import React, { useEffect, useState } from 'react'
import styles from '../styles/Admin.module.css'
import { API_URL } from '../services/theapi'
import { FileText, Database, Users } from 'lucide-react'

type User = { id: string; email: string; full_name?: string; role: 'admin' | 'user' }
type Document = { id: string; title: string; source: 'CIR' | 'SCCS'; ingredient?: string; date?: string }

type ScraperLog = { id: string; when: string; source: string; status: 'pending' | 'running' | 'success' | 'error' }
type Stats = { total_documents?: number; cir_documents?: number; sccs_documents?: number; total_users?: number }

export default function Admin() {
  const [tab, setTab] = useState<'users'|'documents'|'stats'|'scrapers'>('users')

  const [users, setUsers] = useState<User[]>([])
  const [docs, setDocs] = useState<Document[]>([])
  const [stats, setStats] = useState<Stats | null>(null)
  const [logs, setLogs] = useState<ScraperLog[]>([])

  const [loading, setLoading] = useState(false)
  const [error, setError] = useState<string | null>(null)

  const [confirmOpen, setConfirmOpen] = useState(false)
  const [confirmAction, setConfirmAction] = useState<() => void>(()=>{})
  const [confirmText, setConfirmText] = useState('')

  const [search, setSearch] = useState('')
  const [sortKey, setSortKey] = useState<string | null>(null)
  const [sortDir, setSortDir] = useState<'asc'|'desc'>('asc')

  // Jeton posé par App.tsx au login (handleAuthSuccess).
  const token = localStorage.getItem('authToken') ?? ''

  useEffect(() => {
    const fetchTab = async () => {
      setError(null)
      setLoading(true)
      try{
        if(tab==='users'){
          const res = await fetch(`${API_URL}/admin/users?token=${token}`)
          if(!res.ok) throw new Error('Impossible de charger les utilisateurs')
          const data = await res.json()
          setUsers(data || [])
        } else if(tab==='documents'){
          const res = await fetch(`${API_URL}/documents`)
          if(!res.ok) throw new Error('Impossible de charger les documents')
          const data = await res.json()
          setDocs(data || [])
        } else if(tab==='stats'){
          const res = await fetch(`${API_URL}/admin/stats?token=${token}`)
          if(!res.ok) throw new Error('Impossible de charger les statistiques')
          const data = await res.json()
          setStats(data)
        } else if(tab==='scrapers'){
          // logs endpoint (fallback)
          const res = await fetch(`${API_URL}/admin/scrapers/logs?token=${token}`)
          if(!res.ok) throw new Error('Impossible de charger les logs de scrapers')
          const data = await res.json()
          setLogs(data || [])
        }
      }catch(e: unknown){
        const msg = e instanceof Error ? e.message : String(e)
        setError(msg || 'Erreur réseau')
      }finally{setLoading(false)}
    }

    fetchTab()
  }, [tab])

  function openConfirm(text: string, action: ()=>void){
    setConfirmText(text)
    setConfirmAction(()=>action)
    setConfirmOpen(true)
  }

  async function deleteUser(id: string){
    try{
      setLoading(true)
      const res = await fetch(`${API_URL}/admin/users/${id}?token=${token}`, { method: 'DELETE' })
      if(!res.ok) throw new Error('Suppression impossible')
      setUsers(u=>u.filter(x=>x.id!==id))
      window.dispatchEvent(new CustomEvent('app:toast', { detail: { message: 'Utilisateur supprimé', type: 'success' } }))
    }catch(e: unknown){
      const msg = e instanceof Error ? e.message : String(e)
      setError(msg||'Erreur')
      window.dispatchEvent(new CustomEvent('app:toast', { detail: { message: msg||'Erreur', type: 'error' } }))
    }finally{setLoading(false)}
  }

  async function toggleRole(u: User){
    try{
      setLoading(true)
      const newRole = u.role === 'admin' ? 'user' : 'admin'
      const res = await fetch(`${API_URL}/admin/users/${u.id}/role?token=${token}`, { method: 'PATCH', headers:{'Content-Type':'application/json'}, body: JSON.stringify({ role: newRole }) })
      if(!res.ok) throw new Error('Impossible de modifier le rôle')
      setUsers(list=>list.map(x=> x.id===u.id ? {...x, role:newRole} : x))
      window.dispatchEvent(new CustomEvent('app:toast', { detail: { message: `Rôle mis à jour: ${newRole}`, type: 'success' } }))
    }catch(e: unknown){ const msg = e instanceof Error ? e.message : String(e); setError(msg||'Erreur'); window.dispatchEvent(new CustomEvent('app:toast', { detail: { message: msg||'Erreur', type: 'error' } })) }finally{ setLoading(false) }
  }

  async function deleteDocument(id:string){
    try{
      setLoading(true)
      const res = await fetch(`${API_URL}/admin/documents/${id}?token=${token}`, { method: 'DELETE' })
      if(!res.ok) throw new Error('Suppression impossible')
      setDocs(d=>d.filter(x=>x.id!==id))
      window.dispatchEvent(new CustomEvent('app:toast', { detail: { message: 'Document supprimé', type: 'success' } }))
    }catch(e: unknown){ const msg = e instanceof Error ? e.message : String(e); setError(msg||'Erreur'); window.dispatchEvent(new CustomEvent('app:toast', { detail: { message: msg||'Erreur', type: 'error' } })) }finally{ setLoading(false) }
  }

