import { useCallback, useEffect, useState } from 'react'
import { Navigate } from 'react-router-dom'
import { Sparkles } from 'lucide-react'
import { useAuth } from '../context/AuthContext'
import api from '../utils/api'
import AdminPageNav from '../components/AdminPageNav'

/**
 * Pflege von ai_prompts (OpenRouter-Vorlagen) — nur Superadmin.
 */
export default function AdminAiPromptsPage() {
  const { user } = useAuth()
  const isSuperadmin = user?.role === 'superadmin'

  const [prompts, setPrompts] = useState([])
  const [catalog, setCatalog] = useState(null)
  const [selectedId, setSelectedId] = useState(null)
  const [detail, setDetail] = useState(null)
  const [loading, setLoading] = useState(true)
  const [saving, setSaving] = useState(false)
  const [error, setError] = useState('')

  const [draftName, setDraftName] = useState('')
  const [draftDesc, setDraftDesc] = useState('')
  const [draftTemplate, setDraftTemplate] = useState('')
  const [draftActive, setDraftActive] = useState(true)

  const [pvTitle, setPvTitle] = useState('Testübung')
  const [pvGoal, setPvGoal] = useState('<p>Ziel hier</p>')
  const [pvExec, setPvExec] = useState('<p>Ablauf hier</p>')
  const [pvHint, setPvHint] = useState('')
  const [pvFocusId, setPvFocusId] = useState('')
  const [pvPreview, setPvPreview] = useState(null)

  const loadList = useCallback(async () => {
    const [pList, cat] = await Promise.all([
      api.listAdminAiPrompts(),
      api.getAdminAiPromptPlaceholdersCatalog(),
    ])
    setPrompts(Array.isArray(pList) ? pList : [])
    setCatalog(cat || null)
  }, [])

  useEffect(() => {
    if (!isSuperadmin) return
    let cancelled = false
    ;(async () => {
      setLoading(true)
      setError('')
      try {
        await loadList()
      } catch (e) {
        if (!cancelled) setError(e.message || String(e))
      } finally {
        if (!cancelled) setLoading(false)
      }
    })()
    return () => {
      cancelled = true
    }
  }, [isSuperadmin, loadList])

  useEffect(() => {
    if (!isSuperadmin || !selectedId) {
      setDetail(null)
      return
    }
    let cancelled = false
    ;(async () => {
      try {
        const d = await api.getAdminAiPrompt(selectedId)
        if (!cancelled) {
          setDetail(d)
          setDraftName(d.display_name || '')
          setDraftDesc(d.description || '')
          setDraftTemplate(d.template || '')
          setDraftActive(!!d.active)
          setPvPreview(null)
        }
      } catch (e) {
        if (!cancelled) setError(e.message || String(e))
      }
    })()
    return () => {
      cancelled = true
    }
  }, [isSuperadmin, selectedId])

  const save = async () => {
    if (!detail?.id) return
    setSaving(true)
    setError('')
    try {
      await api.updateAdminAiPrompt(detail.id, {
        template: draftTemplate,
        display_name: draftName,
        description: draftDesc,
        active: draftActive,
      })
      await loadList()
      const nd = await api.getAdminAiPrompt(detail.id)
      setDetail(nd)
      setPvPreview(null)
    } catch (e) {
      setError(e.message || String(e))
    } finally {
      setSaving(false)
    }
  }

  const resetTemplate = async () => {
    if (!detail?.id || !detail.has_reference_template) return
    if (!confirm('Template auf gespeicherten Referenztext zurücksetzen?')) return
    setSaving(true)
    try {
      const nd = await api.resetAdminAiPromptTemplate(detail.id)
      setDetail(nd)
      setDraftTemplate(nd.template || '')
      await loadList()
    } catch (e) {
      setError(e.message || String(e))
    } finally {
      setSaving(false)
    }
  }

  const runPreview = async () => {
    if (!detail?.id) return
    setError('')
    try {
      const body = {
        title: pvTitle,
        goal: pvGoal,
        execution: pvExec,
        focus_hint: pvHint || undefined,
      }
      const fid = parseInt(String(pvFocusId).trim(), 10)
      if (Number.isFinite(fid) && fid >= 1) {
        body.focus_areas_context = [{ focus_area_id: fid, is_primary: true }]
      }
      const r = await api.previewAdminAiPrompt(detail.id, body)
      setPvPreview(r)
    } catch (e) {
      setError(e.message || String(e))
    }
  }

