'use client'

import { useState, useEffect } from 'react'
import { Plus, Trash2, X, Search, Edit2, Copy, CheckCircle2, Circle, FileSignature } from 'lucide-react'
import { formatCurrency } from '@/lib/utils'
import { format } from 'date-fns'
import { fr } from 'date-fns/locale'

interface Client {
  id: string
  name: string
  email: string | null
  phone: string | null
  address: string | null
  siret: string | null
  isProfessional: boolean | null
}

interface SaleItem {
  id: string
  label: string
  description: string | null
  quantity: number
  unitPrice: number
  costPrice: number
}

interface Sale {
  id: string
  client: { id: string; name: string }
  date: string
  totalAmount: number
  totalCost: number
  paid: boolean
  notes: string | null
  items: SaleItem[]
}

export function SalesContent() {
  const [sales, setSales] = useState<Sale[]>([])
  const [clients, setClients] = useState<Client[]>([])
  const [loading, setLoading] = useState(true)
  const [showForm, setShowForm] = useState(false)
  const [search, setSearch] = useState('')

  const [selectedClient, setSelectedClient] = useState('')
  const [clientName, setClientName] = useState('')
  const [clientEmail, setClientEmail] = useState('')
  const [clientPhone, setClientPhone] = useState('')
  const [clientAddress, setClientAddress] = useState('')
  const [clientSiret, setClientSiret] = useState('')
  const [isProfessional, setIsProfessional] = useState(true)
  const [saleDate, setSaleDate] = useState(format(new Date(), 'yyyy-MM-dd'))
  const [notes, setNotes] = useState('')
  const [items, setItems] = useState<{ id: string; label: string; description: string; quantity: number; unitPrice: number; costPrice: number }[]>([])
  const [editingId, setEditingId] = useState<string | null>(null)
  const [saving, setSaving] = useState(false)
  const [saved, setSaved] = useState(false)

  const isNewClient = !selectedClient

  useEffect(() => { fetchSales(); fetchClients() }, [])

  const fetchSales = async () => {
    setLoading(true)
    try {
      const res = await fetch('/api/sales')
      if (res.ok) {
        const data = await res.json()
        setSales(data.sales)
      }
    } finally {
      setLoading(false)
    }
  }

  const fetchClients = async () => {
    try {
      const res = await fetch('/api/clients')
      if (res.ok) {
        const data = await res.json()
        setClients(data.clients)
      }
    } catch {}
  }

  const openNew = () => {
    setEditingId(null)
    setSelectedClient('')
    setClientName('')
    setClientEmail('')
    setClientPhone('')
    setClientAddress('')
    setClientSiret('')
    setIsProfessional(true)
    setSaleDate(format(new Date(), 'yyyy-MM-dd'))
    setNotes('')
    setItems([{ id: crypto.randomUUID(), label: '', description: '', quantity: 1, unitPrice: 0, costPrice: 0 }])
    setSaved(false)
    setShowForm(true)
  }

  const openEdit = async (sale: Sale) => {
    setEditingId(sale.id)
    setSelectedClient(sale.client.id)
    setClientName('')
    setClientEmail('')
    setClientPhone('')
    setClientAddress('')
    setClientSiret('')
    setIsProfessional(true)
    setSaleDate(format(new Date(sale.date), 'yyyy-MM-dd'))
    setNotes(sale.notes || '')
    setItems(sale.items.map(i => ({ id: crypto.randomUUID(), label: i.label, description: i.description || '', quantity: i.quantity, unitPrice: i.unitPrice, costPrice: i.costPrice })))
    setSaved(false)
    setShowForm(true)
  }

  const addItem = () => {
    setItems([...items, { id: crypto.randomUUID(), label: '', description: '', quantity: 1, unitPrice: 0, costPrice: 0 }])
  }

  const updateItem = (id: string, field: string, value: any) => {
    setItems(items.map(item => item.id === id ? { ...item, [field]: value } : item))
  }

  const removeItem = (id: string) => {
    setItems(items.filter(item => item.id !== id))
  }

  const totals = items.reduce((acc, item) => {
    acc.amount += (item.unitPrice || 0) * (item.quantity || 1)
    acc.cost += (item.costPrice || 0) * (item.quantity || 1)
    return acc
  }, { amount: 0, cost: 0 })

