// Copyright 2014 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/chromeos/system_logs/debug_log_writer.h"

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/callback.h"
#include "base/command_line.h"
#include "base/files/file.h"
#include "base/files/file_util.h"
#include "base/message_loop/message_loop.h"
#include "base/process/kill.h"
#include "base/process/launch.h"
#include "chrome/common/logging_chrome.h"
#include "chromeos/dbus/dbus_thread_manager.h"
#include "chromeos/dbus/debug_daemon_client.h"
#include "content/public/browser/browser_thread.h"

namespace chromeos {

namespace {

// Callback for returning status of executed external command.
typedef base::Callback<void(bool succeeded)> CommandCompletionCallback;

const char kGzipCommand[] = "/bin/gzip";
const char kTarCommand[] = "/bin/tar";

scoped_refptr<base::SequencedTaskRunner> GetSequencedTaskRunner(
    const std::string sequence_name) {
  base::SequencedWorkerPool* pool = content::BrowserThread::GetBlockingPool();
  return pool->GetSequencedTaskRunnerWithShutdownBehavior(
      pool->GetNamedSequenceToken(sequence_name),
      base::SequencedWorkerPool::BLOCK_SHUTDOWN);
}

// Called upon completion of |WriteDebugLogToFile|. Closes file
// descriptor, deletes log file in the case of failure and calls
// |callback|.
void WriteDebugLogToFileCompleted(
    const base::FilePath& file_path,
    const std::string& sequence_token_name,
    const DebugLogWriter::StoreLogsCallback& callback,
    bool succeeded) {
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  if (!succeeded) {
    bool posted = GetSequencedTaskRunner(sequence_token_name)->PostTaskAndReply(
        FROM_HERE,
        base::Bind(base::IgnoreResult(&base::DeleteFile), file_path, false),
        base::Bind(callback, file_path, false));
    DCHECK(posted);
    return;
  }
  if (!callback.is_null())
    callback.Run(file_path, true);
}

// Stores into |file_path| debug logs in the .tgz format. Calls
// |callback| upon completion.
void WriteDebugLogToFile(base::File* file,
                         const std::string& sequence_token_name,
                         const base::FilePath& file_path,
                         bool should_compress,
                         const DebugLogWriter::StoreLogsCallback& callback) {
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  if (!file->IsValid()) {
    LOG(ERROR) << "Can't create debug log file: " << file_path.AsUTF8Unsafe()
               << ", "
               << "error: " << file->error_details();
    return;
  }
  scoped_refptr<base::TaskRunner> task_runner =
      GetSequencedTaskRunner(sequence_token_name);
  chromeos::DBusThreadManager::Get()->GetDebugDaemonClient()->DumpDebugLogs(
      should_compress,
      file->Pass(),
      task_runner,
      base::Bind(&WriteDebugLogToFileCompleted,
                 file_path,
                 sequence_token_name,
                 callback));
}

// Runs command with its parameters as defined in |argv|.
// Upon completion, it will report command run outcome via |callback| on the
// same thread from where it was initially called from.
void RunCommand(const std::vector<std::string>& argv,
                const CommandCompletionCallback& callback) {
  base::Process process = base::LaunchProcess(argv, base::LaunchOptions());
  if (!process.IsValid()) {
    LOG(ERROR) << "Failed to execute command " << argv[0];
    if (!callback.is_null())
      callback.Run(false);

    return;
  }

  int exit_code = 0;
  if (!process.WaitForExit(&exit_code)) {
    LOG(ERROR) << "Can't get exit code for pid " << process.Pid();
    if (!callback.is_null())
      callback.Run(false);

    return;
  }
  if (!callback.is_null())
    callback.Run(exit_code == 0);
}

// Callback for handling the outcome of CompressArchive(). It reports
// the final outcome of log retreival process at via |callback|.
void OnCompressArchiveCompleted(
    const base::FilePath& tar_file_path,
    const base::FilePath& compressed_output_path,
    const DebugLogWriter::StoreLogsCallback& callback,
    bool compression_command_success) {
  if (!compression_command_success) {
    LOG(ERROR) << "Failed compressing " << compressed_output_path.value();
    content::BrowserThread::PostTask(
        content::BrowserThread::UI,
        FROM_HERE,
        base::Bind(callback, base::FilePath(), false));
    base::DeleteFile(tar_file_path, false);
    base::DeleteFile(compressed_output_path, false);
    return;
  }

  content::BrowserThread::PostTask(
      content::BrowserThread::UI,
      FROM_HERE,
      base::Bind(callback, compressed_output_path, true));
}

