import { MOUNT_CLASS_TO } from "../lib/mtproto/mtproto_config";

export const months = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
export const days = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];

export const ONE_DAY = 86400;

// https://stackoverflow.com/a/6117889
export const getWeekNumber = (date: Date) => {
  const d = new Date(Date.UTC(date.getFullYear(), date.getMonth(), date.getDate()));
  const dayNum = d.getUTCDay() || 7;
  d.setUTCDate(d.getUTCDate() + 4 - dayNum);
  const yearStart = new Date(Date.UTC(d.getUTCFullYear(), 0, 1));
  return Math.ceil((((d.getTime() - yearStart.getTime()) / ONE_DAY) + 1) / 7);
};

export const formatDateAccordingToToday = (time: Date) => {
  const date = new Date();
  const now = date.getTime() / 1000 | 0;
  const timestamp = time.getTime() / 1000 | 0;

  let timeStr: string;
  if((now - timestamp) < ONE_DAY && date.getDate() == time.getDate()) { // if the same day
    timeStr = ('0' + time.getHours()).slice(-2) + ':' + ('0' + time.getMinutes()).slice(-2);
  } else if(date.getFullYear() != time.getFullYear()) { // different year
    timeStr = time.getDate() + '.' + ('0' + (time.getMonth() + 1)).slice(-2) + '.' + ('' + time.getFullYear()).slice(-2);
  } else if((now - timestamp) < (ONE_DAY * 7) && getWeekNumber(date) == getWeekNumber(time)) { // current week
    timeStr = days[time.getDay()].slice(0, 3);
  } else { // same year
    timeStr = months[time.getMonth()].slice(0, 3) + ' ' + ('0' + time.getDate()).slice(-2);
  }

  return timeStr;
};

export const getFullDate = (date: Date, options: Partial<{
  noTime: true, 
  noSeconds: true,
  monthAsNumber: true,
  leadingZero: true
}> = {}) => {
  const joiner = options.monthAsNumber ? '.' : ' ';
  const time = ('0' + date.getHours()).slice(-2) + ':' + ('0' + date.getMinutes()).slice(-2) + (options.noSeconds ? '' : ':' + ('0' + date.getSeconds()).slice(-2));

  return (options.leadingZero ? ('0' + date.getDate()).slice(-2) : date.getDate()) + 
    joiner + (options.monthAsNumber ? ('0' + (date.getMonth() + 1)).slice(-2) : months[date.getMonth()]) + 
    joiner + date.getFullYear() + 
    (options.noTime ? '' : ', ' + time);
};

export function tsNow(seconds?: true) {
  const t = Date.now();
  return seconds ? Math.floor(t / 1000) : t;
}

// https://github.com/DrKLO/Telegram/blob/d52b2c921abd3c1e8d6368858313ad0cb0468c07/TMessagesProj/src/main/java/org/telegram/ui/Adapters/FiltersView.java
const minYear = 2013;
const yearPattern = new RegExp("20[0-9]{1,2}");
const monthYearOrDayPattern = new RegExp("(\\w{3,}) ([0-9]{0,4})", 'i');
const yearOrDayAndMonthPattern = new RegExp("([0-9]{0,4}) (\\w{2,})", 'i');
const shortDate = new RegExp("^([0-9]{1,4})(\\.| |/|\\-)([0-9]{1,4})$", 'i');
const longDate = new RegExp("^([0-9]{1,2})(\\.| |/|\\-)([0-9]{1,2})(\\.| |/|\\-)([0-9]{1,4})$", 'i');
const numberOfDaysEachMonth = [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
export type DateData = {
  title: string,
  minDate: number,
  maxDate: number,
};
export function fillTipDates(query: string, dates: DateData[]) {
  const q = query.trim();

  if(q.length < 3) {
    return;
  }

  let matches: any[];
  if((matches = shortDate.exec(q)) !== null) {
    const g1 = matches[1];
    const g2 = matches[3];
    const k = parseInt(g1);
    const k1 = parseInt(g2);
    if(k > 0 && k <= 31) {
      if(k1 >= minYear && k <= 12) {
        const selectedYear = k1;
        const month = k - 1;
        createForMonthYear(dates, month, selectedYear);
        return;
      } else if (k1 <= 12) {
        const day = k - 1;
        const month = k1 - 1;
        createForDayMonth(dates, day, month);
      }
    } else if (k >= minYear && k1 <= 12) {
      const selectedYear = k;
      const month = k1 - 1;
      createForMonthYear(dates, month, selectedYear);
    }

    return;
  }

  if((matches = longDate.exec(q)) !== null) {
    const g1 = matches[1];
    const g2 = matches[3];
    const g3 = matches[5];
    if(!matches[2] == matches[4]) {
      return;
    }

    const day = parseInt(g1);
    const month = parseInt(g2) - 1;
    let year = parseInt(g3);
    if(year >= 10 && year <= 99) {
      year += 2000;
    }

    const currentYear = new Date().getFullYear();
    if(validDateForMonth(day - 1, month) && year >= minYear && year <= currentYear) {
      const date = new Date();
      date.setFullYear(year, month, day);
      date.setHours(0, 0, 0);
      
      const minDate = date.getTime();
      date.setFullYear(year, month, day + 1);
      date.setHours(0, 0, 0);

      const maxDate = date.getTime() - 1;
      dates.push({
        title: formatterYearMax(minDate),
        minDate,
        maxDate
      });
      return;
    }

    return;
  }

  if((matches = yearPattern.exec(q)) !== null) {
    let selectedYear = +q;
    const currentYear = new Date().getFullYear();
    if(selectedYear < minYear) {
      selectedYear = minYear;
      for(let i = currentYear; i >= selectedYear; i--) {
        const date = new Date();
        date.setFullYear(i, 0, 1);
        date.setHours(0, 0, 0);

