'use client'

import { useState, useEffect } from 'react'

interface PIIRule {
  id: string
  name: string
  rule_type: string
  pattern: string
  severity: string
  is_active: boolean
  created_at: string
  updated_at: string
}

interface PIIMatch {
  rule_id: string
  rule_name: string
  rule_type: string
  severity: string
  match: string
  start_index: number
  end_index: number
}

interface PIITestResult {
  has_pii: boolean
  matches: PIIMatch[]
  should_block: boolean
  block_level: string
}

interface PIIRulesTabProps {
  apiBase: string
  onUpdate?: () => void
}

const RULE_TYPES = [
  { value: 'regex', label: 'Regex (Muster)' },
  { value: 'keyword', label: 'Keyword (Stichwort)' },
]

const SEVERITIES = [
  { value: 'warn', label: 'Warnung', color: 'bg-amber-100 text-amber-700' },
  { value: 'redact', label: 'Schwärzen', color: 'bg-orange-100 text-orange-700' },
  { value: 'block', label: 'Blockieren', color: 'bg-red-100 text-red-700' },
]

export function PIIRulesTab({ apiBase, onUpdate }: PIIRulesTabProps) {
  const [rules, setRules] = useState<PIIRule[]>([])
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState<string | null>(null)

  // Test panel
  const [testText, setTestText] = useState('')
  const [testResult, setTestResult] = useState<PIITestResult | null>(null)
  const [testing, setTesting] = useState(false)

  // Edit modal
  const [editingRule, setEditingRule] = useState<PIIRule | null>(null)
  const [isNewRule, setIsNewRule] = useState(false)
  const [saving, setSaving] = useState(false)

  // New rule form
  const [newRule, setNewRule] = useState({
    name: '',
    rule_type: 'regex',
    pattern: '',
    severity: 'block',
    is_active: true,
  })

  useEffect(() => {
    fetchRules()
  }, [])

  const fetchRules = async () => {
    try {
      setLoading(true)
      const res = await fetch(`${apiBase}/v1/admin/pii-rules`)
      if (!res.ok) throw new Error('Fehler beim Laden')

      const data = await res.json()
      setRules(data.rules || [])
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Unbekannter Fehler')
    } finally {
      setLoading(false)
    }
  }

  const createRule = async () => {
    try {
      setSaving(true)
      const res = await fetch(`${apiBase}/v1/admin/pii-rules`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(newRule),
      })

      if (!res.ok) throw new Error('Fehler beim Erstellen')

      setNewRule({
        name: '',
        rule_type: 'regex',
        pattern: '',
        severity: 'block',
        is_active: true,
      })
      setIsNewRule(false)
      fetchRules()
      onUpdate?.()
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Unbekannter Fehler')
    } finally {
      setSaving(false)
    }
  }

  const updateRule = async () => {
    if (!editingRule) return

    try {
      setSaving(true)
      const res = await fetch(`${apiBase}/v1/admin/pii-rules/${editingRule.id}`, {
        method: 'PUT',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(editingRule),
      })

      if (!res.ok) throw new Error('Fehler beim Aktualisieren')

      setEditingRule(null)
      fetchRules()
      onUpdate?.()
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Unbekannter Fehler')
    } finally {
      setSaving(false)
    }
  }

  const deleteRule = async (id: string) => {
    if (!confirm('Regel wirklich loeschen? Diese Aktion wird im Audit-Log protokolliert.')) return

    try {
      const res = await fetch(`${apiBase}/v1/admin/pii-rules/${id}`, {
        method: 'DELETE',
      })

      if (!res.ok) throw new Error('Fehler beim Loeschen')

      fetchRules()
      onUpdate?.()
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Unbekannter Fehler')
    }
  }

  const toggleRuleStatus = async (rule: PIIRule) => {
    try {
      const res = await fetch(`${apiBase}/v1/admin/pii-rules/${rule.id}`, {
        method: 'PUT',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ is_active: !rule.is_active }),
      })

      if (!res.ok) throw new Error('Fehler beim Aendern des Status')

      fetchRules()
      onUpdate?.()
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Unbekannter Fehler')
    }
  }

  const runTest = async () => {
    if (!testText) return

    try {
      setTesting(true)
      const res = await fetch(`${apiBase}/v1/admin/pii-rules/test`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ text: testText }),
      })

      if (!res.ok) throw new Error('Fehler beim Testen')

      const data = await res.json()
      setTestResult(data)
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Unbekannter Fehler')
    } finally {
      setTesting(false)
    }
  }

  const getSeverityBadge = (severity: string) => {
    const config = SEVERITIES.find((s) => s.value === severity)
    return (
      <span className={`px-2 py-1 rounded text-xs font-medium ${config?.color || 'bg-slate-100 text-slate-700'}`}>
        {config?.label || severity}
      </span>
    )
  }

  return (
    <div>
      {/* Error Display */}
      {error && (
        <div className="mb-4 p-4 bg-red-50 border border-red-200 rounded-lg text-red-700 flex items-center justify-between">
          <span>{error}</span>
          <button onClick={() => setError(null)} className="text-red-500 hover:text-red-700">
            &times;
          </button>
        </div>
      )}

