'use client'

import { useState, useEffect } from 'react'
import Link from 'next/link'

/**
 * CMP Dashboard — Consent Management Platform overview.
 *
 * Aggregates data from: Banner API, Einwilligungen, DSR, Vendors.
 * State-of-the-art layout inspired by OneTrust/Cookiebot dashboards
 * but with EWR-Only as unique differentiator.
 */

const API_BASE = typeof window !== 'undefined'
  ? (process.env.NEXT_PUBLIC_SDK_URL || `${window.location.protocol}//${window.location.hostname}:8093`)
  : ''
const TENANT_ID = '9282a473-5c95-4b3a-bf78-0ecc0ec71d3e'
const HEADERS = { 'X-Tenant-ID': TENANT_ID }

interface BannerStats { total_consents: number; category_acceptance: Record<string, { count: number; rate: number }> }
interface ConsentStats { total_consents: number; active_consents: number; revoked_consents: number; unique_users: number; conversion_rate: number }
interface DSRStats { total: number; by_status: Record<string, number>; by_type: Record<string, number>; overdue: number; due_this_week: number; average_processing_days: number; completed_this_month: number }

const MODULES = [
  { href: '/sdk/cookie-banner', label: 'Cookie-Banner', desc: 'Banner konfigurieren und Code exportieren', icon: 'shield', color: 'purple' },
  { href: '/sdk/cookie-banner/preview', label: 'Live-Vorschau', desc: 'Banner auf simulierter Website testen', icon: 'eye', color: 'blue' },
  { href: '/sdk/einwilligungen', label: 'Consent-Records', desc: 'Einwilligungen einsehen und verwalten', icon: 'clipboard', color: 'green' },
  { href: '/sdk/consent-management', label: 'Consent-Verwaltung', desc: 'Dokument-Lifecycle und DSGVO-Prozesse', icon: 'folder', color: 'indigo' },
  { href: '/sdk/vendor-compliance', label: 'Vendor-Compliance', desc: 'Dienstleister und Auftragsverarbeitung', icon: 'users', color: 'amber' },
  { href: '/sdk/dsr', label: 'DSR Portal', desc: 'Betroffenenrechte Art. 15-21 DSGVO', icon: 'user', color: 'rose' },
  { href: '/sdk/loeschfristen', label: 'Loeschfristen', desc: 'Aufbewahrungsrichtlinien verwalten', icon: 'clock', color: 'teal' },
  { href: '/sdk/email-templates', label: 'E-Mail-Templates', desc: 'Benachrichtigungsvorlagen', icon: 'mail', color: 'slate' },
]

const ICON_MAP: Record<string, JSX.Element> = {
  shield: <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" />,
  eye: <><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M15 12a3 3 0 11-6 0 3 3 0 016 0z" /><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M2.458 12C3.732 7.943 7.523 5 12 5c4.478 0 8.268 2.943 9.542 7-1.274 4.057-5.064 7-9.542 7-4.477 0-8.268-2.943-9.542-7z" /></>,
  clipboard: <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4" />,
  folder: <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M3 7v10a2 2 0 002 2h14a2 2 0 002-2V9a2 2 0 00-2-2h-6l-2-2H5a2 2 0 00-2 2z" />,
  users: <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M17 20h5v-2a3 3 0 00-5.356-1.857M17 20H7m10 0v-2c0-.656-.126-1.283-.356-1.857M7 20H2v-2a3 3 0 015.356-1.857M7 20v-2c0-.656.126-1.283.356-1.857m0 0a5.002 5.002 0 019.288 0M15 7a3 3 0 11-6 0 3 3 0 016 0z" />,
  user: <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M16 7a4 4 0 11-8 0 4 4 0 018 0zM12 14a7 7 0 00-7 7h14a7 7 0 00-7-7z" />,
  clock: <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 8v4l3 3m6-3a9 9 0 11-18 0 9 9 0 0118 0z" />,
  mail: <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M3 8l7.89 5.26a2 2 0 002.22 0L21 8M5 19h14a2 2 0 002-2V7a2 2 0 00-2-2H5a2 2 0 00-2 2v10a2 2 0 002 2z" />,
}