  async function runScraper(source: 'CIR'|'SCCS'){
    try{
      setLoading(true)
      const res = await fetch(`${API_URL}/admin/scrapers/run?source=${source}&token=${token}`, { method: 'POST' })
      if(!res.ok) throw new Error('Erreur lors du lancement')
      const entry = await res.json()
      setLogs(l=>[entry, ...l].slice(0,5))
      window.dispatchEvent(new CustomEvent('app:toast', { detail: { message: `Scraper ${source} lancé`, type: 'success' } }))
    }catch(e: unknown){ const msg = e instanceof Error ? e.message : String(e); setError(msg||'Erreur'); window.dispatchEvent(new CustomEvent('app:toast', { detail: { message: msg||'Erreur', type: 'error' } })) }finally{ setLoading(false) }
  }

  const filteredDocs = docs.filter(d => d.title.toLowerCase().includes(search.toLowerCase()) || (d.ingredient||'').toLowerCase().includes(search.toLowerCase()))

  const sortedUsers = React.useMemo(()=>{
    if(!sortKey) return users
    return [...users].sort((a: User, b: User) =>{
      const ra = a as unknown as Record<string, unknown>
      const rb = b as unknown as Record<string, unknown>
      const va = typeof ra[sortKey as string] === 'string' ? (ra[sortKey as string] as string) : ''
      const vb = typeof rb[sortKey as string] === 'string' ? (rb[sortKey as string] as string) : ''
      if(typeof va === 'string' && typeof vb === 'string'){
        return sortDir==='asc' ? va.localeCompare(vb) : vb.localeCompare(va)
      }
      return 0
    })
  },[users, sortKey, sortDir])

  const sortedDocs = React.useMemo(()=>{
    if(!sortKey) return filteredDocs
    return [...filteredDocs].sort((a: Document, b: Document) =>{
      const ra = a as unknown as Record<string, unknown>
      const rb = b as unknown as Record<string, unknown>
      const va = typeof ra[sortKey as string] === 'string' ? (ra[sortKey as string] as string) : ''
      const vb = typeof rb[sortKey as string] === 'string' ? (rb[sortKey as string] as string) : ''
      if(typeof va === 'string' && typeof vb === 'string'){
        return sortDir==='asc' ? va.localeCompare(vb) : vb.localeCompare(va)
      }
      return 0
    })
  },[filteredDocs, sortKey, sortDir])

  return (
    <div className={styles.page}>
      <header className={styles.header}>
        <h1>Administration</h1>
        <nav className={styles.tabs}>
          <button className={tab==='users'?styles.active:''} onClick={()=>setTab('users')}>Utilisateurs</button>
          <button className={tab==='documents'?styles.active:''} onClick={()=>setTab('documents')}>Documents</button>
          <button className={tab==='stats'?styles.active:''} onClick={()=>setTab('stats')}>Statistiques</button>
          <button className={tab==='scrapers'?styles.active:''} onClick={()=>setTab('scrapers')}>Scrapers</button>
        </nav>
      </header>

      <main className={styles.content}>
        {loading && <div className={styles.spinner}>Chargement...</div>}
        {error && <div className={styles.error}>{error}</div>}

        {tab==='users' && (
          <section>
            <div className={styles.panelHeader}>
              <div>{users.length} utilisateurs au total</div>
            </div>
            <div className={styles.tableWrap}>
              <table className={styles.table}>
                <thead>
                  <tr>
                    <th onClick={()=>{ setSortKey('id'); setSortDir(sortDir==='asc'?'desc':'asc') }}>ID</th>
                    <th onClick={()=>{ setSortKey('email'); setSortDir(sortDir==='asc'?'desc':'asc') }}>Email</th>
                    <th onClick={()=>{ setSortKey('full_name'); setSortDir(sortDir==='asc'?'desc':'asc') }}>Nom complet</th>
                    <th onClick={()=>{ setSortKey('role'); setSortDir(sortDir==='asc'?'desc':'asc') }}>Rôle</th>
                    <th></th>
                  </tr>
                </thead>
                <tbody>
                  {sortedUsers.map(u=> (
                    <tr key={u.id}>
                      <td data-label="ID">{u.id}</td>
                      <td data-label="Email">{u.email}</td>
                      <td data-label="Nom complet">{u.full_name||'-'}</td>
                      <td data-label="Rôle"><span className={u.role==='admin'?styles.badgeAdmin:styles.badgeUser}>{u.role}</span></td>
                      <td className={styles.rowActions}>
                        <button className={styles.danger} onClick={()=>openConfirm('Supprimer cet utilisateur ?', ()=>deleteUser(u.id))}>Supprimer</button>
                        <button onClick={()=>openConfirm(u.role==='admin'? 'Rétrograder cet utilisateur ?' : 'Passer admin ?', ()=>toggleRole(u))}>{u.role==='admin'?'Rétrograder':'Passer admin'}</button>
                      </td>
                    </tr>
                  ))}
                </tbody>
              </table>
            </div>
          </section>
        )}

