// Copyright 2013 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 "chromeos/system/statistics_provider.h"

#include <memory>

#include "base/bind.h"
#include "base/command_line.h"
#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/json/json_file_value_serializer.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/memory/singleton.h"
#include "base/path_service.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "base/synchronization/cancellation_flag.h"
#include "base/synchronization/waitable_event.h"
#include "base/sys_info.h"
#include "base/task_runner.h"
#include "base/threading/thread_restrictions.h"
#include "base/time/time.h"
#include "base/values.h"
#include "chromeos/app_mode/kiosk_oem_manifest_parser.h"
#include "chromeos/chromeos_constants.h"
#include "chromeos/chromeos_paths.h"
#include "chromeos/chromeos_switches.h"
#include "chromeos/system/name_value_pairs_parser.h"

namespace chromeos {
namespace system {

namespace {

// Path to the tool used to get system info, and delimiters for the output
// format of the tool.
const char* kCrosSystemTool[] = { "/usr/bin/crossystem" };
const char kCrosSystemEq[] = "=";
const char kCrosSystemDelim[] = "\n";
const char kCrosSystemCommentDelim[] = "#";
const char kCrosSystemValueError[] = "(error)";

const char kHardwareClassCrosSystemKey[] = "hwid";
const char kHardwareClassValueUnknown[] = "unknown";

const char kIsVmCrosSystemKey[] = "inside_vm";

// Key/value delimiters of machine hardware info file. machine-info is generated
// only for OOBE and enterprise enrollment and may not be present. See
// login-manager/init/machine-info.conf.
const char kMachineHardwareInfoEq[] = "=";
const char kMachineHardwareInfoDelim[] = " \n";

// File to get ECHO coupon info from, and key/value delimiters of
// the file.
const char kEchoCouponFile[] = "/var/cache/echo/vpd_echo.txt";
const char kEchoCouponEq[] = "=";
const char kEchoCouponDelim[] = "\n";

// File to get VPD info from, and key/value delimiters of the file.
const char kVpdFile[] = "/var/log/vpd_2.0.txt";
const char kVpdEq[] = "=";
const char kVpdDelim[] = "\n";

// File to get regional data from.
const char kCrosRegions[] = "/usr/share/misc/cros-regions.json";

// Timeout that we should wait for statistics to get loaded
const int kTimeoutSecs = 3;

// The location of OEM manifest file used to trigger OOBE flow for kiosk mode.
const base::CommandLine::CharType kOemManifestFilePath[] =
    FILE_PATH_LITERAL("/usr/share/oem/oobe/manifest.json");

// Items in region dictionary.
const char kKeyboardsPath[] = "keyboards";
const char kLocalesPath[] = "locales";
const char kTimeZonesPath[] = "time_zones";

// These are the machine serial number keys that we check in order until we
// find a non-empty serial number. The VPD spec says the serial number should be
// in the "serial_number" key for v2+ VPDs. However, legacy devices used a
// different key to report their serial number, which we fall back to if
// "serial_number" is not present.
//
// Product_S/N is still special-cased due to inconsistencies with serial
// numbers on Lumpy devices: On these devices, serial_number is identical to
// Product_S/N with an appended checksum. Unfortunately, the sticker on the
// packaging doesn't include that checksum either (the sticker on the device
// does though!). The former sticker is the source of the serial number used by
// device management service, so we prefer Product_S/N over serial number to
// match the server.
const char* const kMachineInfoSerialNumberKeys[] = {
    "Product_S/N",     // Lumpy/Alex devices
    kSerialNumberKey,  // VPD v2+ devices
    "Product_SN",      // Mario
    "sn",              // old ZGB devices (more recent ones use serial_number)
};

