import { useEffect, useState } from 'react'
import { Link } from 'react-router-dom'
import { useAuth } from '../context/AuthContext'
import api from '../utils/api'
import AdminPageNav from '../components/AdminPageNav'
import { resolveMediaAssetFileUrl } from '../utils/exerciseMediaUrl'

const LC_OPTIONS = [
  { value: 'active', label: 'Aktiv' },
  { value: 'trash_soft', label: 'Papierkorb (Stufe 1)' },
  { value: 'trash_hidden', label: 'Ausgeblendet (Stufe 2)' },
  { value: 'all', label: 'Alle (nicht purgiert)' },
]

function lcLabel(code) {
  const o = LC_OPTIONS.find((x) => x.value === code)
  return o ? o.label : code
}

export default function MediaLibraryPage() {
  const { user } = useAuth()
  const isPlatformAdmin = user?.role === 'admin' || user?.role === 'superadmin'
  const [lifecycle, setLifecycle] = useState('active')
  const [q, setQ] = useState('')
  const [items, setItems] = useState([])
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState('')
  /** @type {Record<number, string>} */
  const [copyrightDrafts, setCopyrightDrafts] = useState({})
  const [busyId, setBusyId] = useState(null)

  useEffect(() => {
    let cancelled = false
    const t = setTimeout(async () => {
      setLoading(true)
      setError('')
      try {
        const res = await api.listMediaAssets({
          lifecycle,
          q: q.trim(),
          limit: 100,
          offset: 0,
        })
        if (cancelled) return
        setItems(res.items || [])
        const nx = {}
        for (const it of res.items || []) {
          nx[it.id] = it.copyright_notice != null ? String(it.copyright_notice) : ''
        }
        setCopyrightDrafts(nx)
      } catch (e) {
        if (!cancelled) setError(e.message || String(e))
      } finally {
        if (!cancelled) setLoading(false)
      }
    }, 320)
    return () => {
      cancelled = true
      clearTimeout(t)
    }
  }, [lifecycle, q])

  const refresh = async () => {
    setLoading(true)
    setError('')
    try {
      const res = await api.listMediaAssets({
        lifecycle,
        q: q.trim(),
        limit: 100,
        offset: 0,
      })
      setItems(res.items || [])
      const nx = {}
      for (const it of res.items || []) {
        nx[it.id] = it.copyright_notice != null ? String(it.copyright_notice) : ''
      }
      setCopyrightDrafts(nx)
    } catch (e) {
      setError(e.message || String(e))
    } finally {
      setLoading(false)
    }
  }

  const saveCopyright = async (id) => {
    const text = copyrightDrafts[id]
    if (text === undefined) return
    setBusyId(id)
    try {
      await api.patchMediaAsset(id, { copyright_notice: text })
      await refresh()
    } catch (e) {
      alert(e.message || String(e))
    } finally {
      setBusyId(null)
    }
  }

  const runLifecycle = async (id, action, confirmMsg) => {
    if (confirmMsg && !window.confirm(confirmMsg)) return
    setBusyId(id)
    try {
      await api.postMediaAssetLifecycle(id, action)
      await refresh()
    } catch (e) {
      alert(e.message || String(e))
    } finally {
      setBusyId(null)
    }
  }

  return (
    <div className="app-page media-library-page">
      {isPlatformAdmin ? <AdminPageNav /> : null}
      <div
        style={{
          display: 'flex',
          flexWrap: 'wrap',
          alignItems: 'baseline',
          gap: '12px',
          marginBottom: '12px',
        }}
      >
        <h1 className="page-title" style={{ margin: 0 }}>
          Medienbibliothek
        </h1>
        <Link to="/exercises" style={{ fontSize: '14px' }}>
          Zu den Übungen
        </Link>
        {isPlatformAdmin ? (
          <Link to="/admin/hierarchy" style={{ fontSize: '14px' }}>
            Administration
          </Link>
        ) : null}
      </div>

      <p style={{ color: 'var(--text2)', fontSize: '14px', maxWidth: '52rem', marginTop: 0 }}>
        Sichtbare Medien gemäß deinen Rechten (privat, Verein, offiziell). Papierkorb- und
        Metadaten-Aktionen wie in der Übungsbearbeitung — hier zentral mit Filter.
      </p>

      <div
        className="form-row"
        style={{ flexWrap: 'wrap', gap: '10px', alignItems: 'flex-end', marginBottom: '16px' }}
      >
        <div>
          <label className="form-label" htmlFor="media-lib-q">
            Suche
          </label>
          <input
            id="media-lib-q"
            type="search"
            className="form-input"
            placeholder="Dateiname …"
            value={q}
            onChange={(e) => setQ(e.target.value)}
            style={{ minWidth: '220px' }}
          />
        </div>
        <div>
          <label className="form-label" htmlFor="media-lib-lc">
            Lebenszyklus
          </label>
          <select
            id="media-lib-lc"
            className="form-input"
            value={lifecycle}
            onChange={(e) => setLifecycle(e.target.value)}
          >
            {LC_OPTIONS.map((o) => (
              <option key={o.value} value={o.value}>
                {o.label}
              </option>
            ))}
          </select>
        </div>
        <button type="button" className="btn btn-secondary" onClick={refresh} disabled={loading}>
          Aktualisieren
        </button>
      </div>

