'use client'

import { useState } from 'react'
import { useVendorCompliance } from '@/lib/sdk/vendor-compliance'
import Link from 'next/link'

// =============================================================================
// VENDOR CREATE MODAL
// =============================================================================

function VendorCreateModal({
  onClose,
  onSuccess
}: {
  onClose: () => void
  onSuccess: () => void
}) {
  const [name, setName] = useState('')
  const [serviceDescription, setServiceDescription] = useState('')
  const [category, setCategory] = useState('data_processor')
  const [country, setCountry] = useState('Germany')
  const [riskLevel, setRiskLevel] = useState('MEDIUM')
  const [dpaStatus, setDpaStatus] = useState('PENDING')
  const [contractUrl, setContractUrl] = useState('')
  const [isSaving, setIsSaving] = useState(false)
  const [error, setError] = useState<string | null>(null)

  const handleSave = async () => {
    if (!name.trim()) {
      setError('Name ist erforderlich.')
      return
    }
    setIsSaving(true)
    setError(null)
    try {
      const res = await fetch('/api/sdk/v1/vendor-compliance/vendors', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          name,
          serviceDescription,
          category,
          country,
          riskLevel,
          dpaStatus,
          contractUrl
        })
      })
      if (!res.ok) {
        const data = await res.json().catch(() => ({}))
        throw new Error(data.detail || data.message || `Fehler: ${res.status}`)
      }
      onSuccess()
    } catch (err: unknown) {
      setError(err instanceof Error ? err.message : 'Unbekannter Fehler')
    } finally {
      setIsSaving(false)
    }
  }

  return (
    <div className="fixed inset-0 z-50 flex items-center justify-center">
      {/* Backdrop */}
      <div
        className="absolute inset-0 bg-black/50"
        onClick={onClose}
      />
      {/* Modal */}
      <div className="relative bg-white rounded-xl shadow-2xl w-full max-w-lg mx-4 p-6 z-10 max-h-[90vh] overflow-y-auto">
        <div className="flex items-center justify-between mb-6">
          <h2 className="text-xl font-semibold text-gray-900">Neuen Vendor anlegen</h2>
          <button
            onClick={onClose}
            className="p-1 text-gray-400 hover:text-gray-600 rounded transition-colors"
          >
            <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>

        {error && (
          <div className="mb-4 p-3 bg-red-50 border border-red-200 rounded-lg text-sm text-red-700">
            {error}
          </div>
        )}

        <div className="space-y-4">
          {/* Name */}
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-1">
              Name <span className="text-red-500">*</span>
            </label>
            <input
              type="text"
              value={name}
              onChange={e => setName(e.target.value)}
              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-blue-500 focus:border-blue-500 text-sm"
              placeholder="Name des Vendors / Dienstleisters"
            />
          </div>

          {/* Service Description */}
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-1">Leistungsbeschreibung</label>
            <input
              type="text"
              value={serviceDescription}
              onChange={e => setServiceDescription(e.target.value)}
              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-blue-500 focus:border-blue-500 text-sm"
              placeholder="Kurze Beschreibung der erbrachten Leistung"
            />
          </div>

          {/* Category */}
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-1">Kategorie</label>
            <select
              value={category}
              onChange={e => setCategory(e.target.value)}
              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-blue-500 focus:border-blue-500 text-sm"
            >
              <option value="data_processor">Auftragsverarbeiter</option>
              <option value="cloud_provider">Cloud-Anbieter</option>
              <option value="saas">SaaS-Anbieter</option>
              <option value="analytics">Analytics</option>
              <option value="payment">Zahlungsabwicklung</option>
              <option value="other">Sonstiges</option>
            </select>
          </div>

          {/* Country */}
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-1">Land</label>
            <input
              type="text"
              value={country}
              onChange={e => setCountry(e.target.value)}
              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-blue-500 focus:border-blue-500 text-sm"
              placeholder="z.B. Germany, USA, Netherlands"
            />
          </div>

          {/* Risk Level */}
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-1">Risikostufe</label>
            <select
              value={riskLevel}
              onChange={e => setRiskLevel(e.target.value)}
              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-blue-500 focus:border-blue-500 text-sm"
            >
              <option value="LOW">Niedrig</option>
              <option value="MEDIUM">Mittel</option>
              <option value="HIGH">Hoch</option>
              <option value="CRITICAL">Kritisch</option>
            </select>
          </div>

