session instead
    // of in the system log directory, for privacy reasons.
    if (command_line.HasSwitch(chromeos::switches::kGuestSession))
      log_path = GetSessionLogFile(command_line);

    // On ChromeOS we log to the symlink.  We force creation of a new
    // symlink if we've been asked to delete the old log, since that
    // indicates the start of a new session.
    target_path = SetUpSymlinkIfNeeded(
        log_path, delete_old_log_file == DELETE_OLD_LOG_FILE);

    // Because ChromeOS manages the move to a new session by redirecting
    // the link, it shouldn't remove the old file in the logging code,
    // since that will remove the newly created link instead.
    delete_old_log_file = APPEND_TO_OLD_LOG_FILE;
#endif  // defined(OS_CHROMEOS)
  } else {
    log_locking_state = DONT_LOCK_LOG_FILE;
  }

  LoggingSettings settings;
  settings.logging_dest = logging_dest;
  settings.log_file = log_path.value().c_str();
  settings.lock_log = log_locking_state;
  settings.delete_old = delete_old_log_file;
  bool success = InitLogging(settings);

#if defined(OS_CHROMEOS)
  if (!success) {
    DPLOG(ERROR) << "Unable to initialize logging to " << log_path.value()
                << " (which should be a link to " << target_path.value() << ")";
    RemoveSymlinkAndLog(log_path, target_path);
    chrome_logging_failed_ = true;
    return;
  }
#else   // defined(OS_CHROMEOS)
  if (!success) {
    DPLOG(ERROR) << "Unable to initialize logging to " << log_path.value();
    chrome_logging_failed_ = true;
    return;
  }
#endif  // defined(OS_CHROMEOS)

  // We call running in unattended mode "headless", and allow headless mode to
  // be configured either by the Environment Variable or by the Command Line
  // Switch. This is for automated test purposes.
  std::unique_ptr<base::Environment> env(base::Environment::Create());
  const bool is_headless = env->HasVar(env_vars::kHeadless) ||
                           command_line.HasSwitch(switches::kNoErrorDialogs);

  // Show fatal log messages in a dialog in debug builds when not headless.
  if (!is_headless)
    SetShowErrorDialogs(true);

  // we want process and thread IDs because we have a lot of things running
  SetLogItems(true,    // enable_process_id
              true,    // enable_thread_id
              true,    // enable_timestamp
              false);  // enable_tickcount

  // Suppress system error dialogs when headless.
  if (is_headless)
    SuppressDialogs();

  // Use a minimum log level if the command line asks for one. Ignore this
  // switch if there's vlog level switch present too (as both of these switches
  // refer to the same underlying log level, and the vlog level switch has
  // already been processed inside InitLogging). If there is neither
  // log level nor vlog level specified, then just leave the default level
  // (INFO).
  if (command_line.HasSwitch(switches::kLoggingLevel) &&
      GetMinLogLevel() >= 0) {
    std::string log_level =
        command_line.GetSwitchValueASCII(switches::kLoggingLevel);
    int level = 0;
    if (base::StringToInt(log_level, &level) && level >= 0 &&
        level < LOG_NUM_SEVERITIES) {
      SetMinLogLevel(level);
    } else {
      DLOG(WARNING) << "Bad log level: " << log_level;
    }
  }

#if defined(OS_WIN)
  // Enable trace control and transport through event tracing for Windows.
  LogEventProvider::Initialize(kChromeTraceProviderName);

  // Enable logging to the Windows Event Log.
  SetEventSource(base::UTF16ToASCII(
                     install_static::InstallDetails::Get().install_full_name()),
                 BROWSER_CATEGORY, MSG_LOG_MESSAGE);
#endif

  base::StatisticsRecorder::InitLogOnShutdown();

  chrome_logging_initialized_ = true;
}

// This is a no-op, but we'll keep it around in case
// we need to do more cleanup in the future.
void CleanupChromeLogging() {
  if (chrome_logging_failed_)
    return;  // We failed to initiailize logging, no cleanup.

  DCHECK(chrome_logging_initialized_) <<
    "Attempted to clean up logging when it wasn't initialized.";

  CloseLogFile();

  chrome_logging_initialized_ = false;
  chrome_logging_redirected_ = false;
}

base::FilePath GetLogFileName(const base::CommandLine& command_line) {
  std::string filename = command_line.GetSwitchValueASCII(switches::kLogFile);
  if (filename.empty())
    base::Environment::Create()->GetVar(env_vars::kLogFileName, &filename);
  if (!filename.empty())
    return base::FilePath::FromUTF8Unsafe(filename);

  const base::FilePath log_filename(FILE_PATH_LITERAL("chrome_debug.log"));
  base::FilePath log_path;

  if (base::PathService::Get(chrome::DIR_LOGS, &log_path)) {
    log_path = log_path.Append(log_filename);
    return log_path;
  } else {
    // error with path service, just use some default file somewhere
    return log_filename;
  }
}

bool DialogsAreSuppressed() {
  return dialogs_are_suppressed_;
}

#if defined(OS_CHROMEOS)
base::FilePath GenerateTimestampedName(const base::FilePath& base_path,
                                       base::Time timestamp) {
  base::Time::Exploded time_deets;
  timestamp.LocalExplode(&time_deets);
  std::string suffix = base::StringPrintf("_%02d%02d%02d-%02d%02d%02d",
                                          time_deets.year,
                                          time_deets.month,
                                          time_deets.day_of_month,
                                          time_deets.hour,
                                          time_deets.minute,
                                          time_deets.second);
  return base_path.InsertBeforeExtensionASCII(suffix);
}
#endif  // defined(OS_CHROMEOS)

}  // namespace logging