'use client'

import { useState, useEffect } from 'react'
import apiClient from '@/lib/api-client'
import AlertDialog from '@/components/ui/AlertDialog'

interface Department {
  id?: number
  parent_id: number | null
  code: string
  name: string
  name_en: string | null
  email_domain: string | null
  email_address: string | null
  email_quota_mb: number
  description: string | null
  is_active: boolean
}

interface ParentDepartment {
  id: number
  name: string
  depth: number
}

interface Props {
  department: Department | null
  parentDepartments: ParentDepartment[]
  onClose: () => void
  onSave: (isEdit: boolean) => void
}

export default function DepartmentFormModal({ department: editingDepartment, parentDepartments, onClose, onSave }: Props) {
  const [formData, setFormData] = useState<Department>({
    parent_id: null,
    code: '',
    name: '',
    name_en: null,
    email_domain: null,
    email_address: null,
    email_quota_mb: 5120,
    description: null,
    is_active: true,
  })

  const [loading, setLoading] = useState(false)
  const [isTopLevel, setIsTopLevel] = useState(true)

  // 對話框狀態
  const [alertDialog, setAlertDialog] = useState<{
    isOpen: boolean
    title: string
    message: string
    type: 'info' | 'warning' | 'error' | 'success'
  }>({
    isOpen: false,
    title: '',
    message: '',
    type: 'info',
  })

  // 如果是編輯模式，填入現有資料
  useEffect(() => {
    if (editingDepartment) {
      setFormData(editingDepartment)
      setIsTopLevel(editingDepartment.parent_id === null)
    }
  }, [editingDepartment])

  const handleChange = (field: keyof Department, value: any) => {
    setFormData(prev => ({ ...prev, [field]: value }))
  }

  const handleParentChange = (value: string) => {
    const parentId = value === '' ? null : parseInt(value)
    setFormData(prev => ({ ...prev, parent_id: parentId }))
    setIsTopLevel(parentId === null)
  }

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault()
    setLoading(true)

    try {
      // 驗證
      if (!formData.code || !formData.name) {
        setAlertDialog({
          isOpen: true,
          title: '欄位驗證',
          message: '請填寫部門代碼和名稱',
          type: 'warning',
        })
        setLoading(false)
        return
      }

      // 第一層部門必須填寫郵件網域
      if (isTopLevel && !formData.email_domain) {
        setAlertDialog({
          isOpen: true,
          title: '欄位驗證',
          message: '第一層部門必須填寫郵件網域',
          type: 'warning',
        })
        setLoading(false)
        return
      }

      // 準備資料
      const submitData: any = {
        parent_id: formData.parent_id,
        code: formData.code,
        name: formData.name,
        name_en: formData.name_en,
        email_address: formData.email_address,
        email_quota_mb: formData.email_quota_mb,
        description: formData.description,
        is_active: formData.is_active,
      }

      // 只有第一層部門才送 email_domain
      if (isTopLevel) {
        submitData.email_domain = formData.email_domain
      }

      const isEdit = !!editingDepartment

      if (isEdit) {
        // 更新
        await apiClient.put(`/departments/${editingDepartment.id}`, submitData)
      } else {
        // 新增
        await apiClient.post('/departments', submitData)
      }

      onSave(isEdit)
      onClose()
    } catch (error: any) {
      console.error('Failed to save department:', error)
      setAlertDialog({
        isOpen: true,
        title: '儲存失敗',
        message: error.response?.data?.detail || '儲存失敗，請稍後再試',
        type: 'error',
      })
    } finally {
      setLoading(false)
    }
  }

  return (
    <div
      className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center z-50 p-4 animate-fadeIn"
      onClick={onClose}
    >
      <div
        className="bg-white rounded-xl shadow-2xl w-full max-w-5xl max-h-[90vh] overflow-hidden animate-slideIn"
        onClick={(e) => e.stopPropagation()}
      >
        {/* Card Header */}
        <div className="bg-gradient-to-r from-blue-600 to-blue-700 px-5 py-3.5 flex justify-between items-center">
          <h2 className="text-lg font-semibold text-white">
            {formData.name || '部門資料'} - {editingDepartment ? '編輯作業' : '新增作業'}
          </h2>
          <button
            type="button"
            onClick={onClose}
            className="text-white hover:text-blue-100 transition-colors"
            aria-label="關閉"
          >
            <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
            </svg>
          </button>
        </div>

        {/* Card Body - Scrollable */}
        <div className="overflow-y-auto max-h-[calc(90vh-180px)]">
          <form onSubmit={handleSubmit} className="p-6">
            {/* Row 1: 上層部門 + 部門代碼 */}
            <div className="grid grid-cols-2 gap-4 mb-4">
              <div>
                <label className="block text-sm font-medium text-gray-700 mb-1">
                  上層部門
                </label>
                <select
                  value={formData.parent_id === null ? '' : formData.parent_id}
                  onChange={(e) => handleParentChange(e.target.value)}
                  className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 text-sm text-gray-900 placeholder:text-gray-500"
                >
                  <option value="">第一層 (無上層)</option>
                  {parentDepartments.map(dept => (
                    <option key={dept.id} value={dept.id}>
                      {dept.name}
                    </option>
                  ))}
                </select>
              </div>

