#include "tlbmc/sensors/intel_cpu_sensor.h"

#include <algorithm>
#include <array>
#include <cctype>
#include <charconv>
#include <cstdint>
#include <cstring>
#include <fstream>
#include <iterator>
#include <memory>
#include <optional>
#include <string>
#include <system_error>  // NOLINT: system_error is commonly used in BMC
#include <tuple>
#include <utility>
#include <vector>

#include "absl/container/flat_hash_map.h"
#include "absl/container/flat_hash_set.h"
#include "absl/functional/any_invocable.h"
#include "absl/log/log.h"
#include "absl/status/status.h"
#include "absl/strings/ascii.h"
#include "absl/strings/match.h"
#include "absl/strings/numbers.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/str_replace.h"
#include "absl/strings/string_view.h"
#include "absl/strings/substitute.h"
#include "g3/macros.h"
#include "intel_cpu_sensor_config.pb.h"
#include "reading_range_config.pb.h"
#include "reading_transform_config.pb.h"
#include "threshold_config.pb.h"
#include "tlbmc/hal/sysfs/peci.h"
#include "resource.pb.h"
#include "sensor.pb.h"
#include "tlbmc/sensors/peci_hwmon_based_sensor.h"
#include "tlbmc/sensors/sensor.h"
#include "tlbmc/time/time.h"
#include "re2/re2.h"

namespace milotic_tlbmc {

template <class TypeNameFirst, class TypeNameSecond>
struct TypeComparator {
  // Compared by the first element which is the type name.
  bool operator()(const std::pair<TypeNameFirst, TypeNameSecond>& lhs,
                  const std::pair<TypeNameFirst, TypeNameSecond>& rhs) const {
    return lhs.first < rhs.first;
  }
};

// Reading properties for IntelCpuSensors are statically configured by type.
// From:
// https://github.com/openbmc/dbus-sensors/blob/master/src/intel-cpu/IntelCPUSensor.cpp#L72
constexpr std::array<IntelCpuSensor::ReadingProperties, 2>
    kDefaultIntelCpuSensorProperties = {
        // Power sensor
        IntelCpuSensor::ReadingProperties{.max_reading = 511,
                                          .min_reading = 0,
                                          .sensor_unit = SensorUnit::UNIT_WATT},
        // Temperature sensor
        IntelCpuSensor::ReadingProperties{
            .max_reading = 127,
            .min_reading = -128,
            .sensor_unit = SensorUnit::UNIT_DEGREE_CELSIUS},
};

// From:
// https://github.com/openbmc/dbus-sensors/blob/master/src/Thresholds.cpp#L492
static const absl::flat_hash_map<
    std::string, std::vector<std::tuple<std::string, ThresholdType>>>
    kThresholdAttributesMap = {  // NOLINT(google3-runtime-global-variables)
        {"average",
         {std::make_tuple("average_min", THRESHOLD_TYPE_LOWER_NON_CRITICAL),
          std::make_tuple("average_max", THRESHOLD_TYPE_UPPER_NON_CRITICAL)}},
        {"input",
         {std::make_tuple("min", THRESHOLD_TYPE_LOWER_NON_CRITICAL),
          std::make_tuple("max", THRESHOLD_TYPE_UPPER_NON_CRITICAL),
          std::make_tuple("lcrit", THRESHOLD_TYPE_LOWER_CRITICAL),
          std::make_tuple("crit", THRESHOLD_TYPE_UPPER_CRITICAL)}}};

ReadingRangeConfigs GetReadingRangeConfig(
    const IntelCpuSensor::ReadingProperties& reading_properties) {
  ReadingRangeConfigs reading_range_configs;
  ReadingRangeConfig* reading_range_max =
      reading_range_configs.add_reading_range_configs();
  reading_range_max->set_type(READING_RANGE_TYPE_MAX);
  reading_range_max->set_reading(reading_properties.max_reading);
  ReadingRangeConfig* reading_range_min =
      reading_range_configs.add_reading_range_configs();
  reading_range_min->set_type(READING_RANGE_TYPE_MIN);
  reading_range_min->set_reading(reading_properties.min_reading);
  return reading_range_configs;
}