        {tab==='documents' && (
          <section>
            <div className={styles.panelHeader}>
              <div>{docs.length} documents au total</div>
              <input className={styles.search} placeholder="Rechercher..." value={search} onChange={e=>setSearch(e.target.value)} />
            </div>

            <div className={styles.tableWrap}>
              <table className={styles.table}>
                <thead>
                  <tr>
                    <th onClick={()=>{ setSortKey('id'); setSortDir(sortDir==='asc'?'desc':'asc') }}>ID</th>
                    <th onClick={()=>{ setSortKey('title'); setSortDir(sortDir==='asc'?'desc':'asc') }}>Titre</th>
                    <th onClick={()=>{ setSortKey('source'); setSortDir(sortDir==='asc'?'desc':'asc') }}>Source</th>
                    <th onClick={()=>{ setSortKey('ingredient'); setSortDir(sortDir==='asc'?'desc':'asc') }}>Ingrédient</th>
                    <th onClick={()=>{ setSortKey('date'); setSortDir(sortDir==='asc'?'desc':'asc') }}>Date</th>
                    <th></th>
                  </tr>
                </thead>
                <tbody>
                  {sortedDocs.map(d=> (
                    <tr key={d.id}>
                      <td data-label="ID">{d.id}</td>
                      <td data-label="Titre">{d.title}</td>
                      <td data-label="Source"><span className={d.source==='CIR'?styles.badgeCIR:styles.badgeSCCS}>{d.source}</span></td>
                      <td data-label="Ingrédient">{d.ingredient||'-'}</td>
                      <td data-label="Date">{d.date||'-'}</td>
                      <td className={styles.rowActions}><button className={styles.danger} onClick={()=>openConfirm('Supprimer ce document ?', ()=>deleteDocument(d.id))}>Supprimer</button></td>
                    </tr>
                  ))}
                </tbody>
              </table>

              {filteredDocs.length===0 && <div className={styles.empty}>Aucun document trouvé.</div>}
            </div>
          </section>
        )}

        {tab==='stats' && (
          <section>
            <div className={styles.cards}>
              <div className={styles.card}><FileText/><div className={styles.cardLabel}>Total documents</div><div className={styles.cardValue}>{stats?.total_documents ?? '-'}</div></div>
              <div className={styles.card}><Database/><div className={styles.cardLabel}>Documents CIR</div><div className={styles.cardValue}>{stats?.cir_documents ?? '-'}</div></div>
              <div className={styles.card}><Database/><div className={styles.cardLabel}>Documents SCCS</div><div className={styles.cardValue}>{stats?.sccs_documents ?? '-'}</div></div>
              <div className={styles.card}><Users/><div className={styles.cardLabel}>Total utilisateurs</div><div className={styles.cardValue}>{stats?.total_users ?? '-'}</div></div>
            </div>

            <div className={styles.chartWrap}>
              <div className={styles.chartLabel}>CIR vs SCCS</div>
              <div className={styles.bars}>
                <div className={styles.barRow}><div className={styles.barTitle}>CIR</div><div className={styles.barFill} style={{width:`${(stats?.cir_documents||0)/(Math.max(1, (stats?.cir_documents||0)+(stats?.sccs_documents||0))) * 100}%`}}></div><div className={styles.barVal}>{stats?.cir_documents||0}</div></div>
                <div className={styles.barRow}><div className={styles.barTitle}>SCCS</div><div className={`${styles.barFill} ${styles.barFillAlt}`} style={{width:`${(stats?.sccs_documents||0)/(Math.max(1, (stats?.cir_documents||0)+(stats?.sccs_documents||0))) * 100}%`}}></div><div className={styles.barVal}>{stats?.sccs_documents||0}</div></div>
              </div>
            </div>
          </section>
        )}

        {tab==='scrapers' && (
          <section>
            <div className={styles.panelHeader}>
              <div>Scrapers</div>
            </div>
            <div className={styles.scraperControls}>
              <div>
                <button onClick={()=>runScraper('CIR')}>Lancer scraper CIR</button>
                <button onClick={()=>runScraper('SCCS')}>Lancer scraper SCCS</button>
              </div>
              <div className={styles.logList}>
                <h4>Dernières exécutions</h4>
                <ul>
                  {logs.map(l=> (
                    <li key={l.id}><strong>{l.when}</strong> — {l.source} — <span className={styles.status}>{l.status}</span></li>
                  ))}
                  {logs.length===0 && <li>Aucune exécution.</li>}
                </ul>
              </div>
            </div>
          </section>
        )}
      </main>

      {confirmOpen && (
        <div className={styles.modalBackdrop}>
          <div className={styles.modal}>
            <p>{confirmText}</p>
            <div className={styles.modalActions}>
              <button onClick={()=>{setConfirmOpen(false)}}>Annuler</button>
              <button className={styles.danger} onClick={()=>{ setConfirmOpen(false); confirmAction(); }}>Confirmer</button>
            </div>
          </div>
        </div>
      )}

    </div>
  )
}