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

const CLUB_ROLE_OPTIONS = [
  { code: 'club_admin', label: 'Vereinsadmin' },
  { code: 'trainer', label: 'Trainer' },
  { code: 'division_lead', label: 'Spartenleitung' },
  { code: 'content_editor', label: 'Inhalte bearbeiten' },
]

const PORTAL_ROLE_LABEL = {
  user: 'Nutzer',
  trainer: 'Portal-Trainer',
  admin: 'Portal-Administrator',
  superadmin: 'Super-Administrator',
}

function portalRoleSelectOptions(viewerIsSuperadmin, currentRole) {
  const base = [
    { value: 'user', label: PORTAL_ROLE_LABEL.user },
    { value: 'trainer', label: `${PORTAL_ROLE_LABEL.trainer} (Legacy)` },
    { value: 'admin', label: PORTAL_ROLE_LABEL.admin },
  ]
  const cur = (currentRole || 'user').toLowerCase()
  if (viewerIsSuperadmin) base.push({ value: 'superadmin', label: PORTAL_ROLE_LABEL.superadmin })
  const values = new Set(base.map((x) => x.value))
  if (cur && !values.has(cur)) {
    base.unshift({ value: cur, label: cur })
  }
  return base
}

/**
 * Nur Super-Admins — globale Nutzer- und Portal-Rollen plus Vereinszuordnung pro Profil.
 * Vereinsorganisation (Mitglieder, Anträge, Rollen vor Ort): unter Vereine → Mitglieder.
 */
export default function AdminUsersPage() {
  const { user } = useAuth()
  const isSuperadminViewer = user?.role === 'superadmin'

  const [platformUsers, setPlatformUsers] = useState([])
  const [clubs, setClubs] = useState([])
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState('')
  const [portalDraft, setPortalDraft] = useState({})
  const [assignModal, setAssignModal] = useState(null)
  const [assignRoles, setAssignRoles] = useState(['trainer'])
  const [clubEditModal, setClubEditModal] = useState(null)
  const [pwdModal, setPwdModal] = useState(null)
  const [pwdNew, setPwdNew] = useState('')
  const [pwdNew2, setPwdNew2] = useState('')

  const loadPlatform = useCallback(async () => {
    const [u, c] = await Promise.all([api.listAdminUsers(), api.listClubs()])
    setPlatformUsers(Array.isArray(u) ? u : [])
    setClubs(Array.isArray(c) ? c : [])
    const d = {}
    for (const row of u || []) {
      d[row.id] = { role: (row.role || 'user').toLowerCase() }
    }
    setPortalDraft(d)
  }, [])

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

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

  const savePortal = async (profileId) => {
    const dr = portalDraft[profileId]
    if (!dr) return
    try {
      await api.updateProfile(profileId, { role: dr.role })
      await loadPlatform()
    } catch (e) {
      alert(e.message || String(e))
    }
  }

  const submitAssignClub = async () => {
    if (!assignModal) return
    const clubId = assignModal.clubId
    const profileId = assignModal.profileId
    if (!clubId || !assignRoles.length) {
      alert('Verein und mindestens eine Rolle wählen.')
      return
    }
    try {
      await api.addClubMember(clubId, { profile_id: profileId, roles: assignRoles })
      setAssignModal(null)
      setAssignRoles(['trainer'])
      await loadPlatform()
    } catch (e) {
      alert(e.message || String(e))
    }
  }

  const saveClubMembership = async () => {
    if (!clubEditModal) return
    const { clubId, profileId, roles, status } = clubEditModal
    try {
      await api.updateClubMember(clubId, profileId, { roles, status })
      setClubEditModal(null)
      await loadPlatform()
    } catch (e) {
      alert(e.message || String(e))
    }
  }

  const removeClubMembership = async () => {
    if (!clubEditModal) return
    if (!confirm('Mitgliedschaft in diesem Verein wirklich entfernen?')) return
    try {
      await api.removeClubMember(clubEditModal.clubId, clubEditModal.profileId)
      setClubEditModal(null)
      await loadPlatform()
    } catch (e) {
      alert(e.message || String(e))
    }
  }