          {/* DPA Status */}
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-1">AVV-Status</label>
            <select
              value={dpaStatus}
              onChange={e => setDpaStatus(e.target.value)}
              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-blue-500 focus:border-blue-500 text-sm"
            >
              <option value="SIGNED">Unterzeichnet</option>
              <option value="PENDING">Ausstehend</option>
              <option value="EXPIRED">Abgelaufen</option>
              <option value="NOT_REQUIRED">Nicht erforderlich</option>
            </select>
          </div>

          {/* Contract URL */}
          <div>
            <label className="block text-sm font-medium text-gray-700 mb-1">AVV-Link (URL)</label>
            <input
              type="text"
              value={contractUrl}
              onChange={e => setContractUrl(e.target.value)}
              className="w-full px-3 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-blue-500 focus:border-blue-500 text-sm"
              placeholder="https://..."
            />
          </div>
        </div>

        {/* Buttons */}
        <div className="flex items-center justify-end gap-3 mt-6 pt-4 border-t border-gray-200">
          <button
            onClick={onClose}
            className="px-4 py-2 text-sm text-gray-700 hover:bg-gray-100 rounded-lg transition-colors"
          >
            Abbrechen
          </button>
          <button
            onClick={handleSave}
            disabled={isSaving}
            className="px-4 py-2 text-sm bg-blue-600 text-white rounded-lg hover:bg-blue-700 transition-colors disabled:opacity-50 disabled:cursor-not-allowed flex items-center gap-2"
          >
            {isSaving && (
              <svg className="animate-spin w-4 h-4" fill="none" viewBox="0 0 24 24">
                <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
                <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z" />
              </svg>
            )}
            Speichern
          </button>
        </div>
      </div>
    </div>
  )
}

// =============================================================================
// MAIN PAGE
// =============================================================================

export default function VendorComplianceDashboard() {
  const {
    vendors,
    processingActivities,
    contracts,
    findings,
    vendorStats,
    complianceStats,
    riskOverview,
    isLoading,
  } = useVendorCompliance()

  const [showVendorCreate, setShowVendorCreate] = useState(false)

  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 & Contract Compliance
          </h1>
          <p className="mt-1 text-sm text-gray-500 dark:text-gray-400">
            Übersicht über Verarbeitungsverzeichnis, Vendor Register und Vertragsprüfung
          </p>
        </div>
        <button
          onClick={() => setShowVendorCreate(true)}
          className="flex items-center gap-2 px-4 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 transition-colors text-sm font-medium"
        >
          <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 6v6m0 0v6m0-6h6m-6 0H6" />
          </svg>
          Neuer Vendor
        </button>
      </div>

      {/* Quick Stats */}
      <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-4">
        <StatCard
          title="Verarbeitungstätigkeiten"
          value={processingActivities.length}
          description="im VVT"
          href="/sdk/vendor-compliance/processing-activities"
          color="blue"
        />
        <StatCard
          title="Vendors"
          value={vendorStats.total}
          description={`${vendorStats.pendingReviews} Review fällig`}
          href="/sdk/vendor-compliance/vendors"
          color="purple"
        />
        <StatCard
          title="Verträge"
          value={contracts.length}
          description={`${contracts.filter(c => c.reviewStatus === 'COMPLETED').length} geprüft`}
          href="/sdk/vendor-compliance/contracts"
          color="green"
        />
        <StatCard
          title="Offene Findings"
          value={complianceStats.openFindings}
          description={`${complianceStats.findingsBySeverity?.CRITICAL || 0} kritisch`}
          href="/sdk/vendor-compliance/risks"
          color="red"
        />
      </div>

