'use client'

/**
 * Quality & Audit Page
 *
 * Ermoeglicht Auditoren:
 * - Chunk-Suche und Stichproben
 * - Traceability: Chunk → Requirement → Control
 * - Dokumenten-Vollstaendigkeitspruefung
 */

import { useState, useCallback } from 'react'
import Link from 'next/link'
import { PagePurpose } from '@/components/common/PagePurpose'

const API_PROXY = '/api/legal-corpus'

// Types
interface ChunkDetail {
  id: string
  text: string
  regulation_code: string
  regulation_name: string
  article: string | null
  paragraph: string | null
  chunk_index: number
  chunk_position: 'beginning' | 'middle' | 'end'
  source_url: string
  score?: number
}

interface Requirement {
  id: string
  text: string
  category: string
  source_chunk_id: string
  regulation_code: string
}

interface Control {
  id: string
  name: string
  description: string
  source_requirement_ids: string[]
  regulation_codes: string[]
}

interface TraceabilityResult {
  chunk: ChunkDetail
  requirements: Requirement[]
  controls: Control[]
}

// Regulations for filtering
const REGULATIONS = [
  { code: 'GDPR', name: 'DSGVO' },
  { code: 'EPRIVACY', name: 'ePrivacy' },
  { code: 'TDDDG', name: 'TDDDG' },
  { code: 'SCC', name: 'Standardvertragsklauseln' },
  { code: 'DPF', name: 'EU-US DPF' },
  { code: 'AIACT', name: 'EU AI Act' },
  { code: 'CRA', name: 'Cyber Resilience Act' },
  { code: 'NIS2', name: 'NIS2' },
  { code: 'EUCSA', name: 'EU Cybersecurity Act' },
  { code: 'DATAACT', name: 'Data Act' },
  { code: 'DGA', name: 'Data Governance Act' },
  { code: 'DSA', name: 'Digital Services Act' },
  { code: 'EAA', name: 'Accessibility Act' },
  { code: 'DSM', name: 'DSM-Urheberrecht' },
  { code: 'PLD', name: 'Produkthaftung' },
  { code: 'GPSR', name: 'Product Safety' },
  { code: 'BSI-TR-03161-1', name: 'BSI-TR Teil 1' },
  { code: 'BSI-TR-03161-2', name: 'BSI-TR Teil 2' },
  { code: 'BSI-TR-03161-3', name: 'BSI-TR Teil 3' },
]

const TYPE_COLORS: Record<string, string> = {
  eu_regulation: 'bg-blue-100 text-blue-700 dark:bg-blue-900/30 dark:text-blue-400',
  eu_directive: 'bg-purple-100 text-purple-700 dark:bg-purple-900/30 dark:text-purple-400',
  de_law: 'bg-yellow-100 text-yellow-700 dark:bg-yellow-900/30 dark:text-yellow-400',
  bsi_standard: 'bg-green-100 text-green-700 dark:bg-green-900/30 dark:text-green-400',
}

export default function QualityPage() {
  // Search state
  const [searchQuery, setSearchQuery] = useState('')
  const [searchResults, setSearchResults] = useState<ChunkDetail[]>([])
  const [searching, setSearching] = useState(false)
  const [selectedRegulation, setSelectedRegulation] = useState<string>('')
  const [topK, setTopK] = useState(10)

  // Traceability state
  const [selectedChunk, setSelectedChunk] = useState<ChunkDetail | null>(null)
  const [traceability, setTraceability] = useState<TraceabilityResult | null>(null)
  const [loadingTrace, setLoadingTrace] = useState(false)

