<template>
  <b-row class="mb-2 mt-2">
    <b-col class="d-sm-flex">
      <b-form-group
        :label="$t('global.table.fromDate')"
        label-for="input-from-date"
        label-class="caption-12px mb-0"
        class="mr-3 my-0 w-100"
      >
        <b-input-group>
          <b-form-input
            id="input-from-date"
            v-model="fromDate"
            placeholder="YYYY-MM-DD"
            :state="getValidationState($v.fromDate)"
            class="form-control-with-button mb-md-0"
            @blur="$v.fromDate.$touch()"
          />
          <b-form-invalid-feedback role="alert">
            <template v-if="!$v.fromDate.pattern">
              {{ $t('global.form.invalidFormat') }}
            </template>
            <template v-if="!$v.fromDate.maxDate">
              {{ $t('global.form.dateMustBeBefore', { date: toDate }) }}
            </template>
          </b-form-invalid-feedback>
          <b-form-datepicker
            v-model="fromDate"
            class="btn-datepicker btn-icon-only"
            button-only
            right
            :max="toDate"
            :hide-header="true"
            :locale="locale"
            :label-help="
              $t('global.calendar.useCursorKeysToNavigateCalendarDates')
            "
            :title="$t('global.calendar.selectDate')"
            button-variant="link"
            aria-controls="input-from-date"
          >
            <template #button-content>
              <icon-calendar />
              <span class="sr-only">
                {{ $t('global.calendar.selectDate') }}
              </span>
            </template>
          </b-form-datepicker>
        </b-input-group>
      </b-form-group>
      <b-form-group
        :label="$t('global.table.toDate')"
        label-for="input-to-date"
        label-class="caption-12px mb-0"
        class="my-0 w-100"
      >
        <b-input-group>
          <b-form-input
            id="input-to-date"
            v-model="toDate"
            placeholder="YYYY-MM-DD"
            :state="getValidationState($v.toDate)"
            class="form-control-with-button"
            @blur="$v.toDate.$touch()"
          />
          <b-form-invalid-feedback role="alert">
            <template v-if="!$v.toDate.pattern">
              {{ $t('global.form.invalidFormat') }}
            </template>
            <template v-if="!$v.toDate.minDate">
              {{ $t('global.form.dateMustBeAfter', { date: fromDate }) }}
            </template>
          </b-form-invalid-feedback>
          <b-form-datepicker
            v-model="toDate"
            class="btn-datepicker btn-icon-only"
            button-only
            right
            :min="fromDate"
            :hide-header="true"
            :locale="locale"
            :label-help="
              $t('global.calendar.useCursorKeysToNavigateCalendarDates')
            "
            :title="$t('global.calendar.selectDate')"
            button-variant="link"
            aria-controls="input-to-date"
          >
            <template #button-content>
              <icon-calendar />
              <span class="sr-only">
                {{ $t('global.calendar.selectDate') }}
              </span>
            </template>
          </b-form-datepicker>
        </b-input-group>
      </b-form-group>
    </b-col>
  </b-row>
</template>

<script>
import IconCalendar from '@carbon/icons-vue/es/calendar/20';
import { helpers } from 'vuelidate/lib/validators';

import VuelidateMixin from '@/components/_sila/Mixins/VuelidateMixin.js';

const isoDateRegex = /([12]\d{3}-(0[1-9]|1[0-2])-(0[1-9]|[12]\d|3[01]))/;

export default {
  components: { IconCalendar },
  mixins: [VuelidateMixin],
  data() {
    return {
      fromDate: '',
      toDate: '',
      offsetToDate: '',
      locale: this.$store.getters['global/languagePreference'],
    };
  },
  validations() {
    return {
      fromDate: {
        pattern: helpers.regex('pattern', isoDateRegex),
        maxDate: (value) => {
          if (!this.toDate) return true;
          const date = new Date(value);
          const maxDate = new Date(this.toDate);
          if (date.getTime() > maxDate.getTime()) return false;
          return true;
        },
      },
      toDate: {
        pattern: helpers.regex('pattern', isoDateRegex),
        minDate: (value) => {
          if (!this.fromDate) return true;
          const date = new Date(value);
          const minDate = new Date(this.fromDate);
          if (date.getTime() < minDate.getTime()) return false;
          return true;
        },
      },
    };
  },
  watch: {
    fromDate() {
      this.emitChange();
    },
    toDate(newVal) {
      // Offset the end date to end of day to make sure all
      // entries from selected end date are included in filter
      this.offsetToDate = new Date(newVal).setUTCHours(23, 59, 59, 999);
      this.emitChange();
    },
  },
  methods: {
    emitChange() {
      if (this.$v.$invalid) return;
      this.$v.$reset(); //reset to re-validate on blur
      this.$emit('change', {
        fromDate: this.fromDate ? new Date(this.fromDate) : null,
        toDate: this.toDate ? new Date(this.offsetToDate) : null,
      });
    },
  },
};
</script>
