'use client'

import { useState, useMemo } from 'react'
import Link from 'next/link'
import {
  useVendorCompliance,
  ContractDocument,
  DocumentType,
  ContractStatus,
  ContractReviewStatus,
  DOCUMENT_TYPE_META,
  formatDate,
} from '@/lib/sdk/vendor-compliance'

export default function ContractsPage() {
  const { contracts, vendors, deleteContract, startContractReview, isLoading } = useVendorCompliance()

  const [searchTerm, setSearchTerm] = useState('')
  const [typeFilter, setTypeFilter] = useState<DocumentType | 'ALL'>('ALL')
  const [statusFilter, setStatusFilter] = useState<ContractStatus | 'ALL'>('ALL')
  const [reviewFilter, setReviewFilter] = useState<ContractReviewStatus | 'ALL'>('ALL')

  const filteredContracts = useMemo(() => {
    let result = [...contracts]

    // Search filter
    if (searchTerm) {
      const term = searchTerm.toLowerCase()
      result = result.filter((c) => {
        const vendor = vendors.find((v) => v.id === c.vendorId)
        return (
          c.originalName.toLowerCase().includes(term) ||
          vendor?.name.toLowerCase().includes(term)
        )
      })
    }

    // Type filter
    if (typeFilter !== 'ALL') {
      result = result.filter((c) => c.documentType === typeFilter)
    }

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

    // Review filter
    if (reviewFilter !== 'ALL') {
      result = result.filter((c) => c.reviewStatus === reviewFilter)
    }

    // Sort by date (newest first)
    result.sort((a, b) => new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime())

    return result
  }, [contracts, vendors, searchTerm, typeFilter, statusFilter, reviewFilter])

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

  const handleStartReview = async (id: string) => {
    await startContractReview(id)
  }

  const getVendorName = (vendorId: string) => {
    return vendors.find((v) => v.id === vendorId)?.name || 'Unbekannt'
  }

  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">
            Verträge
          </h1>
          <p className="mt-1 text-sm text-gray-500 dark:text-gray-400">
            AVV, SCC und andere Verträge mit LLM-gestützter Prüfung
          </p>
        </div>
        <Link
          href="/sdk/vendor-compliance/contracts/upload"
          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="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-8l-4-4m0 0L8 8m4-4v12" />
          </svg>
          Vertrag hochladen
        </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">
          <div className="md:col-span-2">
            <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"
                className="block w-full pl-10 pr-3 py-2 border border-gray-300 dark:border-gray-600 rounded-md 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="Dateiname oder Vendor suchen..."
                value={searchTerm}
                onChange={(e) => setSearchTerm(e.target.value)}
              />
            </div>
          </div>
          <div>
            <select
              className="block w-full pl-3 pr-10 py-2 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={typeFilter}
              onChange={(e) => setTypeFilter(e.target.value as DocumentType | 'ALL')}
            >
              <option value="ALL">Alle Typen</option>
              {Object.entries(DOCUMENT_TYPE_META).map(([key, value]) => (
                <option key={key} value={key}>{value.de}</option>
              ))}
            </select>
          </div>
          <div>
            <select
              className="block w-full pl-3 pr-10 py-2 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 ContractStatus | 'ALL')}
            >
              <option value="ALL">Alle Status</option>
              <option value="DRAFT">Entwurf</option>
              <option value="SIGNED">Unterschrieben</option>
              <option value="ACTIVE">Aktiv</option>
              <option value="EXPIRED">Abgelaufen</option>
              <option value="TERMINATED">Beendet</option>
            </select>
          </div>
          <div>
            <select
              className="block w-full pl-3 pr-10 py-2 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={reviewFilter}
              onChange={(e) => setReviewFilter(e.target.value as ContractReviewStatus | 'ALL')}
            >
              <option value="ALL">Alle Reviews</option>
              <option value="PENDING">Ausstehend</option>
              <option value="IN_PROGRESS">In Bearbeitung</option>
              <option value="COMPLETED">Abgeschlossen</option>
              <option value="FAILED">Fehlgeschlagen</option>
            </select>
          </div>
        </div>
      </div>