std::vector<boost::filesystem::path> IntelCpuSensor::FindFiles(
    const boost::filesystem::path& root_dir, const RE2& regex, int max_depth) {
  std::vector<boost::filesystem::path> files;
  if (!boost::filesystem::exists(root_dir)) {
    LOG(WARNING) << "root_dir does not exist: " << root_dir;
    return files;
  }
  for (auto p = boost::filesystem::recursive_directory_iterator(
           root_dir,
           boost::filesystem::directory_options::follow_directory_symlink);
       p != boost::filesystem::recursive_directory_iterator(); ++p) {
    if (RE2::PartialMatch(p->path().string(), regex)) {
      files.push_back(p->path());
    }
    if (p.depth() >= max_depth) {
      p.disable_recursion_pending();
    }
  }

  return files;
}

std::string IntelCpuSensor::CreateSensorName(const std::string& label,
                                             uint32_t cpuId) {
  std::string sensor_name = label;
  SensorUnit sensor_unit = absl::StrContainsIgnoreCase(sensor_name, "power")
                               ? SensorUnit::UNIT_WATT
                               : SensorUnit::UNIT_DEGREE_CELSIUS;

  std::string cpu_name = absl::StrCat("CPU", cpuId);
  constexpr absl::string_view kDimmLabel = "DIMM";
  std::size_t dimm_found = sensor_name.find(kDimmLabel);
  if (dimm_found == std::string::npos) {
    absl::StrAppend(&sensor_name, "_", cpu_name);
  }

  // Convert to Upper Camel case whole name
  // From:
  // https://github.com/openbmc/dbus-sensors/blob/master/src/intel-cpu/IntelCPUSensorMain.cpp#L138
  bool is_word_end = true;
  std::transform(sensor_name.begin(), sensor_name.end(), sensor_name.begin(),
                 [&is_word_end](int c) {
                   if (c == '_') {
                     is_word_end = true;
                   } else {
                     if (is_word_end) {
                       is_word_end = false;
                       return std::toupper(c);
                     }
                   }
                   return c;
                 });

  switch (sensor_unit) {
    case SensorUnit::UNIT_WATT:
      sensor_name = absl::StrCat("power_", sensor_name);
      break;
    case SensorUnit::UNIT_DEGREE_CELSIUS:
      sensor_name = absl::StrCat("temperature_", sensor_name);
      break;
    default:
      // IntelCpuSensors will never have these units
      LOG(WARNING) << "IntelCpuSensor " << sensor_name
                   << " has unexpected unit: " << sensor_unit;
      break;
  }

  return absl::StrReplaceAll(sensor_name, {{" ", "_"}});
}

absl::StatusOr<std::tuple<std::string, std::string, std::string>>
IntelCpuSensor::SplitInputFile(const boost::filesystem::path& input_file_path) {
  std::string input_file = input_file_path.filename().string();
  size_t find_num = input_file.find_first_of("1234567890");
  size_t find_underscore = input_file.find_first_of('_');
  if (find_num == std::string::npos || find_underscore == std::string::npos ||
      find_underscore <= find_num) {
    return absl::InvalidArgumentError(
        absl::Substitute("Invalid input file: $0", input_file));
  }
  return std::make_tuple(
      input_file.substr(0, find_num),
      input_file.substr(find_num, find_underscore - find_num),
      input_file.substr(find_underscore + 1));
}