  if (!isSuperadmin) return <Navigate to="/" replace />

  if (loading) {
    return (
      <div style={{ padding: 16 }}>
        <AdminPageNav />
        <div className="card" style={{ marginTop: 16, padding: 24, textAlign: 'center' }}>
          <div className="spinner" />
        </div>
      </div>
    )
  }

  return (
    <div style={{ maxWidth: 1100, margin: '0 auto', padding: '16px', paddingBottom: 96 }}>
      <AdminPageNav />
      <div style={{ display: 'flex', alignItems: 'center', gap: 10, marginBottom: 16 }}>
        <Sparkles size={22} />
        <h1 style={{ margin: 0, fontSize: '1.25rem' }}>KI Prompts</h1>
      </div>
      <p style={{ fontSize: '13px', color: 'var(--text3)', marginTop: 0 }}>
        Datenbankvorlagen (<code>ai_prompts</code>) für Übungs-KI. Platzhalter im Mustache-Stil werden serverseitig
        aufgelöst — die Vorschau unten ruft kein externes Modell auf.
      </p>
      {error ? <p style={{ color: 'var(--danger)' }}>{error}</p> : null}

      <div style={{ display: 'grid', gridTemplateColumns: '260px minmax(0,1fr)', gap: 16 }}>
        <div className="card" style={{ padding: 12 }}>
          <strong style={{ fontSize: '13px' }}>Prompts</strong>
          <ul style={{ listStyle: 'none', padding: 0, margin: '12px 0 0 0', maxHeight: '70vh', overflow: 'auto' }}>
            {(prompts || []).map((p) => (
              <li key={p.id} style={{ marginBottom: 8 }}>
                <button
                  type="button"
                  className={`btn ${selectedId === p.id ? 'btn-primary' : 'btn-secondary'}`}
                  style={{
                    width: '100%',
                    justifyContent: 'flex-start',
                    fontSize: 12,
                    padding: '8px 10px',
                    alignItems: 'flex-start',
                    flexDirection: 'column',
                    textAlign: 'left',
                  }}
                  onClick={() => {
                    setSelectedId(p.id)
                    setError('')
                  }}
                >
                  <span style={{ fontWeight: 600 }}>{p.display_name}</span>
                  <span style={{ opacity: 0.85, marginTop: 2 }}>{p.slug}</span>
                  {!p.active ? (
                    <span style={{ color: 'var(--danger)', fontSize: 11 }}>
                      inaktiv
                    </span>
                  ) : null}
                  {p.is_modified ? <span style={{ fontSize: 11 }}>(von Referenz abweichend)</span> : null}
                </button>
              </li>
            ))}
          </ul>
        </div>

        <div>
          {!selectedId ? (
            <p style={{ color: 'var(--text3)' }}>Prompt links wählen.</p>
          ) : (
            <div className="card" style={{ padding: 16 }}>
              <div style={{ marginBottom: 12 }}>
                <div style={{ fontSize: '12px', color: 'var(--text3)' }}>
                  slug: <code>{detail?.slug}</code> · Ausgabe:{' '}
                  <code>{detail?.output_format}</code> · Kategorie: <code>{detail?.category}</code>
                </div>
                <div className="form-row" style={{ marginTop: 10 }}>
                  <label className="form-label">Name</label>
                  <input className="form-input" value={draftName} onChange={(e) => setDraftName(e.target.value)} />
                </div>
                <div className="form-row">
                  <label className="form-label">Beschreibung</label>
                  <textarea
                    className="form-input"
                    rows={3}
                    value={draftDesc}
                    onChange={(e) => setDraftDesc(e.target.value)}
                  />
                </div>
                <label style={{ display: 'flex', alignItems: 'center', gap: 8, marginBottom: 12 }}>
                  <input type="checkbox" checked={draftActive} onChange={(e) => setDraftActive(e.target.checked)} />
                  Aktiv
                </label>
                <label className="form-label">Template (Mustache-Zeilen mit {'{{'}}name{'}'}})</label>
                <textarea
                  className="form-input"
                  style={{ fontFamily: 'ui-monospace, monospace', fontSize: 12 }}
                  rows={22}
                  value={draftTemplate}
                  onChange={(e) => setDraftTemplate(e.target.value)}
                />
              </div>

