Untitled

const getDaysInYear = (year) => {
  const startDate = new Date(year, 0, 1);
  const endDate = new Date(year, 11, 31);
  const oneDay = 1000 * 60 * 60 * 24;
  //console.log(startDate, endDate, (endDate - startDate));
  const days = Math.floor((endDate - startDate) / oneDay) + 1;

  return days;
};

// 2024 şubat için örnek olarak 2024, 2 verilmesi lazım
const getDaysInMonth = (year, month) => new Date(year, month, 0).getDate();

const daysUntilEndOfMonth = (date) => {
  const year = date.getFullYear();
  const month = date.getMonth();
  const endOfMonth = new Date(year, month, getDaysInMonth(year, month));
  const oneDay = 1000 * 60 * 60 * 24;
  const diffInTime = endOfMonth - date;
  const remainingDays = Math.ceil(diffInTime / oneDay);

//  console.log(year, month, endOfMonth, diffInTime, remainingDays);

  return remainingDays;
};

const daysUntilEndOfYear = (date) => {
  const year = date.getFullYear();
  const endOfYear = new Date(year, 11, 31);
  const oneDay = 1000 * 60 * 60 * 24;
  const diffInTime = endOfYear - date;
  const remainingDays = Math.ceil(diffInTime / oneDay);

  return remainingDays;
};

function convertToDate(dateString) {
  const [day, month, year] = dateString.split('/').map(Number);

  return new Date(year, month - 1, day);
};

class DepreciationIFRSHelper {
  calculateIFRSDepreciation(year, month, depreciationStartDate, price, lifetime) {
    let remainingMonth = lifetime * 12;
    let calculations = [];
    let cumulativeDepreciation = 0;
    let netBookValue = 0;

    //console.log('calculateIFRSDepreciation', year, month, depreciationStartDate, price, lifetime);

    function calculateDepreciation(_year, _month) {
      const daysInYear = getDaysInYear(_year);
      const daysInMonth = getDaysInMonth(_year, _month);

      const depreciationRatio = (1 / lifetime);
      const yearlyDepreciation = (price / lifetime);
      const dailyDepreciation = (yearlyDepreciation / daysInYear);
      const monthlyDepreciation = (daysInMonth * dailyDepreciation);

      //console.log('calculateDepreciation', _year, _month, remainingMonth, daysInYear, daysInMonth, depreciationRatio, yearlyDepreciation, dailyDepreciation, monthlyDepreciation);

      let remainingDays = daysInMonth;

      if (_year === depreciationStartDate.getFullYear() && _month === (depreciationStartDate.getMonth() + 1)) {
        remainingDays = daysUntilEndOfMonth(depreciationStartDate);
      }

      let depreciation = Math.min(monthlyDepreciation, (remainingDays * dailyDepreciation));

      if (remainingMonth === 0) {
        depreciation = calculations[calculations.length - 1].netBookValue;
        cumulativeDepreciation += depreciation;
        netBookValue = price - cumulativeDepreciation;
      } else {
        cumulativeDepreciation += depreciation;
        netBookValue = price - cumulativeDepreciation;
      }

      calculations.push({
        year: _year,
        month: _month,
        price,
        depreciationRatio,
        percentage: `%${(depreciationRatio * 100).toFixed(2)}`,
        yearlyDepreciation,
        monthlyDepreciation,
        dailyDepreciation,
        remainingDays,
        depreciation,
        cumulativeDepreciation,
        netBookValue,
      });

      if (remainingMonth > 0) {
        remainingMonth -= 1;
        let nextYear = _month === 12 ? _year + 1 : _year;
        let nextMonth = _month === 12 ? 1 : _month + 1;
        calculateDepreciation(nextYear, nextMonth);
      }
    }

    if (lifetime > 100) {
      return undefined;
    }

    const startYear = depreciationStartDate.getFullYear();
    const startMonth = depreciationStartDate.getMonth() + 1;
    calculateDepreciation(startYear, startMonth);

    const mappedDepreciation = calculations.map(calc => ({
      year: calc.year,
      month: calc.month,
      price: Number(calc.price).toFixed(2),
      percentage: `%${(calc.depreciationRatio * 100).toFixed(2)}`,
      yearlyDepreciation: calc.yearlyDepreciation.toFixed(2),
      monthlyDepreciation: calc.monthlyDepreciation.toFixed(2),
      dailyDepreciation: calc.dailyDepreciation.toFixed(2),
      remainingDays: calc.remainingDays,
      depreciation: calc.depreciation.toFixed(2),
      cumulativeDepreciation: calc.cumulativeDepreciation.toFixed(2),
      netBookValue: calc.netBookValue.toFixed(2),
    }));

    const message = 'Seçilen dönem amortisman hesabı yoktur.';

    function findAndCalculateActiveYearDepreciation(year, month) {
      const cumulativeActiveYearDepreciation = calculations
      .filter(calc => calc.year === year && calc.month <= month)
      .reduce((acc, curr) => acc + curr.depreciation, 0);

      const result = mappedDepreciation.find(calc => calc.year === year && calc.month === month);

      if (result) {
        result.activeYearDepreciation = cumulativeActiveYearDepreciation.toFixed(2);
        return result;
      }

      return undefined;
    }

    //console.log(mappedDepreciation);
    if (mappedDepreciation.length > 1) {
      const first = mappedDepreciation[0];
      const last = mappedDepreciation[mappedDepreciation.length - 1];

      if (year === first.year && month >= first.month) {
        return findAndCalculateActiveYearDepreciation(year, month);
        //return mappedDepreciation.find(calc => calc.year === year && calc.month === month);
      } else if (year === last.year && month <= last.month) {
        return findAndCalculateActiveYearDepreciation(year, month);
        //return mappedDepreciation.find(calc => calc.year === year && calc.month === month);
      } else if (year > first.year && year < last.year) {
        return findAndCalculateActiveYearDepreciation(year, month);
        //return mappedDepreciation.find(calc => calc.year === year && calc.month === month);
      }
    }

    return {
      year: message,
      month: message,
      price: message,
      percentage: message,
      yearlyDepreciation: message,
      monthlyDepreciation: message,
      dailyDepreciation: message,
      remainingDays: message,
      depreciation: message,
      cumulativeDepreciation: message,
      netBookValue: message,
      activeYearDepreciation: message,
    };
  }
}

module.exports = DepreciationIFRSHelper;

//const result = new DepreciationIFRSHelper().calculateIFRSDepreciation(2024, 9, new Date(2024, 6, 10), 33609.00, 4);
//console.log(result);