nativeDate.service.ts

/**
 * @license
 * Copyright Akveo. All Rights Reserved.
 * Licensed under the MIT License. See License.txt in the project root for license information.
 */

import fecha from 'fecha';
import { DateService } from './date.service';
import {
  I18nConfig,
  TranslationWidth,
} from '../i18n/type';
import { EN } from '../i18n/en';

export const LOCALE_DEFAULT = 'en';

export interface NativeDateServiceOptions {
  // 0 for Sunday, 1 for Monday, etc
  startDayOfWeek?: 0 | 1 | 2 | 3 | 4 | 5 | 6;
  i18n?: I18nConfig;
}

const DEFAULT_OPTIONS: NativeDateServiceOptions = {
  startDayOfWeek: 0,
};

/**
 * The `NativeDateService` is basic implementation of `DateService` using
 * native js date objects.
 */
export class NativeDateService extends DateService<Date> {

  protected options: NativeDateServiceOptions;

  constructor(locale: string = LOCALE_DEFAULT, options?: NativeDateServiceOptions) {
    super();
    this.options = { ...DEFAULT_OPTIONS, ...options };
    super.setLocale(this.options.i18n ? locale : LOCALE_DEFAULT);
    this.setFechaLocaleData(this.options.i18n || EN);
  }

  public setLocale(locale: string) {
    console.warn('Runtime locale is not supported');
  }

  public isValidDateString(date: string, format: string): boolean {
    return !isNaN(this.parse(date, format).getTime());
  }

  public today(): Date {
    return new Date();
  }

  public getDate(date: Date): number {
    return date.getDate();
  }

  public getMonth(date: Date): number {
    return date.getMonth();
  }

  public getYear(date: Date): number {
    return date.getFullYear();
  }

  public getDayOfWeek(date: Date): number {
    return date.getDay();
  }

  /**
   * returns first day of the week, it can be 1 if week starts from monday
   * and 0 if from sunday and so on.
   * */
  public getFirstDayOfWeek(): number {
    return this.options.startDayOfWeek;
  }

  public getMonthName(date: Date, style: TranslationWidth = TranslationWidth.SHORT): string {
    const index: number = date.getMonth();

    return this.getMonthNameByIndex(index, style);
  }

  public getMonthNameByIndex(index: number, style: TranslationWidth = TranslationWidth.SHORT): string {
    return this.getFechaMonthNames(style)[index];
  }

  public getDayOfWeekNames(style: TranslationWidth = TranslationWidth.SHORT): string[] {
    const dayNames: string[] = this.getFechaDayNames(style);

    // avoid mutation of source array
    return this.shiftDayOfWeekNames([...dayNames], this.options.startDayOfWeek);
  }

  public format(date: Date, format: string): string {
    return fecha.format(date, format);
  }

  /**
   * We haven't got capability to parse date using formatting without third party libraries.
   * */
  public parse(date: string, format: string): Date {
    return new Date(Date.parse(date));
  }

  public addDay(date: Date, num: number): Date {
    return this.createDate(date.getFullYear(), date.getMonth(), date.getDate() + num);
  }

  public addMonth(date: Date, num: number): Date {
    const month: Date = this.createDate(date.getFullYear(), date.getMonth() + num, 1);

    // In case of date has more days than calculated month js Date will change that month to the next one
    // because of the date overflow.
    month.setDate(Math.min(date.getDate(), this.getMonthEnd(month).getDate()));

    return month;
  }

  public addYear(date: Date, num: number): Date {
    return this.createDate(date.getFullYear() + num, date.getMonth(), date.getDate());
  }

  public clone(date: Date): Date {
    return new Date(date.getTime());
  }

  public compareDates(date1: Date, date2: Date): number {
    return date1.getTime() - date2.getTime();
  }

  public compareDatesSafe(date1: Date, date2: Date): number {
    if (this.compareDates(date1, date2) < 0) {
      return -1;
    } else if (this.compareDates(date1, date2) > 0) {
      return 1;
    } else if (this.compareDates(date1, date2) === 0) {
      return 0;
    }
  }

  public createDate(year: number, month: number, date: number): Date {
    const result = new Date(year, month, date);

    // We need to correct for the fact that JS native Date treats years in range [0, 99] as
    // abbreviations for 19xx.
    if (year >= 0 && year < 100) {
      result.setFullYear(result.getFullYear() - 1900);
    }

    return result;
  }

  public getMonthEnd(date: Date): Date {
    return this.createDate(date.getFullYear(), date.getMonth() + 1, 0);
  }

  public getMonthStart(date: Date): Date {
    return this.createDate(date.getFullYear(), date.getMonth(), 1);
  }

  public getNumberOfDaysInMonth(date: Date): number {
    return this.getMonthEnd(date).getDate();
  }

  public getYearEnd(date: Date): Date {
    return this.createDate(date.getFullYear(), 11, 31);
  }

  public getYearStart(date: Date): Date {
    return this.createDate(date.getFullYear(), 0, 1);
  }

  public isSameDay(date1: Date, date2: Date): boolean {
    return this.isSameMonth(date1, date2) && date1.getDate() === date2.getDate();
  }

  public isSameMonth(date1: Date, date2: Date): boolean {
    return this.isSameYear(date1, date2) && date1.getMonth() === date2.getMonth();
  }

  public isSameYear(date1: Date, date2: Date): boolean {
    return date1.getFullYear() === date2.getFullYear();
  }

  public getId(): string {
    return 'native';
  }

  protected shiftDayOfWeekNames<T>(value: T[], offset: number): T[] {
    return value.splice(offset).concat(value);
  }

  private getFechaDayNames(style: TranslationWidth): string[] {
    switch (style) {
      case TranslationWidth.SHORT:
        return fecha.i18n.dayNamesShort;
      case TranslationWidth.LONG:
        return fecha.i18n.dayNames;
    }
  }

  private getFechaMonthNames(style: TranslationWidth): string[] {
    switch (style) {
      case TranslationWidth.SHORT:
        return fecha.i18n.monthNamesShort;
      case TranslationWidth.LONG:
        return fecha.i18n.monthNames;
    }
  }

  private setFechaLocaleData(config: I18nConfig) {
    fecha.i18n.dayNames = config.dayNames[TranslationWidth.LONG];
    fecha.i18n.dayNamesShort = config.dayNames[TranslationWidth.SHORT];
    fecha.i18n.monthNames = config.monthNames[TranslationWidth.LONG];
    fecha.i18n.monthNamesShort = config.monthNames[TranslationWidth.SHORT];
  }
}