'use client'

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

interface Contract {
  id: string
  name: string
  client: { id: string; name: string }
  startDate: string
  endDate: string | null
  setupPrice: number
  setupCost: number
  monthlyPrice: number
  monthlyCost: number
  status: string
  billingDay: number
  notes: string | null
  _count?: { invoices: number }
}

export function ContractsContent() {
  const [contracts, setContracts] = useState<Contract[]>([])
  const [loading, setLoading] = useState(true)
  const [showForm, setShowForm] = useState(false)
  const [editing, setEditing] = useState<Contract | null>(null)
  const [clients, setClients] = useState<{ id: string; name: string }[]>([])
  const [form, setForm] = useState({
    clientId: '', name: '', startDate: format(new Date(), 'yyyy-MM-dd'),
    endDate: '', setupPrice: '', setupCost: '', monthlyPrice: '', monthlyCost: '',
    billingDay: '1', status: 'ACTIVE', notes: '',
  })
  const [saving, setSaving] = useState(false)

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

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

  const fetchClients = async () => {
    try {
      const res = await fetch('/api/clients')
      if (res.ok) {
        const data = await res.json()
        const sorted = (data.clients || []).sort((a: { name: string }, b: { name: string }) => a.name.localeCompare(b.name))
        setClients(sorted)
      }
    } catch {}
  }

  const openNew = () => {
    setEditing(null)
    setForm({
      clientId: '', name: '', startDate: format(new Date(), 'yyyy-MM-dd'),
      endDate: '', setupPrice: '', setupCost: '', monthlyPrice: '', monthlyCost: '',
      billingDay: '1', status: 'ACTIVE', notes: '',
    })
    setShowForm(true)
  }

  const openEdit = (contract: Contract) => {
    setEditing(contract)
    setForm({
      clientId: contract.client.id,
      name: contract.name,
      startDate: format(new Date(contract.startDate), 'yyyy-MM-dd'),
      endDate: contract.endDate ? format(new Date(contract.endDate), 'yyyy-MM-dd') : '',
      setupPrice: contract.setupPrice.toString(),
      setupCost: contract.setupCost.toString(),
      monthlyPrice: contract.monthlyPrice.toString(),
      monthlyCost: contract.monthlyCost.toString(),
      billingDay: contract.billingDay.toString(),
      status: contract.status,
      notes: contract.notes || '',
    })
    setShowForm(true)
  }

  const handleSave = async () => {
    if (!form.clientId || !form.name.trim()) return
    setSaving(true)
    try {
      const body = {
        clientId: form.clientId,
        name: form.name,
        startDate: form.startDate,
        endDate: form.endDate || null,
        setupPrice: parseFloat(form.setupPrice) || 0,
        setupCost: parseFloat(form.setupCost) || 0,
        monthlyPrice: parseFloat(form.monthlyPrice) || 0,
        monthlyCost: parseFloat(form.monthlyCost) || 0,
        billingDay: parseInt(form.billingDay) || 1,
        status: form.status,
        notes: form.notes || null,
      }

      if (editing) {
        await fetch(`/api/contracts/${editing.id}`, {
          method: 'PUT',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify(body),
        })
      } else {
        await fetch('/api/contracts', {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify(body),
        })
      }
      setShowForm(false)
      setEditing(null)
      fetchContracts()
    } finally {
      setSaving(false)
    }
  }

  const handleDelete = async (id: string) => {
    if (!confirm('Supprimer ce contrat ?')) return
    try {
      await fetch(`/api/contracts/${id}`, { method: 'DELETE' })
      fetchContracts()
    } catch {}
  }

  const statusColors: Record<string, string> = {
    PROPOSAL: 'bg-purple-100 text-purple-700 dark:bg-purple-900/30 dark:text-purple-400',
    ACTIVE: 'bg-green-100 text-green-700 dark:bg-green-900/30 dark:text-green-400',
    PAUSED: 'bg-amber-100 text-amber-700 dark:bg-amber-900/30 dark:text-amber-400',
    CANCELLED: 'bg-red-100 text-red-700 dark:bg-red-900/30 dark:text-red-400',
    EXPIRED: 'bg-slate-100 text-slate-700 dark:bg-slate-700 dark:text-slate-300',
  }

  const statusLabels: Record<string, string> = {
    PROPOSAL: 'Proposition en cours', ACTIVE: 'Actif', PAUSED: 'En pause', CANCELLED: 'Annulé', EXPIRED: 'Expiré',
  }