const COLOR_MAP: Record<string, string> = {
  purple: 'bg-purple-100 text-purple-600', blue: 'bg-blue-100 text-blue-600',
  green: 'bg-green-100 text-green-600', indigo: 'bg-indigo-100 text-indigo-600',
  amber: 'bg-amber-100 text-amber-600', rose: 'bg-rose-100 text-rose-600',
  teal: 'bg-teal-100 text-teal-600', slate: 'bg-slate-100 text-slate-600',
}

export default function CMPDashboardPage() {
  const [bannerStats, setBannerStats] = useState<BannerStats | null>(null)
  const [consentStats, setConsentStats] = useState<ConsentStats | null>(null)
  const [dsrStats, setDSRStats] = useState<DSRStats | null>(null)
  const [sites, setSites] = useState<any[]>([])
  const [loading, setLoading] = useState(true)

  useEffect(() => {
    async function load() {
      const f = (url: string) => fetch(`${API_BASE}${url}`, { headers: HEADERS }).then(r => r.ok ? r.json() : null).catch(() => null)
      const [banner, consent, dsr, siteList] = await Promise.all([
        f('/banner/admin/stats/preview-test-site'),
        f('/einwilligungen/consents/stats'),
        f('/dsr/stats'),
        f('/banner/admin/sites'),
      ])
      setBannerStats(banner)
      setConsentStats(consent)
      setDSRStats(dsr)
      setSites(siteList || [])
      setLoading(false)
    }
    load()
  }, [])

  const totalConsents = (bannerStats?.total_consents || 0) + (consentStats?.total_consents || 0)
  const dsrOpen = dsrStats ? (dsrStats.by_status?.intake || 0) + (dsrStats.by_status?.processing || 0) + (dsrStats.by_status?.identity_verification || 0) : 0
  const dsrOverdue = dsrStats?.overdue || 0
  const catAcceptance = bannerStats?.category_acceptance || {}

  return (
    <div className="space-y-6">
      {/* Header */}
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-2xl font-bold text-gray-900">Consent Management Platform</h1>
          <p className="text-gray-500 mt-1">Ueberblick ueber Einwilligungen, Betroffenenrechte und Vendor-Compliance</p>
        </div>
        <Link href="/sdk/cookie-banner/preview"
          className="px-4 py-2 bg-purple-600 text-white rounded-lg text-sm font-medium hover:bg-purple-700 transition-colors">
          Banner testen
        </Link>
      </div>

      {/* KPI Cards */}
      <div className="grid grid-cols-2 md:grid-cols-4 gap-4">
        <KPICard label="Consents gesamt" value={loading ? '...' : totalConsents} icon="shield" trend={null} />
        <KPICard label="Aktive Einwilligungen" value={loading ? '...' : consentStats?.active_consents ?? 0} icon="check" trend={consentStats?.conversion_rate ? `${consentStats.conversion_rate.toFixed(0)}% Rate` : null} />
        <KPICard label="Offene DSR-Anfragen" value={loading ? '...' : dsrOpen} icon="user" trend={dsrOverdue > 0 ? `${dsrOverdue} ueberfaellig` : null} trendColor={dsrOverdue > 0 ? 'red' : 'green'} />
        <KPICard label="Konfigurierte Sites" value={loading ? '...' : sites.length} icon="globe" trend={null} />
      </div>

