// Copyright 2018 Google LLC. All Rights Reserved. This file and proprietary
// source code may only be used and distributed under the Widevine Master
// License Agreement.
//
// Format mediadrm framework protobuf metrics

#include <fstream>
#include <iomanip>
#include <iostream>
#include <memory>
#include <sstream>
#include <string>

#include "mediadrm_metrics.pb.h"

namespace mediadrm_metrics {

using namespace android::drm_metrics;
using std::string;
using std::to_string;

const string kIndentPerLine = "  ";

string FormatAttributes(const DrmFrameworkMetrics::Attributes& attributes) {
  string result;
  if (attributes.has_error_code()) {
    result.append("error_code:");
    result.append(to_string(attributes.error_code()));
  }
  if (attributes.has_key_status_type()) {
    if (result.size()) result.append(",");
    result.append("key_status_type:");
    result.append(to_string(attributes.key_status_type()));
  }
  if (attributes.has_event_type()) {
    if (result.size()) result.append(",");
    result.append("event_type:");
    result.append(to_string(attributes.event_type()));
  }
  if (result.size()) {
    return string(" {") + result + "}";
  } else {
    return "";
  }
}

string FormatCounter(const DrmFrameworkMetrics::Counter& cm) {
  string result;
  if (cm.has_count()) {
    result = string("count=") + to_string(cm.count());
    if (cm.has_attributes()) {
      result.append(FormatAttributes(cm.attributes()));
    }
  }
  return result;
}

string FormatDistributionMetric(
    const DrmFrameworkMetrics::DistributionMetric& dm) {
  string result;
  if (dm.has_operation_count()) {
    if (dm.operation_count() == 1) {
      if (dm.has_mean()) {
        std::ostringstream buffer;
        buffer << dm.mean();
        result += string("mean=") + buffer.str();
      }
    } else {
      if (dm.has_min()) {
        std::ostringstream buffer;
        buffer << dm.min();
        result = string("min=") + buffer.str();
      }
      if (dm.has_max()) {
        std::ostringstream buffer;
        buffer << dm.max();
        if (result.size()) result.append(" ");
        result += string("max=") + buffer.str();
      }
      if (dm.has_mean()) {
        std::ostringstream buffer;
        buffer << dm.mean();
        if (result.size()) result.append(" ");
        result += string("mean=") + buffer.str();
      }
      if (dm.has_variance()) {
        std::ostringstream buffer;
        buffer << dm.variance();
        if (result.size()) result.append(" ");
        result += string("variance=") + buffer.str();
      }
      if (dm.has_operation_count()) {
        if (result.size()) result.append(" ");
        result += string("count=") + to_string(dm.operation_count());
      }
    }
    if (dm.has_attributes()) {
      result.append(FormatAttributes(dm.attributes()));
    }
  }
  return result;
}

#define FORMAT_REPEATED_DISTRIBUTION(NAME, INDENT)                     \
  if (metrics.NAME##_size() == 1) {                                    \
    result.append(INDENT + #NAME + ": ");                              \
    result.append(FormatDistributionMetric(metrics.NAME(0)) + "\n");   \
  } else {                                                             \
    for (int i = 0; i < metrics.NAME##_size(); i++) {                  \
      result.append(INDENT + #NAME "[" + to_string(i) + "]: ");        \
      result.append(FormatDistributionMetric(metrics.NAME(i)) + "\n"); \
    }                                                                  \
  }

#define FORMAT_REPEATED_COUNTER(NAME, INDENT)                   \
  if (metrics.NAME##_size() == 1) {                             \
    result.append(INDENT + #NAME ": ");                         \
    result.append(FormatCounter(metrics.NAME(0)) + "\n");       \
  } else {                                                      \
    for (int i = 0; i < metrics.NAME##_size(); i++) {           \
      result.append(INDENT + #NAME "[" + to_string(i) + "]: "); \
      result.append(FormatCounter(metrics.NAME(i)) + "\n");     \
    }                                                           \
  }

uint8_t hex2bin(char c) { return isdigit(c) ? c - '0' : tolower(c) - 'a' + 10; }

string hexdecode(string encoded) {
  string result;
  for (size_t i = 0; i < encoded.size(); i += 2) {
    char c = hex2bin(encoded[i]) << 4 | hex2bin(encoded[i + 1]);
    result += c;
  }
  return result;
}

string ms_to_seconds(uint64_t time_ms) {
  uint64_t time_s = time_ms / 1000;
  uint64_t ms = time_ms - time_s * 1000;
  return to_string(time_s) + "." + to_string(ms);
}

void FormatDrmFrameworkMetrics(const DrmFrameworkMetrics& metrics,
                               string& result) {
  string indent = kIndentPerLine;

  result.append("mediadrm_metrics\n");
  FORMAT_REPEATED_COUNTER(open_session_counter, indent);
  FORMAT_REPEATED_COUNTER(close_session_counter, indent);
  FORMAT_REPEATED_DISTRIBUTION(get_key_request_time_us, indent);
  FORMAT_REPEATED_DISTRIBUTION(provide_key_response_time_us, indent);
  FORMAT_REPEATED_COUNTER(get_provisioning_request_counter, indent);
  FORMAT_REPEATED_COUNTER(provide_provisioning_response_counter, indent);
  FORMAT_REPEATED_COUNTER(key_status_change_counter, indent);
  FORMAT_REPEATED_COUNTER(event_callback_counter, indent);
  FORMAT_REPEATED_COUNTER(get_device_unique_id_counter, indent);

  size_t i = 0;
  for (auto const& entry : metrics.session_lifetimes()) {
    DrmFrameworkMetrics_SessionLifetime lifetime = entry.second;
    if (lifetime.has_start_time_ms() && lifetime.has_end_time_ms()) {
      result += indent + "session[" + to_string(++i) + "]: \"" +
                hexdecode(entry.first) + "\"";
      result +=
          string(" start: ") + ms_to_seconds(lifetime.start_time_ms()) + " sec";
      result += string(" duration: ") +
                to_string(lifetime.end_time_ms() - lifetime.start_time_ms()) +
                " ms\n";
    }
  }
}

};  // namespace mediadrm_metrics