'use client'

import { useState, useEffect, useCallback } from 'react'
import type {
  Collection,
  IngestionStatus,
  LiveProgress,
  IndexedStats,
  PendingFile,
  PendingFilesData,
  IngestionHistoryEntry
} from '../types'

const API_BASE = process.env.NEXT_PUBLIC_KLAUSUR_SERVICE_URL || 'http://localhost:8086'

interface IngestionTabProps {
  status: IngestionStatus | null
  onRefresh: () => void
}

function IngestionTab({
  status,
  onRefresh
}: IngestionTabProps) {
  const [starting, setStarting] = useState(false)
  const [liveProgress, setLiveProgress] = useState<LiveProgress | null>(null)
  const [indexedStats, setIndexedStats] = useState<IndexedStats | null>(null)
  const [pendingFiles, setPendingFiles] = useState<PendingFilesData | null>(null)
  const [ingestionHistory, setIngestionHistory] = useState<IngestionHistoryEntry[]>([])
  const [showHistory, setShowHistory] = useState(false)
  const [showPending, setShowPending] = useState(false)

  // Fetch indexed stats, pending files, and history on mount
  useEffect(() => {
    const fetchStats = async () => {
      try {
        const res = await fetch(`${API_BASE}/api/v1/admin/nibis/stats`)
        if (res.ok) {
          const data = await res.json()
          setIndexedStats(data)
        }
      } catch (err) {
        console.error('Failed to fetch stats:', err)
      }
    }

    const fetchPending = async () => {
      try {
        const res = await fetch(`${API_BASE}/api/v1/admin/rag/files/pending`)
        if (res.ok) {
          const data = await res.json()
          setPendingFiles(data)
        }
      } catch (err) {
        console.error('Failed to fetch pending files:', err)
      }
    }

    const fetchHistory = async () => {
      try {
        const res = await fetch(`${API_BASE}/api/v1/admin/rag/ingestion/history?limit=20`)
        if (res.ok) {
          const data = await res.json()
          setIngestionHistory(data.history || [])
        }
      } catch (err) {
        console.error('Failed to fetch history:', err)
      }
    }

    fetchStats()
    fetchPending()
    fetchHistory()
  }, [])

  // Poll for live progress when running
  useEffect(() => {
    let interval: NodeJS.Timeout | null = null

    const fetchProgress = async () => {
      try {
        const res = await fetch(`${API_BASE}/api/v1/admin/nibis/progress`)
        if (res.ok) {
          const data = await res.json()
          setLiveProgress(data)
          // Refresh stats when complete
          if (!data.running && data.phase === 'complete') {
            onRefresh()
            // Also refresh indexed stats
            const statsRes = await fetch(`${API_BASE}/api/v1/admin/nibis/stats`)
            if (statsRes.ok) {
              setIndexedStats(await statsRes.json())
            }
          }
        }
      } catch (err) {
        console.error('Failed to fetch progress:', err)
      }
    }

    // Start polling immediately and every 1.5 seconds
    fetchProgress()
    interval = setInterval(fetchProgress, 1500)

    return () => {
      if (interval) clearInterval(interval)
    }
  }, [onRefresh])

  const startIngestion = async () => {
    setStarting(true)
    try {
      await fetch(`${API_BASE}/api/v1/admin/nibis/ingest`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ ewh_only: true, incremental: true }),
      })
      onRefresh()
    } catch (err) {
      console.error('Failed to start ingestion:', err)
    } finally {
      setStarting(false)
    }
  }

  const phaseLabels: Record<string, string> = {
    idle: 'Bereit',
    extracting: 'Entpacke ZIP-Dateien...',
    discovering: 'Suche Dokumente...',
    indexing: 'Indexiere Dokumente...',
    complete: 'Abgeschlossen',
  }

  return (
    <div className="space-y-6">
      <div className="flex items-center justify-between">
        <div>
          <h2 className="text-lg font-semibold text-slate-900">Ingestion Status</h2>
          <p className="text-sm text-slate-500">
            Übersicht über laufende und vergangene Indexierungsvorgänge
          </p>
        </div>
        <div className="flex gap-3">
          <button
            onClick={onRefresh}
            className="px-4 py-2 text-sm font-medium text-slate-700 bg-white border border-slate-300 rounded-lg hover:bg-slate-50"
          >
            Aktualisieren
          </button>
          <button
            onClick={startIngestion}
            disabled={status?.running || starting}
            className="px-4 py-2 text-sm font-medium text-white bg-primary-600 rounded-lg hover:bg-primary-700 disabled:opacity-50 disabled:cursor-not-allowed"
          >
            {starting ? 'Startet...' : 'Ingestion starten'}
          </button>
        </div>
      </div>