      {/* Test Panel */}
      <div className="bg-white rounded-xl border border-slate-200 p-6 mb-6">
        <h3 className="font-semibold text-slate-900 mb-4">PII-Test</h3>
        <p className="text-sm text-slate-600 mb-4">
          Testen Sie, ob ein Text personenbezogene Daten (PII) enthaelt.
        </p>

        <textarea
          value={testText}
          onChange={(e) => setTestText(e.target.value)}
          placeholder="Geben Sie hier einen Text zum Testen ein...

Beispiel:
Kontaktieren Sie mich unter max.mustermann@example.com oder
rufen Sie mich an unter +49 170 1234567.
Meine IBAN ist DE89 3704 0044 0532 0130 00."
          rows={6}
          className="w-full px-4 py-2 border border-slate-200 rounded-lg focus:ring-2 focus:ring-purple-500 focus:border-transparent font-mono text-sm"
        />

        <div className="flex justify-between items-center mt-4">
          <button
            onClick={() => {
              setTestText('')
              setTestResult(null)
            }}
            className="text-sm text-slate-500 hover:text-slate-700"
          >
            Zuruecksetzen
          </button>
          <button
            onClick={runTest}
            disabled={testing || !testText}
            className="px-6 py-2 bg-purple-600 text-white rounded-lg hover:bg-purple-700 disabled:opacity-50"
          >
            {testing ? 'Teste...' : 'Testen'}
          </button>
        </div>

        {/* Test Results */}
        {testResult && (
          <div className={`mt-4 p-4 rounded-lg ${testResult.should_block ? 'bg-red-50 border border-red-200' : testResult.has_pii ? 'bg-amber-50 border border-amber-200' : 'bg-green-50 border border-green-200'}`}>
            <div className="flex items-center gap-2 mb-3">
              {testResult.should_block ? (
                <>
                  <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="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>
                  <span className="font-medium text-red-800">Blockiert - Kritische PII gefunden</span>
                </>
              ) : testResult.has_pii ? (
                <>
                  <svg className="w-5 h-5 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>
                  <span className="font-medium text-amber-800">Warnung - PII gefunden ({testResult.matches.length} Treffer)</span>
                </>
              ) : (
                <>
                  <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>
                  <span className="font-medium text-green-800">Keine PII gefunden</span>
                </>
              )}
            </div>

            {testResult.matches.length > 0 && (
              <div className="space-y-2">
                {testResult.matches.map((match, idx) => (
                  <div key={idx} className="flex items-center gap-3 text-sm bg-white bg-opacity-50 rounded px-3 py-2">
                    {getSeverityBadge(match.severity)}
                    <span className="text-slate-700 font-medium">{match.rule_name}</span>
                    <code className="text-xs bg-slate-100 px-2 py-1 rounded">
                      {match.match.length > 30 ? match.match.substring(0, 30) + '...' : match.match}
                    </code>
                  </div>
                ))}
              </div>
            )}
          </div>
        )}
      </div>

      {/* Rules List Header */}
      <div className="flex justify-between items-center mb-4">
        <h3 className="font-semibold text-slate-900">PII-Erkennungsregeln</h3>
        <button
          onClick={() => setIsNewRule(true)}
          className="px-4 py-2 bg-purple-600 text-white rounded-lg hover:bg-purple-700 flex items-center gap-2"
        >
          <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 4v16m8-8H4" />
          </svg>
          Neue Regel
        </button>
      </div>

