'use client'

import React, { useState } from 'react'

interface GapItem {
  control_id: string
  control_title: string
  control_domain: string
  status: string
  priority: string
  obligation_ids: string[]
  required_by_count: number
}

interface PriorityAction {
  rank: number
  action: string
  control_ids: string[]
  impact: string
  effort: string
}

interface DomainGap {
  domain_id: string
  domain_name: string
  total_controls: number
  implemented_controls: number
  compliance_percent: number
}

interface GapAnalysisResult {
  compliance_percent: number
  total_controls: number
  implemented_controls: number
  partial_controls: number
  missing_controls: number
  gaps: GapItem[]
  priority_actions: PriorityAction[]
  by_domain: Record<string, DomainGap>
}

const UCCA_API = '/api/sdk/v1/ucca/obligations'

const DOMAIN_LABELS: Record<string, string> = {
  GOV: 'Governance', HR: 'Human Resources', IAM: 'Identity & Access',
  AC: 'Access Control', CRYPTO: 'Kryptographie', LOG: 'Logging & Monitoring',
  SDLC: 'Softwareentwicklung', OPS: 'Betrieb', NET: 'Netzwerk',
  BCP: 'Business Continuity', VENDOR: 'Lieferanten', DATA: 'Datenschutz',
}

const IMPACT_COLORS: Record<string, string> = {
  critical: 'text-red-700 bg-red-50',
  high: 'text-orange-700 bg-orange-50',
  medium: 'text-yellow-700 bg-yellow-50',
  low: 'text-green-700 bg-green-50',
}

export default function GapAnalysisView() {
  const [result, setResult] = useState<GapAnalysisResult | null>(null)
  const [loading, setLoading] = useState(false)
  const [error, setError] = useState<string | null>(null)

  const runAnalysis = async () => {
    setLoading(true)
    setError(null)
    try {
      const res = await fetch(`${UCCA_API}/gap-analysis`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ control_status_map: {} }),
      })
      if (!res.ok) throw new Error(`HTTP ${res.status}`)
      setResult(await res.json())
    } catch (e) {
      setError(e instanceof Error ? e.message : 'Analyse fehlgeschlagen')
    } finally {
      setLoading(false)
    }
  }

  if (!result) {
    return (
      <div className="bg-white rounded-xl border border-gray-200 p-6 text-center">
        <div className="w-12 h-12 mx-auto bg-purple-50 rounded-full flex items-center justify-center mb-3">
          <svg className="w-6 h-6 text-purple-600" fill="none" stroke="currentColor" viewBox="0 0 24 24">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 19v-6a2 2 0 00-2-2H5a2 2 0 00-2 2v6a2 2 0 002 2h2a2 2 0 002-2zm0 0V9a2 2 0 012-2h2a2 2 0 012 2v10m-6 0a2 2 0 002 2h2a2 2 0 002-2m0 0V5a2 2 0 012-2h2a2 2 0 012 2v14a2 2 0 01-2 2h-2a2 2 0 01-2-2z" />
          </svg>
        </div>
        <h3 className="text-sm font-semibold text-gray-900">TOM Gap-Analyse</h3>
        <p className="text-xs text-gray-500 mt-1 mb-4">
          Vergleicht erforderliche TOM Controls mit dem aktuellen Implementierungsstatus.
        </p>
        {error && <p className="text-xs text-red-600 mb-3">{error}</p>}
        <button
          onClick={runAnalysis}
          disabled={loading}
          className="px-5 py-2 bg-purple-600 text-white text-sm rounded-lg hover:bg-purple-700 disabled:opacity-50"
        >
          {loading ? 'Analysiere...' : 'Gap-Analyse starten'}
        </button>
      </div>
    )
  }

  const domains = Object.values(result.by_domain).sort((a, b) => a.compliance_percent - b.compliance_percent)

  return (
    <div className="space-y-4">
      {/* Compliance Score */}
      <div className="bg-white rounded-xl border border-gray-200 p-6">
        <div className="flex items-center justify-between mb-4">
          <h3 className="text-sm font-semibold text-gray-900">Compliance-Status</h3>
          <button
            onClick={runAnalysis}
            disabled={loading}
            className="text-xs text-purple-600 hover:text-purple-700"
          >
            {loading ? 'Aktualisiere...' : 'Aktualisieren'}
          </button>
        </div>