  const submitPasswordEmail = async () => {
    if (!pwdModal) return
    try {
      const res = await api.managementPasswordReset(pwdModal.profileId, null)
      setPwdModal(null)
      setPwdNew('')
      setPwdNew2('')
      let msg =
        'Sofern eine E-Mail-Adresse hinterlegt ist, wurde ein Link zum Setzen eines neuen Passworts versendet. Das bisherige Passwort bleibt bis zur Bestätigung im Link aktiv.'
      if (res?.email_sent === false) {
        msg += ' Hinweis: Der E-Mail-Versand ist fehlgeschlagen (SMTP prüfen).'
      }
      alert(msg)
    } catch (e) {
      alert(e.message || String(e))
    }
  }

  const submitPasswordDirect = async () => {
    if (!pwdModal) return
    if (pwdNew.length < 8) {
      alert('Mindestens 8 Zeichen.')
      return
    }
    if (pwdNew !== pwdNew2) {
      alert('Die beiden Passwörter stimmen nicht überein.')
      return
    }
    try {
      await api.managementPasswordReset(pwdModal.profileId, pwdNew)
      setPwdModal(null)
      setPwdNew('')
      setPwdNew2('')
      alert('Neues Passwort wurde direkt gesetzt.')
    } catch (e) {
      alert(e.message || String(e))
    }
  }

  return (
    <div className="app-page">
      <AdminPageNav />

      <h1 style={{ marginTop: 0 }}>Globale Nutzer &amp; Portal-Rollen</h1>

      <>
        <p style={{ color: 'var(--text2)', maxWidth: '52rem', lineHeight: 1.55, marginBottom: '0.75rem' }}>
          Plattformweite Konten und Vereinszuordnungen im Überblick. <strong>Vereinsmitgliedschaft vor Ort</strong>{' '}
          (Mitglieder, Beitrittsanträge, Vereinszugriffe) liegt unter <strong>Vereine → Mitglieder</strong>. Die
          geschützten <strong>/admin</strong>-Menüpunkte (Hierarchie, Kataloge, …) gibt es nur noch hier für Super-Admins.
        </p>
        <div
          className="card"
          style={{
            marginBottom: '1.25rem',
            padding: '0.85rem 1rem',
            maxWidth: '52rem',
            fontSize: '0.92rem',
            lineHeight: 1.5,
            color: 'var(--text2)',
          }}
        >
          <strong style={{ color: 'var(--text1)' }}>Portal-Rollen auf Profil-Ebene:</strong>
          <ul style={{ margin: '0.5rem 0 0', paddingLeft: '1.2rem' }}>
            <li>
              <strong>Nutzer</strong> — Standard ohne globale Administrationsbereiche.
            </li>
            <li>
              <strong>Portal-Trainer (Legacy)</strong> — historische Kennzeichnung; organisatorisch ist „Trainer“ meist eine{' '}
              <strong>Vereinsrolle</strong>.
            </li>
            <li>
              <strong>Portal-Administrator</strong> — erhöhte API-/Operativ-Rechte nach Backend-Policies; die{' '}
              <strong>Admin-Navigation dieser App</strong> sieht jedoch nur noch der Super-Admin.
            </li>
            <li>
              <strong>Super-Administrator</strong> — volle Plattform-Governance (diese Oberfläche, offizielle Inhalte, …).
            </li>
          </ul>
        </div>
      </>

