'use client'

import React, { useState } from 'react'
import { useAgentAnalysis } from './_hooks/useAgentAnalysis'
import { AnalysisResult } from './_components/AnalysisResult'
import { AnalysisHistory } from './_components/AnalysisHistory'
import { FollowUpQuestions } from './_components/FollowUpQuestions'
import { ScanResult } from './_components/ScanResult'

type AnalysisMode = 'pre_launch' | 'post_launch'
type AnalysisTab = 'quick' | 'scan'

const MODES: { id: AnalysisMode; label: string; desc: string; icon: string }[] = [
  { id: 'pre_launch', label: 'Internes Dokument', desc: 'Vor Veroeffentlichung pruefen', icon: '📋' },
  { id: 'post_launch', label: 'Live-Website', desc: 'Bereits online analysieren', icon: '🌐' },
]

const TABS: { id: AnalysisTab; label: string; info: string }[] = [
  { id: 'quick', label: 'Schnellanalyse', info: 'Analysiert nur die eingegebene URL. Fuer einen umfassenden Check nutzen Sie den Website-Scan.' },
  { id: 'scan', label: 'Website-Scan', info: 'Scannt automatisch 5-10 Unterseiten (Startseite, Datenschutz, Impressum, AGB, Cookies) und gleicht erkannte Dienste mit der Datenschutzerklaerung ab.' },
]

export default function AgentPage() {
  const [url, setUrl] = useState('')
  const [mode, setMode] = useState<AnalysisMode>('post_launch')
  const [tab, setTab] = useState<AnalysisTab>('quick')
  const [scanLoading, setScanLoading] = useState(false)
  const [scanError, setScanError] = useState<string | null>(null)
  const [scanData, setScanData] = useState<any>(null)
  const [scanHistory, setScanHistory] = useState<any[]>([])
  const { analyze, answerFollowUp, loading, error, result, history } = useAgentAnalysis()

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault()
    if (!url.trim()) return

    if (tab === 'quick') {
      analyze(url.trim(), mode)
    } else {
      setScanLoading(true)
      setScanError(null)
      setScanData(null)
      try {
        const res = await fetch('/api/sdk/v1/agent/scan', {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({ url: url.trim(), mode }),
        })
        if (!res.ok) throw new Error(`Scan fehlgeschlagen: ${res.status}`)
        const data = await res.json()
        setScanData(data)
        setScanHistory(prev => [{ url: url.trim(), ...data, scanned_at: new Date().toISOString() }, ...prev].slice(0, 20))
      } catch (e) {
        setScanError(e instanceof Error ? e.message : 'Unbekannter Fehler')
      } finally {
        setScanLoading(false)
      }
    }
  }

  const isLoading = tab === 'quick' ? loading : scanLoading
  const currentError = tab === 'quick' ? error : scanError
  const currentTab = TABS.find(t => t.id === tab)!

  return (
    <div className="space-y-6 max-w-4xl">
      <div>
        <h1 className="text-2xl font-bold text-gray-900">Compliance Agent</h1>
        <p className="text-gray-500 mt-1">Analysiere Dokumente und Webseiten auf DSGVO-Konformitaet.</p>
      </div>

      {/* Mode Selection */}
      <div className="grid grid-cols-2 gap-3">
        {MODES.map(m => (
          <button key={m.id} onClick={() => setMode(m.id)}
            className={`p-3 rounded-xl border-2 text-left transition-all ${
              mode === m.id ? 'border-purple-500 bg-purple-50' : 'border-gray-200 hover:border-gray-300'}`}>
            <div className="flex items-center gap-3">
              <span className="text-xl">{m.icon}</span>
              <div>
                <p className={`text-sm font-semibold ${mode === m.id ? 'text-purple-900' : 'text-gray-900'}`}>{m.label}</p>
                <p className="text-xs text-gray-500">{m.desc}</p>
              </div>
            </div>
          </button>
        ))}
      </div>