// Gzips |tar_file_path| and stores results in |compressed_output_path|.
void CompressArchive(const base::FilePath& tar_file_path,
                     const base::FilePath& compressed_output_path,
                     const DebugLogWriter::StoreLogsCallback& callback,
                     bool add_user_logs_command_success) {
  if (!add_user_logs_command_success) {
    LOG(ERROR) << "Failed adding user logs to " << tar_file_path.value();
    content::BrowserThread::PostTask(
        content::BrowserThread::UI,
        FROM_HERE,
        base::Bind(callback, base::FilePath(), false));
    base::DeleteFile(tar_file_path, false);
    return;
  }

  std::vector<std::string> argv;
  argv.push_back(kGzipCommand);
  argv.push_back(tar_file_path.value());
  RunCommand(argv,
             base::Bind(&OnCompressArchiveCompleted,
                        tar_file_path,
                        compressed_output_path,
                        callback));
}

// Adds user sessions specific logs from |user_log_dir| into tar archive file
// at |tar_file_path|. Upon completion, it will call CompressArchive() to
// produce |compressed_output_path|.
void AddUserLogsToArchive(const base::FilePath& user_log_dir,
                          const base::FilePath& tar_file_path,
                          const base::FilePath& compressed_output_path,
                          const DebugLogWriter::StoreLogsCallback& callback) {
  std::vector<std::string> argv;
  argv.push_back(kTarCommand);
  argv.push_back("-rvf");
  argv.push_back(tar_file_path.value());
  argv.push_back(user_log_dir.value());
  RunCommand(
      argv,
      base::Bind(
          &CompressArchive, tar_file_path, compressed_output_path, callback));
}

// Appends user logs after system logs are archived into |tar_file_path|.
void OnSystemLogsAdded(const DebugLogWriter::StoreLogsCallback& callback,
                       const base::FilePath& tar_file_path,
                       bool succeeded) {
  if (!succeeded) {
    if (!callback.is_null())
      callback.Run(base::FilePath(), false);

    return;
  }

  base::FilePath compressed_output_path =
      tar_file_path.AddExtension(FILE_PATH_LITERAL(".gz"));
  base::FilePath user_log_dir =
      logging::GetSessionLogDir(*base::CommandLine::ForCurrentProcess());

  content::BrowserThread::PostBlockingPoolTask(
      FROM_HERE,
      base::Bind(&AddUserLogsToArchive,
                 user_log_dir,
                 tar_file_path,
                 compressed_output_path,
                 callback));
}

void IntializeLogFile(base::File* file,
                      const base::FilePath& file_path,
                      uint32 flags) {
  base::FilePath dir = file_path.DirName();
  if (!base::DirectoryExists(dir)) {
    if (!base::CreateDirectory(dir)) {
      LOG(ERROR) << "Can not create " << dir.value();
      return;
    }
  }

  file->Initialize(file_path, flags);
}

// Starts logs retrieval process. The output will be stored in file with name
// derived from |file_name_template|.
void StartLogRetrieval(const base::FilePath& file_name_template,
                       bool should_compress,
                       const std::string& sequence_token_name,
                       const DebugLogWriter::StoreLogsCallback& callback) {
  base::FilePath file_path =
      logging::GenerateTimestampedName(file_name_template, base::Time::Now());

  int flags = base::File::FLAG_CREATE_ALWAYS | base::File::FLAG_WRITE;
  base::File* file = new base::File;
  GetSequencedTaskRunner(sequence_token_name)->PostTaskAndReply(
      FROM_HERE,
      base::Bind(&IntializeLogFile, base::Unretained(file), file_path, flags),
      base::Bind(&WriteDebugLogToFile,
                 base::Owned(file),
                 sequence_token_name,
                 file_path,
                 should_compress,
                 callback));
}

const char kDefaultSequenceName[] = "DebugLogWriter";

}  // namespace

// static.
void DebugLogWriter::StoreLogs(const base::FilePath& fileshelf,
                               bool should_compress,
                               const StoreLogsCallback& callback) {
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  DCHECK(!callback.is_null());

  base::FilePath file_path =
      fileshelf.Append(should_compress ? FILE_PATH_LITERAL("debug-logs.tgz")
                                       : FILE_PATH_LITERAL("debug-logs.tar"));

  StartLogRetrieval(file_path, should_compress, kDefaultSequenceName, callback);
}

// static.
void DebugLogWriter::StoreCombinedLogs(const base::FilePath& fileshelf,
                                       const std::string& sequence_token_name,
                                       const StoreLogsCallback& callback) {
  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  DCHECK(!callback.is_null());

  base::FilePath file_path =
      fileshelf.Append(FILE_PATH_LITERAL("combined-logs.tar"));

  // Get system logs from /var/log first, then add user-specific stuff.
  StartLogRetrieval(file_path,
                    false,
                    sequence_token_name,
                    base::Bind(&OnSystemLogsAdded, callback));
}

}  // namespace chromeos