      {/* Category Acceptance + DSR Breakdown */}
      <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">
        {/* Cookie Category Acceptance */}
        <div className="bg-white rounded-xl border border-gray-200 p-6">
          <h3 className="font-semibold text-gray-900 mb-4">Cookie-Kategorie Akzeptanz</h3>
          {Object.keys(catAcceptance).length > 0 ? (
            <div className="space-y-3">
              {Object.entries(catAcceptance).map(([cat, data]) => (
                <div key={cat} className="flex items-center gap-4">
                  <span className="text-sm text-gray-600 w-24 capitalize">{cat}</span>
                  <div className="flex-1 h-6 bg-gray-100 rounded-full overflow-hidden">
                    <div
                      className={`h-full rounded-full transition-all ${
                        cat === 'necessary' ? 'bg-gray-400' : cat === 'marketing' ? 'bg-rose-500' : cat === 'statistics' ? 'bg-blue-500' : 'bg-green-500'
                      }`}
                      style={{ width: `${data.rate}%` }}
                    />
                  </div>
                  <span className="text-sm font-medium text-gray-700 w-16 text-right">{data.rate}%</span>
                  <span className="text-xs text-gray-400 w-12 text-right">{data.count}x</span>
                </div>
              ))}
            </div>
          ) : (
            <div className="text-center py-8 text-gray-400">
              <p className="text-sm">Noch keine Consent-Daten vorhanden</p>
              <Link href="/sdk/cookie-banner/preview" className="text-purple-600 text-sm underline mt-2 inline-block">
                Jetzt Banner testen
              </Link>
            </div>
          )}
        </div>

        {/* DSR Breakdown */}
        <div className="bg-white rounded-xl border border-gray-200 p-6">
          <div className="flex items-center justify-between mb-4">
            <h3 className="font-semibold text-gray-900">Betroffenenrechte (DSR)</h3>
            <Link href="/sdk/dsr" className="text-xs text-purple-600 hover:underline">Alle anzeigen</Link>
          </div>
          {dsrStats && dsrStats.total > 0 ? (
            <div className="space-y-4">
              <div className="grid grid-cols-3 gap-3">
                <MiniStat label="Gesamt" value={dsrStats.total} />
                <MiniStat label="Abgeschlossen" value={dsrStats.by_status?.completed || 0} color="green" />
                <MiniStat label="Ueberfaellig" value={dsrOverdue} color={dsrOverdue > 0 ? 'red' : 'gray'} />
              </div>
              <div className="border-t border-gray-100 pt-3">
                <div className="text-xs text-gray-500 mb-2">Nach Typ</div>
                <div className="grid grid-cols-2 gap-2">
                  {Object.entries(dsrStats.by_type || {}).filter(([, v]) => v > 0).map(([type, count]) => (
                    <div key={type} className="flex items-center justify-between text-sm">
                      <span className="text-gray-600">{DSR_TYPE_LABELS[type] || type}</span>
                      <span className="font-medium text-gray-800">{count}</span>
                    </div>
                  ))}
                </div>
              </div>
              {dsrStats.average_processing_days > 0 && (
                <div className="border-t border-gray-100 pt-3 flex items-center justify-between text-sm">
                  <span className="text-gray-500">Durchschnittl. Bearbeitungszeit</span>
                  <span className="font-medium text-gray-800">{dsrStats.average_processing_days.toFixed(1)} Tage</span>
                </div>
              )}
            </div>
          ) : (
            <div className="text-center py-8 text-gray-400 text-sm">
              Keine DSR-Anfragen vorhanden
            </div>
          )}
        </div>
      </div>

