'use strict';

const { toEnglishDigits } = require('../../utils/jalaliDate');

const TITLE_PREFIX = /^(آقای|اقای|خانم|آقا)\s+/;
const HONORIFIC_MIDDLE = /\s+خ\s+/g;

const normalizePersonName = (value) => {
  const text = String(value ?? '')
    .replace(/ي/g, 'ی')
    .replace(/ك/g, 'ک')
    .replace(/[\u200c\u200d]/g, ' ')
    .replace(/\s+/g, ' ')
    .trim()
    .replace(TITLE_PREFIX, '')
    .replace(HONORIFIC_MIDDLE, ' ')
    .replace(/^خ\s+/, '')
    .trim();
  return text;
};

const namesMatch = (left, right) => {
  const a = normalizePersonName(left);
  const b = normalizePersonName(right);
  return Boolean(a) && a === b;
};

const normalizePhone = (raw) => {
  if (raw == null || raw === '') return '';
  let digits = toEnglishDigits(raw).replace(/\D/g, '');
  if (digits.startsWith('98') && digits.length === 12) digits = `0${digits.slice(2)}`;
  if (digits.length === 10 && digits.startsWith('9')) digits = `0${digits}`;
  return digits;
};

const normalizeNationalId = (raw) => {
  if (raw == null || raw === '') return '';
  return toEnglishDigits(raw).replace(/\D/g, '');
};

const mapAttendanceStatus = (raw) => {
  const value = String(raw ?? '').trim();
  if (!value) return null;
  if (value === '*' || value === 'ح' || value === 'حاضر' || /^present$/i.test(value) || /^p$/i.test(value)) {
    return 'present';
  }
  if (value === 'غ' || value === 'غایب' || /^absent$/i.test(value) || /^a$/i.test(value)) {
    return 'absent';
  }
  if (value === 'ت' || value === 'تأخیر' || value === 'تاخیر' || /^late$/i.test(value)) {
    return 'late';
  }
  if (value === 'م' || value === 'موجه' || /^excused$/i.test(value)) {
    return 'excused';
  }
  return null;
};

const projectSessionDates = (existingIsoDates, totalCount) => {
  const dates = [...existingIsoDates].filter(Boolean).sort();
  if (!dates.length || dates.length >= totalCount) return dates.slice(0, totalCount);

  const weekdaySet = new Set(dates.map((iso) => new Date(`${iso}T12:00:00.000Z`).getUTCDay()));
  const last = new Date(`${dates[dates.length - 1]}T12:00:00.000Z`);
  const projected = [...dates];
  const cursor = new Date(last);

  while (projected.length < totalCount) {
    cursor.setUTCDate(cursor.getUTCDate() + 1);
    if (weekdaySet.has(cursor.getUTCDay())) {
      projected.push(cursor.toISOString().slice(0, 10));
    }
  }
  return projected;
};

module.exports = {
  normalizePersonName,
  namesMatch,
  normalizePhone,
  normalizeNationalId,
  mapAttendanceStatus,
  projectSessionDates
};