import { Pipe, PipeTransform } from '@angular/core';
import { TranslateService } from '@ngx-translate/core';

// Components //
import * as _ from 'underscore';
import * as moment from 'moment';

/**
 * @param input Input: string. The time string that should be converted
 * @param showFullDate Input: boolean. If true, display date in YYYY-MM-DD format
 * @param showTime Input: boolean. If true, adds time to the return date
 */

@Pipe({name: 'niceDate'})
export class NiceDatePipe implements PipeTransform {
  constructor (
    private readonly translate: TranslateService
  ) {}

  transform(input: string, showFullDate: boolean, showTime: boolean, onlyDate: boolean = false): string {

    if (input === null || input === undefined || (!_.isString(input) && !_.isNumber(input))) {
        return input;
    }
    let inputMom: any;
    let isNoTime: boolean;
    if (_.isNumber(input)) {
        inputMom = moment(input);
        isNoTime = false;
    } else {
        const dateNoTimeMom: Moment = moment(!onlyDate ? input : input + 'T00:00:00.00', 'YYYY-MM-DD[T]00:00:00.00', true);

        const millisecondIndex: number = input.indexOf('.');

        input = millisecondIndex !== -1 // Strippa ev. bort millisekunder
        ? input.substring(0, millisecondIndex)
        : input;

        const dateTimeMom: Moment = moment(input, 'YYYY-MM-DD[T]HH:mm:ss', true);

        if (!dateNoTimeMom.isValid() && !dateTimeMom.isValid()) {
            const timeMom: Moment = moment(input, 'HH:mm:ss', true);
            const noTimeMom: boolean = input === '00:00:00.00';

            return timeMom.isValid()
                ? timeMom.format('HH:mm')
                : noTimeMom
                ? ''
                : input;
        }
        isNoTime = dateNoTimeMom.isValid();
        inputMom = isNoTime
            ? dateNoTimeMom
            : dateTimeMom;
    }

    let locale: string = this.translate.currentLang || 'sv_SE';
    locale = locale.substring(0, locale.indexOf('_'));


    const now: Moment = moment().startOf('day');
    const diffDays: number = moment(inputMom).startOf('day').diff(now, 'days', true);
    let niceDate: string = '';
    if (showFullDate) {
        niceDate = inputMom.lang(locale).format('YYYY-MM-DD');

    } else {
        if (diffDays < -1 || diffDays > 1) { // Mer än en dags skillnad
            const isSameYear: boolean = now.year() === inputMom.year();
            niceDate = isSameYear ? inputMom.lang(locale).format('D/M') : inputMom.lang(locale).format('YYYY-MM-DD');
        } else {
            niceDate = diffDays === 0 ? this.translate.instant('DATE.IDAG') :
                diffDays < 0 ? this.translate.instant('DATE.IGAAR') :
                this.translate.instant('DATE.IMORGON');
        }
    }
    if (!isNoTime && showTime) {
        niceDate += inputMom.format('[ ]HH:mm');
    }
    return niceDate;
  }
}