  // Quick sample queries for auditors
  const sampleQueries = [
    { label: 'Art. 17 DSGVO (Recht auf Loeschung)', query: 'Recht auf Löschung Artikel 17', reg: 'GDPR' },
    { label: 'Einwilligung TDDDG', query: 'Einwilligung Endeinrichtung speichern', reg: 'TDDDG' },
    { label: 'AI Act Hochrisiko', query: 'Hochrisiko-KI-System Anforderungen', reg: 'AIACT' },
    { label: 'NIS2 Sicherheitsmaßnahmen', query: 'Cybersicherheitsrisikomanagement Maßnahmen', reg: 'NIS2' },
    { label: 'BSI Authentifizierung', query: 'Authentifizierung Zwei-Faktor mobile', reg: 'BSI-TR-03161-1' },
  ]

  const handleSearch = useCallback(async () => {
    if (!searchQuery.trim()) return

    setSearching(true)
    setSearchResults([])
    setSelectedChunk(null)
    setTraceability(null)

    try {
      let url = `${API_PROXY}?action=search&query=${encodeURIComponent(searchQuery)}&top_k=${topK}`
      if (selectedRegulation) {
        url += `&regulations=${encodeURIComponent(selectedRegulation)}`
      }

      const res = await fetch(url)
      if (res.ok) {
        const data = await res.json()
        setSearchResults(data.results || [])
      }
    } catch (error) {
      console.error('Search failed:', error)
    } finally {
      setSearching(false)
    }
  }, [searchQuery, selectedRegulation, topK])

  const loadTraceability = useCallback(async (chunk: ChunkDetail) => {
    setSelectedChunk(chunk)
    setLoadingTrace(true)

    try {
      // Try to load traceability (requirements and controls derived from this chunk)
      const res = await fetch(`${API_PROXY}?action=traceability&chunk_id=${encodeURIComponent(chunk.id || chunk.regulation_code + '_' + chunk.chunk_index)}&regulation=${encodeURIComponent(chunk.regulation_code)}`)

      if (res.ok) {
        const data = await res.json()
        setTraceability({
          chunk,
          requirements: data.requirements || [],
          controls: data.controls || [],
        })
      } else {
        // If traceability endpoint doesn't exist yet, show placeholder
        setTraceability({
          chunk,
          requirements: [],
          controls: [],
        })
      }
    } catch (error) {
      console.error('Failed to load traceability:', error)
      setTraceability({
        chunk,
        requirements: [],
        controls: [],
      })
    } finally {
      setLoadingTrace(false)
    }
  }, [])

  const handleSampleQuery = (query: string, reg: string) => {
    setSearchQuery(query)
    setSelectedRegulation(reg)
    // Auto-search after setting
    setTimeout(() => {
      handleSearch()
    }, 100)
  }

  const highlightText = (text: string, query: string) => {
    if (!query) return text
    const words = query.toLowerCase().split(' ').filter(w => w.length > 2)
    let result = text
    words.forEach(word => {
      const regex = new RegExp(`(${word})`, 'gi')
      result = result.replace(regex, '<mark class="bg-yellow-200 dark:bg-yellow-800 px-0.5 rounded">$1</mark>')
    })
    return result
  }

  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">
            Qualitaet & Audit
          </h1>
          <p className="mt-1 text-sm text-gray-500 dark:text-gray-400">
            Stichproben und Traceability fuer Compliance-Auditoren
          </p>
        </div>
        <Link
          href="/ai/rag"
          className="text-sm text-blue-600 hover:text-blue-800 dark:text-blue-400"
        >
          ← Zurueck zu RAG
        </Link>
      </div>

      <PagePurpose
        title="Audit-Werkzeuge"
        purpose="Pruefen Sie die Qualitaet der Compliance-Datenbank. Suchen Sie gezielt nach Paragraphen, Saetzen oder Begriffen und verfolgen Sie, wie Anforderungen und Controls abgeleitet wurden."
        audience={['Auditoren', 'Compliance-Beauftragte', 'Qualitaetssicherung']}
        architecture={{
          services: ['klausur-service', 'embedding-service', 'qdrant'],
          databases: ['Qdrant Vector DB']
        }}
      />

      {/* Quick Sample Queries */}
      <div className="bg-white dark:bg-slate-800 rounded-lg shadow p-4">
        <h3 className="text-sm font-medium text-gray-700 dark:text-gray-300 mb-3">
          Schnell-Stichproben
        </h3>
        <div className="flex flex-wrap gap-2">
          {sampleQueries.map((sq, idx) => (
            <button
              key={idx}
              onClick={() => handleSampleQuery(sq.query, sq.reg)}
              className="px-3 py-1.5 text-xs bg-gray-100 hover:bg-gray-200 dark:bg-slate-700 dark:hover:bg-slate-600 text-gray-700 dark:text-gray-300 rounded-full transition-colors"
            >
              {sq.label}
            </button>
          ))}
        </div>
      </div>