      {error ? (
        <p style={{ color: 'var(--danger, crimson)' }} role="alert">
          {error}
        </p>
      ) : null}
      {loading && items.length === 0 ? <div className="spinner" /> : null}

      {!loading && !error && items.length === 0 ? (
        <p style={{ color: 'var(--text2)' }}>Keine Einträge.</p>
      ) : null}

      <div style={{ overflowX: 'auto' }}>
        <table className="table" style={{ width: '100%', fontSize: '14px' }}>
          <thead>
            <tr>
              <th style={{ width: 56 }} aria-hidden />
              <th>Datei</th>
              <th>Sichtbarkeit</th>
              <th>Status</th>
              <th style={{ minWidth: '220px' }}>Copyright</th>
              <th style={{ minWidth: '200px' }}>Aktionen</th>
            </tr>
          </thead>
          <tbody>
            {items.map((it) => {
              const mime = (it.mime_type || '').toLowerCase()
              const isImg = mime.startsWith('image/')
              const busy = busyId === it.id
              const lc = (it.lifecycle_state || '').toLowerCase()
              return (
                <tr key={it.id}>
                  <td>
                    {isImg ? (
                      <img
                        src={resolveMediaAssetFileUrl(it.id)}
                        alt=""
                        width={48}
                        height={48}
                        loading="lazy"
                        style={{
                          objectFit: 'cover',
                          borderRadius: 6,
                          background: 'var(--surface2, #eee)',
                        }}
                        onError={(e) => {
                          e.target.style.visibility = 'hidden'
                        }}
                      />
                    ) : (
                      <div
                        style={{
                          width: 48,
                          height: 48,
                          borderRadius: 6,
                          background: 'var(--surface2, #eee)',
                          fontSize: 10,
                          display: 'flex',
                          alignItems: 'center',
                          justifyContent: 'center',
                          color: 'var(--text2)',
                        }}
                      >
                        {mime.includes('video') ? '▶' : '◆'}
                      </div>
                    )}
                  </td>
                  <td>
                    <div style={{ fontWeight: 600 }}>{it.original_filename || `Asset #${it.id}`}</div>
                    <div style={{ fontSize: '12px', color: 'var(--text2)' }}>
                      ID {it.id}
                      {it.byte_size != null ? ` · ${Math.round(it.byte_size / 1024)} KB` : ''}
                    </div>
                  </td>
                  <td>{it.visibility}</td>
                  <td>{lcLabel(lc)}</td>
                  <td>
                    <textarea
                      className="form-input"
                      rows={2}
                      style={{ width: '100%', resize: 'vertical', minHeight: '48px' }}
                      value={copyrightDrafts[it.id] ?? ''}
                      onChange={(e) =>
                        setCopyrightDrafts((prev) => ({ ...prev, [it.id]: e.target.value }))
                      }
                      disabled={busy}
                    />
                    <button
                      type="button"
                      className="btn btn-secondary"
                      style={{ marginTop: 6 }}
                      disabled={busy}
                      onClick={() => saveCopyright(it.id)}
                    >
                      Copyright speichern
                    </button>
                  </td>
                  <td>
                    <div style={{ display: 'flex', flexDirection: 'column', gap: 6 }}>
                      {lc === 'active' ? (
                        <button
                          type="button"
                          className="btn btn-secondary"
                          disabled={busy}
                          onClick={() =>
                            runLifecycle(
                              it.id,
                              'trash_soft',
                              'Medium in den Papierkorb (Stufe 1) legen?',
                            )
                          }
                        >
                          Papierkorb
                        </button>
                      ) : null}
                      {lc === 'trash_soft' ? (
                        <>
                          <button
                            type="button"
                            className="btn btn-secondary"
                            disabled={busy}
                            onClick={() => runLifecycle(it.id, 'reactivate', null)}
                          >
                            Wieder aktiv
                          </button>
                          <button
                            type="button"
                            className="btn btn-secondary"
                            disabled={busy}
                            onClick={() =>
                              runLifecycle(
                                it.id,
                                'trash_hidden',
                                'Medium ausblenden (Stufe 2)? In öffentlichen Ansichten unsichtbar.',
                              )
                            }
                          >
                            Ausblenden
                          </button>
                        </>
                      ) : null}
                      {lc === 'trash_hidden' ? (
                        <>
                          <button
                            type="button"
                            className="btn btn-secondary"
                            disabled={busy}
                            onClick={() => runLifecycle(it.id, 'recover', null)}
                          >
                            Zurück Stufe 1
                          </button>
                          <button
                            type="button"
                            className="btn btn-secondary"
                            disabled={busy}
                            onClick={() => runLifecycle(it.id, 'reactivate', null)}
                          >
                            Wieder aktiv
                          </button>
                          <button
                            type="button"
                            className="btn btn-secondary"
                            disabled={busy}
                            onClick={() =>
                              runLifecycle(
                                it.id,
                                'purge',
                                'Endgültig löschen (Datei und DB-Eintrag)?',
                              )
                            }
                          >
                            Endgültig löschen
                          </button>
                        </>
                      ) : null}
                    </div>
                  </td>
                </tr>
              )
            })}
          </tbody>
        </table>
      </div>
    </div>
  )
}