      {/* Live Progress (when running) */}
      {liveProgress?.running && (
        <div className="bg-primary-50 rounded-lg border border-primary-200 p-6">
          <div className="flex items-center gap-4 mb-4">
            <div className="w-3 h-3 bg-primary-500 rounded-full animate-pulse"></div>
            <span className="text-lg font-medium text-primary-900">
              {liveProgress.phase ? (phaseLabels[liveProgress.phase] || liveProgress.phase) : 'Läuft...'}
            </span>
            <span className="ml-auto text-sm text-primary-700 font-mono">
              {(liveProgress.percent ?? 0).toFixed(1)}%
            </span>
          </div>

          {/* Progress Bar */}
          <div className="h-3 bg-primary-200 rounded-full overflow-hidden mb-4">
            <div
              className="h-full bg-primary-600 transition-all duration-300"
              style={{ width: `${liveProgress.percent ?? 0}%` }}
            />
          </div>

          {/* Current File */}
          {liveProgress.current_filename && (
            <p className="text-sm text-primary-700 mb-4 truncate">
              <span className="font-medium">[{liveProgress.current_doc}/{liveProgress.total_docs}]</span>{' '}
              {liveProgress.current_filename}
            </p>
          )}

          {/* Live Stats */}
          <div className="grid grid-cols-2 md:grid-cols-4 gap-4 text-sm">
            <div className="bg-white/50 rounded p-2">
              <p className="text-primary-600 text-xs uppercase">Indexiert</p>
              <p className="text-lg font-semibold text-primary-900">{liveProgress.documents_indexed}</p>
            </div>
            <div className="bg-white/50 rounded p-2">
              <p className="text-primary-600 text-xs uppercase">Übersprungen</p>
              <p className="text-lg font-semibold text-primary-900">{liveProgress.documents_skipped}</p>
            </div>
            <div className="bg-white/50 rounded p-2">
              <p className="text-primary-600 text-xs uppercase">Chunks</p>
              <p className="text-lg font-semibold text-primary-900">{liveProgress.chunks_created}</p>
            </div>
            <div className="bg-white/50 rounded p-2">
              <p className="text-primary-600 text-xs uppercase">Fehler</p>
              <p className={`text-lg font-semibold ${(liveProgress.errors_count ?? 0) > 0 ? 'text-red-600' : 'text-primary-900'}`}>
                {liveProgress.errors_count ?? 0}
              </p>
            </div>
          </div>
        </div>
      )}

      {/* Indexed Data Overview - Always visible */}
      {indexedStats?.indexed && (
        <div className="bg-gradient-to-r from-green-50 to-emerald-50 rounded-lg border border-green-200 p-6">
          <h3 className="text-lg font-semibold text-green-900 mb-4 flex items-center gap-2">
            <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M5 13l4 4L19 7" />
            </svg>
            Indexierte Daten (Gesamt)
          </h3>

          <div className="grid grid-cols-2 md:grid-cols-4 gap-6 mb-4">
            <div className="bg-white/60 rounded-lg p-3">
              <p className="text-xs text-green-700 uppercase tracking-wider">Chunks gesamt</p>
              <p className="text-2xl font-bold text-green-900">
                {(indexedStats.total_chunks ?? 0).toLocaleString()}
              </p>
            </div>
            <div className="bg-white/60 rounded-lg p-3">
              <p className="text-xs text-green-700 uppercase tracking-wider">Jahre</p>
              <p className="text-2xl font-bold text-green-900">
                {indexedStats.years?.length ?? 0}
              </p>
              <p className="text-xs text-green-600 mt-1">
                {(indexedStats.years?.length ?? 0) > 0
                  ? `${Math.min(...indexedStats.years!)} - ${Math.max(...indexedStats.years!)}`
                  : '-'
                }
              </p>
            </div>
            <div className="bg-white/60 rounded-lg p-3">
              <p className="text-xs text-green-700 uppercase tracking-wider">Fächer</p>
              <p className="text-2xl font-bold text-green-900">
                {indexedStats.subjects?.length || 0}
              </p>
            </div>
            <div className="bg-white/60 rounded-lg p-3">
              <p className="text-xs text-green-700 uppercase tracking-wider">Status</p>
              <p className="text-lg font-bold text-green-600">Bereit</p>
            </div>
          </div>

