'use client'

/**
 * Snapshot-Detail — öffnet einen gespeicherten Check aus der Historie und
 * zeigt die Ergebnis-Views aus den Rohdaten (kein Re-Crawl), als Modul-Tabs:
 * Cookies & Tracking + Impressum (DSE/AGB folgen). Impressum wird beim Öffnen
 * des Tabs nachgeladen (ImpressumAgent auf dem gespeicherten Text).
 */

import React, { use as useUnwrap, useEffect, useMemo, useState } from 'react'
import Link from 'next/link'

import { CookieLibraryPanel } from '../../_components/CookieLibraryPanel'
import { CookieResultView } from '../../_components/CookieResultView'
import { AgentResultTab } from '../../_components/AgentResultTab'

export default function SnapshotDetail(
  { params }: { params: Promise<{ snapshotId: string }> },
) {
  const { snapshotId } = useUnwrap(params)
  const [snap, setSnap] = useState<any>(null)
  const [check, setCheck] = useState<any>(null)            // cookie-check
  const [impressum, setImpressum] = useState<any>(null)    // impressum-check (lazy)
  const [impLoading, setImpLoading] = useState(false)
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState<string | null>(null)
  const [tab, setTab] = useState<string>('')

  useEffect(() => {
    let cancelled = false
    fetch(`/api/sdk/v1/agent/snapshots/${snapshotId}`)
      .then(r => r.json())
      .then(d => {
        if (cancelled) return
        if (d?.error) setError(d.error); else setSnap(d)
      })
      .catch(e => { if (!cancelled) setError(String(e)) })
      .finally(() => { if (!cancelled) setLoading(false) })
    return () => { cancelled = true }
  }, [snapshotId])

  // Cookie-Abgleich einmal laden (Findings + cookie_categories für beide Views).
  useEffect(() => {
    let cancelled = false
    fetch(`/api/sdk/v1/agent/snapshots/${snapshotId}/cookie-check`)
      .then(r => r.json())
      .then(d => { if (!cancelled) setCheck(d) })
      .catch(() => { if (!cancelled) setCheck(null) })
    return () => { cancelled = true }
  }, [snapshotId])

  const docs = snap?.doc_entries || []
  const hasCookies = (snap?.cmp_vendors?.length ?? 0) > 0
  const hasImpressum = docs.some(
    (e: any) => e.doc_type === 'impressum' && (e.text || e.content || '').length > 100)

  const modules = useMemo(() => [
    ...(hasCookies ? [{ key: 'cookie', label: 'Cookies & Tracking' }] : []),
    ...(hasImpressum ? [{ key: 'impressum', label: 'Impressum' }] : []),
  ], [hasCookies, hasImpressum])

  useEffect(() => {
    if (!tab && modules.length) setTab(modules[0].key)
  }, [modules, tab])

  // Impressum erst beim Öffnen des Tabs analysieren (ImpressumAgent, ggf. LLM).
  useEffect(() => {
    if (tab !== 'impressum' || impressum || impLoading) return
    setImpLoading(true)
    fetch(`/api/sdk/v1/agent/snapshots/${snapshotId}/impressum-check`)
      .then(r => r.json())
      .then(setImpressum)
      .catch(() => setImpressum({ error: 'Impressum-Analyse fehlgeschlagen', findings: [] }))
      .finally(() => setImpLoading(false))
  }, [tab, snapshotId, impressum, impLoading])

  const tabBtn = (key: string, label: string) => (
    <button key={key} onClick={() => setTab(key)}
      className={`px-3 py-1.5 text-sm border-b-2 -mb-px ${tab === key ? 'border-blue-600 text-blue-700 font-medium' : 'border-transparent text-gray-500 hover:text-gray-700'}`}>
      {label}
    </button>
  )

  return (
    <div className="p-6 max-w-6xl space-y-4">
      <Link href="/sdk/agent/snapshots" className="text-xs text-blue-700 hover:underline">
        ‹ Zurück zur Historie
      </Link>
      {loading ? (
        <div className="text-sm text-gray-500">Lade Snapshot…</div>
      ) : error || !snap ? (
        <div className="text-sm text-red-600">Snapshot nicht gefunden.</div>
      ) : modules.length === 0 ? (
        <div className="text-sm text-gray-500">
          Dieser Snapshot enthält keine auswertbaren Daten.
        </div>
      ) : (
        <>
          <div className="flex gap-1 border-b border-gray-200">
            {modules.map(m => tabBtn(m.key, m.label))}
          </div>

          {tab === 'cookie' && hasCookies && (
            <div className="space-y-4">
              <CookieLibraryPanel snapshotId={snapshotId} data={check ?? undefined} />
              <CookieResultView snapshot={snap} cookieCategories={check?.cookie_categories} />
            </div>
          )}

          {tab === 'impressum' && (
            impLoading ? (
              <div className="text-sm text-gray-500">Impressum-Analyse läuft…</div>
            ) : impressum?.error ? (
              <div className="text-sm text-red-600">{impressum.error}</div>
            ) : impressum && (impressum.findings?.length || impressum.mc_coverage?.length) ? (
              <AgentResultTab topicLabel="Impressum" output={impressum} />
            ) : impressum ? (
              <div className="text-sm text-gray-500">
                {impressum.notes || 'Keine Impressum-Auswertung verfügbar.'}
              </div>
            ) : null
          )}
        </>
      )}
    </div>
  )
}