      {/* Search Section */}
      <div className="bg-white dark:bg-slate-800 rounded-lg shadow p-6">
        <h2 className="text-lg font-semibold text-gray-900 dark:text-white mb-4">
          Chunk-Suche
        </h2>

        <div className="space-y-4">
          {/* Search Input */}
          <div className="flex gap-4">
            <div className="flex-1">
              <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-1">
                Suchbegriff / Paragraph / Artikeltext
              </label>
              <input
                type="text"
                value={searchQuery}
                onChange={(e) => setSearchQuery(e.target.value)}
                onKeyDown={(e) => e.key === 'Enter' && handleSearch()}
                placeholder="z.B. 'Recht auf Löschung' oder 'Art. 17 Abs. 1'"
                className="w-full px-4 py-2 border border-gray-300 dark:border-slate-600 rounded-lg focus:ring-2 focus:ring-blue-500 dark:bg-slate-700 dark:text-white"
              />
            </div>
            <div className="w-48">
              <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-1">
                Regulierung
              </label>
              <select
                value={selectedRegulation}
                onChange={(e) => setSelectedRegulation(e.target.value)}
                className="w-full px-3 py-2 border border-gray-300 dark:border-slate-600 rounded-lg focus:ring-2 focus:ring-blue-500 dark:bg-slate-700 dark:text-white"
              >
                <option value="">Alle</option>
                {REGULATIONS.map((reg) => (
                  <option key={reg.code} value={reg.code}>
                    {reg.name}
                  </option>
                ))}
              </select>
            </div>
            <div className="w-24">
              <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-1">
                Anzahl
              </label>
              <select
                value={topK}
                onChange={(e) => setTopK(parseInt(e.target.value))}
                className="w-full px-3 py-2 border border-gray-300 dark:border-slate-600 rounded-lg focus:ring-2 focus:ring-blue-500 dark:bg-slate-700 dark:text-white"
              >
                <option value="5">5</option>
                <option value="10">10</option>
                <option value="20">20</option>
              </select>
            </div>
          </div>

          <button
            onClick={handleSearch}
            disabled={searching || !searchQuery.trim()}
            className="px-6 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
          >
            {searching ? 'Suche laeuft...' : 'Suchen'}
          </button>
        </div>
      </div>

      {/* Results Grid */}
      {searchResults.length > 0 && (
        <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">
          {/* Search Results List */}
          <div className="bg-white dark:bg-slate-800 rounded-lg shadow p-4">
            <h3 className="text-md font-semibold text-gray-900 dark:text-white mb-4">
              Gefundene Chunks ({searchResults.length})
            </h3>
            <div className="space-y-3 max-h-[600px] overflow-y-auto">
              {searchResults.map((result, idx) => (
                <div
                  key={idx}
                  onClick={() => loadTraceability(result)}
                  className={`p-4 border rounded-lg cursor-pointer transition-all ${
                    selectedChunk?.text === result.text
                      ? 'border-blue-500 bg-blue-50 dark:bg-blue-900/20'
                      : 'border-gray-200 dark:border-slate-700 hover:border-gray-300 dark:hover:border-slate-600'
                  }`}
                >
                  {/* Header */}
                  <div className="flex items-center justify-between mb-2">
                    <div className="flex items-center gap-2">
                      <span className="text-xs font-medium px-2 py-0.5 bg-blue-100 text-blue-700 dark:bg-blue-900/30 dark:text-blue-400 rounded">
                        {result.regulation_code}
                      </span>
                      {result.article && (
                        <span className="text-xs text-gray-500 dark:text-gray-400">
                          Art. {result.article}
                          {result.paragraph && ` Abs. ${result.paragraph}`}
                        </span>
                      )}
                    </div>
                    <span className="text-xs text-gray-400">
                      Score: {(result.score || 0).toFixed(3)}
                    </span>
                  </div>