          {/* Years breakdown */}
          {indexedStats.years && indexedStats.years.length > 0 && (
            <div className="flex flex-wrap gap-2">
              {indexedStats.years.sort((a, b) => a - b).map((year) => (
                <span
                  key={year}
                  className="px-3 py-1 bg-white/80 text-green-800 text-sm rounded-full font-medium"
                >
                  {year}
                </span>
              ))}
            </div>
          )}
        </div>
      )}

      {/* Last Run Status */}
      {!liveProgress?.running && (
        <div className="bg-white rounded-lg border border-slate-200 p-6">
          <h3 className="text-sm font-medium text-slate-700 mb-4">Letzter Indexierungslauf</h3>

          <div className="flex items-center gap-4 mb-4">
            <div className="w-3 h-3 bg-green-500 rounded-full"></div>
            <span className="text-lg font-medium text-slate-900">
              {liveProgress?.phase === 'complete' ? 'Abgeschlossen' : 'Bereit'}
            </span>
          </div>

          {status && (
            <div className="grid grid-cols-2 md:grid-cols-4 gap-6">
              <div>
                <p className="text-xs text-slate-500 uppercase tracking-wider">Zeitpunkt</p>
                <p className="text-lg font-semibold text-slate-900">
                  {status.lastRun
                    ? new Date(status.lastRun).toLocaleString('de-DE')
                    : 'Noch nie'
                  }
                </p>
              </div>
              <div>
                <p className="text-xs text-slate-500 uppercase tracking-wider">Neu indexiert</p>
                <p className="text-lg font-semibold text-slate-900">
                  {status.documentsIndexed ?? '-'}
                </p>
              </div>
              <div>
                <p className="text-xs text-slate-500 uppercase tracking-wider">Neue Chunks</p>
                <p className="text-lg font-semibold text-slate-900">
                  {status.chunksCreated ?? '-'}
                </p>
              </div>
              <div>
                <p className="text-xs text-slate-500 uppercase tracking-wider">Fehler</p>
                <p className={`text-lg font-semibold ${status.errors.length > 0 ? 'text-red-600' : 'text-slate-900'}`}>
                  {status.errors.length}
                </p>
              </div>
            </div>
          )}

          {/* Show skipped info from live progress */}
          {liveProgress && (liveProgress.documents_skipped ?? 0) > 0 && (
            <p className="mt-3 text-sm text-slate-500">
              {liveProgress.documents_skipped} Dokumente übersprungen (bereits indexiert)
            </p>
          )}

          {status?.errors && status.errors.length > 0 && (
            <div className="mt-4 p-4 bg-red-50 rounded-lg">
              <h4 className="text-sm font-medium text-red-800 mb-2">Fehler</h4>
              <ul className="text-sm text-red-700 space-y-1">
                {status.errors.slice(0, 5).map((error, i) => (
                  <li key={i}>{error}</li>
                ))}
                {status.errors.length > 5 && (
                  <li className="text-red-500">... und {status.errors.length - 5} weitere</li>
                )}
              </ul>
            </div>
          )}
        </div>
      )}

      {/* Pending Files Section */}
      {pendingFiles && (pendingFiles.pending_count ?? 0) > 0 && (
        <div className="bg-amber-50 rounded-lg border border-amber-200 p-6">
          <div className="flex items-center justify-between mb-4">
            <div className="flex items-center gap-3">
              <svg className="w-6 h-6 text-amber-600" 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 1.732-3L13.732 4c-.77-1.333-2.694-1.333-3.464 0L3.34 16c-.77 1.333.192 3 1.732 3z" />
              </svg>
              <div>
                <h3 className="text-lg font-semibold text-amber-900">
                  {pendingFiles.pending_count} Dateien warten auf Indexierung
                </h3>
                <p className="text-sm text-amber-700">
                  {pendingFiles.indexed_count} von {pendingFiles.total_files} Dateien sind indexiert
                </p>
              </div>
            </div>
            <button
              onClick={() => setShowPending(!showPending)}
              className="text-sm text-amber-700 hover:text-amber-900 font-medium"
            >
              {showPending ? 'Ausblenden' : 'Details anzeigen'}
            </button>
          </div>

          {/* Pending by year summary */}
          {pendingFiles.by_year && Object.keys(pendingFiles.by_year).length > 0 && (
            <div className="flex flex-wrap gap-2 mb-4">
              {Object.entries(pendingFiles.by_year)
                .sort(([a], [b]) => Number(b) - Number(a))
                .map(([year, count]) => (
                  <span
                    key={year}
                    className="px-3 py-1 bg-amber-100 text-amber-800 text-sm rounded-full font-medium"
                  >
                    {year}: {count} Dateien
                  </span>
                ))}
            </div>
          )}