              <div style={{ display: 'flex', flexWrap: 'wrap', gap: 8 }}>
                <button type="button" className="btn btn-primary" disabled={saving} onClick={() => save()}>
                  Speichern
                </button>
                <button
                  type="button"
                  className="btn btn-secondary"
                  disabled={saving || !detail?.has_reference_template}
                  title={!detail?.has_reference_template ? 'Nach Migration 069 bzw. manuell default_template gesetzt' : ''}
                  onClick={() => resetTemplate()}
                >
                  Auf Referenz zurücksetzen
                </button>
              </div>

              <details style={{ marginTop: 20 }}>
                <summary style={{ cursor: 'pointer', fontWeight: 600 }}>Platzhalter-Katalog (Übung)</summary>
                {catalog?.placeholders ? (
                  <ul style={{ paddingLeft: 18, marginTop: 8 }}>
                    {catalog.placeholders.map((ph) => (
                      <li key={ph.key} style={{ marginBottom: 10, fontSize: 13 }}>
                        <code>{ph.placeholder}</code> — {ph.description}{' '}
                        <span style={{ color: 'var(--text3)' }}>
                          [{Array.isArray(ph.used_by_slugs) ? ph.used_by_slugs.join(', ') : ''}]
                        </span>
                      </li>
                    ))}
                  </ul>
                ) : (
                  <p>Wird geladen …</p>
                )}
              </details>

              <section style={{ marginTop: 20, paddingTop: 16, borderTop: '1px solid var(--border)' }}>
                <h4 style={{ margin: '0 0 12px', fontSize: '15px' }}>Vorschau (ohne OpenRouter)</h4>
                <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: 12 }}>
                  <div className="form-row">
                    <label className="form-label">Titel</label>
                    <input className="form-input" value={pvTitle} onChange={(e) => setPvTitle(e.target.value)} />
                  </div>
                  <div className="form-row">
                    <label className="form-label">Fokus-ID (optional, Retrieval‑Raster)</label>
                    <input
                      className="form-input"
                      placeholder="numerisch"
                      value={pvFocusId}
                      onChange={(e) => setPvFocusId(e.target.value)}
                    />
                  </div>
                </div>
                <div className="form-row">
                  <label className="form-label">Fokus-Hinweistext</label>
                  <input className="form-input" value={pvHint} onChange={(e) => setPvHint(e.target.value)} />
                </div>
                <div className="form-row">
                  <label className="form-label">Ziel (HTML möglich)</label>
                  <textarea className="form-input" rows={4} value={pvGoal} onChange={(e) => setPvGoal(e.target.value)} />
                </div>
                <div className="form-row">
                  <label className="form-label">Durchführung (HTML möglich)</label>
                  <textarea className="form-input" rows={4} value={pvExec} onChange={(e) => setPvExec(e.target.value)} />
                </div>
                <button type="button" className="btn btn-secondary" onClick={() => runPreview()}>
                  Platzhalter auflösen
                </button>
                {pvPreview?.warning ? (
                  <p style={{ marginTop: 10, color: 'var(--text3)', fontSize: 13 }}>{pvPreview.warning}</p>
                ) : null}
                {pvPreview?.placeholders_remaining?.length ? (
                  <p style={{ color: 'var(--danger)', fontSize: 13 }}>
                    Unbekannte Platzhalter im Ergebnis:{' '}
                    {pvPreview.placeholders_remaining.join(', ')}
                  </p>
                ) : null}
                {pvPreview?.resolved_template != null ? (
                  <pre
                    style={{
                      marginTop: 12,
                      padding: 12,
                      background: 'var(--surface2)',
                      borderRadius: 8,
                      fontSize: 12,
                      whiteSpace: 'pre-wrap',
                      wordBreak: 'break-word',
                      maxHeight: 360,
                      overflow: 'auto',
                    }}
                  >
                    {pvPreview.resolved_template}
                  </pre>
                ) : null}
              </section>
            </div>
          )}
        </div>
      </div>
    </div>
  )
}