// Gets ListValue from given |dictionary| by given |key| and (unless |result| is
// nullptr) sets |result| to a string with all list values joined by ','.
// Returns true on success.
bool JoinListValuesToString(const base::DictionaryValue* dictionary,
                            const std::string key,
                            std::string* result) {
  const base::ListValue* list = nullptr;
  if (!dictionary->GetListWithoutPathExpansion(key, &list))
    return false;

  std::string buffer;
  bool first = true;
  for (const auto& v : *list) {
    std::string value;
    if (!v->GetAsString(&value))
      return false;

    if (first)
      first = false;
    else
      buffer += ',';

    buffer += value;
  }
  if (result != nullptr)
    *result = buffer;
  return true;
}

// Gets ListValue from given |dictionary| by given |key| and (unless |result| is
// nullptr) sets |result| to the first value as string.  Returns true on
// success.
bool GetFirstListValueAsString(const base::DictionaryValue* dictionary,
                               const std::string key,
                               std::string* result) {
  const base::ListValue* list = nullptr;
  if (!dictionary->GetListWithoutPathExpansion(key, &list))
    return false;

  std::string value;
  if (!list->GetString(0, &value))
    return false;
  if (result != nullptr)
    *result = value;
  return true;
}

bool GetKeyboardLayoutFromRegionalData(const base::DictionaryValue* region_dict,
                                       std::string* result) {
  return JoinListValuesToString(region_dict, kKeyboardsPath, result);
}

bool GetInitialTimezoneFromRegionalData(
    const base::DictionaryValue* region_dict,
    std::string* result) {
  return GetFirstListValueAsString(region_dict, kTimeZonesPath, result);
}

bool GetInitialLocaleFromRegionalData(const base::DictionaryValue* region_dict,
                                      std::string* result) {
  return JoinListValuesToString(region_dict, kLocalesPath, result);
}

}  // namespace

// Key values for GetMachineStatistic()/GetMachineFlag() calls.
const char kActivateDateKey[] = "ActivateDate";
const char kCheckEnrollmentKey[] = "check_enrollment";
const char kCustomizationIdKey[] = "customization_id";
const char kDevSwitchBootKey[] = "devsw_boot";
const char kDevSwitchBootValueDev[] = "1";
const char kDevSwitchBootValueVerified[] = "0";
const char kFirmwareTypeKey[] = "mainfw_type";
const char kFirmwareTypeValueDeveloper[] = "developer";
const char kFirmwareTypeValueNonchrome[] = "nonchrome";
const char kFirmwareTypeValueNormal[] = "normal";
const char kHardwareClassKey[] = "hardware_class";
const char kIsVmKey[] = "is_vm";
const char kIsVmValueTrue[] = "1";
const char kIsVmValueFalse[] = "0";
const char kOffersCouponCodeKey[] = "ubind_attribute";
const char kOffersGroupCodeKey[] = "gbind_attribute";
const char kRlzBrandCodeKey[] = "rlz_brand_code";
const char kWriteProtectSwitchBootKey[] = "wpsw_boot";
const char kWriteProtectSwitchBootValueOff[] = "0";
const char kWriteProtectSwitchBootValueOn[] = "1";
const char kRegionKey[] = "region";
const char kSerialNumberKey[] = "serial_number";
const char kInitialLocaleKey[] = "initial_locale";
const char kInitialTimezoneKey[] = "initial_timezone";
const char kKeyboardLayoutKey[] = "keyboard_layout";

// OEM specific statistics. Must be prefixed with "oem_".
const char kOemCanExitEnterpriseEnrollmentKey[] = "oem_can_exit_enrollment";
const char kOemDeviceRequisitionKey[] = "oem_device_requisition";
const char kOemIsEnterpriseManagedKey[] = "oem_enterprise_managed";
const char kOemKeyboardDrivenOobeKey[] = "oem_keyboard_driven_oobe";

bool HasOemPrefix(const std::string& name) {
  return name.substr(0, 4) == "oem_";
}

// The StatisticsProvider implementation used in production.
class StatisticsProviderImpl : public StatisticsProvider {
 public:
  // StatisticsProvider implementation:
  void StartLoadingMachineStatistics(
      const scoped_refptr<base::TaskRunner>& file_task_runner,
      bool load_oem_manifest) override;
  bool GetMachineStatistic(const std::string& name,
                           std::string* result) override;
  bool GetMachineFlag(const std::string& name, bool* result) override;
  void Shutdown() override;

