// /src/utils/professorShare.js
// Mirrors gameno-api/utils/professorShare.js so the dashboard can preview payout
// calculations client-side before saving a class.

const toNonNegativeNumber = (value) => {
  const n = Number(value);
  if (!Number.isFinite(n) || n < 0) return 0;
  return n;
};

const toPercentage = (value) => Math.min(100, toNonNegativeNumber(value));

const parseClockTime = (value) => {
  const raw = String(value || '').trim();
  const match = raw.match(/^(\d{1,2}):(\d{2})$/);
  if (!match) return null;
  const hours = Number(match[1]);
  const minutes = Number(match[2]);
  if (hours > 23 || minutes > 59) return null;
  return hours * 60 + minutes;
};

export function calculateSessionDurationHours(startTime, endTime) {
  const start = parseClockTime(startTime);
  const end = parseClockTime(endTime);
  if (start == null || end == null) return 0;
  let diffMinutes = end - start;
  if (diffMinutes <= 0) diffMinutes += 24 * 60;
  return diffMinutes / 60;
}

export function resolveSessionDurationHours({ hoursPerSection, startTime, endTime } = {}) {
  const hours = toNonNegativeNumber(hoursPerSection);
  if (hours > 0) return hours;
  return calculateSessionDurationHours(startTime, endTime);
}

export function calculatePercentageShare({ payoutPercentage = 0, revenue = 0, serviceFeePerPerson = 0, studentsCount = 0 } = {}) {
  const totalServiceFee = toNonNegativeNumber(serviceFeePerPerson) * toNonNegativeNumber(studentsCount);
  const netRevenue = Math.max(0, toNonNegativeNumber(revenue) - totalServiceFee);
  return (toPercentage(payoutPercentage) / 100) * netRevenue;
}

export function calculateHourlyShare({ payoutHourlyRate = 0, sessionDurationHours = 0, sessionsCount = 0 } = {}) {
  return toNonNegativeNumber(payoutHourlyRate) * toNonNegativeNumber(sessionDurationHours) * toNonNegativeNumber(sessionsCount);
}

export function calculateExtraExpenses({ extraExpensePerSession = 0, sessionsCount = 0 } = {}) {
  return toNonNegativeNumber(extraExpensePerSession) * toNonNegativeNumber(sessionsCount);
}

export function calculateProfessorPayout(params = {}) {
  const baseShare = params.payoutType === 'hourly'
    ? calculateHourlyShare(params)
    : calculatePercentageShare(params);
  const extraExpenses = calculateExtraExpenses(params);
  return {
    baseShare,
    extraExpenses,
    totalPayout: baseShare + extraExpenses
  };
}

export function calculateNetProfit({ totalIncome = 0, professorTotalPayout = 0 } = {}) {
  return toNonNegativeNumber(totalIncome) - toNonNegativeNumber(professorTotalPayout);
}

export function calculatePendingReceivables(expectedRevenue = 0, actualReceivedRevenue = 0) {
  return Math.max(0, toNonNegativeNumber(expectedRevenue) - toNonNegativeNumber(actualReceivedRevenue));
}

export function calculateOverpaidAmount(expectedRevenue = 0, actualReceivedRevenue = 0) {
  return Math.max(0, toNonNegativeNumber(actualReceivedRevenue) - toNonNegativeNumber(expectedRevenue));
}