/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "intcnt.h"

IntCount::IntCount() : numInts(0), iPair(nullptr) {}
IntCount::~IntCount() { delete[] iPair; }
int IntCount::getSize() { return numInts; }
int IntCount::getCount(int pos) { return iPair[pos].cnt; }
int IntCount::getIndex(int pos) { return iPair[pos].idx; }

void IntCount::clear() {
  delete[] iPair;
  iPair = new IntPair[0];
  numInts = 0;
}

int IntCount::countAdd(int index, int increment) {
  if (numInts) {
    // Do a binary search to find the element
    int divPoint = 0;

    if (index > iPair[numInts - 1].idx) {
      divPoint = numInts;
    } else if (index < iPair[0].idx) {
      divPoint = 0;
    } else {
      int low = 0, high = numInts - 1;
      int mid = (low + high) / 2;
      while (1) {
        mid = (low + high) / 2;

        if (index < iPair[mid].idx) {
          high = mid;
        } else if (index > iPair[mid].idx) {
          if (mid < numInts - 1 && index < iPair[mid + 1].idx) {
            divPoint = mid + 1;
            break;
          } else {
            low = mid + 1;
          }
        } else if (index == iPair[mid].idx) {
          return iPair[mid].cnt += increment;
        }
      }
    }

    int i;
    IntPair* tpair = new IntPair[numInts + 1];
    for (i = 0; i < divPoint; i++) {
      tpair[i] = iPair[i];
    }
    for (i = divPoint; i < numInts; i++) {
      tpair[i + 1] = iPair[i];
    }
    ++numInts;
    delete[] iPair;
    iPair = tpair;
    iPair[divPoint].idx = index;
    iPair[divPoint].cnt = increment;
    return increment;
  } else {
    iPair = new IntPair[1];
    numInts = 1;
    iPair[0].idx = index;
    return iPair[0].cnt = increment;
  }
}