void IntelCpuSensor::HandleRefreshResult(const boost::system::error_code& error,
                                         size_t bytes_read) {
  if (error) {
    State state;
    state.set_status(STATUS_STALE);
    state.set_status_message(absl::Substitute(
        "Failed to read from input device: $0; input device path: $1",
        error.message(), GetInputDevicePath()));
    UpdateState(std::move(state));
    return;
  }
  const char* buffer_end = GetConstReadBuffer().data() + bytes_read;
  int64_t value = 0;
  std::from_chars_result result =
      std::from_chars(GetConstReadBuffer().data(), buffer_end, value);
  if (result.ec != std::errc()) {
    State state;
    state.set_status(STATUS_STALE);
    state.set_status_message(
        absl::StrCat("Read data can't be converted to a number: ",
                     std::make_error_condition(result.ec).message()));
    UpdateState(std::move(state));
    return;
  }
  // TODO(b/449557765): Parse thresholds when tControl value changes instead of
  // on every refresh.
  ParseThresholdsFromHwmonFiles();
  SensorValue sensor_data;
  *sensor_data.mutable_timestamp() = Now();
  sensor_data.set_reading(
      (static_cast<double>(value) /
       sensor_attributes_static_.reading_transform().scale()) +
      sensor_attributes_static_.reading_transform().offset());
  StoreSensorData(std::make_shared<const SensorValue>(std::move(sensor_data)));
  State state;
  state.set_status(STATUS_READY);
  UpdateState(std::move(state));
}

absl::StatusOr<std::vector<std::shared_ptr<Sensor>>>
IntelCpuSensor::CreateInitialSensors(
    const IntelCpuSensorConfig& sensor_config,
    const std::shared_ptr<boost::asio::io_context>& io_context,
    const PeciSysfs& peci_sysfs,
    std::optional<NotificationCb> on_batch_notify) {
  std::vector<std::shared_ptr<Sensor>> sensors;
  for (const auto& [label, name] : sensor_config.label_to_name()) {
    std::string base_name = name.empty() ? label : name;
    IntelCpuSensor::ReadingProperties reading_properties =
        absl::StrContainsIgnoreCase(base_name, "power")
            ? kDefaultIntelCpuSensorProperties[0]
            : kDefaultIntelCpuSensorProperties[1];
    std::string sensor_name =
        CreateSensorName(base_name, sensor_config.cpu_id());
    ReadingTransformConfig reading_transform_config;
    reading_transform_config.set_scale(IntelCpuSensor::kScaleFactor);
    std::shared_ptr<IntelCpuSensor> sensor = std::make_shared<IntelCpuSensor>(
        Token(), sensor_config.type(), reading_properties.sensor_unit, "",
        sensor_name, label, sensor_config.hal_common_config(),
        sensor_config.thresholds(), GetReadingRangeConfig(reading_properties),
        reading_transform_config, sensor_config.entity_common_config(),
        sensor_config.dts_offset(), io_context, on_batch_notify, peci_sysfs);
    State state;
    state.set_status(STATUS_CREATION_PENDING);
    state.set_status_message("Initial creation, CPU/DIMM not detected yet");
    sensor->UpdateState(std::move(state));
    LOG(INFO) << "Created IntelCpuSensor: " << sensor_name;
    sensors.push_back(sensor);
  }

  return sensors;
}

absl::flat_hash_map<std::string, std::string>
IntelCpuSensor::CreateLabelToInputFileMap(
    const boost::filesystem::path& peci_device_path,
    const HalCommonConfig& hal_config) {
  absl::flat_hash_map<std::string, std::string> label_to_input_file;

  // Expected directory structure is
  // /sys/bus/peci/devices/peci-$BUS/$BUS-$ADDRESS/peci-*.0/hwmon/hwmon*/name
  // So we search with max depth of 4 for potential name files.
  // From:
  // https://github.com/openbmc/dbus-sensors/blob/master/src/intel-cpu/IntelCPUSensorMain.cpp#L195
  std::vector<boost::filesystem::path> hwmon_name_paths = FindFiles(
      peci_sysfs_.GetBusPath(hal_config.bus()) /
          peci_sysfs_.GetDeviceDirectoryName(hal_config),
      RE2(absl::Substitute(IntelCpuSensor::kHwmonNameRegex, hal_config.bus(),
                           absl::Hex(hal_config.address()))),
      4);
  if (hwmon_name_paths.empty()) {
    LOG(ERROR) << "No hwmon paths found for CPU sensors in system";
    return label_to_input_file;
  }

  absl::flat_hash_set<std::string> scanned_directories;
  for (const boost::filesystem::path& hwmon_name_path : hwmon_name_paths) {
    auto hwmon_dir = hwmon_name_path.parent_path();
    auto ret = scanned_directories.insert(hwmon_dir.string());
    if (!ret.second) {
      continue;  // already processed this directory
    }