      {loading ? (
        <p style={{ color: 'var(--text2)' }}>Laden…</p>
      ) : error ? (
        <div className="card" style={{ borderColor: 'var(--danger)', color: 'var(--danger)' }}>
          {error}
        </div>
      ) : (
        <div style={{ display: 'grid', gap: '1rem' }}>
          {platformUsers.map((row) => {
            const portalRoleChoices = portalRoleSelectOptions(isSuperadminViewer, row.role)
            return (
              <div key={row.id} className="card">
                <div style={{ display: 'flex', justifyContent: 'space-between', flexWrap: 'wrap', gap: '0.75rem' }}>
                  <div>
                    <strong style={{ fontSize: '1.05rem' }}>
                      {row.name || '—'} <span style={{ color: 'var(--text2)', fontWeight: 400 }}>#{row.id}</span>
                    </strong>
                    <div style={{ fontSize: '0.875rem', color: 'var(--text2)' }}>{row.email || '—'}</div>
                    <div style={{ fontSize: '0.78rem', color: 'var(--text3)', marginTop: '0.35rem' }}>
                      Verifiziert: {row.email_verified ? 'ja' : 'nein'}
                    </div>
                  </div>
                  <div style={{ display: 'flex', flexWrap: 'wrap', gap: '0.5rem', alignItems: 'flex-end' }}>
                    <div>
                      <label className="form-label" style={{ fontSize: '0.75rem' }}>
                        Portal-Zugriff
                      </label>
                      <select
                        className="form-input"
                        style={{ minWidth: '200px' }}
                        value={(portalDraft[row.id]?.role || row.role || 'user').toLowerCase()}
                        onChange={(e) =>
                          setPortalDraft((prev) => ({
                            ...prev,
                            [row.id]: { role: e.target.value },
                          }))
                        }
                      >
                        {portalRoleChoices.map((r) => (
                          <option key={r.value} value={r.value}>
                            {r.label}
                          </option>
                        ))}
                      </select>
                    </div>
                    <button
                      type="button"
                      className="btn btn-secondary"
                      disabled={row.id === user?.id}
                      title={row.id === user?.id ? 'Eigenes Passwort unter Einstellungen' : undefined}
                      onClick={() =>
                        setPwdModal({
                          profileId: row.id,
                          label: row.name || row.email || `#${row.id}`,
                        })
                      }
                    >
                      Passwort / Link
                    </button>
                    <button type="button" className="btn btn-secondary" onClick={() => savePortal(row.id)}>
                      Portal speichern
                    </button>
                    <button
                      type="button"
                      className="btn btn-primary"
                      disabled={!clubs.length}
                      title={!clubs.length ? 'Zuerst einen Verein anlegen' : undefined}
                      onClick={() => {
                        if (!clubs.length) return
                        setAssignRoles(['trainer'])
                        setAssignModal({
                          profileId: row.id,
                          profileLabel: row.name || row.email || `#${row.id}`,
                          clubId: clubs[0]?.id ?? '',
                        })
                      }}
                    >
                      Verein zuweisen
                    </button>
                  </div>
                </div>

                <div style={{ marginTop: '1rem', paddingTop: '0.75rem', borderTop: '1px solid var(--border)' }}>
                  <strong style={{ fontSize: '0.85rem' }}>Vereinsmitgliedschaften</strong>
                  {!row.clubs?.length ? (
                    <p style={{ color: 'var(--text2)', fontSize: '0.875rem', margin: '0.35rem 0 0' }}>
                      Keine Zuordnung.
                    </p>
                  ) : (
                    <ul style={{ margin: '0.5rem 0 0', paddingLeft: '1.2rem', fontSize: '0.9rem' }}>
                      {(row.clubs || []).map((c) => (
                        <li key={c.id} style={{ marginBottom: '0.35rem' }}>
                          <strong>{c.name}</strong>
                          {c.abbreviation ? ` (${c.abbreviation})` : ''} —{' '}
                          {(c.roles || []).join(', ') || '—'}
                          {c.membership_status === 'inactive' ? (
                            <span style={{ color: 'var(--warning, #d4a012)', fontSize: '0.8rem', fontWeight: 600 }}>
                              {' '}
                              (Vereinszugang deaktiviert)
                            </span>
                          ) : null}{' '}
                          <button
                            type="button"
                            style={{
                              marginLeft: '0.35rem',
                              fontSize: '0.75rem',
                              padding: '0.12rem 0.45rem',
                              borderRadius: '6px',
                              border: '1px solid var(--border)',
                              background: 'var(--surface2)',
                              cursor: 'pointer',
                            }}
                            onClick={() =>
                              setClubEditModal({
                                clubId: c.id,
                                clubName: c.name,
                                profileId: row.id,
                                profileLabel: row.name || row.email,
                                roles: [...(c.roles || [])],
                                status: (c.membership_status || 'active').toLowerCase(),
                              })
                            }
                          >
                            bearbeiten
                          </button>
                          {c.membership_status === 'inactive' ? (
                            <button
                              type="button"
                              style={{
                                marginLeft: '0.35rem',
                                fontSize: '0.75rem',
                                padding: '0.12rem 0.45rem',
                                borderRadius: '6px',
                                border: '1px solid var(--accent, #0366d6)',
                                background: 'var(--surface)',
                                cursor: 'pointer',
                              }}
                              onClick={async () => {
                                try {
                                  await api.updateClubMember(c.id, row.id, {
                                    roles: [...(c.roles || [])],
                                    status: 'active',
                                  })
                                  await loadPlatform()
                                } catch (e) {
                                  alert(e.message || String(e))
                                }
                              }}
                            >
                              Zugang aktivieren
                            </button>
                          ) : null}
                        </li>
                      ))}
                    </ul>
                  )}
                </div>
              </div>
            )
          })}
        </div>
      )}