  const handleSave = async () => {
    if (!selectedClient && !clientName.trim()) return
    if (items.length === 0 || !items.some(i => i.label.trim())) return
    setSaving(true)
    setSaved(false)
    try {
      const body: any = {
        clientId: selectedClient || null,
        clientName: isNewClient ? clientName.trim() : undefined,
        clientEmail: isNewClient ? clientEmail || null : undefined,
        clientPhone: isNewClient ? clientPhone || null : undefined,
        clientAddress: isNewClient ? clientAddress || null : undefined,
        clientSiret: isNewClient ? clientSiret || null : undefined,
        isProfessional: isNewClient ? isProfessional : undefined,
        date: saleDate,
        totalAmount: totals.amount,
        totalCost: totals.cost,
        notes: notes || null,
        items: items.filter(i => i.label.trim()).map(i => ({
          label: i.label,
          description: i.description || null,
          quantity: i.quantity || 1,
          unitPrice: i.unitPrice || 0,
          costPrice: i.costPrice || 0,
        })),
      }
      const method = editingId ? 'PUT' : 'POST'
      const url = editingId ? `/api/sales/${editingId}` : '/api/sales'
      const res = await fetch(url, {
        method,
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(body),
      })
      if (res.ok) {
        setSaved(true)
        setShowForm(false)
        setEditingId(null)
        fetchSales()
        fetchClients()
      }
    } finally {
      setSaving(false)
    }
  }

  const handleDuplicate = async (sale: Sale) => {
    if (!confirm('Dupliquer cette vente ?')) return
    try {
      const body = {
        clientId: sale.client.id,
        date: format(new Date(), 'yyyy-MM-dd'),
        totalAmount: sale.totalAmount,
        totalCost: sale.totalCost,
        notes: sale.notes,
        items: sale.items.map(i => ({
          label: i.label,
          description: i.description,
          quantity: i.quantity,
          unitPrice: i.unitPrice,
          costPrice: i.costPrice,
        })),
      }
      await fetch('/api/sales', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(body),
      })
      fetchSales()
    } catch {}
  }

  const togglePaid = async (sale: Sale) => {
    try {
      await fetch(`/api/sales/${sale.id}`, {
        method: 'PUT',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ paid: !sale.paid }),
      })
      fetchSales()
    } catch {}
  }

  const convertToQuote = async (sale: Sale) => {
    if (!confirm(`Convertir cette vente en devis ? La vente sera supprimée.`)) return
    try {
      const items = sale.items.map(i => ({
        type: 'CUSTOM',
        label: i.label,
        description: i.description,
        quantity: i.quantity,
        unitPrice: i.unitPrice,
        costPrice: i.costPrice,
        isRecurring: false,
        setupPrice: i.unitPrice,
        setupCost: i.costPrice,
        monthlyPrice: 0,
        monthlyCost: 0,
      }))
      const res = await fetch('/api/quotes', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          clientId: sale.client.id,
          name: `Devis - ${sale.client.name}`,
          setupTotal: sale.totalAmount,
          costTotal: sale.totalCost,
          marginTotal: sale.totalAmount - sale.totalCost,
          notes: sale.notes,
          items,
        }),
      })
      if (res.ok) {
        await fetch(`/api/sales/${sale.id}`, { method: 'DELETE' })
        fetchSales()
      }
    } catch {}
  }

  const handleDelete = async (id: string) => {
    if (!confirm('Supprimer cette vente ?')) return
    try {
      await fetch(`/api/sales/${id}`, { method: 'DELETE' })
      fetchSales()
    } catch {}
  }

  const filtered = sales.filter(s =>
    search === '' || s.client.name.toLowerCase().includes(search.toLowerCase())
  )

  return (
    <div className="space-y-6">
      <div className="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-4">
        <h2 className="text-2xl font-bold text-slate-900 dark:text-white">Ventes hors contrat</h2>
        <button onClick={openNew}
          className="inline-flex items-center gap-2 bg-primary-600 hover:bg-primary-700 text-white px-4 py-2 rounded-lg text-sm font-medium transition-colors">
          <Plus className="h-4 w-4" />
          Nouvelle vente
        </button>
      </div>

      <div className="relative">
        <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-slate-400" />
        <input type="text" placeholder="Rechercher..." value={search} onChange={(e) => setSearch(e.target.value)}
          className="w-full pl-9 pr-4 py-2 rounded-lg border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-800 text-slate-900 dark:text-white text-sm" />
      </div>