  // Returns true when Chrome OS is running in a VM. NOTE: if crossystem is not
  // installed it will return false even if Chrome OS is running in a VM.
  bool IsRunningOnVm() override;

  static StatisticsProviderImpl* GetInstance();

 protected:
  typedef std::map<std::string, bool> MachineFlags;
  typedef bool (*RegionDataExtractor)(const base::DictionaryValue*,
                                      std::string*);
  friend struct base::DefaultSingletonTraits<StatisticsProviderImpl>;

  StatisticsProviderImpl();
  ~StatisticsProviderImpl() override;

  // Waits up to |kTimeoutSecs| for statistics to be loaded. Returns true if
  // they were loaded successfully.
  bool WaitForStatisticsLoaded();

  // Loads the machine statistics off of disk. Runs on the file thread.
  void LoadMachineStatistics(bool load_oem_manifest);

  // Loads the OEM statistics off of disk. Runs on the file thread.
  void LoadOemManifestFromFile(const base::FilePath& file);

  // Loads regional data off of disk. Runs on the file thread.
  void LoadRegionsFile(const base::FilePath& filename);

  // Extracts known data from regional_data_;
  // Returns true on success;
  bool GetRegionalInformation(const std::string& name,
                              std::string* result) const;

  // Returns current region dictionary or NULL if not found.
  const base::DictionaryValue* GetRegionDictionary() const;

  // Returns extractor from regional_data_extractors_ or nullptr.
  RegionDataExtractor GetRegionalDataExtractor(const std::string& name) const;

  bool load_statistics_started_;
  NameValuePairsParser::NameValueMap machine_info_;
  MachineFlags machine_flags_;
  base::CancellationFlag cancellation_flag_;
  // |on_statistics_loaded_| protects |machine_info_| and |machine_flags_|.
  base::WaitableEvent on_statistics_loaded_;
  bool oem_manifest_loaded_;
  std::string region_;
  std::unique_ptr<base::Value> regional_data_;
  base::hash_map<std::string, RegionDataExtractor> regional_data_extractors_;

 private:
  DISALLOW_COPY_AND_ASSIGN(StatisticsProviderImpl);
};

bool StatisticsProviderImpl::WaitForStatisticsLoaded() {
  CHECK(load_statistics_started_);
  if (on_statistics_loaded_.IsSignaled())
    return true;

  // Block if the statistics are not loaded yet. Normally this shouldn't
  // happen except during OOBE.
  base::Time start_time = base::Time::Now();
  base::ThreadRestrictions::ScopedAllowWait allow_wait;
  on_statistics_loaded_.TimedWait(base::TimeDelta::FromSeconds(kTimeoutSecs));

  base::TimeDelta dtime = base::Time::Now() - start_time;
  if (on_statistics_loaded_.IsSignaled()) {
    LOG(WARNING) << "Statistics loaded after waiting "
                 << dtime.InMilliseconds() << "ms.";
    return true;
  }

  LOG(ERROR) << "Statistics not loaded after waiting "
             << dtime.InMilliseconds() << "ms.";
  return false;
}

const base::DictionaryValue* StatisticsProviderImpl::GetRegionDictionary()
    const {
  const base::DictionaryValue* full_dict = nullptr;
  if (!regional_data_->GetAsDictionary(&full_dict))
    return nullptr;

  const base::DictionaryValue* region_dict = nullptr;
  if (!full_dict->GetDictionaryWithoutPathExpansion(region_, &region_dict))
    return nullptr;

  return region_dict;
}

StatisticsProviderImpl::RegionDataExtractor
StatisticsProviderImpl::GetRegionalDataExtractor(
    const std::string& name) const {
  const auto it = regional_data_extractors_.find(name);
  if (it == regional_data_extractors_.end())
    return nullptr;