      {assignModal && (
        <div
          style={{
            position: 'fixed',
            inset: 0,
            background: 'rgba(0,0,0,0.5)',
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center',
            zIndex: 1200,
            padding: '1rem',
          }}
        >
          <div
            style={{
              background: 'var(--surface)',
              borderRadius: '12px',
              padding: '1.5rem',
              maxWidth: '440px',
              width: '100%',
            }}
          >
            <h2 style={{ marginTop: 0 }}>Verein zuweisen</h2>
            <p style={{ color: 'var(--text2)', fontSize: '0.9rem' }}>{assignModal.profileLabel}</p>
            <div className="form-row">
              <label className="form-label">Verein</label>
              <select
                className="form-input"
                value={assignModal.clubId === '' ? '' : String(assignModal.clubId)}
                onChange={(e) =>
                  setAssignModal((prev) =>
                    prev ? { ...prev, clubId: e.target.value ? parseInt(e.target.value, 10) : '' } : prev
                  )
                }
              >
                {clubs.map((c) => (
                  <option key={c.id} value={String(c.id)}>
                    {c.name}
                  </option>
                ))}
              </select>
            </div>
            <div className="form-row">
              <span className="form-label">Rollen im Verein</span>
              <div style={{ display: 'flex', flexDirection: 'column', gap: '0.35rem' }}>
                {CLUB_ROLE_OPTIONS.map((opt) => (
                  <label key={opt.code} style={{ display: 'flex', alignItems: 'center', gap: '0.35rem' }}>
                    <input
                      type="checkbox"
                      checked={assignRoles.includes(opt.code)}
                      onChange={() => {
                        setAssignRoles((prev) => {
                          const s = new Set(prev)
                          if (s.has(opt.code)) s.delete(opt.code)
                          else s.add(opt.code)
                          const out = Array.from(s)
                          return out.length ? out : ['trainer']
                        })
                      }}
                    />
                    {opt.label}
                  </label>
                ))}
              </div>
            </div>
            <div style={{ display: 'flex', gap: '0.5rem', marginTop: '1rem' }}>
              <button type="button" className="btn btn-primary" style={{ flex: 1 }} onClick={submitAssignClub}>
                Zuweisen
              </button>
              <button type="button" className="btn btn-secondary" onClick={() => setAssignModal(null)}>
                Abbrechen
              </button>
            </div>
          </div>
        </div>
      )}