        <div className="flex items-center gap-6">
          <div className="flex-shrink-0">
            <div className={`text-4xl font-bold ${result.compliance_percent >= 80 ? 'text-green-600' : result.compliance_percent >= 50 ? 'text-yellow-600' : 'text-red-600'}`}>
              {Math.round(result.compliance_percent)}%
            </div>
            <p className="text-xs text-gray-500">Compliance</p>
          </div>
          <div className="flex-1">
            <div className="w-full bg-gray-200 rounded-full h-3">
              <div
                className={`h-3 rounded-full transition-all ${result.compliance_percent >= 80 ? 'bg-green-500' : result.compliance_percent >= 50 ? 'bg-yellow-500' : 'bg-red-500'}`}
                style={{ width: `${Math.min(result.compliance_percent, 100)}%` }}
              />
            </div>
            <div className="flex justify-between mt-2 text-xs text-gray-500">
              <span>{result.implemented_controls} implementiert</span>
              <span>{result.partial_controls} teilweise</span>
              <span>{result.missing_controls} fehlend</span>
            </div>
          </div>
        </div>
      </div>

      {/* Domain Breakdown */}
      {domains.length > 0 && (
        <div className="bg-white rounded-xl border border-gray-200 p-5">
          <h4 className="text-sm font-semibold text-gray-900 mb-3">Nach Domaene</h4>
          <div className="space-y-2">
            {domains.map(d => (
              <div key={d.domain_id} className="flex items-center gap-3">
                <span className="text-xs text-gray-600 w-32 flex-shrink-0 truncate">
                  {DOMAIN_LABELS[d.domain_id] || d.domain_id}
                </span>
                <div className="flex-1 bg-gray-100 rounded-full h-2">
                  <div
                    className={`h-2 rounded-full ${d.compliance_percent >= 80 ? 'bg-green-400' : d.compliance_percent >= 50 ? 'bg-yellow-400' : 'bg-red-400'}`}
                    style={{ width: `${Math.min(d.compliance_percent, 100)}%` }}
                  />
                </div>
                <span className="text-xs text-gray-500 w-14 text-right">
                  {d.implemented_controls}/{d.total_controls}
                </span>
              </div>
            ))}
          </div>
        </div>
      )}

      {/* Priority Actions */}
      {result.priority_actions.length > 0 && (
        <div className="bg-white rounded-xl border border-gray-200 p-5">
          <h4 className="text-sm font-semibold text-gray-900 mb-3">Prioritaere Massnahmen</h4>
          <div className="space-y-2">
            {result.priority_actions.slice(0, 5).map(a => (
              <div key={a.rank} className="flex items-start gap-3 p-3 bg-gray-50 rounded-lg">
                <span className="text-xs font-bold text-purple-600 bg-purple-50 rounded-full w-6 h-6 flex items-center justify-center flex-shrink-0">
                  {a.rank}
                </span>
                <div className="flex-1 min-w-0">
                  <p className="text-sm text-gray-900">{a.action}</p>
                  <div className="flex items-center gap-2 mt-1">
                    <span className={`text-[10px] px-1.5 py-0.5 rounded ${IMPACT_COLORS[a.impact] || 'bg-gray-100 text-gray-600'}`}>
                      {a.impact}
                    </span>
                    <span className="text-[10px] text-gray-400">
                      Aufwand: {a.effort}
                    </span>
                    <span className="text-[10px] text-gray-400">
                      {a.control_ids.length} Controls
                    </span>
                  </div>
                </div>
              </div>
            ))}
          </div>
        </div>
      )}

      {/* Gap List */}
      {result.gaps.length > 0 && (
        <div className="bg-white rounded-xl border border-gray-200 p-5">
          <h4 className="text-sm font-semibold text-gray-900 mb-3">
            Offene Gaps ({result.gaps.length})
          </h4>
          <div className="space-y-1 max-h-64 overflow-y-auto">
            {result.gaps.map(g => (
              <div key={g.control_id} className="flex items-center justify-between py-2 px-3 hover:bg-gray-50 rounded text-xs">
                <div className="flex items-center gap-2 min-w-0">
                  <span className="font-mono text-purple-600 flex-shrink-0">{g.control_id}</span>
                  <span className="text-gray-700 truncate">{g.control_title}</span>
                </div>
                <div className="flex items-center gap-2 flex-shrink-0">
                  <span className={`px-1.5 py-0.5 rounded ${g.status === 'NOT_IMPLEMENTED' ? 'bg-red-50 text-red-600' : 'bg-yellow-50 text-yellow-600'}`}>
                    {g.status === 'NOT_IMPLEMENTED' ? 'Fehlend' : 'Teilweise'}
                  </span>
                  <span className="text-gray-400">{g.required_by_count}x</span>
                </div>
              </div>
            ))}
          </div>
        </div>
      )}
    </div>
  )
}