      {/* Risk Overview */}
      <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">
        {/* Vendor Risk Distribution */}
        <div className="bg-white dark:bg-gray-800 rounded-lg shadow p-6">
          <h2 className="text-lg font-semibold text-gray-900 dark:text-white mb-4">
            Vendor Risiko-Verteilung
          </h2>
          <div className="space-y-4">
            <RiskBar
              label="Kritisch"
              count={vendorStats.byRiskLevel?.CRITICAL || 0}
              total={vendorStats.total}
              color="bg-red-500"
            />
            <RiskBar
              label="Hoch"
              count={vendorStats.byRiskLevel?.HIGH || 0}
              total={vendorStats.total}
              color="bg-orange-500"
            />
            <RiskBar
              label="Mittel"
              count={vendorStats.byRiskLevel?.MEDIUM || 0}
              total={vendorStats.total}
              color="bg-yellow-500"
            />
            <RiskBar
              label="Niedrig"
              count={vendorStats.byRiskLevel?.LOW || 0}
              total={vendorStats.total}
              color="bg-green-500"
            />
          </div>
          <div className="mt-4 pt-4 border-t border-gray-200 dark:border-gray-700">
            <div className="flex justify-between text-sm">
              <span className="text-gray-500 dark:text-gray-400">
                Durchschn. Inherent Risk
              </span>
              <span className="font-medium text-gray-900 dark:text-white">
                {Math.round(riskOverview.averageInherentRisk)}%
              </span>
            </div>
            <div className="flex justify-between text-sm mt-1">
              <span className="text-gray-500 dark:text-gray-400">
                Durchschn. Residual Risk
              </span>
              <span className="font-medium text-gray-900 dark:text-white">
                {Math.round(riskOverview.averageResidualRisk)}%
              </span>
            </div>
          </div>
        </div>

        {/* Compliance Score */}
        <div className="bg-white dark:bg-gray-800 rounded-lg shadow p-6">
          <h2 className="text-lg font-semibold text-gray-900 dark:text-white mb-4">
            Compliance Status
          </h2>
          <div className="flex items-center justify-center mb-6">
            <div className="relative w-32 h-32">
              <svg className="w-full h-full transform -rotate-90" viewBox="0 0 36 36">
                <path
                  d="M18 2.0845
                    a 15.9155 15.9155 0 0 1 0 31.831
                    a 15.9155 15.9155 0 0 1 0 -31.831"
                  fill="none"
                  stroke="#E5E7EB"
                  strokeWidth="3"
                />
                <path
                  d="M18 2.0845
                    a 15.9155 15.9155 0 0 1 0 31.831
                    a 15.9155 15.9155 0 0 1 0 -31.831"
                  fill="none"
                  stroke="#3B82F6"
                  strokeWidth="3"
                  strokeDasharray={`${complianceStats.averageComplianceScore}, 100`}
                />
              </svg>
              <div className="absolute inset-0 flex items-center justify-center">
                <span className="text-2xl font-bold text-gray-900 dark:text-white">
                  {Math.round(complianceStats.averageComplianceScore)}%
                </span>
              </div>
            </div>
          </div>
          <div className="grid grid-cols-2 gap-4">
            <div className="text-center">
              <div className="text-2xl font-bold text-green-600">
                {complianceStats.resolvedFindings}
              </div>
              <div className="text-sm text-gray-500 dark:text-gray-400">
                Behoben
              </div>
            </div>
            <div className="text-center">
              <div className="text-2xl font-bold text-red-600">
                {complianceStats.openFindings}
              </div>
              <div className="text-sm text-gray-500 dark:text-gray-400">
                Offen
              </div>
            </div>
          </div>
          <div className="mt-4 pt-4 border-t border-gray-200 dark:border-gray-700">
            <div className="flex justify-between text-sm">
              <span className="text-gray-500 dark:text-gray-400">
                Control Pass Rate
              </span>
              <span className="font-medium text-gray-900 dark:text-white">
                {Math.round(complianceStats.controlPassRate)}%
              </span>
            </div>
          </div>
        </div>
      </div>

      {/* Quick Actions */}
      <div className="grid grid-cols-1 md:grid-cols-3 gap-4">
        <QuickActionCard
          title="Neue Verarbeitung"
          description="Verarbeitungstätigkeit anlegen"
          href="/sdk/vendor-compliance/processing-activities"
          icon={
            <svg className="w-6 h-6" 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>
          }
        />
        <QuickActionCard
          title="Neuer Vendor"
          description="Auftragsverarbeiter anlegen"
          onClick={() => setShowVendorCreate(true)}
          icon={
            <svg className="w-6 h-6" 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>
          }
        />
        <QuickActionCard
          title="Vertrag hochladen"
          description="AVV zur Prüfung hochladen"
          href="/sdk/vendor-compliance/contracts/upload"
          icon={
            <svg className="w-6 h-6" 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>
          }
        />
      </div>