  return it->second;
}

bool StatisticsProviderImpl::GetRegionalInformation(const std::string& name,
                                                    std::string* result) const {
  if (region_.empty() || !regional_data_.get())
    return false;

  const RegionDataExtractor extractor = GetRegionalDataExtractor(name);
  if (!extractor)
    return false;

  const base::DictionaryValue* region_dict = GetRegionDictionary();
  if (!region_dict)
    return false;

  return extractor(region_dict, result);
}

bool StatisticsProviderImpl::GetMachineStatistic(const std::string& name,
                                                 std::string* result) {
  VLOG(1) << "Machine Statistic requested: " << name;
  if (!WaitForStatisticsLoaded()) {
    LOG(ERROR) << "GetMachineStatistic called before load started: " << name;
    return false;
  }

  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
  std::string cros_regions_mode;
  if (command_line->HasSwitch(chromeos::switches::kCrosRegionsMode)) {
    cros_regions_mode =
        command_line->GetSwitchValueASCII(chromeos::switches::kCrosRegionsMode);
  }

  // These two modes override existing machine statistics keys.
  // By default (cros_regions_mode is empty), the same keys are emulated if
  // they do not exist in machine statistics.
  if (cros_regions_mode == chromeos::switches::kCrosRegionsModeOverride ||
      cros_regions_mode == chromeos::switches::kCrosRegionsModeHide) {
    if (GetRegionalInformation(name, result))
      return true;
  }

  if (cros_regions_mode == chromeos::switches::kCrosRegionsModeHide &&
      GetRegionalDataExtractor(name)) {
    return false;
  }

  NameValuePairsParser::NameValueMap::iterator iter = machine_info_.find(name);
  if (iter == machine_info_.end()) {
    if (GetRegionalInformation(name, result))
      return true;
    if (result != nullptr &&
        base::SysInfo::IsRunningOnChromeOS() &&
        (oem_manifest_loaded_ || !HasOemPrefix(name))) {
      LOG(WARNING) << "Requested statistic not found: " << name;
    }
    return false;
  }
  if (result != nullptr)
    *result = iter->second;
  return true;
}

bool StatisticsProviderImpl::GetMachineFlag(const std::string& name,
                                            bool* result) {
  VLOG(1) << "Machine Flag requested: " << name;
  if (!WaitForStatisticsLoaded()) {
    LOG(ERROR) << "GetMachineFlag called before load started: " << name;
    return false;
  }

  MachineFlags::const_iterator iter = machine_flags_.find(name);
  if (iter == machine_flags_.end()) {
    if (result != nullptr &&
        base::SysInfo::IsRunningOnChromeOS() &&
        (oem_manifest_loaded_ || !HasOemPrefix(name))) {
      LOG(WARNING) << "Requested machine flag not found: " << name;
    }
    return false;
  }
  if (result != nullptr)
    *result = iter->second;
  return true;
}

void StatisticsProviderImpl::Shutdown() {
  cancellation_flag_.Set();  // Cancel any pending loads
}

bool StatisticsProviderImpl::IsRunningOnVm() {
  if (!base::SysInfo::IsRunningOnChromeOS())
    return false;
  std::string is_vm;
  return GetMachineStatistic(kIsVmKey, &is_vm) && is_vm == kIsVmValueTrue;
}

StatisticsProviderImpl::StatisticsProviderImpl()
    : load_statistics_started_(false),
      on_statistics_loaded_(base::WaitableEvent::ResetPolicy::MANUAL,
                            base::WaitableEvent::InitialState::NOT_SIGNALED),
      oem_manifest_loaded_(false) {
  regional_data_extractors_[kInitialLocaleKey] =
      &GetInitialLocaleFromRegionalData;
  regional_data_extractors_[kKeyboardLayoutKey] =
      &GetKeyboardLayoutFromRegionalData;
  regional_data_extractors_[kInitialTimezoneKey] =
      &GetInitialTimezoneFromRegionalData;
}

