'use client'

import { useState, useEffect, useCallback, useMemo } from 'react'
import {
  CATEGORY_VENDORS, countNonEWRVendors, isEWR, isOutsideEWR,
  type VendorInfo,
} from './cookie-banner-vendors'

/**
 * CookieBannerOverlay — DSGVO/CNIL-konformer Cookie-Banner mit "Nur EU/EWR" Toggle.
 *
 * Alle 4 Kategorien sind auf der ersten Ebene sichtbar (DSK OH Telemedien 2022).
 * Vendor-Details aufklappbar per Kategorie. EWR-Toggle blockiert Non-EU-Anbieter
 * auch bei aktivierter Kategorie — einzigartiges CMP-Feature.
 */

const STORAGE_KEY = 'bp-sdk-cookie-consent'

interface ConsentState {
  necessary: boolean
  statistics: boolean
  marketing: boolean
  functional: boolean
  ewrOnly: boolean
  blockedVendors: string[]
  timestamp: string
}

function getStoredConsent(): ConsentState | null {
  if (typeof window === 'undefined') return null
  try {
    const raw = localStorage.getItem(STORAGE_KEY)
    if (!raw) return null
    return JSON.parse(raw)
  } catch {
    return null
  }
}

export function CookieBannerOverlay() {
  const [isOpen, setIsOpen] = useState(false)
  const [consent, setConsent] = useState<ConsentState>({
    necessary: true, statistics: false, marketing: false, functional: false,
    ewrOnly: false, blockedVendors: [], timestamp: '',
  })

  const nonEWRCount = useMemo(() => countNonEWRVendors(), [])

  const blockedVendors = useMemo(() => {
    if (!consent.ewrOnly) return []
    const blocked: string[] = []
    for (const [key, cat] of Object.entries(CATEGORY_VENDORS)) {
      const catEnabled = key === 'necessary' || consent[key as keyof ConsentState]
      if (!catEnabled) continue
      for (const v of cat.vendors) {
        if (isOutsideEWR(v.country)) blocked.push(v.name)
      }
    }
    return blocked
  }, [consent])

  useEffect(() => {
    const stored = getStoredConsent()
    if (!stored) setIsOpen(true)
    else setConsent(stored)
  }, [])

  useEffect(() => {
    const handler = () => setIsOpen(true)
    window.addEventListener('openCookieBanner', handler)
    return () => window.removeEventListener('openCookieBanner', handler)
  }, [])

  const saveConsent = useCallback((state: ConsentState) => {
    const blocked: string[] = []
    if (state.ewrOnly) {
      for (const [key, cat] of Object.entries(CATEGORY_VENDORS)) {
        const catEnabled = key === 'necessary' || state[key as keyof ConsentState]
        if (!catEnabled) continue
        for (const v of cat.vendors) {
          if (isOutsideEWR(v.country)) blocked.push(v.name)
        }
      }
    }
    const withMeta = { ...state, blockedVendors: blocked, timestamp: new Date().toISOString() }
    localStorage.setItem(STORAGE_KEY, JSON.stringify(withMeta))
    setConsent(withMeta)
    setIsOpen(false)
    window.dispatchEvent(new CustomEvent('sdkCookieConsentUpdated', { detail: withMeta }))
  }, [])

  if (!isOpen) return null

  return (
    <>
      <div className="fixed inset-0 bg-black/40 z-[9998]" />

      <div className="fixed bottom-0 left-0 right-0 z-[9999]">
        <div className="max-w-3xl mx-auto m-4 bg-white rounded-2xl shadow-2xl border border-gray-200 overflow-hidden">

          {/* Header with EWR toggle */}
          <div className="px-6 pt-5 pb-3">
            <div className="flex items-start justify-between gap-4">
              <div className="flex-1">
                <h2 className="text-lg font-semibold text-gray-900">Cookie-Einstellungen</h2>
                <p className="text-sm text-gray-600 mt-1">
                  Waehlen Sie, welche Cookie-Kategorien Sie zulassen moechten.
                </p>
              </div>
              <EWRToggle
                checked={consent.ewrOnly}
                onChange={() => setConsent(prev => ({ ...prev, ewrOnly: !prev.ewrOnly }))}
                blockedCount={blockedVendors.length}
                nonEWRCount={nonEWRCount}
              />
            </div>
          </div>

          {/* Categories — always visible (CNIL/DSK compliant) */}
          <div className="px-6 pb-3 space-y-1.5 max-h-[45vh] overflow-y-auto border-t border-gray-100 pt-3">
            {Object.entries(CATEGORY_VENDORS).map(([key, cat]) => (
              <CategorySection
                key={key}
                label={cat.label}
                description={cat.description}
                vendors={cat.vendors}
                checked={key === 'necessary' ? true : consent[key as keyof ConsentState] as boolean}
                disabled={key === 'necessary'}
                ewrOnly={consent.ewrOnly}
                onChange={(v) => key !== 'necessary' && setConsent(prev => ({ ...prev, [key]: v }))}
              />
            ))}
          </div>