      {showForm && (
        <div className="fixed inset-0 z-50 flex items-start justify-center bg-black/50 p-4 pt-8 overflow-y-auto">
          <div className="bg-white dark:bg-slate-800 rounded-xl w-full max-w-2xl p-6 shadow-xl">
            <div className="flex items-center justify-between mb-5">
              <h3 className="text-lg font-semibold text-slate-900 dark:text-white">{editingId ? 'Modifier la vente' : 'Nouvelle vente'}</h3>
              <button onClick={() => setShowForm(false)} className="p-1 rounded hover:bg-slate-100 dark:hover:bg-slate-700">
                <X className="h-5 w-5 text-slate-500" />
              </button>
            </div>

            <div className="space-y-4">
              <div>
                <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">Client</label>
                <select value={selectedClient} onChange={(e) => setSelectedClient(e.target.value)}
                  className="w-full px-3 py-2 rounded-lg border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-700 text-slate-900 dark:text-white text-sm mb-2">
                  <option value="">Nouveau client...</option>
                  {clients.map(c => <option key={c.id} value={c.id}>{c.name}</option>)}
                </select>
              </div>

              {isNewClient && (
                <div className="p-4 rounded-lg bg-slate-50 dark:bg-slate-700/50 space-y-3">
                  <div className="grid grid-cols-1 sm:grid-cols-2 gap-3">
                    <div>
                      <label className="block text-xs font-medium text-slate-500 mb-1">Nom *</label>
                      <input type="text" value={clientName} onChange={(e) => setClientName(e.target.value)}
                        className="w-full px-3 py-2 rounded-lg border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-700 text-sm" />
                    </div>
                    <div>
                      <label className="block text-xs font-medium text-slate-500 mb-1">Email</label>
                      <input type="email" value={clientEmail} onChange={(e) => setClientEmail(e.target.value)}
                        className="w-full px-3 py-2 rounded-lg border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-700 text-sm" />
                    </div>
                    <div>
                      <label className="block text-xs font-medium text-slate-500 mb-1">Téléphone</label>
                      <input type="text" value={clientPhone} onChange={(e) => setClientPhone(e.target.value)}
                        className="w-full px-3 py-2 rounded-lg border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-700 text-sm" />
                    </div>
                    <div>
                      <label className="block text-xs font-medium text-slate-500 mb-1">Adresse</label>
                      <input type="text" value={clientAddress} onChange={(e) => setClientAddress(e.target.value)}
                        className="w-full px-3 py-2 rounded-lg border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-700 text-sm" />
                    </div>
                  </div>
                  <div className="flex items-center gap-4">
                    <label className="flex items-center gap-2">
                      <input type="checkbox" checked={isProfessional} onChange={(e) => setIsProfessional(e.target.checked)}
                        className="rounded border-slate-300 text-primary-600 focus:ring-primary-500" />
                      <span className="text-sm text-slate-700 dark:text-slate-300">Client professionnel</span>
                    </label>
                    {isProfessional && (
                      <div className="flex-1">
                        <label className="block text-xs font-medium text-slate-500 mb-1">SIRET</label>
                        <input type="text" value={clientSiret} onChange={(e) => setClientSiret(e.target.value)}
                          className="w-full px-3 py-2 rounded-lg border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-700 text-sm" />
                      </div>
                    )}
                  </div>
                </div>
              )}

              <div>
                <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">Date</label>
                <input type="date" value={saleDate} onChange={(e) => setSaleDate(e.target.value)}
                  className="w-full px-3 py-2 rounded-lg border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-700 text-sm" />
              </div>

