'use client'

import { useState, useEffect } from 'react'
import { Building2, Plus, Trash2, Loader2 } from 'lucide-react'
import { Button } from '@/components/ui/button'
import { Input } from '@/components/ui/input'
import { Label } from '@/components/ui/label'
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from '@/components/ui/dialog'
import { getPartners, createPartner, deletePartner } from '@/lib/actions/partners'

export default function PartnersPage() {
  const [partners, setPartners] = useState<any[]>([])
  const [loading, setLoading] = useState(true)
  const [isCreateOpen, setIsCreateOpen] = useState(false)
  const [name, setName] = useState('')
  const [creating, setCreating] = useState(false)
  const [createError, setCreateError] = useState<string | null>(null)
  const [deletingId, setDeletingId] = useState<string | null>(null)

  const loadPartners = async () => {
    setLoading(true)
    try {
      const data = await getPartners()
      setPartners(data)
    } catch (err) {
      console.error('Fehler beim Laden der Partner:', err)
    } finally {
      setLoading(false)
    }
  }

  useEffect(() => {
    loadPartners()
  }, [])

  const handleCreate = async (e: React.FormEvent) => {
    e.preventDefault()
    setCreating(true)
    setCreateError(null)
    try {
      await createPartner(name)
      setIsCreateOpen(false)
      setName('')
      loadPartners()
    } catch (err: any) {
      setCreateError(err.message || 'Fehler beim Anlegen.')
    } finally {
      setCreating(false)
    }
  }

  const handleDelete = async (id: string, partnerName: string) => {
    if (!confirm(`Partner "${partnerName}" wirklich löschen?`)) return
    setDeletingId(id)
    try {
      await deletePartner(id)
      loadPartners()
    } catch (err) {
      console.error('Fehler beim Löschen:', err)
    } finally {
      setDeletingId(null)
    }
  }

  return (
    <div className="p-6 max-w-4xl mx-auto text-slate-900 dark:text-white space-y-8">
      {/* Header */}
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-3xl font-extrabold tracking-tight flex items-center gap-3">
            <Building2 className="w-8 h-8 text-blue-500" /> Partnerverwaltung
          </h1>
          <p className="text-slate-500 dark:text-slate-400 text-sm mt-1">
            Verwalten Sie Partner.
          </p>
        </div>
        <Button onClick={() => setIsCreateOpen(true)} className="bg-blue-600 hover:bg-blue-700 text-white font-semibold">
          <Plus className="w-4 h-4 mr-2" /> Partner anlegen
        </Button>
      </div>

      {/* Partner Table */}
      <div className="p-5 bg-white dark:bg-slate-900/50 rounded-xl border border-slate-200 dark:border-white/10 shadow-sm">
        {loading ? (
          <div className="flex justify-center items-center py-16">
            <Loader2 className="w-8 h-8 text-blue-500 animate-spin" />
            <span className="ml-3 text-slate-400 text-sm">Lade Partner…</span>
          </div>
        ) : partners.length === 0 ? (
          <div className="text-center py-16 border-2 border-dashed border-slate-200 dark:border-white/5 rounded-xl text-slate-500">
            <Building2 className="w-10 h-10 mx-auto mb-3 opacity-30" />
            Noch keine Partner angelegt.
          </div>
        ) : (
          <table className="w-full text-left">
            <thead>
              <tr className="border-b border-slate-200 dark:border-white/10 text-slate-400 text-xs font-semibold uppercase">
                <th className="pb-3">Partnername</th>
                <th className="pb-3">Erstellt am</th>
                <th className="pb-3 text-right">Aktionen</th>
              </tr>
            </thead>
            <tbody className="divide-y divide-slate-100 dark:divide-white/5">
              {partners.map((partner) => (
                <tr key={partner.id} className="hover:bg-slate-50 dark:hover:bg-white/3 transition-colors">
                  <td className="py-4 font-semibold text-slate-900 dark:text-white">
                    <div className="flex items-center gap-2">
                      <Building2 className="w-4 h-4 text-blue-500 shrink-0" />
                      {partner.name}
                    </div>
                  </td>
                  <td className="py-4 text-sm text-slate-500 dark:text-slate-400">
                    {partner.created_at ? new Date(partner.created_at).toLocaleDateString('de-DE') : '–'}
                  </td>
                  <td className="py-4 text-right">
                    <Button
                      variant="ghost"
                      size="icon"
                      disabled={deletingId === partner.id}
                      onClick={() => handleDelete(partner.id, partner.name)}
                      className="h-8 w-8 text-red-500 hover:text-red-400 hover:bg-red-500/10"
                      title="Partner löschen"
                    >
                      {deletingId === partner.id ? <Loader2 className="h-4 w-4 animate-spin" /> : <Trash2 className="h-4 w-4" />}
                    </Button>
                  </td>
                </tr>
              ))}
            </tbody>
          </table>
        )}
      </div>

      {/* Dialog: Neuer Partner */}
      <Dialog open={isCreateOpen} onOpenChange={setIsCreateOpen}>
        <DialogContent className="bg-white dark:bg-slate-950 border-slate-200 dark:border-white/10 text-slate-900 dark:text-white shadow-2xl">
          <DialogHeader>
            <DialogTitle>Neuen Partner anlegen</DialogTitle>
            <DialogDescription className="text-slate-500 dark:text-slate-400">
              Geben Sie den Namen des Partners ein.
            </DialogDescription>
          </DialogHeader>
          <form onSubmit={handleCreate} className="space-y-4 mt-2">
            <div className="space-y-2">
              <Label htmlFor="partner-name">Partnername</Label>
              <Input
                id="partner-name"
                type="text"
                required
                placeholder="Muster Partner GmbH"
                value={name}
                onChange={(e) => setName(e.target.value)}
                className="bg-slate-50 dark:bg-white/5 border-slate-200 dark:border-white/10"
              />
            </div>
            {createError && (
              <p className="text-sm text-red-600 dark:text-red-400">{createError}</p>
            )}
            <DialogFooter className="pt-2">
              <Button type="button" variant="outline" onClick={() => setIsCreateOpen(false)} disabled={creating}>
                Abbrechen
              </Button>
              <Button type="submit" disabled={creating} className="bg-blue-600 hover:bg-blue-700 text-white font-semibold">
                {creating ? <Loader2 className="w-4 h-4 mr-2 animate-spin" /> : null}
                Anlegen
              </Button>
            </DialogFooter>
          </form>
        </DialogContent>
      </Dialog>
    </div>
  )
}