import * as dayjs from 'dayjs';
import { Dayjs } from 'dayjs';
import * as quarterOfYear from 'dayjs/plugin/quarterOfYear';
import * as timezone from 'dayjs/plugin/timezone';

import { DurationUnitEnum } from '../enums/duration-unit.enum';
import { TicketTypeEnum } from '../enums/ticket-type.enum';
import { ValidationBehaviour } from '../enums/validation-behaviour.enum';
import { ComputeValidationDateParams } from '../interfaces/validation/compute-validation-date.params';

export class VanillaDurationCalculationService {
  constructor() {
    dayjs.extend(quarterOfYear);
    dayjs.extend(timezone);
    dayjs.tz.setDefault('Europe/Paris');
  }

  public computeValidationDate(computeValidationDateParams: ComputeValidationDateParams): {
    validFrom: Date;
    validUntil: Date;
  } {
    const {
      fromDate,
      timeUnit,
      timeValue,
      ticketType,
      validityDateFrom,
      validityDateUntil,
      overrideUnit,
      overrideEndingHour,
      validationDateBehavior,
    } = computeValidationDateParams;
    let formattedFromDate: Date = dayjs(fromDate).toDate();

    // handle "start of period" => force validation date to be at start of period (for calendar to be equal to ticket.dateFrom)
    if (validationDateBehavior === ValidationBehaviour.START_OF_PERIOD) {
      if ([TicketTypeEnum.DYNAMIC_CALENDAR].includes(ticketType)) {
        formattedFromDate = this.findBeginningOfPeriod(
          dayjs(fromDate),
          overrideUnit ?? timeUnit,
        ).toDate();
      } else if ([TicketTypeEnum.CALENDAR].includes(ticketType)) {
        formattedFromDate = dayjs(validityDateFrom).toDate();
      }
    }
    return {
      validFrom: formattedFromDate,
      validUntil: this.addDurationBoundedByValidity(
        dayjs(formattedFromDate),
        timeUnit,
        timeValue,
        validityDateUntil,
        overrideEndingHour,
      ).toDate(),
    };
  }

  public addDurationBoundedByValidity(
    dateFrom: Dayjs,
    timeUnit: DurationUnitEnum,
    timeValue: number,
    validityDateUntil?: Date,
    overrideEndingHour?: string,
  ): Dayjs {
    // We subtract 1 second at each duration to have a 23:59 to avoid confusion at display in the front-end app
    let currentValidationUntilDate: Dayjs = this.subtractOneSecond(
      this.addDuration(dateFrom, timeUnit, timeValue),
    );

    if (validityDateUntil) {
      const validityDateUntilAsDayJs: Dayjs = dayjs(validityDateUntil);

      if (currentValidationUntilDate.isAfter(validityDateUntilAsDayJs)) {
        currentValidationUntilDate = validityDateUntilAsDayJs;
      }
    }

    if (overrideEndingHour) {
      currentValidationUntilDate = this.overrideEndingHour(
        currentValidationUntilDate,
        overrideEndingHour,
      );
    }

    return currentValidationUntilDate;
  }

  public findBeginningOfPeriod(dateFrom: Dayjs, periodUnit: DurationUnitEnum): Dayjs {
    switch (periodUnit) {
      case DurationUnitEnum.QUARTER:
        return dateFrom.startOf('quarter');
      case DurationUnitEnum.YEAR:
        return dateFrom.startOf('year');
      case DurationUnitEnum.MONTH:
        return dateFrom.startOf('month');
      case DurationUnitEnum.WEEK:
        return dateFrom.startOf('week');
      case DurationUnitEnum.DAY:
        return dateFrom.startOf('day');
      case DurationUnitEnum.HOUR:
        return dateFrom.startOf('hour');
      case DurationUnitEnum.MINUTE:
        return dateFrom.startOf('minute');
      case DurationUnitEnum.SECOND:
        return dateFrom.startOf('second');
    }
  }

  public addDuration(dateFrom: Dayjs, timeUnit: DurationUnitEnum, timeValue: number): Dayjs {
    switch (timeUnit) {
      case DurationUnitEnum.QUARTER:
        return dateFrom.add(timeValue, 'quarter');
      case DurationUnitEnum.YEAR:
        return dateFrom.add(timeValue, 'year');
      case DurationUnitEnum.MONTH:
        return dateFrom.add(timeValue, 'month');
      case DurationUnitEnum.WEEK:
        return dateFrom.add(timeValue, 'week');
      case DurationUnitEnum.DAY:
        return dateFrom.add(timeValue, 'day');
      case DurationUnitEnum.HOUR:
        return dateFrom.add(timeValue, 'hour');
      case DurationUnitEnum.MINUTE:
        return dateFrom.add(timeValue, 'minute');
      case DurationUnitEnum.SECOND:
        return dateFrom.add(timeValue, 'second');
    }
  }

  public overrideEndingHour(date: Dayjs, endingHour: string): Dayjs {
    const [hour, minutes] = endingHour.split(':');
    date = date.hour(parseInt(hour)).minute(parseInt(minutes)).second(0).millisecond(0);
    return date;
  }

  public subtractOneSecond(date: Dayjs): Dayjs {
    return date.subtract(1, 'second');
  }
}