              <div>
                <div className="flex items-center justify-between mb-2">
                  <label className="text-sm font-medium text-slate-700 dark:text-slate-300">Prestations</label>
                  <button onClick={addItem}
                    className="inline-flex items-center gap-1 px-2 py-1 text-xs font-medium text-primary-600 hover:bg-primary-50 dark:hover:bg-primary-900/20 rounded transition-colors">
                    <Plus className="h-3 w-3" /> Ajouter une ligne
                  </button>
                </div>
                <div className="space-y-2">
                  {items.map((item, idx) => (
                    <div key={item.id} className="flex flex-wrap items-end gap-2 p-2 rounded bg-slate-50 dark:bg-slate-700/50">
                      <div className="flex-1 min-w-[120px]">
                        <label className="block text-xs text-slate-500 mb-0.5">Libellé</label>
                        <input type="text" value={item.label} onChange={(e) => updateItem(item.id, 'label', e.target.value)}
                          placeholder={`Prestation ${idx + 1}`}
                          className="w-full px-2 py-1.5 rounded border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-700 text-sm" />
                      </div>
                      <div className="w-16">
                        <label className="block text-xs text-slate-500 mb-0.5">Qté</label>
                        <input type="number" min={1} value={item.quantity} onChange={(e) => updateItem(item.id, 'quantity', parseInt(e.target.value) || 1)}
                          className="w-full px-2 py-1.5 rounded border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-700 text-sm text-center" />
                      </div>
                      <div className="w-24">
                        <label className="block text-xs text-slate-500 mb-0.5">Prix vente</label>
                        <input type="number" step="0.01" value={item.unitPrice} onChange={(e) => updateItem(item.id, 'unitPrice', parseFloat(e.target.value) || 0)}
                          className="w-full px-2 py-1.5 rounded border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-700 text-sm" />
                      </div>
                      <div className="w-24">
                        <label className="block text-xs text-slate-500 mb-0.5">Coût achat</label>
                        <input type="number" step="0.01" value={item.costPrice} onChange={(e) => updateItem(item.id, 'costPrice', parseFloat(e.target.value) || 0)}
                          className="w-full px-2 py-1.5 rounded border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-700 text-sm" />
                      </div>
                      <div className="w-20 text-right self-end pb-1">
                        <span className="text-xs text-slate-500">{formatCurrency((item.unitPrice || 0) * (item.quantity || 1))}</span>
                      </div>
                      <button onClick={() => removeItem(item.id)} className="p-1 text-red-500 hover:bg-red-50 dark:hover:bg-red-900/20 rounded self-end mb-0.5">
                        <Trash2 className="h-4 w-4" />
                      </button>
                    </div>
                  ))}
                </div>
              </div>

              <div className="flex justify-end gap-6 p-3 bg-slate-50 dark:bg-slate-700/50 rounded-lg">
                <div className="text-right">
                  <p className="text-xs text-slate-500">Total vente</p>
                  <p className="text-lg font-bold text-green-600">{formatCurrency(totals.amount)}</p>
                </div>
                <div className="text-right">
                  <p className="text-xs text-slate-500">Coût total</p>
                  <p className="text-lg font-bold text-red-500">{formatCurrency(totals.cost)}</p>
                </div>
                <div className="text-right">
                  <p className="text-xs text-slate-500">Marge</p>
                  <p className={`text-lg font-bold ${totals.amount - totals.cost >= 0 ? 'text-primary-600' : 'text-red-500'}`}>
                    {formatCurrency(totals.amount - totals.cost)}
                    <span className="text-sm ml-1">
                      ({totals.amount > 0 ? ((totals.amount - totals.cost) / totals.amount * 100).toFixed(0) : 0}%)
                    </span>
                  </p>
                </div>
              </div>

              <div>
                <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">Notes</label>
                <textarea value={notes} onChange={(e) => setNotes(e.target.value)} rows={2}
                  className="w-full px-3 py-2 rounded-lg border border-slate-300 dark:border-slate-600 bg-white dark:bg-slate-700 text-sm" />
              </div>
            </div>

            <div className="flex justify-end gap-3 mt-6">
              <button onClick={() => setShowForm(false)}
                className="px-4 py-2 text-sm font-medium text-slate-600 dark:text-slate-300 hover:bg-slate-100 dark:hover:bg-slate-700 rounded-lg">Annuler</button>
              <button onClick={handleSave} disabled={saving || (!selectedClient && !clientName.trim()) || !items.some(i => i.label.trim())}
                className="px-4 py-2 text-sm font-medium bg-primary-600 hover:bg-primary-700 text-white rounded-lg disabled:opacity-50">
                {saving ? 'Enregistrement...' : editingId ? 'Enregistrer les modifications' : 'Enregistrer la vente'}
              </button>
            </div>
          </div>
        </div>
      )}