      {/* Contracts Table */}
      <div className="bg-white dark:bg-gray-800 rounded-lg shadow overflow-hidden">
        <table className="min-w-full divide-y divide-gray-200 dark:divide-gray-700">
          <thead className="bg-gray-50 dark:bg-gray-700">
            <tr>
              <th scope="col" className="px-6 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-300 uppercase tracking-wider">
                Dokument
              </th>
              <th scope="col" className="px-6 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-300 uppercase tracking-wider">
                Vendor
              </th>
              <th scope="col" className="px-6 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-300 uppercase tracking-wider">
                Typ
              </th>
              <th scope="col" className="px-6 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-300 uppercase tracking-wider">
                Status
              </th>
              <th scope="col" className="px-6 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-300 uppercase tracking-wider">
                Compliance
              </th>
              <th scope="col" className="px-6 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-300 uppercase tracking-wider">
                Laufzeit
              </th>
              <th scope="col" className="relative px-6 py-3">
                <span className="sr-only">Aktionen</span>
              </th>
            </tr>
          </thead>
          <tbody className="bg-white dark:bg-gray-800 divide-y divide-gray-200 dark:divide-gray-700">
            {filteredContracts.map((contract) => (
              <tr key={contract.id} className="hover:bg-gray-50 dark:hover:bg-gray-700">
                <td className="px-6 py-4">
                  <div className="flex items-center">
                    <div className="flex-shrink-0 h-10 w-10 flex items-center justify-center bg-gray-100 dark:bg-gray-700 rounded">
                      <svg className="h-6 w-6 text-gray-400" 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>
                    </div>
                    <div className="ml-4">
                      <div className="text-sm font-medium text-gray-900 dark:text-white">
                        {contract.originalName}
                      </div>
                      <div className="text-sm text-gray-500 dark:text-gray-400">
                        v{contract.version} • {(contract.fileSize / 1024).toFixed(1)} KB
                      </div>
                    </div>
                  </div>
                </td>
                <td className="px-6 py-4 whitespace-nowrap">
                  <Link
                    href={`/sdk/vendor-compliance/vendors/${contract.vendorId}`}
                    className="text-sm text-blue-600 hover:text-blue-500 dark:text-blue-400"
                  >
                    {getVendorName(contract.vendorId)}
                  </Link>
                </td>
                <td className="px-6 py-4 whitespace-nowrap">
                  <span className="inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-medium bg-gray-100 text-gray-800 dark:bg-gray-700 dark:text-gray-200">
                    {DOCUMENT_TYPE_META[contract.documentType]?.de || contract.documentType}
                  </span>
                </td>
                <td className="px-6 py-4 whitespace-nowrap">
                  <ContractStatusBadge status={contract.status} />
                </td>
                <td className="px-6 py-4 whitespace-nowrap">
                  <ReviewStatusBadge
                    reviewStatus={contract.reviewStatus}
                    complianceScore={contract.complianceScore}
                  />
                </td>
                <td className="px-6 py-4 whitespace-nowrap text-sm text-gray-500 dark:text-gray-400">
                  {contract.effectiveDate ? (
                    <>
                      {formatDate(contract.effectiveDate)}
                      {contract.expirationDate && (
                        <> - {formatDate(contract.expirationDate)}</>
                      )}
                    </>
                  ) : (
                    '-'
                  )}
                </td>
                <td className="px-6 py-4 whitespace-nowrap text-right text-sm font-medium">
                  <div className="flex items-center justify-end gap-2">
                    <Link
                      href={`/sdk/vendor-compliance/contracts/${contract.id}`}
                      className="text-blue-600 hover:text-blue-900 dark:text-blue-400"
                    >
                      Anzeigen
                    </Link>
                    {contract.reviewStatus === 'PENDING' && (
                      <button
                        onClick={() => handleStartReview(contract.id)}
                        className="text-green-600 hover:text-green-900 dark:text-green-400"
                      >
                        Prüfen
                      </button>
                    )}
                    {contract.reviewStatus === 'COMPLETED' && (
                      <Link
                        href={`/sdk/vendor-compliance/contracts/${contract.id}/review`}
                        className="text-purple-600 hover:text-purple-900 dark:text-purple-400"
                      >
                        Ergebnis
                      </Link>
                    )}
                    <button
                      onClick={() => handleDelete(contract.id)}
                      className="text-red-600 hover:text-red-900 dark:text-red-400"
                    >
                      Löschen
                    </button>
                  </div>
                </td>
              </tr>
            ))}
          </tbody>
        </table>

