import * as jstz from 'jstz';
import { Injectable, Inject, LOCALE_ID } from '@angular/core';
import { formatDate, getLocaleFirstDayOfWeek, WeekDay } from '@angular/common';

@Injectable()
export class MwCoreDateTimeService {
  static getFirstDayOfWeek(firstDayOfWeek: WeekDay, date?: Date): Date {
    const result = new Date(+(date || new Date()));
    let subDays = firstDayOfWeek - result.getDay();
    subDays = subDays > 0 ? -6 : subDays;
    result.setHours(subDays * 24, 0, 0, 0);
    return result;
  }

  constructor(@Inject(LOCALE_ID) private localeId: string) {}

  copyUtcTimeToLocalTime(date: Date): Date {
    const result = new Date(date);
    result.setHours(result.getUTCHours());
    return result;
  }
  getLocalOlsonTimeZone(): string {
    return jstz.determine().name();
  }

  areDatesSame(d1: Date, d2: Date): boolean {
    return +d1 === +d2;
  }

  mergeDateTime(date: Date, time: Date): Date {
    if (date && !Object.is(+date, NaN) && time && !Object.is(+time, NaN)) {
      const result = new Date(
        date.getFullYear(),
        date.getMonth(),
        date.getDate()
      );

      result.setHours(time.getHours());
      result.setMinutes(time.getMinutes());

      return result;
    }

    return new Date(NaN);
  }

  formatTime(value: Date, format?: string): string {
    return value && formatDate(value, format || 'shortTime', this.localeId);
  }

  formatDate(value: Date, format?: string): string {
    return value && formatDate(value, format || 'shortDate', this.localeId);
  }

  formatDateTime(value: Date, format?: string): string {
    return value && formatDate(value, format || 'short', this.localeId);
  }

  getLocalDateFormat(): string {
    const date = new Date(1950, 11, 13);
    const formattedDate = formatDate(date, 'short', this.localeId);

    return formattedDate
      .replace('1950', 'yyyy')
      .replace('12', 'MM')
      .replace('13', 'dd');
  }

  getLocalDateSafeCharsPattern(): string {
    return (
      '^[0-9\\' +
      this.getLocalDateFormat()
        .replace(/[y|M|d]/g, '')
        .replace(/(.*)/g, '$1')[0] +
      '-]$'
    );
  }

  getLocalDatePattern(): string {
    return (
      '^' +
      this.getLocalDateFormat()
        .replace(/y/g, 'd')
        .replace(/[M|d]/g, 'd??')
        .replace(/([^.?])/g, '\\$1') +
      '$'
    );
  }

  getStartOfWeek(date?: Date): Date {
    const firstDayOfWeek = getLocaleFirstDayOfWeek(this.localeId);
    return MwCoreDateTimeService.getFirstDayOfWeek(firstDayOfWeek, date);
  }

  getWeekRange(date?: Date): {
    start: Date;
    end: Date;
  } {
    const start = new Date(+this.getStartOfWeek(date));
    const end = new Date(+start);
    end.setHours(7 * 24, 0, 0, -1);
    return {
      start,
      end,
    };
  }

  getWorkWeekRange(date?: Date): {
    start: Date;
    end: Date;
  } {
    const start = new Date(+this.getStartOfWeek(date));
    const end = new Date(+start);
    end.setHours(5 * 24, 0, 0, -1);
    return {
      start,
      end,
    };
  }

  getDayRange(date?: Date): { start: Date; end: Date } {
    const start = new Date(+(date || new Date()));
    const end = new Date(+start);
    start.setHours(0, 0, 0, 0);
    end.setHours(24, 0, 0, -1);
    return {
      start,
      end,
    };
  }

  getTwoWeeksRange(date?: Date): {
    start: Date;
    end: Date;
  } {
    const start = new Date(+this.getStartOfWeek(date));
    const end = new Date(+start);
    end.setHours(14 * 24, 0, 0, -1);
    return {
      start,
      end,
    };
  }

  getMonthRange(date?: Date): { start: Date; end: Date } {
    const localDate = new Date(+(date || new Date()));
    const start = new Date(localDate.getFullYear(), localDate.getMonth(), 1);
    const end = new Date(
      localDate.getFullYear(),
      localDate.getMonth() + 1,
      1,
      0,
      0,
      0,
      -1
    );

    return {
      start,
      end,
    };
  }

  isInRange(
    value: Date,
    range: { start: Date; end: Date },
    isIncludeStart?: boolean
  ): boolean {
    if (typeof value === 'string') {
      value = new Date(value);
    }

    return (
      ((range.start === null ||
        value > range.start ||
        (isIncludeStart && value >= range.start)) &&
        (range.end === null || value <= range.end)) === true
    );
  }

  equalTime(t1: Date, t2: Date, includeSeconds = false): boolean {
    return (
      t1.getUTCHours() === t2.getUTCHours() &&
      t1.getUTCMinutes() === t2.getUTCMinutes() &&
      (includeSeconds ? t1.getUTCSeconds() === t2.getUTCSeconds() : true)
    );
  }

  equalDate(t1: Date, t2: Date): boolean {
    return (
      t1.getFullYear() === t2.getFullYear() &&
      t1.getMonth() === t2.getMonth() &&
      t1.getDate() === t2.getDate()
    );
  }

  isToday(date: Date): boolean {
    const now = new Date();
    return this.equalDate(date, now);
  }
}