/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

// author Kevin Lang, Oath Research

/*******************************************************/

#include "common.h"
#include "fm85.h"
#include "iconEstimator.h"

#include <stdexcept>

/*******************************************************/
// ln 2.0
double iconErrorConstant = 0.693147180559945286;

//  1,    2,    3, // kappa
Short iconLowSideData [33] = {   // Empirically measured at N = 1000 * K.
 6037, 5720, 5328, // 4 1000000
 6411, 6262, 5682, // 5 1000000
 6724, 6403, 6127, // 6 1000000
 6665, 6411, 6208, // 7 1000000
 6959, 6525, 6427, // 8 1000000
 6892, 6665, 6619, // 9 1000000
 6792, 6752, 6690, // 10 1000000
 6899, 6818, 6708, // 11 1000000
 6871, 6845, 6812, // 12 1046369
 6909, 6861, 6828, // 13 1043411
 6919, 6897, 6842, // 14 1000297
};                // lgK numtrials

//  1,    2,    3, // kappa
Short iconHighSideData [33] = {   // Empirically measured at N = 1000 * K.
 8031, 8559, 9309, // 4 1000000
 7084, 7959, 8660, // 5 1000000
 7141, 7514, 7876, // 6 1000000
 7458, 7430, 7572, // 7 1000000
 6892, 7141, 7497, // 8 1000000
 6889, 7132, 7290, // 9 1000000
 7075, 7118, 7185, // 10 1000000
 7040, 7047, 7085, // 11 1000000
 6993, 7019, 7053, // 12 1046369
 6953, 7001, 6983, // 13 1043411
 6944, 6966, 7004, // 14 1000297
};                // lgK numtrials

/*******************************************************/
// sqrt((ln 2.0) / 2.0)
double hipErrorConstant = 0.588705011257737332;

//  1,    2,    3, // kappa
Short hipLowSideData [33] = {   // Empirically measured at N = 1000 * K.
 5871, 5247, 4826, // 4 1000000
 5877, 5403, 5070, // 5 1000000
 5873, 5533, 5304, // 6 1000000
 5878, 5632, 5464, // 7 1000000
 5874, 5690, 5564, // 8 1000000
 5880, 5745, 5619, // 9 1000000
 5875, 5784, 5701, // 10 1000000
 5866, 5789, 5742, // 11 1000000
 5869, 5827, 5784, // 12 1046369
 5876, 5860, 5827, // 13 1043411
 5881, 5853, 5842, // 14 1000297
};                // lgK numtrials

//  1,    2,    3, // kappa
Short hipHighSideData [33] = {   // Empirically measured at N = 1000 * K.
 5855, 6688, 7391, // 4 1000000
 5886, 6444, 6923, // 5 1000000
 5885, 6254, 6594, // 6 1000000
 5889, 6134, 6326, // 7 1000000
 5900, 6072, 6203, // 8 1000000
 5875, 6005, 6089, // 9 1000000
 5871, 5980, 6040, // 10 1000000
 5889, 5941, 6015, // 11 1000000
 5871, 5926, 5973, // 12 1046369
 5866, 5901, 5915, // 13 1043411
 5880, 5914, 5953, // 14 1000297
};                // lgK numtrials

/*******************************************************/

double getIconConfidenceLB (FM85 * sketch, int kappa) {
  if (sketch->numCoupons == 0) return 0.0;
  int lgK = sketch->lgK;
  long k = (1LL << lgK);
  if (lgK < 4) throw std::logic_error("lgk < 4");
  if (kappa < 1 || kappa > 3) throw std::invalid_argument("kappa must be between 1 and 3");
  double x = iconErrorConstant;
  if (lgK <= 14) x = ((double) iconHighSideData[3*(lgK-4) + (kappa-1)]) / 10000.0;
  double rel = x / (sqrt((double) k));
  double eps = ((double) kappa) * rel;
  double est = getIconEstimate (lgK, sketch->numCoupons);
  double result = est / (1.0 + eps);
  double check = (double) sketch->numCoupons;
  if (result < check) result = check;
  return (result);
}

double getIconConfidenceUB (FM85 * sketch, int kappa) {
  if (sketch->numCoupons == 0) return 0.0;
  int lgK = sketch->lgK;
  long k = (1LL << lgK);
  if (lgK < 4) throw std::logic_error("lgk < 4");
  if (kappa < 1 || kappa > 3) throw std::invalid_argument("kappa must be between 1 and 3");
  double x = iconErrorConstant;
  if (lgK <= 14) x = ((double) iconLowSideData[3*(lgK-4) + (kappa-1)]) / 10000.0;
  double rel = x / (sqrt((double) k));
  double eps = ((double) kappa) * rel;
  double est = getIconEstimate (lgK, sketch->numCoupons);
  double result = est / (1.0 - eps);
  return (ceil(result));  // widening for coverage
}

/*******************************************************/

double getHIPConfidenceLB (FM85 * sketch, int kappa) {
  if (sketch->numCoupons == 0) return 0.0;
  int lgK = sketch->lgK;
  long k = (1LL << lgK);
  if (lgK < 4) throw std::logic_error("lgk < 4");
  if (kappa < 1 || kappa > 3) throw std::invalid_argument("kappa must be between 1 and 3");
  double x = hipErrorConstant;
  if (lgK <= 14) x = ((double) hipHighSideData[3*(lgK-4) + (kappa-1)]) / 10000.0;
  double rel = x / (sqrt((double) k));
  double eps = ((double) kappa) * rel;
  double est = getHIPEstimate (sketch);
  double result = est / (1.0 + eps);
  double check = (double) sketch->numCoupons;
  if (result < check) result = check;
  return (result);
}

double getHIPConfidenceUB (FM85 * sketch, int kappa) {
  if (sketch->numCoupons == 0) return 0.0;
  int lgK = sketch->lgK;
  long k = (1LL << lgK);
  if (lgK < 4) throw std::logic_error("lgk < 4");
  if (kappa < 1 || kappa > 3) throw std::invalid_argument("kappa must be between 1 and 3");
  double x = hipErrorConstant;
  if (lgK <= 14) x = ((double) hipLowSideData[3*(lgK-4) + (kappa-1)]) / 10000.0;
  double rel = x / (sqrt((double) k));
  double eps = ((double) kappa) * rel;
  double est = getHIPEstimate (sketch);
  double result = est / (1.0 - eps);
  return (ceil(result)); // widening for coverage
}

/*******************************************************/