        {filteredContracts.length === 0 && (
          <div className="text-center py-12">
            <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="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>
            <h3 className="mt-2 text-sm font-medium text-gray-900 dark:text-white">
              Keine Verträge gefunden
            </h3>
            <p className="mt-1 text-sm text-gray-500 dark:text-gray-400">
              Laden Sie einen Vertrag hoch, um zu beginnen.
            </p>
            <div className="mt-6">
              <Link
                href="/sdk/vendor-compliance/contracts/upload"
                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"
              >
                Vertrag hochladen
              </Link>
            </div>
          </div>
        )}
      </div>

      {/* Summary */}
      <div className="text-sm text-gray-500 dark:text-gray-400">
        {filteredContracts.length} von {contracts.length} Verträgen
      </div>
    </div>
  )
}

function ContractStatusBadge({ status }: { status: ContractStatus }) {
  const config = {
    DRAFT: { label: 'Entwurf', color: 'bg-gray-100 text-gray-800 dark:bg-gray-700 dark:text-gray-200' },
    SIGNED: { label: 'Unterschrieben', color: 'bg-blue-100 text-blue-800 dark:bg-blue-900 dark:text-blue-200' },
    ACTIVE: { label: 'Aktiv', color: 'bg-green-100 text-green-800 dark:bg-green-900 dark:text-green-200' },
    EXPIRED: { label: 'Abgelaufen', color: 'bg-orange-100 text-orange-800 dark:bg-orange-900 dark:text-orange-200' },
    TERMINATED: { label: 'Beendet', color: 'bg-red-100 text-red-800 dark:bg-red-900 dark:text-red-200' },
  }

  return (
    <span className={`inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-medium ${config[status].color}`}>
      {config[status].label}
    </span>
  )
}

function ReviewStatusBadge({
  reviewStatus,
  complianceScore,
}: {
  reviewStatus: ContractReviewStatus
  complianceScore?: number
}) {
  if (reviewStatus === 'COMPLETED' && complianceScore !== undefined) {
    const scoreColor =
      complianceScore >= 80
        ? 'text-green-600 dark:text-green-400'
        : complianceScore >= 60
        ? 'text-yellow-600 dark:text-yellow-400'
        : 'text-red-600 dark:text-red-400'

    return (
      <div className="flex items-center gap-2">
        <div className="w-16 bg-gray-200 dark:bg-gray-700 rounded-full h-2">
          <div
            className={`h-2 rounded-full ${
              complianceScore >= 80
                ? 'bg-green-500'
                : complianceScore >= 60
                ? 'bg-yellow-500'
                : 'bg-red-500'
            }`}
            style={{ width: `${complianceScore}%` }}
          />
        </div>
        <span className={`text-sm font-medium ${scoreColor}`}>{complianceScore}%</span>
      </div>
    )
  }

  const config = {
    PENDING: { label: 'Ausstehend', color: 'bg-gray-100 text-gray-800 dark:bg-gray-700 dark:text-gray-200' },
    IN_PROGRESS: { label: 'In Prüfung', color: 'bg-blue-100 text-blue-800 dark:bg-blue-900 dark:text-blue-200' },
    COMPLETED: { label: 'Geprüft', color: 'bg-green-100 text-green-800 dark:bg-green-900 dark:text-green-200' },
    FAILED: { label: 'Fehlgeschlagen', color: 'bg-red-100 text-red-800 dark:bg-red-900 dark:text-red-200' },
  }

  return (
    <span className={`inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-medium ${config[reviewStatus].color}`}>
      {config[reviewStatus].label}
    </span>
  )
}