<template>
  <div class="app-container mobile-optimized">
    <el-card class="box-card" shadow="never">
      <template #header>
        <div class="card-header">
          <div class="title-box">
            <span>借库作业 (领用人签字)</span>
            <el-tag v-if="cartItems.length > 0" type="warning" size="small" effect="dark">
              已选 {{ cartItems.length }} 项
            </el-tag>
          </div>
        </div>
      </template>

      <div class="scan-section">
        <div v-if="showCamera" class="camera-wrapper">
          <QrScanner @decode="onScanSuccess" />
          <div class="scan-overlay">
            <el-button type="info" size="small" bg text @click="showCamera = false" icon="Close">
              关闭摄像头
            </el-button>
          </div>
        </div>

        <div v-else class="camera-placeholder" @click="showCamera = true">
          <el-icon :size="40" color="#409EFF"><CameraFilled /></el-icon>
          <span class="text">点击开启扫码</span>
        </div>

        <div class="input-box">
          <el-input
              v-model="barcodeInput"
              placeholder="扫描或输入条码回车"
              @keyup.enter="handleManualInput"
              clearable
              ref="barcodeRef"
              size="large"
          >
            <template #prefix>
              <el-icon><Scissor /></el-icon>
            </template>
            <template #append>
              <el-button @click="handleManualInput">添加</el-button>
            </template>
          </el-input>
        </div>
      </div>

      <div class="cart-section">
        <div v-if="cartItems.length > 0">
          <el-table :data="cartItems" border stripe style="width: 100%">
            <el-table-column prop="name" label="物品名称" min-width="120" show-overflow-tooltip />
            <el-table-column prop="sku" label="SKU" width="120" show-overflow-tooltip />

            <el-table-column label="可用库存" width="90" align="center">
              <template #default="{row}">
                <el-tag type="info">{{ parseFloat(row.available_quantity) }}</el-tag>
              </template>
            </el-table-column>

            <el-table-column label="借用数" width="130" align="center">
              <template #default="{row}">
                <el-input-number
                    v-model="row.out_quantity"
                    :min="1"
                    :max="parseFloat(row.available_quantity)"
                    size="small"
                    style="width: 100px"
                />
              </template>
            </el-table-column>

            <el-table-column label="操作" width="60" align="center" fixed="right">
              <template #default="{$index}">
                <el-button type="danger" icon="Delete" circle size="small" @click="removeFromCart($index)" />
              </template>
            </el-table-column>
          </el-table>
        </div>
        <el-empty v-else description="暂无物品，请扫码借出" :image-size="80" />
      </div>

      <div v-if="cartItems.length > 0" class="form-section">
        <el-divider content-position="left">借用登记信息</el-divider>

        <el-form :model="form" ref="formRef" :rules="rules" label-position="top">
          <el-row :gutter="15">
            <el-col :span="24">
              <el-form-item label="领用人/借用人" prop="borrower_name">
                <el-input v-model="form.borrower_name" placeholder="请输入姓名" size="large" />
              </el-form-item>
            </el-col>

            <el-col :span="24">
              <el-form-item label="预计归还日期" prop="expected_return_time">
                <el-date-picker
                    v-model="form.expected_return_time"
                    type="date"
                    placeholder="请选择日期"
                    style="width: 100%"
                    size="large"
                    value-format="YYYY-MM-DD"
                    :disabled-date="disabledDate"
                />
              </el-form-item>
            </el-col>
          </el-row>

          <el-form-item label="备注说明" prop="remark">
            <el-input v-model="form.remark" type="textarea" :rows="2" placeholder="用途说明..." />
          </el-form-item>

          <el-form-item label="领用人签名确认" required>
            <div class="signature-box" @click="openSignatureDialog">
              <div v-if="signaturePreviewUrl" class="signed-img">
                <img :src="signaturePreviewUrl" alt="签名" />
                <span class="re-sign-tip">点击重签</span>
              </div>
              <div v-else class="unsigned-placeholder">
                <el-icon :size="24"><EditPen /></el-icon>
                <span>点击此处进行全屏签名</span>
              </div>
            </div>
          </el-form-item>

          <div class="bottom-actions">
            <el-button @click="clearAll" icon="Refresh">清空</el-button>
            <el-button type="primary" size="large" :loading="loading" @click="submitForm" icon="Select">
              确认借出
            </el-button>
          </div>
        </el-form>
      </div>
    </el-card>