    std::ifstream name_file(hwmon_name_path.string());
    if (!name_file.good()) {
      LOG(WARNING) << "Failed to open file: " << hwmon_name_path.string();
      continue;
    }
    std::string name = {std::istreambuf_iterator<char>(name_file),
                        std::istreambuf_iterator<char>()};
    name_file.close();
    if (name.empty()) {
      continue;
    }

    auto parent_dir = hwmon_name_path.parent_path();
    std::vector<boost::filesystem::path> input_paths =
        FindFiles(parent_dir, *IntelCpuSensor::kInputRegex, 0);
    if (input_paths.empty()) {
      LOG(WARNING) << "No input files for sensors in system at " << parent_dir;
      continue;
    }
    std::vector<std::shared_ptr<Sensor>> sensors;
    for (const boost::filesystem::path& input_path : input_paths) {
      auto find_underscore = input_path.filename().string().find('_');
      if (find_underscore == std::string::npos) {
        continue;
      }
      absl::StatusOr<std::tuple<std::string, std::string, std::string>>
          input_file_parts = SplitInputFile(input_path);
      if (!input_file_parts.ok()) {
        LOG(INFO) << "Invalid input file: " << input_file_parts.status();
        continue;
      }
      auto& [prefix, number, suffix] = *input_file_parts;
      std::string label_file_path =
          (parent_dir / absl::StrCat(prefix, number, "_label")).string();
      std::ifstream label_file(label_file_path);
      if (!label_file.good()) {
        LOG(WARNING) << "Failed to open file: " << label_file_path;
        continue;
      }
      std::string label = {std::istreambuf_iterator<char>(label_file),
                           std::istreambuf_iterator<char>()};
      label = std::string(absl::StripTrailingAsciiWhitespace(label));

      if (std::find(IntelCpuSensor::kHiddenProperties.begin(),
                    IntelCpuSensor::kHiddenProperties.end(),
                    label) != IntelCpuSensor::kHiddenProperties.end()) {
        continue;
      }

      label_to_input_file[label] = input_path.string();
    }
  }
  return label_to_input_file;
}

void IntelCpuSensor::ParseThresholdsFromHwmonFiles() {
  if (absl::StatusOr<std::tuple<std::string, std::string, std::string>>
          input_file_parts = SplitInputFile(input_dev_path_);
      input_file_parts.ok()) {
    auto& [prefix, number, suffix] = *input_file_parts;
    if (kThresholdAttributesMap.contains(suffix)) {
      ThresholdConfigs new_threshold_configs;
      bool has_valid_threshold = false;
      for (const auto& [attribute, threshold_type] :
           kThresholdAttributesMap.at(suffix)) {
        ThresholdConfig* threshold_config =
            new_threshold_configs.add_threshold_configs();
        threshold_config->set_type(threshold_type);
        boost::filesystem::path attribute_file_path =
            boost::filesystem::path(input_dev_path_).parent_path() /
            absl::StrCat(prefix, number, "_", attribute);
        std::ifstream attr_file(attribute_file_path.string());
        if (!attr_file.good()) {
          LOG(INFO) << "Failed to open file: " << attribute_file_path;
          continue;
        }
        std::string attr_value_str = {std::istreambuf_iterator<char>(attr_file),
                                      std::istreambuf_iterator<char>()};
        double value = 0;
        if (!absl::SimpleAtod(attr_value_str, &value)) {
          LOG(INFO) << "Failed to convert value: " << attr_value_str
                    << " to double";
          continue;
        }
        double offset = (attribute == "crit") ? dts_offset_ : 0;
        value = value / IntelCpuSensor::kScaleFactor + offset;
        threshold_config->set_value(value);
        // If at least one of the thresholds has a valid value, we should update
        // this sensor's thresholds.
        has_valid_threshold = true;
        LOG(INFO) << "IntelCPUSensor parsed threshold: " << attribute_file_path
                  << " " << attribute << " " << threshold_type << " " << value;
      }

      if (has_valid_threshold) {
        UpdateThresholds(new_threshold_configs);
      }
    }
  }
}

absl::Status IntelCpuSensor::ReinitializeInternal() {
  if (IsInputDeviceUsable()) {
    return absl::FailedPreconditionError(
        absl::StrCat("Attempted to reinitialize usable sensor: ", sensor_name_,
                     ". Ignoring reinitialization."));
  }