          {/* Pending files list */}
          {showPending && pendingFiles.pending_files && (
            <div className="mt-4 max-h-64 overflow-y-auto">
              <table className="w-full text-sm">
                <thead className="text-left text-amber-700 border-b border-amber-200">
                  <tr>
                    <th className="pb-2">Dateiname</th>
                    <th className="pb-2">Jahr</th>
                    <th className="pb-2">Fach</th>
                    <th className="pb-2">Niveau</th>
                  </tr>
                </thead>
                <tbody className="divide-y divide-amber-100">
                  {pendingFiles.pending_files.map((file) => (
                    <tr key={file.id} className="text-amber-900">
                      <td className="py-2 font-mono text-xs">{file.filename}</td>
                      <td className="py-2">{file.year}</td>
                      <td className="py-2">{file.subject}</td>
                      <td className="py-2">{file.niveau}</td>
                    </tr>
                  ))}
                </tbody>
              </table>
              {(pendingFiles.pending_count ?? 0) > 100 && (
                <p className="mt-2 text-xs text-amber-600">
                  Zeige 100 von {pendingFiles.pending_count} Dateien
                </p>
              )}
            </div>
          )}
        </div>
      )}

      {/* Ingestion History Section */}
      <div className="bg-white rounded-lg border border-slate-200 p-6">
        <div className="flex items-center justify-between mb-4">
          <h3 className="text-lg font-semibold text-slate-900">Indexierungs-Historie</h3>
          <button
            onClick={() => setShowHistory(!showHistory)}
            className="text-sm text-slate-600 hover:text-slate-900 font-medium"
          >
            {showHistory ? 'Ausblenden' : `Alle anzeigen (${ingestionHistory.length})`}
          </button>
        </div>

        {ingestionHistory.length === 0 ? (
          <p className="text-slate-500 text-sm">Noch keine Indexierungsläufe durchgeführt.</p>
        ) : (
          <div className="space-y-3">
            {(showHistory ? ingestionHistory : ingestionHistory.slice(0, 3)).map((entry) => (
              <div
                key={entry.id}
                className={`rounded-lg p-4 ${
                  entry.status === 'success'
                    ? 'bg-green-50 border border-green-200'
                    : 'bg-red-50 border border-red-200'
                }`}
              >
                <div className="flex items-center justify-between mb-2">
                  <div className="flex items-center gap-2">
                    {entry.status === 'success' ? (
                      <svg className="w-5 h-5 text-green-600" 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-5 h-5 text-red-600" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
                      </svg>
                    )}
                    <span className="font-medium text-slate-900">
                      {new Date(entry.started_at || entry.startedAt).toLocaleString('de-DE')}
                    </span>
                  </div>
                  <span className="text-xs text-slate-500 font-mono">{entry.collection}</span>
                </div>

                {entry.stats && (
                  <div className="grid grid-cols-4 gap-4 text-sm">
                    <div>
                      <span className="text-slate-500">Gefunden:</span>{' '}
                      <span className="font-medium">{entry.stats.documents_found}</span>
                    </div>
                    <div>
                      <span className="text-slate-500">Indexiert:</span>{' '}
                      <span className="font-medium text-green-700">{entry.stats.documents_indexed}</span>
                    </div>
                    <div>
                      <span className="text-slate-500">Übersprungen:</span>{' '}
                      <span className="font-medium">{entry.stats.documents_skipped}</span>
                    </div>
                    <div>
                      <span className="text-slate-500">Chunks:</span>{' '}
                      <span className="font-medium">{entry.stats.chunks_created}</span>
                    </div>
                  </div>
                )}

                {entry.filters && (
                  <div className="mt-2 flex flex-wrap gap-2">
                    {entry.filters.year && (
                      <span className="px-2 py-0.5 bg-slate-200 text-slate-700 text-xs rounded">
                        Jahr: {entry.filters.year}
                      </span>
                    )}
                    {entry.filters.subject && (
                      <span className="px-2 py-0.5 bg-slate-200 text-slate-700 text-xs rounded">
                        Fach: {entry.filters.subject}
                      </span>
                    )}
                    {entry.filters.incremental && (
                      <span className="px-2 py-0.5 bg-blue-100 text-blue-700 text-xs rounded">
                        Inkrementell
                      </span>
                    )}
                  </div>
                )}

                {entry.error && (
                  <p className="mt-2 text-sm text-red-700">{entry.error}</p>
                )}
              </div>
            ))}
          </div>
        )}
      </div>
    </div>
  )
}

// ============================================================================
// Documents Tab
// ============================================================================


export { IngestionTab }