      {/* Rules Table */}
      {loading ? (
        <div className="text-center py-12 text-slate-500">Lade Regeln...</div>
      ) : rules.length === 0 ? (
        <div className="bg-white rounded-xl border border-slate-200 p-8 text-center">
          <svg className="w-12 h-12 mx-auto text-slate-300 mb-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 15v2m-6 4h12a2 2 0 002-2v-6a2 2 0 00-2-2H6a2 2 0 00-2 2v6a2 2 0 002 2zm10-10V7a4 4 0 00-8 0v4h8z" />
          </svg>
          <h3 className="text-lg font-medium text-slate-700 mb-2">Keine Regeln vorhanden</h3>
          <p className="text-sm text-slate-500">
            Fuegen Sie PII-Erkennungsregeln hinzu.
          </p>
        </div>
      ) : (
        <div className="bg-white rounded-xl border border-slate-200 overflow-hidden">
          <table className="w-full">
            <thead className="bg-slate-50 border-b border-slate-200">
              <tr>
                <th className="text-left px-4 py-3 text-xs font-medium text-slate-500 uppercase">Name</th>
                <th className="text-left px-4 py-3 text-xs font-medium text-slate-500 uppercase">Typ</th>
                <th className="text-left px-4 py-3 text-xs font-medium text-slate-500 uppercase">Muster</th>
                <th className="text-left px-4 py-3 text-xs font-medium text-slate-500 uppercase">Severity</th>
                <th className="text-left px-4 py-3 text-xs font-medium text-slate-500 uppercase">Status</th>
                <th className="text-right px-4 py-3 text-xs font-medium text-slate-500 uppercase">Aktionen</th>
              </tr>
            </thead>
            <tbody className="divide-y divide-slate-100">
              {rules.map((rule) => (
                <tr key={rule.id} className="hover:bg-slate-50">
                  <td className="px-4 py-3 text-sm font-medium text-slate-800">{rule.name}</td>
                  <td className="px-4 py-3">
                    <span className="text-xs bg-slate-100 text-slate-700 px-2 py-1 rounded">
                      {rule.rule_type}
                    </span>
                  </td>
                  <td className="px-4 py-3">
                    <code className="text-xs bg-slate-100 px-2 py-1 rounded max-w-xs truncate block">
                      {rule.pattern.length > 40 ? rule.pattern.substring(0, 40) + '...' : rule.pattern}
                    </code>
                  </td>
                  <td className="px-4 py-3">{getSeverityBadge(rule.severity)}</td>
                  <td className="px-4 py-3">
                    <button
                      onClick={() => toggleRuleStatus(rule)}
                      className={`text-xs px-2 py-1 rounded ${
                        rule.is_active
                          ? 'bg-green-100 text-green-700'
                          : 'bg-red-100 text-red-700'
                      }`}
                    >
                      {rule.is_active ? 'Aktiv' : 'Inaktiv'}
                    </button>
                  </td>
                  <td className="px-4 py-3 text-right">
                    <button
                      onClick={() => setEditingRule(rule)}
                      className="text-purple-600 hover:text-purple-700 mr-3"
                    >
                      Bearbeiten
                    </button>
                    <button
                      onClick={() => deleteRule(rule.id)}
                      className="text-red-600 hover:text-red-700"
                    >
                      Loeschen
                    </button>
                  </td>
                </tr>
              ))}
            </tbody>
          </table>
        </div>
      )}

      {/* New Rule Modal */}
      {isNewRule && (
        <div className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center z-50">
          <div className="bg-white rounded-xl p-6 w-full max-w-lg mx-4">
            <h3 className="text-lg font-semibold text-slate-900 mb-4">Neue PII-Regel</h3>

            <div className="space-y-4">
              <div>
                <label className="block text-sm font-medium text-slate-700 mb-1">Name *</label>
                <input
                  type="text"
                  value={newRule.name}
                  onChange={(e) => setNewRule({ ...newRule, name: e.target.value })}
                  placeholder="z.B. Deutsche Telefonnummern"
                  className="w-full px-4 py-2 border border-slate-200 rounded-lg focus:ring-2 focus:ring-purple-500 focus:border-transparent"
                />
              </div>

              <div>
                <label className="block text-sm font-medium text-slate-700 mb-1">Typ *</label>
                <select
                  value={newRule.rule_type}
                  onChange={(e) => setNewRule({ ...newRule, rule_type: e.target.value })}
                  className="w-full px-4 py-2 border border-slate-200 rounded-lg focus:ring-2 focus:ring-purple-500 focus:border-transparent"
                >
                  {RULE_TYPES.map((t) => (
                    <option key={t.value} value={t.value}>
                      {t.label}
                    </option>
                  ))}
                </select>
              </div>

              <div>
                <label className="block text-sm font-medium text-slate-700 mb-1">Muster *</label>
                <textarea
                  value={newRule.pattern}
                  onChange={(e) => setNewRule({ ...newRule, pattern: e.target.value })}
                  placeholder={newRule.rule_type === 'regex' ? 'Regex-Muster, z.B. (?:\\+49|0)[\\s.-]?\\d{2,4}...' : 'Keywords getrennt durch Komma, z.B. password,secret,api_key'}
                  rows={3}
                  className="w-full px-4 py-2 border border-slate-200 rounded-lg focus:ring-2 focus:ring-purple-500 focus:border-transparent font-mono text-sm"
                />
              </div>

