// Copyright 2016 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 "components/browser_watcher/stability_debugging.h"

#include <string>

#include "base/debug/activity_tracker.h"
#include "base/feature_list.h"
#include "base/files/file.h"
#include "base/metrics/persistent_memory_allocator.h"
#include "base/path_service.h"
#include "base/process/process.h"
#include "base/strings/stringprintf.h"
#include "base/time/time.h"
#include "components/browser_watcher/features.h"

namespace browser_watcher {

namespace {

#if defined(OS_WIN)
bool GetCreationTime(const base::Process& process, base::Time* time) {
  DCHECK(time);

  FILETIME creation_time = {};
  FILETIME ignore1 = {};
  FILETIME ignore2 = {};
  FILETIME ignore3 = {};
  if (!::GetProcessTimes(process.Handle(), &creation_time, &ignore1, &ignore2,
                         &ignore3)) {
    return false;
  }
  *time = base::Time::FromFileTime(creation_time);
  return true;
}
#endif  // defined(OS_WIN)

}  // namespace

#if defined(OS_WIN)

base::FilePath GetStabilityDir(const base::FilePath& user_data_dir) {
  return user_data_dir.AppendASCII("Stability");
}

bool GetStabilityFileForProcess(const base::Process& process,
                                const base::FilePath& user_data_dir,
                                base::FilePath* file_path) {
  DCHECK(file_path);
  base::FilePath stability_dir = GetStabilityDir(user_data_dir);

  // Build the name using the pid and creation time. On windows, this is unique
  // even after the process exits.
  base::Time creation_time;
  if (!GetCreationTime(process, &creation_time))
    return false;

  std::string file_name =
      base::StringPrintf("%u-%llu", process.Pid(), creation_time.ToJavaTime());
  *file_path = stability_dir.AppendASCII(file_name).AddExtension(
      base::PersistentMemoryAllocator::kFileExtension);
  return true;
}

base::FilePath::StringType GetStabilityFilePattern() {
  return base::FilePath::StringType(FILE_PATH_LITERAL("*-*")) +
         base::PersistentMemoryAllocator::kFileExtension;
}

void MarkStabilityFileForDeletion(const base::FilePath& user_data_dir) {
  if (!base::FeatureList::IsEnabled(
          browser_watcher::kStabilityDebuggingFeature)) {
    return;
  }

  base::FilePath stability_file;
  if (!GetStabilityFileForProcess(base::Process::Current(), user_data_dir,
                                  &stability_file)) {
    // TODO(manzagop): add a metric for this.
    return;
  }

  // Open (with delete) and then immediately close the file by going out of
  // scope. This should cause the stability debugging file to be deleted prior
  // to the next execution.
  base::File file(stability_file, base::File::FLAG_OPEN |
                                      base::File::FLAG_READ |
                                      base::File::FLAG_DELETE_ON_CLOSE);
}
#endif  // defined(OS_WIN)

void SetStabilityDataInt(base::StringPiece name, int64_t value) {
  base::debug::GlobalActivityTracker* global_tracker =
      base::debug::GlobalActivityTracker::Get();
  if (!global_tracker)
    return;  // Activity tracking isn't enabled.

  global_tracker->global_data().SetInt(name, value);
}

}  // namespace browser_watcher