<template>
  <div>
    <div style="margin-bottom: 10px;">当前选择：<el-input v-model="isoString" readonly style="width: 300px;" /></div>
    <div v-for="unit in units" :key="unit.key" style="margin-bottom: 8px;">
      <span>{{ unit.label }}：</span>
      <el-button-group>
        <el-button v-for="val in unit.presets" :key="val" size="mini" @click="setUnit(unit.key, val)">{{ val }}</el-button>
        <el-input v-model.number="custom[unit.key]" size="mini" style="width: 60px; margin-left: 8px;" placeholder="自定义" @change="setUnit(unit.key, custom[unit.key])" />
      </el-button-group>
    </div>
  </div>
</template>

<script setup>
import { ref, watch, computed } from 'vue'
const props = defineProps({ value: String })
const emit = defineEmits(['change'])

const units = [
  { key: 'Y', label: '年', presets: [1, 2, 3, 4] },
  { key: 'M', label: '月', presets: [1, 2, 3, 4] },
  { key: 'D', label: '天', presets: [1, 2, 3, 4] },
  { key: 'H', label: '时', presets: [4, 8, 12, 24] },
  { key: 'm', label: '分', presets: [5, 10, 30, 50] },
  { key: 'S', label: '秒', presets: [5, 10, 30, 50] }
]
const custom = ref({ Y: '', M: '', D: '', H: '', m: '', S: '' })
const isoString = ref('')

function setUnit(key, val) {
  if (!val || isNaN(val)) {
    custom.value[key] = ''
    return
  }
  custom.value[key] = val
  updateIsoString()
}

function updateIsoString() {
  let str = 'P'
  if (custom.value.Y) str += custom.value.Y + 'Y'
  if (custom.value.M) str += custom.value.M + 'M'
  if (custom.value.D) str += custom.value.D + 'D'
  if (custom.value.H || custom.value.m || custom.value.S) str += 'T'
  if (custom.value.H) str += custom.value.H + 'H'
  if (custom.value.m) str += custom.value.m + 'M'
  if (custom.value.S) str += custom.value.S + 'S'
  isoString.value = str === 'P' ? '' : str
  emit('change', isoString.value)
}

watch(() => props.value, (val) => {
  if (!val) return
  // 解析ISO 8601字符串到custom
  const match = val.match(/^P(?:(\d+)Y)?(?:(\d+)M)?(?:(\d+)D)?(?:T(?:(\d+)H)?(?:(\d+)M)?(?:(\d+)S)?)?$/)
  if (match) {
    custom.value.Y = match[1] || ''
    custom.value.M = match[2] || ''
    custom.value.D = match[3] || ''
    custom.value.H = match[4] || ''
    custom.value.m = match[5] || ''
    custom.value.S = match[6] || ''
    updateIsoString()
  }
}, { immediate: true })
</script> 