        const minDate = date.getTime();
        date.setFullYear(i + 1, 0, 1);
        date.setHours(0, 0, 0);

        const maxDate = date.getTime() - 1;
        dates.push({
          title: '' + i,
          minDate,
          maxDate
        });
      }
    } else if(selectedYear <= currentYear) {
      const date = new Date();
      date.setFullYear(selectedYear, 0, 1);
      date.setHours(0, 0, 0);

      const minDate = date.getTime();
      date.setFullYear(selectedYear + 1, 0, 1);
      date.setHours(0, 0, 0);

      const maxDate = date.getTime() - 1;
      dates.push({
        title: '' + selectedYear,
        minDate,
        maxDate
      });
    }

    return;
  }

  if((matches = monthYearOrDayPattern.exec(q)) !== null) {
    const g1 = matches[1];
    const g2 = matches[2];
    const month = getMonth(g1);
    if(month >= 0) {
      const k = +g2;
      if(k > 0 && k <= 31) {
        const day = k - 1;
        createForDayMonth(dates, day, month);
        return;
      } else if(k >= minYear) {
        const selectedYear = k;
        createForMonthYear(dates, month, selectedYear);
        return;
      }
    }
  }

  if((matches = yearOrDayAndMonthPattern.exec(q)) !== null) {
    const g1 = matches[1];
    const g2 = matches[2];
    const month = getMonth(g2);
    if(month >= 0) {
      const k = +g1;
      if(k > 0 && k <= 31) {
        const day = k - 1;
        createForDayMonth(dates, day, month);
        return;
      } else if (k >= minYear) {
        const selectedYear = k;
        createForMonthYear(dates, month, selectedYear);
      }
    }
  }
}

function createForMonthYear(dates: DateData[], month: number, selectedYear: number) {
  const currentYear = new Date().getFullYear();
  const today = Date.now();
  if(selectedYear >= minYear && selectedYear <= currentYear) {
    const date = new Date();
    date.setFullYear(selectedYear, month, 1);
    date.setHours(0, 0, 0);
    const minDate = date.getTime();
    if(minDate > today) {
      return;
    }
    date.setMonth(date.getMonth() + 1);
    const maxDate = date.getTime() - 1;

    dates.push({
      title: formatterMonthYear(minDate),
      minDate,
      maxDate
    });
  }
}

function createForDayMonth(dates: DateData[], day: number, month: number) {
  if(validDateForMonth(day, month)) {
    const currentYear = new Date().getFullYear();
    const today = Date.now();
    
    for(let i = currentYear; i >= minYear; i--) {
      if(month == 1 && day == 28 && !isLeapYear(i)) {
        continue;
      }

      const date = new Date();
      date.setFullYear(i, month, day + 1);
      date.setHours(0, 0, 0);
      
      const minDate = date.getTime();
      if(minDate > today) {
        continue;
      }

      date.setFullYear(i, month, day + 2);
      date.setHours(0, 0, 0);
      const maxDate = date.getTime() - 1;
      if(i == currentYear) {
        dates.push({
          title: formatterDayMonth(minDate),
          minDate,
          maxDate
        });
      } else {
        dates.push({
          title: formatterYearMax(minDate),
          minDate,
          maxDate
        });
      }
    }
  }
}

function formatterMonthYear(timestamp: number) {
  const date = new Date(timestamp);
  return months[date.getMonth()].slice(0, 3) + ' ' + date.getFullYear();
}

function formatterDayMonth(timestamp: number) {
  const date = new Date(timestamp);
  return months[date.getMonth()].slice(0, 3) + ' ' + date.getDate();
}

function formatterYearMax(timestamp: number) {
  const date = new Date(timestamp);
  return ('0' + date.getDate()).slice(-2) + '.' + ('0' + (date.getMonth() + 1)).slice(-2) + '.' + date.getFullYear();
}

function validDateForMonth(day: number, month: number) {
  if(month >= 0 && month < 12) {
    if(day >= 0 && day < numberOfDaysEachMonth[month]) {
      return true;
    }
  }
  return false;
}

function isLeapYear(year: number) {
  return ((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0);
}

function getMonth(q: string) {
  /* String[] months = new String[]{
          LocaleController.getString("January", R.string.January).toLowerCase(),
          LocaleController.getString("February", R.string.February).toLowerCase(),
          LocaleController.getString("March", R.string.March).toLowerCase(),
          LocaleController.getString("April", R.string.April).toLowerCase(),
          LocaleController.getString("May", R.string.May).toLowerCase(),
          LocaleController.getString("June", R.string.June).toLowerCase(),
          LocaleController.getString("July", R.string.July).toLowerCase(),
          LocaleController.getString("August", R.string.August).toLowerCase(),
          LocaleController.getString("September", R.string.September).toLowerCase(),
          LocaleController.getString("October", R.string.October).toLowerCase(),
          LocaleController.getString("November", R.string.November).toLowerCase(),
          LocaleController.getString("December", R.string.December).toLowerCase()
  }; */

  /* String[] monthsEng = new String[12];
  Calendar c = Calendar.getInstance();
  for (int i = 1; i <= 12; i++) {
      c.set(0, 0, 0, 0, 0, 0);
      c.set(Calendar.MONTH, i);
      monthsEng[i - 1] = c.getDisplayName(Calendar.MONTH, Calendar.LONG, Locale.ENGLISH).toLowerCase();
  } */

  q = q.toLowerCase();
  for(let i = 0; i < 12; i++) {
    const month = months[i].toLowerCase();
    if(month.indexOf(q) === 0) {
      return i;
    }
  }
  return -1;
}

MOUNT_CLASS_TO && (MOUNT_CLASS_TO.fillTipDates = fillTipDates);