      {/* Recent Activity */}
      <div className="bg-white dark:bg-gray-800 rounded-lg shadow">
        <div className="px-6 py-4 border-b border-gray-200 dark:border-gray-700">
          <h2 className="text-lg font-semibold text-gray-900 dark:text-white">
            Fällige Reviews
          </h2>
        </div>
        <div className="divide-y divide-gray-200 dark:divide-gray-700">
          {vendors
            .filter((v) => v.nextReviewDate && new Date(v.nextReviewDate) <= new Date())
            .slice(0, 5)
            .map((vendor) => (
              <Link
                key={vendor.id}
                href={`/sdk/vendor-compliance/vendors/${vendor.id}`}
                className="block px-6 py-4 hover:bg-gray-50 dark:hover:bg-gray-700 transition-colors"
              >
                <div className="flex items-center justify-between">
                  <div>
                    <p className="text-sm font-medium text-gray-900 dark:text-white">
                      {vendor.name}
                    </p>
                    <p className="text-sm text-gray-500 dark:text-gray-400">
                      {vendor.serviceDescription}
                    </p>
                  </div>
                  <span className="inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-medium bg-red-100 text-red-800 dark:bg-red-900 dark:text-red-200">
                    Review fällig
                  </span>
                </div>
              </Link>
            ))}
          {vendors.filter((v) => v.nextReviewDate && new Date(v.nextReviewDate) <= new Date()).length === 0 && (
            <div className="px-6 py-8 text-center text-gray-500 dark:text-gray-400">
              Keine fälligen Reviews
            </div>
          )}
        </div>
      </div>

      {/* Vendor Create Modal */}
      {showVendorCreate && (
        <VendorCreateModal
          onClose={() => setShowVendorCreate(false)}
          onSuccess={() => { setShowVendorCreate(false); window.location.reload() }}
        />
      )}
    </div>
  )
}

function StatCard({
  title,
  value,
  description,
  href,
  color,
}: {
  title: string
  value: number
  description: string
  href: string
  color: 'blue' | 'purple' | 'green' | 'red'
}) {
  const colors = {
    blue: 'bg-blue-50 dark:bg-blue-900/20',
    purple: 'bg-purple-50 dark:bg-purple-900/20',
    green: 'bg-green-50 dark:bg-green-900/20',
    red: 'bg-red-50 dark:bg-red-900/20',
  }

  return (
    <Link
      href={href}
      className={`${colors[color]} rounded-lg p-6 hover:opacity-80 transition-opacity`}
    >
      <p className="text-sm font-medium text-gray-600 dark:text-gray-400">{title}</p>
      <p className="mt-2 text-3xl font-bold text-gray-900 dark:text-white">{value}</p>
      <p className="mt-1 text-sm text-gray-500 dark:text-gray-400">{description}</p>
    </Link>
  )
}

function RiskBar({
  label,
  count,
  total,
  color,
}: {
  label: string
  count: number
  total: number
  color: string
}) {
  const percentage = total > 0 ? (count / total) * 100 : 0

  return (
    <div>
      <div className="flex justify-between text-sm mb-1">
        <span className="text-gray-600 dark:text-gray-400">{label}</span>
        <span className="font-medium text-gray-900 dark:text-white">{count}</span>
      </div>
      <div className="w-full bg-gray-200 dark:bg-gray-700 rounded-full h-2">
        <div
          className={`${color} h-2 rounded-full transition-all`}
          style={{ width: `${percentage}%` }}
        />
      </div>
    </div>
  )
}

function QuickActionCard({
  title,
  description,
  href,
  onClick,
  icon,
}: {
  title: string
  description: string
  href?: string
  onClick?: () => void
  icon: React.ReactNode
}) {
  const inner = (
    <>
      <div className="flex-shrink-0 p-3 bg-blue-50 dark:bg-blue-900/20 rounded-lg text-blue-600 dark:text-blue-400">
        {icon}
      </div>
      <div>
        <h3 className="font-medium text-gray-900 dark:text-white">{title}</h3>
        <p className="text-sm text-gray-500 dark:text-gray-400">{description}</p>
      </div>
    </>
  )

  if (onClick) {
    return (
      <button
        onClick={onClick}
        className="bg-white dark:bg-gray-800 rounded-lg shadow p-6 hover:shadow-md transition-shadow flex items-start gap-4 w-full text-left"
      >
        {inner}
      </button>
    )
  }

  return (
    <Link
      href={href!}
      className="bg-white dark:bg-gray-800 rounded-lg shadow p-6 hover:shadow-md transition-shadow flex items-start gap-4"
    >
      {inner}
    </Link>
  )
}