    <el-dialog
        v-model="showSignatureDialog"
        fullscreen
        destroy-on-close
        :show-close="false"
        class="fullscreen-signature-dialog"
        @opened="initCanvas"
    >
      <div class="signature-wrapper">
        <div class="signature-canvas-container" ref="canvasContainerRef">
          <canvas
              ref="nativeCanvasRef"
              class="native-canvas"
              @mousedown="startDrawing"
              @mousemove="draw"
              @mouseup="stopDrawing"
              @mouseleave="stopDrawing"
              @touchstart="startDrawing"
              @touchmove="draw"
              @touchend="stopDrawing"
          ></canvas>
          <div class="canvas-tip">请在此区域横屏书写</div>
        </div>

        <div class="signature-sidebar">
          <div class="sidebar-title">电子签名</div>
          <div class="sidebar-actions">
            <el-button type="warning" @click="clearCanvas">重写</el-button>
            <el-button @click="handleSignCancel">取消</el-button>
            <el-button type="success" class="confirm-btn" @click="handleSignConfirm">确认使用</el-button>
          </div>
        </div>
      </div>
    </el-dialog>

  </div>
</template>

<script setup lang="ts">
import { ref, reactive, nextTick, onUnmounted } from 'vue'
import { ElMessage, ElMessageBox } from 'element-plus'
import { Scissor, EditPen, Delete, CameraFilled, Close, Refresh, Select } from '@element-plus/icons-vue'
import QrScanner from '@/components/QrScanner/index.vue'
import { getStockByBarcode } from '@/api/outbound'
import request from '@/utils/request'
import { uploadFile } from '@/api/common/upload'

// --- 状态定义 ---
const barcodeInput = ref('')
const cartItems = ref<any[]>([])
const loading = ref(false)
const showCamera = ref(false)
const barcodeRef = ref()
const formRef = ref()

// 签名相关
const showSignatureDialog = ref(false)
const signaturePreviewUrl = ref('')
const signatureFile = ref<File | null>(null)
const nativeCanvasRef = ref<HTMLCanvasElement | null>(null)
const canvasContainerRef = ref<HTMLElement | null>(null)
const ctx = ref<CanvasRenderingContext2D | null>(null)
const isDrawing = ref(false)
const lastX = ref(0)
const lastY = ref(0)

const form = reactive({
  borrower_name: '',
  expected_return_time: '',
  remark: ''
})

// ★ 修改点：增强校验规则
const rules = {
  borrower_name: [
    { required: true, message: '请输入借用人姓名', trigger: 'blur' }
  ],
  expected_return_time: [
    { required: true, message: '请选择预计归还日期', trigger: 'change' }
  ]
}

// ★ 新增：禁止选择今天之前的日期
const disabledDate = (time: Date) => {
  return time.getTime() < Date.now() - 8.64e7 // 禁止选择昨天及之前
}

// --- 核心扫码逻辑 ---
const onScanSuccess = (code: string) => {
  if (!code) return
  const trimCode = code.trim()

  const validPattern = /^[A-Za-z0-9\-\.]+$/
  if (!validPattern.test(trimCode)) {
    ElMessage.warning(`识别到异常符号，已忽略：${trimCode}`)
    return
  }

  if (trimCode.length < 3) {
    ElMessage.warning('扫描结果过短，请对准重试')
    return
  }

  if (loading.value) return

  barcodeInput.value = trimCode
  handleManualInput()
}

const handleManualInput = async () => {
  const code = barcodeInput.value.trim()
  if (!code) return

  try {
    loading.value = true

    // 查重
    const existIndex = cartItems.value.findIndex(item => item.barcode === code || item.sku === code)
    if (existIndex > -1) {
      const item = cartItems.value[existIndex]
      const maxQty = parseFloat(item.available_quantity)
      if (item.out_quantity < maxQty) {
        item.out_quantity++
        ElMessage.success(`数量+1 (当前: ${item.out_quantity})`)
        if (navigator.vibrate) navigator.vibrate(50)
      } else {
        ElMessage.warning(`库存不足 (余: ${maxQty})`)
      }
      barcodeInput.value = ''
      return
    }