  ECCLESIA_ASSIGN_OR_RETURN(boost::filesystem::path peci_device_path,
                            PeciHwmonBasedSensor::CreateDevice(
                                sensor_attributes_static_.hal_common_config()));

  absl::flat_hash_map<std::string, std::string> label_to_input_file =
      CreateLabelToInputFileMap(peci_device_path,
                                sensor_attributes_static_.hal_common_config());

  auto it = label_to_input_file.find(sensor_label_);
  if (it == label_to_input_file.end()) {
    // We expect 32 or 16 DIMM sensors. Since tlBMC must statically configure
    // all sensors, we leave the uninitialized DIMM sensors as is if not found.
    // (b/449180255) - CPU Core sensors vary on machine startup, allow for tlBMC
    // to ignore missing Core sensors from static configuration.
    if (absl::StrContains(sensor_label_, "DIMM") ||
        absl::StrContains(sensor_label_, "Core")) {
      LOG(WARNING) << absl::StrCat("Failed to find ", sensor_label_,
                                   " in hwmon folder ",
                                   peci_device_path.string());
      return absl::OkStatus();
    }
    // Set state to CREATION_FAILED with error message to indicate that the
    // sensor was attempted to be created but failed.
    std::string error_message =
        absl::StrCat("Failed to find ", sensor_label_, " in hwmon folder ",
                     peci_device_path.string());
    State state;
    state.set_status(STATUS_CREATION_FAILED);
    state.set_status_message(error_message);
    UpdateState(std::move(state));
    return absl::NotFoundError(error_message);
  }

  SetInputDevicePath(it->second);

  ParseThresholdsFromHwmonFiles();

  // Set to Status UNKNOWN to simulate fresh creation of Sensor object.
  State state;
  state.set_status(STATUS_UNKNOWN);
  state.set_status_message("Reinitialized, pending sensor refresh");
  UpdateState(std::move(state));

  // Set up the input device file for reading. This must be done last as right
  // after this function is done, the sensor is readable.
  SetUpInput();

  LOG(INFO) << "Successfully reinitialized IntelCpuSensor: " << sensor_name_;

  return absl::OkStatus();
}

void IntelCpuSensor::Reinitialize(
    absl::AnyInvocable<void(absl::Status)> callback) {
  boost::asio::post(*io_context_,
                    [this, callback = std::move(callback)]() mutable {
                      callback(ReinitializeInternal());
                    });
}

IntelCpuSensor::IntelCpuSensor(
    Token token, IntelCpuSensorType sensor_type, SensorUnit sensor_unit,
    const std::string& input_dev_path, const std::string& sensor_name,
    const std::string& sensor_label, const HalCommonConfig& hal_common_config,
    const ThresholdConfigs& threshold_configs,
    const ReadingRangeConfigs& reading_range_configs,
    const ReadingTransformConfig& reading_transform_config,
    const EntityCommonConfig& entity_common_config, const double dts_offset,
    const std::shared_ptr<boost::asio::io_context>& io_context,
    std::optional<NotificationCb> on_batch_notify, const PeciSysfs& peci_sysfs)
    : PeciHwmonBasedSensor(
          input_dev_path, io_context,
          CreateStaticAttributes(sensor_name, sensor_unit, hal_common_config,
                                 entity_common_config, reading_range_configs,
                                 reading_transform_config),
          threshold_configs, std::move(on_batch_notify), peci_sysfs),
      sensor_type_(sensor_type),
      sensor_name_(sensor_name),
      sensor_label_(sensor_label),
      dts_offset_(dts_offset) {}

IntelCpuSensor::IntelCpuSensor(const PeciSysfs& peci_sysfs)
    : PeciHwmonBasedSensor("", nullptr, SensorAttributesStatic(),
                           ThresholdConfigs(), std::nullopt, peci_sysfs) {}

}  // namespace milotic_tlbmc