'use client'

import { useState, useMemo } from 'react'
import Link from 'next/link'
import {
  useVendorCompliance,
  Vendor,
  VendorStatus,
  VendorRole,
  ServiceCategory,
  VENDOR_ROLE_META,
  SERVICE_CATEGORY_META,
  getRiskLevelFromScore,
  formatDate,
} from '@/lib/sdk/vendor-compliance'

type SortField = 'name' | 'role' | 'status' | 'riskScore' | 'nextReviewDate'
type SortOrder = 'asc' | 'desc'

export default function VendorsPage() {
  const { vendors, contracts, deleteVendor, isLoading } = useVendorCompliance()

  const [searchTerm, setSearchTerm] = useState('')
  const [statusFilter, setStatusFilter] = useState<VendorStatus | 'ALL'>('ALL')
  const [roleFilter, setRoleFilter] = useState<VendorRole | 'ALL'>('ALL')
  const [categoryFilter, setCategoryFilter] = useState<ServiceCategory | 'ALL'>('ALL')
  const [sortField, setSortField] = useState<SortField>('name')
  const [sortOrder, setSortOrder] = useState<SortOrder>('asc')

  const filteredVendors = useMemo(() => {
    let result = [...vendors]

    // Search filter
    if (searchTerm) {
      const term = searchTerm.toLowerCase()
      result = result.filter(
        (v) =>
          v.name.toLowerCase().includes(term) ||
          v.serviceDescription.toLowerCase().includes(term)
      )
    }

    // Status filter
    if (statusFilter !== 'ALL') {
      result = result.filter((v) => v.status === statusFilter)
    }

    // Role filter
    if (roleFilter !== 'ALL') {
      result = result.filter((v) => v.role === roleFilter)
    }

    // Category filter
    if (categoryFilter !== 'ALL') {
      result = result.filter((v) => v.serviceCategory === categoryFilter)
    }

    // Sort
    result.sort((a, b) => {
      let comparison = 0
      switch (sortField) {
        case 'name':
          comparison = a.name.localeCompare(b.name)
          break
        case 'role':
          comparison = a.role.localeCompare(b.role)
          break
        case 'status':
          comparison = a.status.localeCompare(b.status)
          break
        case 'riskScore':
          comparison = a.residualRiskScore - b.residualRiskScore
          break
        case 'nextReviewDate':
          const dateA = a.nextReviewDate ? new Date(a.nextReviewDate).getTime() : Infinity
          const dateB = b.nextReviewDate ? new Date(b.nextReviewDate).getTime() : Infinity
          comparison = dateA - dateB
          break
      }
      return sortOrder === 'asc' ? comparison : -comparison
    })

    return result
  }, [vendors, searchTerm, statusFilter, roleFilter, categoryFilter, sortField, sortOrder])

  const handleSort = (field: SortField) => {
    if (sortField === field) {
      setSortOrder(sortOrder === 'asc' ? 'desc' : 'asc')
    } else {
      setSortField(field)
      setSortOrder('asc')
    }
  }

  const handleDelete = async (id: string) => {
    if (confirm('Möchten Sie diesen Vendor wirklich löschen?')) {
      await deleteVendor(id)
    }
  }

  const getContractCount = (vendorId: string) => {
    return contracts.filter((c) => c.vendorId === vendorId).length
  }

  if (isLoading) {
    return (
      <div className="flex items-center justify-center h-64">
        <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-blue-600"></div>
      </div>
    )
  }

  return (
    <div className="space-y-6">
      {/* Header */}
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-2xl font-bold text-gray-900 dark:text-white">
            Vendor Register
          </h1>
          <p className="mt-1 text-sm text-gray-500 dark:text-gray-400">
            Verwaltung von Auftragsverarbeitern und Dienstleistern
          </p>
        </div>
        <Link
          href="/sdk/vendor-compliance/vendors/new"
          className="inline-flex items-center px-4 py-2 border border-transparent rounded-md shadow-sm text-sm font-medium text-white bg-blue-600 hover:bg-blue-700 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-blue-500"
        >
          <svg className="w-5 h-5 mr-2" fill="none" viewBox="0 0 24 24" stroke="currentColor">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 4v16m8-8H4" />
          </svg>
          Neuer Vendor
        </Link>
      </div>

      {/* Filters */}
      <div className="bg-white dark:bg-gray-800 rounded-lg shadow p-4">
        <div className="grid grid-cols-1 md:grid-cols-5 gap-4">
          {/* Search */}
          <div className="md:col-span-2">
            <label htmlFor="search" className="sr-only">Suchen</label>
            <div className="relative">
              <div className="absolute inset-y-0 left-0 pl-3 flex items-center pointer-events-none">
                <svg className="h-5 w-5 text-gray-400" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z" />
                </svg>
              </div>
              <input
                type="text"
                id="search"
                className="block w-full pl-10 pr-3 py-2 border border-gray-300 dark:border-gray-600 rounded-md leading-5 bg-white dark:bg-gray-700 text-gray-900 dark:text-white placeholder-gray-500 focus:outline-none focus:ring-1 focus:ring-blue-500 focus:border-blue-500 sm:text-sm"
                placeholder="Name oder Beschreibung suchen..."
                value={searchTerm}
                onChange={(e) => setSearchTerm(e.target.value)}
              />
            </div>
          </div>