StatisticsProviderImpl::~StatisticsProviderImpl() {
}

void StatisticsProviderImpl::StartLoadingMachineStatistics(
    const scoped_refptr<base::TaskRunner>& file_task_runner,
    bool load_oem_manifest) {
  CHECK(!load_statistics_started_);
  load_statistics_started_ = true;

  VLOG(1) << "Started loading statistics. Load OEM Manifest: "
          << load_oem_manifest;

  file_task_runner->PostTask(
      FROM_HERE,
      base::Bind(&StatisticsProviderImpl::LoadMachineStatistics,
                 base::Unretained(this),
                 load_oem_manifest));
}

void StatisticsProviderImpl::LoadMachineStatistics(bool load_oem_manifest) {
  // Run from the file task runner. StatisticsProviderImpl is a Singleton<> and
  // will not be destroyed until after threads have been stopped, so this test
  // is always safe.
  if (cancellation_flag_.IsSet())
    return;

  NameValuePairsParser parser(&machine_info_);
  if (base::SysInfo::IsRunningOnChromeOS()) {
    // Parse all of the key/value pairs from the crossystem tool.
    if (!parser.ParseNameValuePairsFromTool(arraysize(kCrosSystemTool),
                                            kCrosSystemTool,
                                            kCrosSystemEq,
                                            kCrosSystemDelim,
                                            kCrosSystemCommentDelim)) {
      LOG(ERROR) << "Errors parsing output from: " << kCrosSystemTool;
    }
  }

  base::FilePath machine_info_path;
  PathService::Get(chromeos::FILE_MACHINE_INFO, &machine_info_path);
  if (!base::SysInfo::IsRunningOnChromeOS() &&
      !base::PathExists(machine_info_path)) {
    // Use time value to create an unique stub serial because clashes of the
    // same serial for the same domain invalidate earlier enrollments. Persist
    // to disk to keep it constant across restarts (required for re-enrollment
    // testing).
    std::string stub_contents =
        "\"serial_number\"=\"stub_" +
        base::Int64ToString(base::Time::Now().ToJavaTime()) + "\"\n";
    int bytes_written = base::WriteFile(machine_info_path,
                                        stub_contents.c_str(),
                                        stub_contents.size());
    // static_cast<int> is fine because stub_contents is small.
    if (bytes_written < static_cast<int>(stub_contents.size())) {
      LOG(ERROR) << "Error writing machine info stub: "
                 << machine_info_path.value();
    }
  }

  parser.GetNameValuePairsFromFile(machine_info_path,
                                   kMachineHardwareInfoEq,
                                   kMachineHardwareInfoDelim);
  parser.GetNameValuePairsFromFile(base::FilePath(kEchoCouponFile),
                                   kEchoCouponEq,
                                   kEchoCouponDelim);
  parser.GetNameValuePairsFromFile(base::FilePath(kVpdFile),
                                   kVpdEq,
                                   kVpdDelim);

  // Ensure that the hardware class key is present with the expected
  // key name, and if it couldn't be retrieved, that the value is "unknown".
  std::string hardware_class = machine_info_[kHardwareClassCrosSystemKey];
  if (hardware_class.empty() || hardware_class == kCrosSystemValueError) {
    machine_info_[kHardwareClassKey] = kHardwareClassValueUnknown;
  } else {
    machine_info_[kHardwareClassKey] = hardware_class;
  }

  if (base::SysInfo::IsRunningOnChromeOS()) {
    // By default, assume that this is *not* a VM. If crossystem is not present,
    // report that we are not in a VM.
    machine_info_[kIsVmKey] = kIsVmValueFalse;
    const auto is_vm_iter = machine_info_.find(kIsVmCrosSystemKey);
    if (is_vm_iter != machine_info_.end() &&
        is_vm_iter->second == kIsVmValueTrue) {
      machine_info_[kIsVmKey] = kIsVmValueTrue;
    }
  }

  if (load_oem_manifest) {
    // If kAppOemManifestFile switch is specified, load OEM Manifest file.
    base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
    if (command_line->HasSwitch(switches::kAppOemManifestFile)) {
      LoadOemManifestFromFile(
          command_line->GetSwitchValuePath(switches::kAppOemManifestFile));
    } else if (base::SysInfo::IsRunningOnChromeOS()) {
      LoadOemManifestFromFile(base::FilePath(kOemManifestFilePath));
    }
  }