              <div>
                <label className="block text-sm font-medium text-gray-700 mb-1">
                  部門代碼 <span className="text-red-500">*</span>
                </label>
                <input
                  type="text"
                  value={formData.code}
                  onChange={(e) => handleChange('code', e.target.value)}
                  className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 text-sm text-gray-900 placeholder:text-gray-500"
                  placeholder="例如: BD"
                  required
                />
              </div>
            </div>

            {/* Row 2: 部門名稱 + 英文名稱 */}
            <div className="grid grid-cols-2 gap-4 mb-4">
              <div>
                <label className="block text-sm font-medium text-gray-700 mb-1">
                  部門名稱 <span className="text-red-500">*</span>
                </label>
                <input
                  type="text"
                  value={formData.name}
                  onChange={(e) => handleChange('name', e.target.value)}
                  className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 text-sm text-gray-900 placeholder:text-gray-500"
                  placeholder="例如: 業務發展部"
                  required
                />
              </div>

              <div>
                <label className="block text-sm font-medium text-gray-700 mb-1">
                  英文名稱
                </label>
                <input
                  type="text"
                  value={formData.name_en || ''}
                  onChange={(e) => handleChange('name_en', e.target.value)}
                  className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 text-sm text-gray-900 placeholder:text-gray-500"
                  placeholder="例如: Business Development"
                />
              </div>
            </div>

            {/* Row 3: 郵件網域 (只在第一層顯示) */}
            {isTopLevel && (
              <div className="mb-4">
                <label className="block text-sm font-medium text-gray-700 mb-1">
                  郵件網域 <span className="text-red-500">*</span>
                </label>
                <input
                  type="text"
                  value={formData.email_domain || ''}
                  onChange={(e) => handleChange('email_domain', e.target.value)}
                  className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 text-sm text-gray-900 placeholder:text-gray-500"
                  placeholder="例如: ease.taipei"
                  required
                />
              </div>
            )}

            {/* Row 4: 部門信箱 + 信箱配額 */}
            <div className="grid grid-cols-2 gap-4 mb-4">
              <div>
                <label className="block text-sm font-medium text-gray-700 mb-1">
                  部門信箱
                </label>
                <input
                  type="email"
                  value={formData.email_address || ''}
                  onChange={(e) => handleChange('email_address', e.target.value)}
                  className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 text-sm text-gray-900 placeholder:text-gray-500"
                  placeholder="例如: bd@ease.taipei"
                />
              </div>

              <div>
                <label className="block text-sm font-medium text-gray-700 mb-1">
                  信箱配額 (MB)
                </label>
                <input
                  type="number"
                  value={formData.email_quota_mb}
                  onChange={(e) => handleChange('email_quota_mb', parseInt(e.target.value))}
                  className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 text-sm text-gray-900 placeholder:text-gray-500"
                  min={0}
                />
              </div>
            </div>

            {/* 說明 */}
            <div className="mb-4">
              <label className="block text-sm font-medium text-gray-700 mb-1">
                說明
              </label>
              <textarea
                value={formData.description || ''}
                onChange={(e) => handleChange('description', e.target.value)}
                className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 text-sm text-gray-900 placeholder:text-gray-500"
                rows={2}
                placeholder="部門說明..."
              />
            </div>

            {/* 啟用 */}
            <div>
              <label className="flex items-center cursor-pointer">
                <input
                  type="checkbox"
                  checked={formData.is_active}
                  onChange={(e) => handleChange('is_active', e.target.checked)}
                  className="mr-2 w-4 h-4"
                />
                <span className="text-sm font-medium text-gray-700">啟用</span>
              </label>
            </div>
          </form>
        </div>

        {/* Card Footer */}
        <div className="border-t bg-gray-50 px-5 py-2.5 flex justify-end gap-3">
          <button
            type="button"
            onClick={onClose}
            className="px-4 py-1.5 border border-gray-300 text-gray-700 rounded-lg hover:bg-gray-100 transition-colors text-sm font-medium"
            disabled={loading}
          >
            取消
          </button>
          <button
            type="submit"
            onClick={handleSubmit}
            className="px-4 py-1.5 bg-blue-600 text-white rounded-lg hover:bg-blue-700 transition-colors disabled:opacity-50 text-sm font-medium"
            disabled={loading}
          >
            {loading ? '儲存中...' : '儲存'}
          </button>
        </div>

        {/* Alert Dialog */}
        <AlertDialog
          isOpen={alertDialog.isOpen}
          title={alertDialog.title}
          message={alertDialog.message}
          type={alertDialog.type}
          onConfirm={() => setAlertDialog({ ...alertDialog, isOpen: false })}
        />
      </div>
    </div>
  )
}