                  {/* Text Preview */}
                  <p
                    className="text-sm text-gray-700 dark:text-gray-300 line-clamp-4"
                    dangerouslySetInnerHTML={{
                      __html: highlightText(result.text.substring(0, 400) + (result.text.length > 400 ? '...' : ''), searchQuery)
                    }}
                  />

                  {/* Metadata */}
                  <div className="mt-2 flex items-center gap-4 text-xs text-gray-400">
                    <span>Chunk #{result.chunk_index || idx}</span>
                    <span>{result.text.length} Zeichen</span>
                  </div>
                </div>
              ))}
            </div>
          </div>

          {/* Traceability Panel */}
          <div className="bg-white dark:bg-slate-800 rounded-lg shadow p-4">
            <h3 className="text-md font-semibold text-gray-900 dark:text-white mb-4">
              Traceability
            </h3>

            {!selectedChunk ? (
              <div className="text-center py-12 text-gray-500 dark:text-gray-400">
                <svg className="w-12 h-12 mx-auto mb-4 opacity-50" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z" />
                </svg>
                <p>Waehlen Sie einen Chunk aus der Liste, um die Traceability zu sehen.</p>
              </div>
            ) : loadingTrace ? (
              <div className="text-center py-12">
                <div className="animate-spin w-8 h-8 border-2 border-blue-500 border-t-transparent rounded-full mx-auto mb-4"></div>
                <p className="text-gray-500 dark:text-gray-400">Lade Traceability...</p>
              </div>
            ) : traceability ? (
              <div className="space-y-6">
                {/* Selected Chunk Detail */}
                <div className="border-l-4 border-blue-500 pl-4">
                  <h4 className="text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
                    📄 Ausgewaehlter Chunk
                  </h4>
                  <div className="bg-gray-50 dark:bg-slate-700 rounded p-3">
                    <div className="flex items-center gap-2 mb-2">
                      <span className="text-xs font-medium px-2 py-0.5 bg-blue-100 text-blue-700 dark:bg-blue-900/30 dark:text-blue-400 rounded">
                        {traceability.chunk.regulation_code}
                      </span>
                      {traceability.chunk.article && (
                        <span className="text-xs text-gray-500 dark:text-gray-400">
                          Art. {traceability.chunk.article}
                          {traceability.chunk.paragraph && ` Abs. ${traceability.chunk.paragraph}`}
                        </span>
                      )}
                    </div>
                    <p className="text-sm text-gray-600 dark:text-gray-300 whitespace-pre-wrap">
                      {traceability.chunk.text}
                    </p>
                    {traceability.chunk.source_url && (
                      <a
                        href={traceability.chunk.source_url}
                        target="_blank"
                        rel="noopener noreferrer"
                        className="mt-2 inline-flex items-center gap-1 text-xs text-blue-600 hover:underline"
                      >
                        🔗 Quelle oeffnen
                      </a>
                    )}
                  </div>
                </div>

                {/* Arrow Down */}
                <div className="flex justify-center">
                  <svg className="w-6 h-6 text-gray-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 14l-7 7m0 0l-7-7m7 7V3" />
                  </svg>
                </div>

                {/* Requirements */}
                <div className="border-l-4 border-orange-500 pl-4">
                  <h4 className="text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
                    📋 Extrahierte Anforderungen ({traceability.requirements.length})
                  </h4>
                  {traceability.requirements.length > 0 ? (
                    <div className="space-y-2">
                      {traceability.requirements.map((req, idx) => (
                        <div key={idx} className="bg-orange-50 dark:bg-orange-900/20 rounded p-3">
                          <div className="flex items-center gap-2 mb-1">
                            <span className="text-xs font-medium text-orange-700 dark:text-orange-400">
                              {req.category || 'Anforderung'}
                            </span>
                          </div>
                          <p className="text-sm text-gray-600 dark:text-gray-300">{req.text}</p>
                        </div>
                      ))}
                    </div>
                  ) : (
                    <p className="text-sm text-gray-500 dark:text-gray-400 italic">
                      Keine Anforderungen aus diesem Chunk extrahiert.
                      <br />
                      <span className="text-xs">(Requirements-Extraktion ist noch nicht implementiert)</span>
                    </p>
                  )}
                </div>