  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">Contrats</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" />
          Nouveau contrat
        </button>
      </div>

      {showForm && (
        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/50 p-4">
          <div className="bg-white dark:bg-slate-800 rounded-xl w-full max-w-lg p-6 shadow-xl max-h-[90vh] overflow-y-auto">
            <div className="flex items-center justify-between mb-5">
              <h3 className="text-lg font-semibold text-slate-900 dark:text-white">
                {editing ? 'Modifier' : 'Nouveau'} contrat
              </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={form.clientId}
                  onChange={(e) => setForm({ ...form, clientId: 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"
                >
                  <option value="">Sélectionner un client</option>
                  {clients.map(c => <option key={c.id} value={c.id}>{c.name}</option>)}
                </select>
              </div>
              <div>
                <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">Nom du contrat *</label>
                <input
                  type="text"
                  value={form.name}
                  onChange={(e) => setForm({ ...form, name: 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"
                />
              </div>
              <div className="grid grid-cols-2 gap-4">
                <div>
                  <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">Date début</label>
                  <input
                    type="date"
                    value={form.startDate}
                    onChange={(e) => setForm({ ...form, startDate: 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"
                  />
                </div>
                <div>
                  <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">Date fin</label>
                  <input
                    type="date"
                    value={form.endDate}
                    onChange={(e) => setForm({ ...form, endDate: 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"
                  />
                </div>
              </div>
              <div className="grid grid-cols-2 gap-4">
                <div>
                  <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">Prix mise en place</label>
                  <input
                    type="number"
                    step="0.01"
                    value={form.setupPrice}
                    onChange={(e) => setForm({ ...form, setupPrice: 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"
                  />
                </div>
                <div>
                  <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">Coût mise en place</label>
                  <input
                    type="number"
                    step="0.01"
                    value={form.setupCost}
                    onChange={(e) => setForm({ ...form, setupCost: 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"
                  />
                </div>
              </div>
              <div className="grid grid-cols-2 gap-4">
                <div>
                  <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">Prix mensuel</label>
                  <input
                    type="number"
                    step="0.01"
                    value={form.monthlyPrice}
                    onChange={(e) => setForm({ ...form, monthlyPrice: 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"
                  />
                </div>
                <div>
                  <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">Coût mensuel</label>
                  <input
                    type="number"
                    step="0.01"
                    value={form.monthlyCost}
                    onChange={(e) => setForm({ ...form, monthlyCost: 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"
                  />
                </div>
              </div>
              <div className="grid grid-cols-2 gap-4">
                <div>
                  <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">Jour de facturation</label>
                  <input
                    type="number"
                    min={1}
                    max={31}
                    value={form.billingDay}
                    onChange={(e) => setForm({ ...form, billingDay: 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"
                  />
                </div>
                <div>
                  <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">Statut</label>
                  <select
                    value={form.status}
                    onChange={(e) => setForm({ ...form, status: 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"
                  >
                    <option value="PROPOSAL">Proposition en cours</option>
                    <option value="ACTIVE">Actif</option>
                    <option value="PAUSED">En pause</option>
                    <option value="CANCELLED">Annulé</option>
                    <option value="EXPIRED">Expiré</option>
                  </select>
                </div>
              </div>
              <div>
                <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-1">Notes</label>
                <textarea
                  value={form.notes}
                  onChange={(e) => setForm({ ...form, notes: e.target.value })}
                  rows={3}
                  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"
                />
              </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 || !form.clientId || !form.name.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...' : editing ? 'Modifier' : 'Créer'}
              </button>
            </div>
          </div>
        </div>
      )}