  LoadRegionsFile(base::FilePath(kCrosRegions));

  // Set region
  const auto region_iter = machine_info_.find(kRegionKey);
  if (region_iter != machine_info_.end())
    region_ = region_iter->second;
  else
    region_ = std::string();

  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
  if (command_line->HasSwitch(chromeos::switches::kCrosRegion)) {
    region_ =
        command_line->GetSwitchValueASCII(chromeos::switches::kCrosRegion);
    machine_info_[kRegionKey] = region_;
    LOG(WARNING) << "CrOS region set to '" << region_ << "'";
  }

  if (regional_data_.get() && !region_.empty() && !GetRegionDictionary())
    LOG(ERROR) << "Bad regional data: '" << region_ << "' << not found.";

  // Finished loading the statistics.
  on_statistics_loaded_.Signal();
  VLOG(1) << "Finished loading statistics.";
}

void StatisticsProviderImpl::LoadRegionsFile(const base::FilePath& filename) {
  JSONFileValueDeserializer regions_file(filename);
  int regions_error_code = 0;
  std::string regions_error_message;
  regional_data_ =
      regions_file.Deserialize(&regions_error_code, &regions_error_message);
  if (!regional_data_.get()) {
    if (base::SysInfo::IsRunningOnChromeOS())
      LOG(ERROR) << "Failed to load regions file '" << filename.value()
                 << "': error='" << regions_error_message << "'";

    return;
  }
  const base::DictionaryValue* full_dict = nullptr;
  if (!regional_data_->GetAsDictionary(&full_dict)) {
    LOG(ERROR) << "Bad regions file '" << filename.value()
               << "': not a dictionary.";
    regional_data_.reset();
  }
}

void StatisticsProviderImpl::LoadOemManifestFromFile(
    const base::FilePath& file) {
  // Called from LoadMachineStatistics. Check cancellation_flag_ again here.
  if (cancellation_flag_.IsSet())
    return;

  KioskOemManifestParser::Manifest oem_manifest;
  if (!KioskOemManifestParser::Load(file, &oem_manifest)) {
    LOG(WARNING) << "Unable to load OEM Manifest file: " << file.value();
    return;
  }
  machine_info_[kOemDeviceRequisitionKey] =
      oem_manifest.device_requisition;
  machine_flags_[kOemIsEnterpriseManagedKey] =
      oem_manifest.enterprise_managed;
  machine_flags_[kOemCanExitEnterpriseEnrollmentKey] =
      oem_manifest.can_exit_enrollment;
  machine_flags_[kOemKeyboardDrivenOobeKey] =
      oem_manifest.keyboard_driven_oobe;

  oem_manifest_loaded_ = true;
  VLOG(1) << "Loaded OEM Manifest statistics from " << file.value();
}

StatisticsProviderImpl* StatisticsProviderImpl::GetInstance() {
  return base::Singleton<
      StatisticsProviderImpl,
      base::DefaultSingletonTraits<StatisticsProviderImpl>>::get();
}

std::string StatisticsProvider::GetEnterpriseMachineID() {
  std::string machine_id;
  for (const char* key : kMachineInfoSerialNumberKeys) {
    if (GetMachineStatistic(key, &machine_id) && !machine_id.empty()) {
      break;
    }
  }
  return machine_id;
}

static StatisticsProvider* g_test_statistics_provider = NULL;

// static
StatisticsProvider* StatisticsProvider::GetInstance() {
  if (g_test_statistics_provider)
    return g_test_statistics_provider;
  return StatisticsProviderImpl::GetInstance();
}

// static
void StatisticsProvider::SetTestProvider(StatisticsProvider* test_provider) {
  g_test_statistics_provider = test_provider;
}

}  // namespace system
}  // namespace chromeos