<template>
  <div class="bill-form">
    <van-form @submit="handleSubmit">
      <van-cell-group inset>
        <!-- 日期时间 -->
        <van-field label="时间">
          <template #input>
            <div style="display: flex; gap: 16px">
              <div @click="showDatePicker = true">{{ form.date }}</div>
              <div @click="showTimePicker = true">{{ form.time }}</div>
            </div>
          </template>
        </van-field>

        <!-- 金额 -->
        <van-field
          v-model="form.amount"
          name="amount"
          label="金额"
          type="number"
          placeholder="0.00"
          :rules="[{ required: true, message: '请输入金额' }]"
        />

        <!-- 备注 -->
        <van-field
          v-model="form.note"
          name="note"
          label="摘要"
          placeholder="摘要信息"
          rows="2"
          autosize
          type="textarea"
        />

        <!-- 交易类型 -->
        <van-field name="type" label="类型">
          <template #input>
            <van-radio-group v-model="form.type" direction="horizontal" @change="handleTypeChange">
              <van-radio :name="0">支出</van-radio>
              <van-radio :name="1">收入</van-radio>
              <van-radio :name="2">不计</van-radio>
            </van-radio-group>
          </template>
        </van-field>

        <!-- 分类 -->
        <van-field name="category" label="分类">
          <template #input>
            <span v-if="!categoryName" style="color: #c8c9cc;">请选择分类</span>
            <span v-else>{{ categoryName }}</span>
          </template>
        </van-field>
        
        <!-- 分类选择组件 -->
        <ClassifySelector
          v-model="categoryName"
          :type="form.type"
        />
      </van-cell-group>

      <div class="actions">
        <van-button round block type="primary" native-type="submit" :loading="loading">
          {{ submitText }}
        </van-button>
        <slot name="actions"></slot>
      </div>
    </van-form>

    <!-- 日期选择弹窗 -->
    <van-popup v-model:show="showDatePicker" position="bottom" round teleport="body">
      <van-date-picker
        v-model="currentDate"
        title="选择日期"
        @confirm="onConfirmDate"
        @cancel="showDatePicker = false"
      />
    </van-popup>

    <!-- 时间选择弹窗 -->
    <van-popup v-model:show="showTimePicker" position="bottom" round teleport="body">
      <van-time-picker
        v-model="currentTime"
        title="选择时间"
        @confirm="onConfirmTime"
        @cancel="showTimePicker = false"
      />
    </van-popup>
  </div>
</template>

<script setup>
import { ref, onMounted, watch } from 'vue'
import { showToast } from 'vant'
import dayjs from 'dayjs'
import ClassifySelector from '@/components/ClassifySelector.vue'

const props = defineProps({
  initialData: {
    type: Object,
    default: () => ({})
  },
  loading: {
    type: Boolean,
    default: false
  },
  submitText: {
    type: String,
    default: '保存'
  }
})

const emit = defineEmits(['submit'])

// 表单数据
const form = ref({
  type: 0, // 0: 支出, 1: 收入, 2: 不计
  amount: '',
  date: dayjs().format('YYYY-MM-DD'),
  time: dayjs().format('HH:mm'),
  note: ''
})

const categoryName = ref('')

// 弹窗控制
const showDatePicker = ref(false)
const showTimePicker = ref(false)

// 日期时间临时变量 (Vant DatePicker 需要数组 or 特定格式)
const currentDate = ref(dayjs().format('YYYY-MM-DD').split('-'))
const currentTime = ref(dayjs().format('HH:mm').split(':'))

// 初始化数据
const initForm = async () => {
  if (props.initialData) {
    const { occurredAt, amount, reason, type, classify } = props.initialData
    
    if (occurredAt) {
      const dt = dayjs(occurredAt)
      form.value.date = dt.format('YYYY-MM-DD')
      form.value.time = dt.format('HH:mm')
      currentDate.value = form.value.date.split('-')
      currentTime.value = form.value.time.split(':')
    }
    
    if (amount !== undefined) form.value.amount = amount
    if (reason !== undefined) form.value.note = reason
    if (type !== undefined) form.value.type = type
    
    // 如果有传入分类名称，尝试设置
    if (classify) {
      categoryName.value = classify
    }
  }
}

onMounted(() => {
  initForm()
})

// 监听 initialData 变化 (例如重新解析后)
watch(() => props.initialData, () => {
  initForm()
}, { deep: true })

const handleTypeChange = (newType) => {
  categoryName.value = ''
}

const onConfirmDate = ({ selectedValues }) => {
  form.value.date = selectedValues.join('-')
  showDatePicker.value = false
}

const onConfirmTime = ({ selectedValues }) => {
  form.value.time = selectedValues.join(':')
  showTimePicker.value = false
}

const handleSubmit = () => {
  if (!form.value.amount) {
    showToast('请输入金额')
    return
  }
  if (!categoryName.value) {
    showToast('请选择分类')
    return
  }

  const fullDateTime = `${form.value.date}T${form.value.time}:00`
  
  const payload = {
    occurredAt: fullDateTime,
    classify: categoryName.value,
    amount: parseFloat(form.value.amount),
    reason: form.value.note || '',
    type: form.value.type
  }
  
  emit('submit', payload)
}

// 暴露重置方法给父组件
const reset = () => {
  form.value.amount = ''
  form.value.note = ''
  // 保留日期和类型
}

defineExpose({ reset })
</script>

<style scoped>
.bill-form {
  padding-top: 10px;
}
.actions {
  margin: 20px 16px;
}
.classify-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 12px 16px;
}
.classify-btn {
  flex: 0 0 auto;
  min-width: 70px;
  border-radius: 16px;
}
</style>