          {/* Buttons — two equal-weight options */}
          <div className="px-6 py-4 bg-gray-50 border-t border-gray-100">
            <div className="flex items-center gap-3">
              <button
                onClick={() => saveConsent({ ...consent, necessary: true, statistics: true, marketing: true, functional: true })}
                className="flex-1 px-4 py-2.5 bg-purple-600 text-white rounded-lg font-medium hover:bg-purple-700 transition-colors text-sm"
              >
                Alle akzeptieren
              </button>
              <button
                onClick={() => saveConsent(consent)}
                className="flex-1 px-4 py-2.5 bg-gray-200 text-gray-700 rounded-lg font-medium hover:bg-gray-300 transition-colors text-sm"
              >
                Auswahl speichern
              </button>
            </div>
            <div className="flex items-center justify-between mt-3">
              <button
                onClick={() => saveConsent({ ...consent, necessary: true, statistics: false, marketing: false, functional: false })}
                className="text-xs text-gray-500 hover:text-gray-700 underline"
              >
                Nur notwendige Cookies
              </button>
              <div className="flex items-center gap-3 text-xs text-gray-400">
                <a href="/sdk/einwilligungen/cookie-banner" className="hover:text-purple-600 underline">
                  Datenschutzerklaerung
                </a>
                <a href="/sdk/einwilligungen" className="hover:text-purple-600 underline">
                  Impressum
                </a>
              </div>
            </div>
          </div>

        </div>
      </div>
    </>
  )
}


export function CookieBannerFAB() {
  const [hasConsent, setHasConsent] = useState(false)

  useEffect(() => {
    setHasConsent(!!getStoredConsent())
    const handler = () => setHasConsent(true)
    window.addEventListener('sdkCookieConsentUpdated', handler)
    return () => window.removeEventListener('sdkCookieConsentUpdated', handler)
  }, [])

  if (!hasConsent) return null

  return (
    <button
      onClick={() => window.dispatchEvent(new Event('openCookieBanner'))}
      className="fixed bottom-6 right-[10rem] w-14 h-14 bg-gray-700 hover:bg-gray-800 text-white rounded-full shadow-lg flex items-center justify-center transition-all duration-200 hover:scale-110 z-50"
      aria-label="Cookie-Einstellungen oeffnen"
      title="Cookie-Einstellungen"
    >
      <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
        <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>
    </button>
  )
}


// ─── EWR Toggle with Info Button ──────────────────────────

function EWRToggle({ checked, onChange, blockedCount, nonEWRCount }: {
  checked: boolean; onChange: () => void; blockedCount: number; nonEWRCount: number
}) {
  const [showInfo, setShowInfo] = useState(false)

  return (
    <div className="relative flex flex-col items-end gap-1 shrink-0">
      <div className="flex items-center gap-2">
        <button
          onClick={() => setShowInfo(!showInfo)}
          className="w-5 h-5 rounded-full bg-blue-100 text-blue-600 hover:bg-blue-200 flex items-center justify-center text-xs font-bold"
          aria-label="Info zu Nur EU/EWR"
        >
          i
        </button>
        <span className={`text-xs font-medium whitespace-nowrap ${checked ? 'text-blue-700' : 'text-gray-500'}`}>
          Nur EU/EWR
        </span>
        <button
          onClick={onChange}
          className={`relative inline-flex h-6 w-11 items-center rounded-full transition-colors shrink-0 cursor-pointer ${
            checked ? 'bg-blue-600' : 'bg-gray-200'
          }`}
        >
          <span className={`inline-block h-4 w-4 transform rounded-full bg-white shadow-sm transition-transform ${
            checked ? 'translate-x-6' : 'translate-x-1'
          }`} />
        </button>
      </div>
      {checked && blockedCount > 0 && (
        <span className="text-[10px] text-red-600 font-medium">{blockedCount} blockiert</span>
      )}
      {showInfo && (
        <div className="absolute right-0 top-12 w-72 p-3 bg-blue-50 border border-blue-200 rounded-lg shadow-lg z-10 text-xs text-blue-800 leading-relaxed">
          <div className="font-semibold mb-1">Nur EU/EWR-Anbieter</div>
          <p>
            Erlaubt nur Anbieter mit Sitz im EWR (EU + Island, Liechtenstein, Norwegen) oder
            der Schweiz. {nonEWRCount} Anbieter ausserhalb werden blockiert — auch bei
            aktivierter Cookie-Kategorie.
          </p>
          <button onClick={() => setShowInfo(false)} className="mt-2 text-blue-600 hover:text-blue-800 font-medium">
            Verstanden
          </button>
        </div>
      )}
    </div>
  )
}