      {/* Tab Selection + Info */}
      <div>
        <div className="flex border-b border-gray-200">
          {TABS.map(t => (
            <button key={t.id} onClick={() => setTab(t.id)}
              className={`px-4 py-2.5 text-sm font-medium border-b-2 transition-colors ${
                tab === t.id
                  ? 'border-purple-500 text-purple-700'
                  : 'border-transparent text-gray-500 hover:text-gray-700'}`}>
              {t.label}
            </button>
          ))}
        </div>
        <p className="text-xs text-gray-400 mt-2 px-1">{currentTab.info}</p>
      </div>

      {/* URL Input */}
      <form onSubmit={handleSubmit} className="flex gap-3">
        <input type="url" value={url} onChange={e => setUrl(e.target.value)}
          placeholder={tab === 'scan' ? 'https://www.example.com/' : 'https://example.com/datenschutz'}
          className="flex-1 px-4 py-3 border border-gray-300 rounded-lg focus:ring-2 focus:ring-purple-500 focus:border-transparent text-sm"
          disabled={isLoading} required />
        <button type="submit" disabled={isLoading || !url.trim()}
          className="px-6 py-3 bg-purple-600 text-white rounded-lg hover:bg-purple-700 disabled:opacity-50 transition-colors flex items-center gap-2 text-sm font-medium">
          {isLoading ? (
            <><svg className="animate-spin w-4 h-4" fill="none" viewBox="0 0 24 24">
              <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
              <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z" />
            </svg>{tab === 'scan' ? 'Scanne...' : 'Analysiere...'}</>
          ) : tab === 'scan' ? 'Website scannen' : 'Analysieren'}
        </button>
      </form>

      {/* Error */}
      {currentError && (
        <div className="bg-red-50 border border-red-200 rounded-lg p-4 text-sm text-red-700">{currentError}</div>
      )}

      {/* Quick Analysis Result */}
      {tab === 'quick' && result && (
        <div className="bg-white border border-gray-200 rounded-xl p-6 shadow-sm space-y-6">
          <AnalysisResult result={result} />
          {result.follow_up_questions.length > 0 && (
            <div className="border-t pt-4">
              <FollowUpQuestions questions={result.follow_up_questions} answers={result.follow_up_answers} onAnswer={answerFollowUp} />
            </div>
          )}
        </div>
      )}

      {/* Scan Result */}
      {tab === 'scan' && scanData && (
        <div className="bg-white border border-gray-200 rounded-xl p-6 shadow-sm">
          <ScanResult data={scanData} />
        </div>
      )}

      {/* History */}
      {tab === 'quick' && (
        <AnalysisHistory history={history} onSelect={r => { setUrl(r.url); analyze(r.url, mode) }} />
      )}
      {tab === 'scan' && scanHistory.length > 0 && (
        <div>
          <h3 className="text-sm font-medium text-gray-700 mb-3">Letzte Scans</h3>
          <div className="space-y-2">
            {scanHistory.map((item, i) => (
              <button key={i} onClick={() => { setUrl(item.url); }}
                className="w-full text-left p-3 bg-white border border-gray-200 rounded-lg hover:border-purple-300 hover:bg-purple-50 transition-colors">
                <div className="flex items-center gap-3">
                  <span className="text-xs font-medium text-gray-500 w-8">{item.pages_scanned}p</span>
                  <span className="text-sm text-gray-700 truncate flex-1">{item.url}</span>
                  <span className={`text-xs px-2 py-0.5 rounded ${item.findings?.length > 0 ? 'bg-red-100 text-red-700' : 'bg-green-100 text-green-700'}`}>
                    {item.findings?.length || 0} Findings
                  </span>
                  <span className="text-xs text-gray-400">
                    {new Date(item.scanned_at).toLocaleTimeString('de-DE', { hour: '2-digit', minute: '2-digit' })}
                  </span>
                </div>
              </button>
            ))}
          </div>
        </div>
      )}
    </div>
  )
}