    // 查库
    const res = await getStockByBarcode(code)
    if (res.data) {
      const item = res.data
      const availQty = parseFloat(item.available_quantity || 0)

      if (availQty <= 0) {
        ElMessage.warning(`库存不足 (余: ${availQty})`)
      } else {
        cartItems.value.push({
          ...item,
          out_quantity: 1,
          price: 0
        })
        ElMessage.success(`添加成功: ${item.name}`)
        if (navigator.vibrate) navigator.vibrate(100)
      }
      barcodeInput.value = ''
    }
  } catch (error: any) {
    if (error.response && error.response.status === 404) {
      ElMessage.error(`未找到条码: ${code}`)
    } else {
      ElMessage.error('查询出错')
    }
  } finally {
    loading.value = false
    nextTick(() => { barcodeRef.value?.focus() })
  }
}

const removeFromCart = (index: number) => {
  cartItems.value.splice(index, 1)
}

const clearAll = () => {
  ElMessageBox.confirm('确定清空所有已选物品吗?', '提示', { type: 'warning' })
      .then(() => {
        cartItems.value = []
        form.borrower_name = ''
        form.remark = ''
        form.expected_return_time = ''
        signatureFile.value = null
        signaturePreviewUrl.value = ''
        barcodeInput.value = ''
      })
}

// --- 提交逻辑 ---
const submitForm = async () => {
  if (!formRef.value) return
  if (cartItems.value.length === 0) return ElMessage.warning('请先添加物品')

  // ★ 核心修改：等待校验通过后再提交，否则报错会被拦截在前端
  await formRef.value.validate(async (valid: boolean) => {
    if (!valid) {
      ElMessage.error('请填写完整的必填项（姓名、归还日期）')
      return
    }

    if (!signatureFile.value) {
      ElMessage.error('请领用人进行电子签名')
      return
    }

    try {
      loading.value = true

      // 上传签名
      const uploadRes = await uploadFile(signatureFile.value)
      const signatureUrl = uploadRes.data.url

      await request({
        url: '/v1/transactions/borrow',
        method: 'post',
        data: {
          items: cartItems.value,
          ...form, // 此时 form.expected_return_time 已经是 YYYY-MM-DD 格式
          signature_path: signatureUrl
        }
      })

      ElMessage.success('借用成功')
      cartItems.value = []
      form.borrower_name = ''
      form.expected_return_time = ''
      form.remark = ''
      signatureFile.value = null
      signaturePreviewUrl.value = ''
      showCamera.value = false

    } catch (error: any) {
      console.error(error)
      ElMessage.error(error.response?.data?.msg || '提交失败')
    } finally {
      loading.value = false
    }
  })
}

// --- 签名逻辑 ---
const openSignatureDialog = () => { showSignatureDialog.value = true }

const initCanvas = async () => {
  await nextTick()
  const canvas = nativeCanvasRef.value
  const container = canvasContainerRef.value

  if (canvas && container) {
    canvas.width = container.clientWidth
    canvas.height = container.clientHeight
    ctx.value = canvas.getContext('2d')
    if (ctx.value) {
      ctx.value.lineWidth = 4
      ctx.value.lineCap = 'round'
      ctx.value.lineJoin = 'round'
      ctx.value.strokeStyle = '#000000'
      ctx.value.fillStyle = '#ffffff'
      ctx.value.fillRect(0, 0, canvas.width, canvas.height)
    }
  }
}

const getPos = (e: MouseEvent | TouchEvent) => {
  if (!nativeCanvasRef.value) return { x: 0, y: 0 }
  const rect = nativeCanvasRef.value.getBoundingClientRect()
  const clientX = e.type.startsWith('touch') ? (e as TouchEvent).touches[0].clientX : (e as MouseEvent).clientX
  const clientY = e.type.startsWith('touch') ? (e as TouchEvent).touches[0].clientY : (e as MouseEvent).clientY
  return { x: clientX - rect.left, y: clientY - rect.top }
}

const startDrawing = (e: MouseEvent | TouchEvent) => {
  e.preventDefault()
  isDrawing.value = true
  const { x, y } = getPos(e)
  lastX.value = x; lastY.value = y
  ctx.value?.beginPath()
  ctx.value?.moveTo(x, y)
}

const draw = (e: MouseEvent | TouchEvent) => {
  e.preventDefault()
  if (!isDrawing.value || !ctx.value) return
  const { x, y } = getPos(e)
  ctx.value.lineTo(x, y)
  ctx.value.stroke()
}