// ─── Category Section with Vendor Table ───────────────────

function CategorySection({ label, description, vendors, checked, disabled, ewrOnly, onChange }: {
  label: string; description: string; vendors: VendorInfo[]; checked: boolean
  disabled?: boolean; ewrOnly: boolean; onChange: (v: boolean) => void
}) {
  const [expanded, setExpanded] = useState(false)
  const nonEuVendors = vendors.filter(v => isOutsideEWR(v.country))
  const blockedCount = ewrOnly && checked ? nonEuVendors.length : 0
  const activeCount = checked ? vendors.length - blockedCount : 0

  return (
    <div className="border border-gray-100 rounded-lg overflow-hidden">
      <div className="flex items-center justify-between gap-3 px-4 py-2.5 bg-gray-50/50">
        <button onClick={() => setExpanded(!expanded)} className="flex items-center gap-2 flex-1 text-left">
          <svg className={`w-3.5 h-3.5 text-gray-400 transition-transform ${expanded ? 'rotate-90' : ''}`}
            fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 5l7 7-7 7" />
          </svg>
          <div>
            <div className="text-sm font-medium text-gray-900">
              {label}
              <span className="ml-2 text-xs font-normal text-gray-400">
                {checked && blockedCount > 0
                  ? `${activeCount} aktiv, ${blockedCount} blockiert`
                  : `${vendors.length} Verarbeiter`}
              </span>
            </div>
            <div className="text-xs text-gray-500">{description}</div>
          </div>
        </button>
        <button
          onClick={() => !disabled && onChange(!checked)}
          disabled={disabled}
          className={`relative inline-flex h-6 w-11 items-center rounded-full transition-colors shrink-0 ${
            checked ? (disabled ? 'bg-gray-400' : 'bg-purple-600') : 'bg-gray-200'
          } ${disabled ? 'cursor-not-allowed opacity-60' : 'cursor-pointer'}`}
        >
          <span className={`inline-block h-4 w-4 transform rounded-full bg-white shadow-sm transition-transform ${
            checked ? 'translate-x-6' : 'translate-x-1'
          }`} />
        </button>
      </div>

      {expanded && (
        <div className="px-4 pb-2.5">
          <table className="w-full text-xs">
            <thead>
              <tr className="text-gray-400 border-b border-gray-100">
                <th className="text-left py-1 font-medium w-5"></th>
                <th className="text-left py-1 font-medium">Verarbeiter</th>
                <th className="text-left py-1 font-medium">Cookies</th>
                <th className="text-left py-1 font-medium">Dauer</th>
                <th className="text-left py-1 font-medium">Land</th>
              </tr>
            </thead>
            <tbody>
              {vendors.map((v, i) => {
                const blocked = ewrOnly && checked && isOutsideEWR(v.country)
                const active = checked && !blocked
                return (
                  <tr key={i} className={`border-b border-gray-50 last:border-0 ${blocked ? 'opacity-40' : ''}`}>
                    <td className="py-1 w-5">
                      {blocked ? (
                        <svg className="w-3.5 h-3.5 text-red-500" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M18.364 18.364A9 9 0 005.636 5.636m12.728 12.728A9 9 0 015.636 5.636m12.728 12.728L5.636 5.636" />
                        </svg>
                      ) : active ? (
                        <svg className="w-3.5 h-3.5 text-green-500" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M5 13l4 4L19 7" />
                        </svg>
                      ) : (
                        <svg className="w-3.5 h-3.5 text-gray-300" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M20 12H4" />
                        </svg>
                      )}
                    </td>
                    <td className={`py-1 font-medium ${blocked ? 'line-through text-gray-400' : 'text-gray-700'}`}>{v.name}</td>
                    <td className={`py-1 font-mono ${blocked ? 'line-through text-gray-300' : 'text-gray-500'}`}>{v.cookies}</td>
                    <td className="py-1 text-gray-500">{v.retention}</td>
                    <td className="py-1">
                      {isOutsideEWR(v.country) ? (
                        <span className={`inline-flex items-center gap-1 ${blocked ? 'text-red-400' : 'text-amber-600'}`}>
                          <svg className="w-3 h-3" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-2.5L13.732 4c-.77-.833-1.964-.833-2.732 0L4.082 16.5c-.77.833.192 2.5 1.732 2.5z" />
                          </svg>
                          {v.country}
                        </span>
                      ) : (
                        <span className="text-green-600 flex items-center gap-1">
                          <svg className="w-3 h-3" viewBox="0 0 24 24" fill="none" stroke="currentColor">
                            <circle cx="12" cy="12" r="10" strokeWidth={2} />
                            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 12l2 2 4-4" />
                          </svg>
                          {v.country}
                        </span>
                      )}
                    </td>
                  </tr>
                )
              })}
            </tbody>
          </table>
        </div>
      )}
    </div>
  )
}