import { Injectable } from '@nestjs/common';
import { DateTime, TimeZone } from 'timezonecomplete';
import { TimeConverterPort } from '../core/application/ports/time-converter.port';

@Injectable()
export class TimeConverter implements TimeConverterPort {
  private readonly UNIX_EPOCH = '1970-01-01';

  localStringTimeToUtcStringTime = (time: string, timezone: string): string =>
    new DateTime(`${this.UNIX_EPOCH}T${time}`, TimeZone.zone(timezone))
      .convert(TimeZone.zone('UTC'))
      .format('HH:mm');

  utcStringTimeToLocalStringTime = (time: string, timezone: string): string =>
    new DateTime(`${this.UNIX_EPOCH}T${time}`, TimeZone.zone('UTC'))
      .convert(TimeZone.zone(timezone))
      .format('HH:mm');

  localStringDateTimeToUtcDate = (
    date: string,
    time: string,
    timezone: string,
    dst = false,
  ): Date =>
    new Date(
      new DateTime(
        `${date}T${time}`,
        TimeZone.zone(timezone, dst),
      ).toIsoString(),
    );

  utcStringDateTimeToLocalIsoString = (
    date: string,
    time: string,
    timezone: string,
    dst = false,
  ): string =>
    new DateTime(`${date}T${time}`, TimeZone.zone('UTC'))
      .convert(TimeZone.zone(timezone, dst))
      .toIsoString();

  utcUnixEpochDayFromTime = (time: string, timezone: string): number =>
    new Date(
      new DateTime(`${this.UNIX_EPOCH}T${time}`, TimeZone.zone(timezone, false))
        .convert(TimeZone.zone('UTC'))
        .toIsoString()
        .split('T')[0],
    ).getUTCDay();

  localUnixEpochDayFromTime = (time: string, timezone: string): number =>
    new Date(
      new DateTime(`${this.UNIX_EPOCH}T${time}`, TimeZone.zone('UTC'))
        .convert(TimeZone.zone(timezone))
        .toIsoString()
        .split('T')[0],
    ).getUTCDay();
}