const stopDrawing = () => { isDrawing.value = false }

const clearCanvas = () => {
  if (!ctx.value || !nativeCanvasRef.value) return
  ctx.value.clearRect(0, 0, nativeCanvasRef.value.width, nativeCanvasRef.value.height)
  ctx.value.fillStyle = '#ffffff'
  ctx.value.fillRect(0, 0, nativeCanvasRef.value.width, nativeCanvasRef.value.height)
}

const handleSignConfirm = () => {
  nativeCanvasRef.value?.toBlob((blob) => {
    if (blob) {
      const file = new File([blob], `sign_${Date.now()}.png`, { type: 'image/png' })
      signatureFile.value = file
      signaturePreviewUrl.value = URL.createObjectURL(file)
      showSignatureDialog.value = false
    }
  }, 'image/png')
}

const handleSignCancel = () => { showSignatureDialog.value = false }

onUnmounted(() => {
  if (signaturePreviewUrl.value) URL.revokeObjectURL(signaturePreviewUrl.value)
})
</script>

<style scoped>
.app-container.mobile-optimized {
  padding: 10px; max-width: 600px; margin: 0 auto;
}

/* 头部 */
.card-header { display: flex; justify-content: space-between; align-items: center; }
.title-box { font-size: 16px; font-weight: bold; display: flex; align-items: center; gap: 8px; }

/* 扫码区 */
.scan-section { margin-bottom: 20px; }
.camera-wrapper {
  height: 25vh; background: #000; border-radius: 12px; overflow: hidden; position: relative; margin-bottom: 10px;
}
.scan-overlay {
  position: absolute; bottom: 10px; right: 10px; z-index: 10;
}
.camera-placeholder {
  height: 120px; background: #f5f7fa; border: 1px dashed #dcdfe6; border-radius: 8px;
  display: flex; flex-direction: column; justify-content: center; align-items: center;
  color: #909399; margin-bottom: 10px; cursor: pointer;
}
.camera-placeholder .text { margin-top: 5px; font-size: 13px; }

/* 表单与购物车 */
.cart-section { margin-bottom: 20px; }
.form-section { background: #fff; }
.signature-box {
  border: 1px dashed #dcdfe6; border-radius: 6px; height: 100px;
  background: #fcfcfc; display: flex; justify-content: center; align-items: center; cursor: pointer;
}
.unsigned-placeholder { display: flex; flex-direction: column; align-items: center; color: #909399; font-size: 13px; }
.signed-img img { max-height: 90px; }
.re-sign-tip { display: block; text-align: center; font-size: 12px; color: #409EFF; margin-top: 2px; }

.bottom-actions { display: flex; justify-content: space-between; margin-top: 30px; }
.bottom-actions .el-button { width: 48%; }

/* 全屏签名弹窗 */
:deep(.fullscreen-signature-dialog .el-dialog__body) { padding: 0; height: 100%; display: flex; }
.signature-wrapper { display: flex; width: 100%; height: 100%; }
.signature-canvas-container { flex: 1; position: relative; background: #fff; overflow: hidden; }
.native-canvas { display: block; width: 100%; height: 100%; touch-action: none; }
.canvas-tip {
  position: absolute; bottom: 20px; left: 50%; transform: translateX(-50%);
  color: #ccc; font-size: 20px; pointer-events: none; opacity: 0.5; writing-mode: vertical-lr;
}
.signature-sidebar {
  width: 120px; background: #333; color: #fff;
  display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 20px 10px;
}
.sidebar-title { writing-mode: vertical-rl; font-size: 18px; letter-spacing: 5px; margin-bottom: 30px; font-weight: bold; }
.sidebar-actions { display: flex; flex-direction: column; gap: 20px; width: 100%; }
.sidebar-actions .el-button { width: 100%; margin: 0; height: 50px; }

@media screen and (max-width: 768px) {
  .signature-wrapper { flex-direction: column; }
  .signature-canvas-container { flex: 1; }
  .canvas-tip { writing-mode: horizontal-tb; bottom: 50%; }
  .signature-sidebar { width: 100%; height: auto; flex-direction: row; padding: 10px; justify-content: space-between; }
  .sidebar-title { display: none; }
  .sidebar-actions { flex-direction: row; width: 100%; gap: 10px; }
  .sidebar-actions .el-button { flex: 1; height: 40px; }
}
</style>