<template>
  <div class="kole-numrange" :class="{ 'is-error': !!errorMsg }">
    <input type="number" :value="modelValue[0]" :step="step" :min="min" :max="max"
           :placeholder="placeholder[0]" @input="onMin" />
    <span class="kole-numrange-sep">{{ separator }}</span>
    <input type="number" :value="modelValue[1]" :step="step" :min="min" :max="max"
           :placeholder="placeholder[1]" @input="onMax" />
    <span class="kole-numrange-unit" v-if="unit">{{ unit }}</span>
    <span class="kole-numrange-msg" v-if="errorMsg">{{ errorMsg }}</span>
  </div>
</template>

<script setup>
import { ref } from 'vue';
const props = defineProps({
  modelValue: { type: Array, default: () => ['', ''] },
  step: { type: Number, default: 1 },
  min: { type: Number, default: -Infinity },
  max: { type: Number, default: Infinity },
  separator: { type: String, default: '—' },
  unit: { type: String, default: '' },
  placeholder: { type: Array, default: () => ['最小', '最大'] }
});
const emit = defineEmits(['update:modelValue', 'error']);
const errorMsg = ref('');

function validate(arr) {
  const a = parseFloat(arr[0]), b = parseFloat(arr[1]);
  let err = '';
  if (arr[0] !== '' && (a < props.min || a > props.max)) err = `最小值需在 ${props.min}~${props.max}`;
  else if (arr[1] !== '' && (b < props.min || b > props.max)) err = `最大值需在 ${props.min}~${props.max}`;
  else if (arr[0] !== '' && arr[1] !== '' && a > b) err = '最小值不能大于最大值';
  errorMsg.value = err;
  emit('error', err);
}
function onMin(e) {
  const arr = [e.target.value, props.modelValue[1]];
  validate(arr);
  emit('update:modelValue', arr);
}
function onMax(e) {
  const arr = [props.modelValue[0], e.target.value];
  validate(arr);
  emit('update:modelValue', arr);
}
</script>

<style src="./NumberRangeInput.css"></style>