              <div>
                <label className="block text-sm font-medium text-slate-700 mb-1">Severity *</label>
                <select
                  value={newRule.severity}
                  onChange={(e) => setNewRule({ ...newRule, severity: e.target.value })}
                  className="w-full px-4 py-2 border border-slate-200 rounded-lg focus:ring-2 focus:ring-purple-500 focus:border-transparent"
                >
                  {SEVERITIES.map((s) => (
                    <option key={s.value} value={s.value}>
                      {s.label}
                    </option>
                  ))}
                </select>
              </div>
            </div>

            <div className="flex justify-end gap-3 mt-6 pt-4 border-t border-slate-100">
              <button
                onClick={() => setIsNewRule(false)}
                className="px-4 py-2 text-slate-600 hover:text-slate-700"
              >
                Abbrechen
              </button>
              <button
                onClick={createRule}
                disabled={saving || !newRule.name || !newRule.pattern}
                className="px-6 py-2 bg-purple-600 text-white rounded-lg hover:bg-purple-700 disabled:opacity-50"
              >
                {saving ? 'Speichere...' : 'Erstellen'}
              </button>
            </div>
          </div>
        </div>
      )}

      {/* Edit Rule Modal */}
      {editingRule && (
        <div className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center z-50">
          <div className="bg-white rounded-xl p-6 w-full max-w-lg mx-4">
            <h3 className="text-lg font-semibold text-slate-900 mb-4">PII-Regel bearbeiten</h3>

            <div className="space-y-4">
              <div>
                <label className="block text-sm font-medium text-slate-700 mb-1">Name *</label>
                <input
                  type="text"
                  value={editingRule.name}
                  onChange={(e) => setEditingRule({ ...editingRule, name: e.target.value })}
                  className="w-full px-4 py-2 border border-slate-200 rounded-lg focus:ring-2 focus:ring-purple-500 focus:border-transparent"
                />
              </div>

              <div>
                <label className="block text-sm font-medium text-slate-700 mb-1">Typ</label>
                <select
                  value={editingRule.rule_type}
                  onChange={(e) => setEditingRule({ ...editingRule, rule_type: e.target.value })}
                  className="w-full px-4 py-2 border border-slate-200 rounded-lg focus:ring-2 focus:ring-purple-500 focus:border-transparent"
                >
                  {RULE_TYPES.map((t) => (
                    <option key={t.value} value={t.value}>
                      {t.label}
                    </option>
                  ))}
                </select>
              </div>

              <div>
                <label className="block text-sm font-medium text-slate-700 mb-1">Muster *</label>
                <textarea
                  value={editingRule.pattern}
                  onChange={(e) => setEditingRule({ ...editingRule, pattern: e.target.value })}
                  rows={3}
                  className="w-full px-4 py-2 border border-slate-200 rounded-lg focus:ring-2 focus:ring-purple-500 focus:border-transparent font-mono text-sm"
                />
              </div>

              <div>
                <label className="block text-sm font-medium text-slate-700 mb-1">Severity</label>
                <select
                  value={editingRule.severity}
                  onChange={(e) => setEditingRule({ ...editingRule, severity: e.target.value })}
                  className="w-full px-4 py-2 border border-slate-200 rounded-lg focus:ring-2 focus:ring-purple-500 focus:border-transparent"
                >
                  {SEVERITIES.map((s) => (
                    <option key={s.value} value={s.value}>
                      {s.label}
                    </option>
                  ))}
                </select>
              </div>

              <div className="flex items-center gap-2">
                <input
                  type="checkbox"
                  id="edit_is_active"
                  checked={editingRule.is_active}
                  onChange={(e) => setEditingRule({ ...editingRule, is_active: e.target.checked })}
                  className="w-4 h-4 text-purple-600"
                />
                <label htmlFor="edit_is_active" className="text-sm text-slate-700">
                  Aktiv
                </label>
              </div>
            </div>

            <div className="flex justify-end gap-3 mt-6 pt-4 border-t border-slate-100">
              <button
                onClick={() => setEditingRule(null)}
                className="px-4 py-2 text-slate-600 hover:text-slate-700"
              >
                Abbrechen
              </button>
              <button
                onClick={updateRule}
                disabled={saving}
                className="px-6 py-2 bg-purple-600 text-white rounded-lg hover:bg-purple-700 disabled:opacity-50"
              >
                {saving ? 'Speichere...' : 'Speichern'}
              </button>
            </div>
          </div>
        </div>
      )}
    </div>
  )
}