      {loading ? (
        <div className="text-center py-12 text-slate-500">Chargement...</div>
      ) : filtered.length === 0 ? (
        <div className="text-center py-12 text-slate-500">Aucune vente</div>
      ) : (
        (() => {
          const groupedByMonth = filtered.reduce((acc: Record<string, Sale[]>, sale) => {
            const key = sale.date.substring(0, 7)
            if (!acc[key]) acc[key] = []
            acc[key].push(sale)
            return acc
          }, {} as Record<string, Sale[]>)
          const months = Object.keys(groupedByMonth).sort().reverse()
          return months.map(monthKey => {
            const [year, month] = monthKey.split('-')
            const totalMonth = groupedByMonth[monthKey].reduce((s, sale) => s + sale.totalAmount, 0)
            const dateObj = new Date(parseInt(year), parseInt(month) - 1)
            return (
              <div key={monthKey} className="bg-white dark:bg-slate-800 rounded-xl border border-slate-200 dark:border-slate-700">
                <div className="px-5 py-3 border-b border-slate-200 dark:border-slate-700 flex items-center justify-between">
                  <h3 className="font-semibold text-slate-900 dark:text-white">
                    {format(dateObj, 'MMMM yyyy', { locale: fr })}
                  </h3>
                  <span className="text-sm font-medium text-primary-600">{formatCurrency(totalMonth)}</span>
                </div>
                <div className="overflow-x-auto">
                  <table className="w-full">
                    <thead>
                      <tr className="border-b border-slate-100 dark:border-slate-700 text-xs text-slate-500">
                        <th className="text-left px-4 py-2 font-medium">Date</th>
                        <th className="text-left px-4 py-2 font-medium">Client</th>
                        <th className="text-right px-4 py-2 font-medium">Montant</th>
                        <th className="text-right px-4 py-2 font-medium">Coût</th>
                        <th className="text-right px-4 py-2 font-medium">Marge</th>
                        <th className="text-center px-4 py-2 font-medium">Statut</th>
                        <th className="text-center px-4 py-2 font-medium">Actions</th>
                      </tr>
                    </thead>
                    <tbody className="divide-y divide-slate-100 dark:divide-slate-700">
                      {groupedByMonth[monthKey].map(sale => {
                        const margin = sale.totalAmount - sale.totalCost
                        const marginPct = sale.totalAmount > 0 ? (margin / sale.totalAmount) * 100 : 0
                        return (
                          <tr key={sale.id} className="hover:bg-slate-50 dark:hover:bg-slate-700/50">
                            <td className="px-4 py-2.5 text-sm text-slate-600 dark:text-slate-300">
                              {format(new Date(sale.date), 'dd/MM/yyyy', { locale: fr })}
                            </td>
                            <td className="px-4 py-2.5 font-medium text-slate-900 dark:text-white">{sale.client.name}</td>
                            <td className="px-4 py-2.5 text-right font-medium text-green-600">{formatCurrency(sale.totalAmount)}</td>
                            <td className="px-4 py-2.5 text-right text-sm text-slate-600 dark:text-slate-300">{formatCurrency(sale.totalCost)}</td>
                            <td className="px-4 py-2.5 text-right">
                              <span className={`font-medium ${margin >= 0 ? 'text-green-600' : 'text-red-500'}`}>
                                {formatCurrency(margin)}
                                <span className="text-xs ml-1">({marginPct.toFixed(0)}%)</span>
                              </span>
                            </td>
                            <td className="px-4 py-2.5 text-center">
                              <button onClick={() => togglePaid(sale)}
                                className={`inline-flex items-center gap-1 px-2 py-1 rounded-full text-xs font-medium transition-colors ${
                                  sale.paid
                                    ? 'bg-green-100 text-green-700 dark:bg-green-900/30 dark:text-green-400'
                                    : 'bg-amber-100 text-amber-700 dark:bg-amber-900/30 dark:text-amber-400'
                                }`}>
                                {sale.paid ? <CheckCircle2 className="h-3.5 w-3.5" /> : <Circle className="h-3.5 w-3.5" />}
                                {sale.paid ? 'Payé' : 'Non payé'}
                              </button>
                            </td>
                            <td className="px-4 py-2.5 text-center">
                              <div className="flex items-center justify-center gap-1">
                                <button onClick={() => openEdit(sale)}
                                  className="p-1.5 rounded text-slate-500 hover:text-primary-600 hover:bg-primary-50 dark:hover:bg-primary-900/20">
                                  <Edit2 className="h-4 w-4" />
                                </button>
                                <button onClick={() => handleDuplicate(sale)}
                                  className="p-1.5 rounded text-slate-500 hover:text-green-600 hover:bg-green-50 dark:hover:bg-green-900/20">
                                  <Copy className="h-4 w-4" />
                                </button>
                                <button onClick={() => convertToQuote(sale)}
                                  className="p-1.5 rounded text-purple-600 hover:bg-purple-50 dark:hover:bg-purple-900/20"
                                  title="Convertir en devis">
                                  <FileSignature className="h-4 w-4" />
                                </button>
                                <button onClick={() => handleDelete(sale.id)}
                                  className="p-1.5 rounded text-red-600 hover:bg-red-50 dark:hover:bg-red-900/20">
                                  <Trash2 className="h-4 w-4" />
                                </button>
                              </div>
                            </td>
                          </tr>
                        )
                      })}
                    </tbody>
                  </table>
                </div>
              </div>
            )
          })
        })()
      )}
    </div>
  )
}