                {/* Arrow Down */}
                <div className="flex justify-center">
                  <svg className="w-6 h-6 text-gray-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 14l-7 7m0 0l-7-7m7 7V3" />
                  </svg>
                </div>

                {/* Controls */}
                <div className="border-l-4 border-green-500 pl-4">
                  <h4 className="text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
                    ✅ Abgeleitete Controls ({traceability.controls.length})
                  </h4>
                  {traceability.controls.length > 0 ? (
                    <div className="space-y-2">
                      {traceability.controls.map((ctrl, idx) => (
                        <div key={idx} className="bg-green-50 dark:bg-green-900/20 rounded p-3">
                          <div className="font-medium text-sm text-green-700 dark:text-green-400 mb-1">
                            {ctrl.name}
                          </div>
                          <p className="text-sm text-gray-600 dark:text-gray-300">{ctrl.description}</p>
                        </div>
                      ))}
                    </div>
                  ) : (
                    <p className="text-sm text-gray-500 dark:text-gray-400 italic">
                      Keine Controls aus diesem Chunk abgeleitet.
                      <br />
                      <span className="text-xs">(Control-Ableitung ist noch nicht implementiert)</span>
                    </p>
                  )}
                </div>
              </div>
            ) : null}
          </div>
        </div>
      )}

      {/* Empty State */}
      {!searching && searchResults.length === 0 && searchQuery && (
        <div className="bg-white dark:bg-slate-800 rounded-lg shadow p-12 text-center">
          <svg className="w-16 h-16 mx-auto mb-4 text-gray-300 dark:text-gray-600" fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9.172 16.172a4 4 0 015.656 0M9 10h.01M15 10h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z" />
          </svg>
          <h3 className="text-lg font-medium text-gray-900 dark:text-white mb-2">
            Keine Ergebnisse gefunden
          </h3>
          <p className="text-gray-500 dark:text-gray-400">
            Versuchen Sie einen anderen Suchbegriff oder waehlen Sie eine andere Regulierung.
          </p>
        </div>
      )}

      {/* Initial State */}
      {!searching && searchResults.length === 0 && !searchQuery && (
        <div className="bg-white dark:bg-slate-800 rounded-lg shadow p-12 text-center">
          <svg className="w-16 h-16 mx-auto mb-4 text-gray-300 dark:text-gray-600" fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z" />
          </svg>
          <h3 className="text-lg font-medium text-gray-900 dark:text-white mb-2">
            Bereit fuer Stichproben
          </h3>
          <p className="text-gray-500 dark:text-gray-400 max-w-md mx-auto">
            Geben Sie einen Suchbegriff ein, um Chunks zu finden. Sie koennen nach Artikeln,
            Paragraphen oder spezifischen Textpassagen suchen.
          </p>
        </div>
      )}

      {/* Audit Info */}
      <div className="bg-blue-50 dark:bg-blue-900/20 border border-blue-200 dark:border-blue-800 rounded-lg p-4">
        <h3 className="text-sm font-medium text-blue-800 dark:text-blue-400 mb-2">
          ℹ️ Hinweise fuer Auditoren
        </h3>
        <ul className="text-sm text-blue-700 dark:text-blue-300 space-y-1 list-disc list-inside">
          <li>Die Suche ist semantisch - aehnliche Begriffe werden gefunden, auch wenn die exakte Formulierung abweicht</li>
          <li>Jeder Chunk entspricht einem logischen Textabschnitt aus dem Originaldokument</li>
          <li>Die Traceability zeigt, wie aus dem Originaltext Anforderungen und Controls abgeleitet wurden</li>
          <li>Klicken Sie auf "Quelle oeffnen", um das Originaldokument zu pruefen</li>
        </ul>
      </div>
    </div>
  )
}