          {/* Status Filter */}
          <div>
            <select
              className="block w-full pl-3 pr-10 py-2 text-base border-gray-300 dark:border-gray-600 focus:outline-none focus:ring-blue-500 focus:border-blue-500 sm:text-sm rounded-md bg-white dark:bg-gray-700 text-gray-900 dark:text-white"
              value={statusFilter}
              onChange={(e) => setStatusFilter(e.target.value as VendorStatus | 'ALL')}
            >
              <option value="ALL">Alle Status</option>
              <option value="ACTIVE">Aktiv</option>
              <option value="INACTIVE">Inaktiv</option>
              <option value="PENDING_REVIEW">Review ausstehend</option>
              <option value="TERMINATED">Beendet</option>
            </select>
          </div>

          {/* Role Filter */}
          <div>
            <select
              className="block w-full pl-3 pr-10 py-2 text-base border-gray-300 dark:border-gray-600 focus:outline-none focus:ring-blue-500 focus:border-blue-500 sm:text-sm rounded-md bg-white dark:bg-gray-700 text-gray-900 dark:text-white"
              value={roleFilter}
              onChange={(e) => setRoleFilter(e.target.value as VendorRole | 'ALL')}
            >
              <option value="ALL">Alle Rollen</option>
              <option value="PROCESSOR">Auftragsverarbeiter</option>
              <option value="SUB_PROCESSOR">Unterauftragnehmer</option>
              <option value="CONTROLLER">Verantwortlicher</option>
              <option value="JOINT_CONTROLLER">Gemeinsam Verantwortlicher</option>
              <option value="THIRD_PARTY">Dritter</option>
            </select>
          </div>

          {/* Category Filter */}
          <div>
            <select
              className="block w-full pl-3 pr-10 py-2 text-base border-gray-300 dark:border-gray-600 focus:outline-none focus:ring-blue-500 focus:border-blue-500 sm:text-sm rounded-md bg-white dark:bg-gray-700 text-gray-900 dark:text-white"
              value={categoryFilter}
              onChange={(e) => setCategoryFilter(e.target.value as ServiceCategory | 'ALL')}
            >
              <option value="ALL">Alle Kategorien</option>
              {Object.entries(SERVICE_CATEGORY_META).map(([key, value]) => (
                <option key={key} value={key}>
                  {value.de}
                </option>
              ))}
            </select>
          </div>
        </div>
      </div>

      {/* Vendor Cards */}
      <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
        {filteredVendors.map((vendor) => (
          <VendorCard
            key={vendor.id}
            vendor={vendor}
            contractCount={getContractCount(vendor.id)}
            onDelete={handleDelete}
          />
        ))}
      </div>

      {filteredVendors.length === 0 && (
        <div className="text-center py-12 bg-white dark:bg-gray-800 rounded-lg shadow">
          <svg
            className="mx-auto h-12 w-12 text-gray-400"
            fill="none"
            viewBox="0 0 24 24"
            stroke="currentColor"
          >
            <path
              strokeLinecap="round"
              strokeLinejoin="round"
              strokeWidth={2}
              d="M19 21V5a2 2 0 00-2-2H7a2 2 0 00-2 2v16m14 0h2m-2 0h-5m-9 0H3m2 0h5M9 7h1m-1 4h1m4-4h1m-1 4h1m-5 10v-5a1 1 0 011-1h2a1 1 0 011 1v5m-4 0h4"
            />
          </svg>
          <h3 className="mt-2 text-sm font-medium text-gray-900 dark:text-white">
            Keine Vendors gefunden
          </h3>
          <p className="mt-1 text-sm text-gray-500 dark:text-gray-400">
            Erstellen Sie einen neuen Vendor, um zu beginnen.
          </p>
          <div className="mt-6">
            <Link
              href="/sdk/vendor-compliance/vendors/new"
              className="inline-flex items-center px-4 py-2 border border-transparent rounded-md shadow-sm text-sm font-medium text-white bg-blue-600 hover:bg-blue-700"
            >
              <svg className="w-5 h-5 mr-2" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 4v16m8-8H4" />
              </svg>
              Neuer Vendor
            </Link>
          </div>
        </div>
      )}