      {clubEditModal && (
        <div
          style={{
            position: 'fixed',
            inset: 0,
            background: 'rgba(0,0,0,0.5)',
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center',
            zIndex: 1200,
            padding: '1rem',
          }}
        >
          <div
            style={{
              background: 'var(--surface)',
              borderRadius: '12px',
              padding: '1.5rem',
              maxWidth: '440px',
              width: '100%',
            }}
          >
            <h2 style={{ marginTop: 0 }}>Vereinsmitgliedschaft</h2>
            <p style={{ color: 'var(--text2)', fontSize: '0.9rem' }}>
              {clubEditModal.profileLabel} → {clubEditModal.clubName}
            </p>
            <p className="muted" style={{ fontSize: '0.82rem', lineHeight: 1.45 }}>
              „Deaktiviert“ betrifft nur den Zugriff auf Inhalte dieses Vereins; Login und andere Vereine bleiben unberührt.
            </p>
            <div className="form-row">
              <label className="form-label">Vereinszugang</label>
              <select
                className="form-input"
                value={clubEditModal.status}
                onChange={(e) =>
                  setClubEditModal((prev) => (prev ? { ...prev, status: e.target.value } : prev))
                }
              >
                <option value="active">aktiv — sieht Vereinsinhalte</option>
                <option value="inactive">deaktiviert — kein Zugriff auf Vereinsinhalte</option>
              </select>
            </div>
            <div className="form-row">
              <span className="form-label">Rollen</span>
              <div style={{ display: 'flex', flexDirection: 'column', gap: '0.35rem' }}>
                {CLUB_ROLE_OPTIONS.map((opt) => (
                  <label key={opt.code} style={{ display: 'flex', alignItems: 'center', gap: '0.35rem' }}>
                    <input
                      type="checkbox"
                      checked={clubEditModal.roles.includes(opt.code)}
                      onChange={() => {
                        setClubEditModal((prev) => {
                          if (!prev) return prev
                          const s = new Set(prev.roles)
                          if (s.has(opt.code)) s.delete(opt.code)
                          else s.add(opt.code)
                          let roles = Array.from(s)
                          if (!roles.length) roles = ['trainer']
                          return { ...prev, roles }
                        })
                      }}
                    />
                    {opt.label}
                  </label>
                ))}
              </div>
            </div>
            <div style={{ display: 'flex', flexDirection: 'column', gap: '0.5rem', marginTop: '1rem' }}>
              <button type="button" className="btn btn-primary" onClick={saveClubMembership}>
                Speichern
              </button>
              <button
                type="button"
                className="btn"
                style={{ background: 'var(--danger)', color: '#fff', border: 'none' }}
                onClick={removeClubMembership}
              >
                Aus Verein entfernen
              </button>
              <button type="button" className="btn btn-secondary" onClick={() => setClubEditModal(null)}>
                Schließen
              </button>
            </div>
          </div>
        </div>
      )}

      {pwdModal ? (
        <div
          style={{
            position: 'fixed',
            inset: 0,
            background: 'rgba(0,0,0,0.5)',
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center',
            zIndex: 1250,
            padding: '1rem',
          }}
        >
          <div
            style={{
              background: 'var(--surface)',
              borderRadius: '12px',
              padding: '1.5rem',
              maxWidth: '440px',
              width: '100%',
            }}
          >
            <h2 style={{ marginTop: 0 }}>Passwort zurücksetzen</h2>
            <p style={{ color: 'var(--text2)', fontSize: '0.9rem' }}>{pwdModal.label}</p>
            <p className="muted" style={{ fontSize: '0.82rem', marginBottom: '0.75rem' }}>
              Standard: Es wird ein sicherer Link per E-Mail verschickt (wie „Passwort vergessen“). Das bisherige Passwort
              bleibt gültig, bis die Person den Link nutzt und ein neues Passwort wählt.
            </p>
            <div style={{ display: 'flex', flexDirection: 'column', gap: '0.5rem' }}>
              <button type="button" className="btn btn-primary" onClick={submitPasswordEmail}>
                Reset-Link per E-Mail senden
              </button>
            </div>
            <>
              <hr style={{ margin: '1rem 0', borderColor: 'var(--border, #333)' }} />
              <p className="muted" style={{ fontSize: '0.82rem', marginBottom: '0.5rem' }}>
                Ausnahme: Passwort direkt setzen (nur bei Bedarf). Das bisherige Passwort ist danach ungültig.
              </p>
              <div className="form-row">
                <label className="form-label">Neues Passwort</label>
                <input
                  type="password"
                  className="form-input"
                  autoComplete="new-password"
                  value={pwdNew}
                  onChange={(e) => setPwdNew(e.target.value)}
                />
              </div>
              <div className="form-row">
                <label className="form-label">Wiederholen</label>
                <input
                  type="password"
                  className="form-input"
                  autoComplete="new-password"
                  value={pwdNew2}
                  onChange={(e) => setPwdNew2(e.target.value)}
                />
              </div>
              <button type="button" className="btn btn-secondary" style={{ width: '100%' }} onClick={submitPasswordDirect}>
                Passwort direkt setzen
              </button>
            </>
            <div style={{ marginTop: '1rem' }}>
              <button
                type="button"
                className="btn btn-secondary"
                style={{ width: '100%' }}
                onClick={() => {
                  setPwdModal(null)
                  setPwdNew('')
                  setPwdNew2('')
                }}
              >
                Schließen
              </button>
            </div>
          </div>
        </div>
      ) : null}
    </div>
  )
}