      <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-4 gap-4">
        <div className="bg-white dark:bg-slate-800 rounded-xl p-4 border border-slate-200 dark:border-slate-700">
          <p className="text-sm text-slate-500">Total revenus mensuels</p>
          <p className="text-xl font-bold text-green-600">{formatCurrency(contracts.reduce((s, c) => s + (c.status === 'ACTIVE' ? c.monthlyPrice : 0), 0))}</p>
        </div>
        <div className="bg-white dark:bg-slate-800 rounded-xl p-4 border border-slate-200 dark:border-slate-700">
          <p className="text-sm text-slate-500">Total coûts mensuels</p>
          <p className="text-xl font-bold text-red-500">{formatCurrency(contracts.reduce((s, c) => s + (c.status === 'ACTIVE' ? c.monthlyCost : 0), 0))}</p>
        </div>
        <div className="bg-white dark:bg-slate-800 rounded-xl p-4 border border-slate-200 dark:border-slate-700">
          <p className="text-sm text-slate-500">Marge mensuelle</p>
          <p className="text-xl font-bold text-primary-600">
            {formatCurrency(contracts.reduce((s, c) => s + (c.status === 'ACTIVE' ? c.monthlyPrice - c.monthlyCost : 0), 0))}
          </p>
        </div>
        <div className="bg-white dark:bg-slate-800 rounded-xl p-4 border border-slate-200 dark:border-slate-700">
          <p className="text-sm text-slate-500">Contrats actifs</p>
          <p className="text-xl font-bold text-slate-900 dark:text-white">{contracts.filter(c => c.status === 'ACTIVE').length}</p>
        </div>
      </div>

      <div className="bg-white dark:bg-slate-800 rounded-xl border border-slate-200 dark:border-slate-700 overflow-hidden">
        <div className="overflow-x-auto">
          <table className="w-full">
            <thead>
              <tr className="border-b border-slate-200 dark:border-slate-700 bg-slate-50 dark:bg-slate-800/50">
                <th className="text-left px-4 py-3 text-xs font-medium text-slate-500 uppercase">Contrat</th>
                <th className="text-left px-4 py-3 text-xs font-medium text-slate-500 uppercase">Client</th>
                <th className="text-center px-4 py-3 text-xs font-medium text-slate-500 uppercase">Mensuel</th>
                <th className="text-center px-4 py-3 text-xs font-medium text-slate-500 uppercase">Coût</th>
                <th className="text-center px-4 py-3 text-xs font-medium text-slate-500 uppercase">Marge</th>
                <th className="text-center px-4 py-3 text-xs font-medium text-slate-500 uppercase">Statut</th>
                <th className="text-right px-4 py-3 text-xs font-medium text-slate-500 uppercase">Actions</th>
              </tr>
            </thead>
            <tbody className="divide-y divide-slate-200 dark:divide-slate-700">
              {loading ? (
                <tr>
                  <td colSpan={7} className="text-center py-8 text-slate-500">Chargement...</td>
                </tr>
              ) : contracts.length === 0 ? (
                <tr>
                  <td colSpan={7} className="text-center py-8 text-slate-500">Aucun contrat</td>
                </tr>
              ) : (
                contracts.map((contract) => {
                  const margin = contract.monthlyPrice - contract.monthlyCost
                  const marginPct = contract.monthlyPrice > 0 ? (margin / contract.monthlyPrice) * 100 : 0
                  return (
                    <tr key={contract.id} className="hover:bg-slate-50 dark:hover:bg-slate-700/50">
                      <td className="px-4 py-3">
                        <p className="font-medium text-slate-900 dark:text-white">{contract.name}</p>
                        <p className="text-xs text-slate-400">
                          Début: {format(new Date(contract.startDate), 'dd/MM/yyyy', { locale: fr })}
                          {contract.endDate && ` - Fin: ${format(new Date(contract.endDate), 'dd/MM/yyyy', { locale: fr })}`}
                        </p>
                      </td>
                      <td className="px-4 py-3 text-sm text-slate-600 dark:text-slate-300">
                        {contract.client.name}
                      </td>
                      <td className="px-4 py-3 text-center font-medium text-green-600">
                        {formatCurrency(contract.monthlyPrice)}
                      </td>
                      <td className="px-4 py-3 text-center text-sm text-slate-600 dark:text-slate-300">
                        {formatCurrency(contract.monthlyCost)}
                      </td>
                      <td className="px-4 py-3 text-center">
                        <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-3 text-center">
                        <span className={`inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium ${statusColors[contract.status] || ''}`}>
                          {statusLabels[contract.status] || contract.status}
                        </span>
                      </td>
                      <td className="px-4 py-3">
                        <div className="flex items-center justify-end gap-2">
                          <button onClick={() => openEdit(contract)} className="p-1.5 rounded text-blue-600 hover:bg-blue-50 dark:hover:bg-blue-900/20">
                            <Edit2 className="h-4 w-4" />
                          </button>
                          <button onClick={() => handleDelete(contract.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>
  )
}