      {/* Summary */}
      <div className="text-sm text-gray-500 dark:text-gray-400">
        {filteredVendors.length} von {vendors.length} Vendors
      </div>
    </div>
  )
}

function VendorCard({
  vendor,
  contractCount,
  onDelete,
}: {
  vendor: Vendor
  contractCount: number
  onDelete: (id: string) => void
}) {
  const riskLevel = getRiskLevelFromScore(vendor.residualRiskScore / 4)
  const isReviewDue = vendor.nextReviewDate && new Date(vendor.nextReviewDate) <= new Date()

  const riskColors = {
    LOW: 'border-l-green-500',
    MEDIUM: 'border-l-yellow-500',
    HIGH: 'border-l-orange-500',
    CRITICAL: 'border-l-red-500',
  }

  const statusConfig = {
    ACTIVE: { label: 'Aktiv', color: 'bg-green-100 text-green-800 dark:bg-green-900 dark:text-green-200' },
    INACTIVE: { label: 'Inaktiv', color: 'bg-gray-100 text-gray-800 dark:bg-gray-700 dark:text-gray-200' },
    PENDING_REVIEW: { label: 'Review ausstehend', color: 'bg-yellow-100 text-yellow-800 dark:bg-yellow-900 dark:text-yellow-200' },
    TERMINATED: { label: 'Beendet', color: 'bg-red-100 text-red-800 dark:bg-red-900 dark:text-red-200' },
  }

  return (
    <div className={`bg-white dark:bg-gray-800 rounded-lg shadow border-l-4 ${riskColors[riskLevel]} overflow-hidden`}>
      <div className="p-5">
        <div className="flex items-start justify-between">
          <div className="flex-1 min-w-0">
            <h3 className="text-lg font-semibold text-gray-900 dark:text-white truncate">
              {vendor.name}
            </h3>
            <p className="mt-1 text-sm text-gray-500 dark:text-gray-400">
              {SERVICE_CATEGORY_META[vendor.serviceCategory]?.de}
            </p>
          </div>
          <span className={`inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-medium ${statusConfig[vendor.status].color}`}>
            {statusConfig[vendor.status].label}
          </span>
        </div>

        <p className="mt-3 text-sm text-gray-600 dark:text-gray-300 line-clamp-2">
          {vendor.serviceDescription}
        </p>

        <div className="mt-4 grid grid-cols-2 gap-4">
          <div>
            <p className="text-xs text-gray-500 dark:text-gray-400">Rolle</p>
            <p className="text-sm font-medium text-gray-900 dark:text-white">
              {VENDOR_ROLE_META[vendor.role]?.de}
            </p>
          </div>
          <div>
            <p className="text-xs text-gray-500 dark:text-gray-400">Risiko-Score</p>
            <div className="flex items-center gap-2">
              <div className="flex-1 bg-gray-200 dark:bg-gray-700 rounded-full h-2">
                <div
                  className={`h-2 rounded-full ${
                    riskLevel === 'LOW'
                      ? 'bg-green-500'
                      : riskLevel === 'MEDIUM'
                      ? 'bg-yellow-500'
                      : riskLevel === 'HIGH'
                      ? 'bg-orange-500'
                      : 'bg-red-500'
                  }`}
                  style={{ width: `${vendor.residualRiskScore}%` }}
                />
              </div>
              <span className="text-sm font-medium text-gray-900 dark:text-white">
                {vendor.residualRiskScore}
              </span>
            </div>
          </div>
        </div>

        <div className="mt-4 flex items-center gap-4 text-sm text-gray-500 dark:text-gray-400">
          <span className="flex items-center gap-1">
            <svg className="w-4 h-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 12h6m-6 4h6m2 5H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z" />
            </svg>
            {contractCount} Verträge
          </span>
          {vendor.certifications.length > 0 && (
            <span className="flex items-center gap-1">
              <svg className="w-4 h-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 12l2 2 4-4m5.618-4.016A11.955 11.955 0 0112 2.944a11.955 11.955 0 01-8.618 3.04A12.02 12.02 0 003 9c0 5.591 3.824 10.29 9 11.622 5.176-1.332 9-6.03 9-11.622 0-1.042-.133-2.052-.382-3.016z" />
              </svg>
              {vendor.certifications.length} Zertifizierungen
            </span>
          )}
        </div>

        {isReviewDue && (
          <div className="mt-3 p-2 bg-red-50 dark:bg-red-900/20 rounded-md">
            <p className="text-xs text-red-600 dark:text-red-400 flex items-center gap-1">
              <svg className="w-4 h-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-3L13.732 4c-.77-1.333-2.694-1.333-3.464 0L3.34 16c-.77 1.333.192 3 1.732 3z" />
              </svg>
              Review fällig seit {formatDate(vendor.nextReviewDate)}
            </p>
          </div>
        )}
      </div>

      <div className="px-5 py-3 bg-gray-50 dark:bg-gray-700/50 flex items-center justify-between">
        <Link
          href={`/sdk/vendor-compliance/vendors/${vendor.id}`}
          className="text-sm font-medium text-blue-600 hover:text-blue-500 dark:text-blue-400"
        >
          Details anzeigen
        </Link>
        <div className="flex items-center gap-3">
          <Link
            href={`/sdk/vendor-compliance/vendors/${vendor.id}/contracts`}
            className="text-sm text-gray-600 hover:text-gray-900 dark:text-gray-400 dark:hover:text-gray-300"
          >
            Verträge
          </Link>
          <button
            onClick={() => onDelete(vendor.id)}
            className="text-sm text-red-600 hover:text-red-900 dark:text-red-400 dark:hover:text-red-300"
          >
            Löschen
          </button>
        </div>
      </div>
    </div>
  )
}