      {/* Compliance Status */}
      <div className="bg-white rounded-xl border border-gray-200 p-6">
        <h3 className="font-semibold text-gray-900 mb-1">Compliance-Status</h3>
        <p className="text-xs text-gray-500 mb-4">Pruefung der wichtigsten DSGVO-Anforderungen</p>
        <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-3">
          <ComplianceCheck label="Cookie-Banner konfiguriert" ok={sites.length > 0} href="/sdk/cookie-banner" />
          <ComplianceCheck label="Datenschutzerklaerung erstellt" ok={false} href="/sdk/einwilligungen/privacy-policy" />
          <ComplianceCheck label="Impressum verlinkt" ok={false} href="/sdk/document-generator" />
          <ComplianceCheck label="Consent-Nachweis (Art. 7)" ok={totalConsents > 0} href="/sdk/einwilligungen" />
          <ComplianceCheck label="DSR-Prozess eingerichtet" ok={dsrStats?.total !== undefined} href="/sdk/dsr" />
          <ComplianceCheck label="Loeschfristen definiert" ok={false} href="/sdk/loeschfristen" />
          <ComplianceCheck label="Vendor-AVV vorhanden" ok={false} href="/sdk/vendor-compliance" />
          <ComplianceCheck label="E-Mail-Templates aktiv" ok={false} href="/sdk/email-templates" />
          <ComplianceCheck label="EWR-Only Modus verfuegbar" ok={true} href="/sdk/cookie-banner" />
        </div>
      </div>

      {/* Module Grid */}
      <div>
        <h3 className="font-semibold text-gray-900 mb-3">CMP Module</h3>
        <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-3">
          {MODULES.map(m => (
            <Link key={m.href} href={m.href}
              className="group bg-white border border-gray-200 rounded-xl p-4 hover:border-purple-300 hover:shadow-md transition-all">
              <div className={`w-10 h-10 rounded-lg ${COLOR_MAP[m.color]} flex items-center justify-center mb-3`}>
                <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                  {ICON_MAP[m.icon]}
                </svg>
              </div>
              <div className="font-medium text-gray-900 group-hover:text-purple-700 text-sm">{m.label}</div>
              <div className="text-xs text-gray-500 mt-0.5">{m.desc}</div>
            </Link>
          ))}
        </div>
      </div>
    </div>
  )
}

const DSR_TYPE_LABELS: Record<string, string> = {
  access: 'Auskunft (Art. 15)', rectification: 'Berichtigung (Art. 16)',
  erasure: 'Loeschung (Art. 17)', restriction: 'Einschraenkung (Art. 18)',
  portability: 'Portabilitaet (Art. 20)', objection: 'Widerspruch (Art. 21)',
}

function KPICard({ label, value, icon, trend, trendColor }: {
  label: string; value: number | string; icon: string; trend: string | null; trendColor?: string
}) {
  return (
    <div className="bg-white rounded-xl border border-gray-200 p-4">
      <div className="text-xs text-gray-500">{label}</div>
      <div className="text-2xl font-bold text-gray-900 mt-1">{value}</div>
      {trend && (
        <div className={`text-xs mt-1 ${trendColor === 'red' ? 'text-red-600' : trendColor === 'green' ? 'text-green-600' : 'text-gray-500'}`}>
          {trend}
        </div>
      )}
    </div>
  )
}

function MiniStat({ label, value, color }: { label: string; value: number; color?: string }) {
  const c = color === 'red' ? 'text-red-600' : color === 'green' ? 'text-green-600' : 'text-gray-900'
  return (
    <div className="text-center">
      <div className={`text-xl font-bold ${c}`}>{value}</div>
      <div className="text-xs text-gray-500">{label}</div>
    </div>
  )
}

function ComplianceCheck({ label, ok, href }: { label: string; ok: boolean; href: string }) {
  return (
    <Link href={href} className="flex items-center gap-3 p-3 rounded-lg border border-gray-100 hover:border-purple-200 hover:bg-purple-50/30 transition-all">
      {ok ? (
        <svg className="w-5 h-5 text-green-500 shrink-0" fill="none" stroke="currentColor" viewBox="0 0 24 24">
          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 12l2 2 4-4m6 2a9 9 0 11-18 0 9 9 0 0118 0z" />
        </svg>
      ) : (
        <svg className="w-5 h-5 text-amber-400 shrink-0" fill="none" stroke="currentColor" viewBox="0 0 24 24">
          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 8v4m0 4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z" />
        </svg>
      )}
      <span className="text-sm text-gray-700">{label}</span>
    </Link>
  )
}