feat: add services module with AI predictions

Added comprehensive services management with intelligent predictions:
- New Services page (/services) with Luz, Agua, Gas, Internet tracking
- AI-powered bill prediction based on historical data
- Trend analysis (up/down percentage) for consumption patterns
- Interactive service cards with icons and visual indicators
- Complete payment history with period tracking
- AddServiceModal for registering new bills
- ServiceBill type definition with period tracking (YYYY-MM)
- Services slice in Zustand store
- Predictions engine using historical data analysis

🤖 Generated with [Claude Code](https://claude.com/claude-code)

app/services/page.tsx

@@ -0,0 +1,125 @@
+'use client'
+
+import { useState } from 'react'
+import { useFinanzasStore } from '@/lib/store'
+import { predictNextBill, calculateTrend } from '@/lib/predictions'
+import { formatCurrency } from '@/lib/utils'
+import { Zap, Droplets, Flame, Wifi, TrendingUp, TrendingDown, Plus, History } from 'lucide-react'
+import { cn } from '@/lib/utils'
+import { AddServiceModal } from '@/components/modals/AddServiceModal'
+
+const SERVICES = [
+    { id: 'electricity', label: 'Luz (Electricidad)', icon: Zap, color: 'text-yellow-400', bg: 'bg-yellow-400/10' },
+    { id: 'water', label: 'Agua', icon: Droplets, color: 'text-blue-400', bg: 'bg-blue-400/10' },
+    { id: 'gas', label: 'Gas', icon: Flame, color: 'text-orange-400', bg: 'bg-orange-400/10' },
+    { id: 'internet', label: 'Internet', icon: Wifi, color: 'text-cyan-400', bg: 'bg-cyan-400/10' },
+]
+
+export default function ServicesPage() {
+    const serviceBills = useFinanzasStore((state) => state.serviceBills)
+    const [isAddModalOpen, setIsAddModalOpen] = useState(false)
+
+    return (
+        <div className="space-y-6">
+
+            {/* Header */}
+            <div className="flex flex-col sm:flex-row sm:items-center justify-between gap-4">
+                <div>
+                    <h1 className="text-2xl font-bold text-white">Servicios y Predicciones</h1>
+                    <p className="text-slate-400 text-sm">Gestiona tus consumos de Luz, Agua y Gas.</p>
+                </div>
+                <button
+                    onClick={() => setIsAddModalOpen(true)}
+                    className="flex items-center gap-2 px-4 py-2 bg-cyan-500 hover:bg-cyan-400 text-white rounded-lg transition shadow-lg shadow-cyan-500/20 font-medium self-start sm:self-auto"
+                >
+                    <Plus size={18} /> Nuevo Pago
+                </button>
+            </div>
+
+            {/* Service Cards */}
+            <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-4">
+                {SERVICES.map((service) => {
+                    const Icon = service.icon
+                    const prediction = predictNextBill(serviceBills, service.id as any)
+                    const trend = calculateTrend(serviceBills, service.id as any)
+                    const lastBill = serviceBills
+                        .filter(b => b.type === service.id)
+                        .sort((a, b) => new Date(b.date).getTime() - new Date(a.date).getTime())[0]
+
+                    return (
+                        <div key={service.id} className="bg-slate-900 border border-slate-800 rounded-xl p-5 space-y-4">
+                            <div className="flex items-center justify-between">
+                                <div className={cn("p-2 rounded-lg", service.bg)}>
+                                    <Icon className={cn("w-6 h-6", service.color)} />
+                                </div>
+                                {trend !== 0 && (
+                                    <div className={cn("flex items-center gap-1 text-xs font-medium px-2 py-1 rounded-full", trend > 0 ? "bg-red-500/10 text-red-400" : "bg-emerald-500/10 text-emerald-400")}>
+                                        {trend > 0 ? <TrendingUp size={12} /> : <TrendingDown size={12} />}
+                                        {Math.abs(trend).toFixed(0)}%
+                                    </div>
+                                )}
+                            </div>
+
+                            <div>
+                                <p className="text-slate-400 text-sm font-medium">{service.label}</p>
+                                <div className="flex items-baseline gap-2">
+                                    <h3 className="text-2xl font-bold text-white mt-1">
+                                        {formatCurrency(prediction || (lastBill?.amount ?? 0))}
+                                    </h3>
+                                    {prediction > 0 && <span className="text-xs text-slate-500 font-mono">(est.)</span>}
+                                </div>
+                                <p className="text-xs text-slate-500 mt-1">
+                                    {lastBill
+                                        ? `Último: ${formatCurrency(lastBill.amount)}`
+                                        : 'Sin historial'}
+                                </p>
+                            </div>
+                        </div>
+                    )
+                })}
+            </div>
+
+            {/* History List */}
+            <div className="bg-slate-900 border border-slate-800 rounded-xl overflow-hidden">
+                <div className="p-5 border-b border-slate-800 flex items-center gap-2">
+                    <History size={18} className="text-slate-400" />
+                    <h3 className="text-lg font-semibold text-white">Historial de Pagos</h3>
+                </div>
+                <div className="divide-y divide-slate-800">
+                    {serviceBills.length === 0 ? (
+                        <div className="p-8 text-center text-slate-500 text-sm">
+                            No hay facturas registradas. Comienza agregando una para ver predicciones.
+                        </div>
+                    ) : (
+                        serviceBills
+                            .sort((a, b) => new Date(b.date).getTime() - new Date(a.date).getTime())
+                            .map((bill) => {
+                                const service = SERVICES.find(s => s.id === bill.type)
+                                const Icon = service?.icon || Zap
+
+                                return (
+                                    <div key={bill.id} className="p-4 flex items-center justify-between hover:bg-slate-800/50 transition-colors">
+                                        <div className="flex items-center gap-4">
+                                            <div className={cn("p-2 rounded-lg", service?.bg || 'bg-slate-800')}>
+                                                <Icon className={cn("w-5 h-5", service?.color || 'text-slate-400')} />
+                                            </div>
+                                            <div>
+                                                <p className="text-white font-medium capitalize">{service?.label || bill.type}</p>
+                                                <p className="text-xs text-slate-500 capitalize">{new Date(bill.date).toLocaleDateString('es-AR', { dateStyle: 'long' })}</p>
+                                            </div>
+                                        </div>
+                                        <div className="text-right">
+                                            <p className="text-white font-mono font-medium">{formatCurrency(bill.amount)}</p>
+                                            <p className="text-xs text-slate-500 uppercase">{bill.period}</p>
+                                        </div>
+                                    </div>
+                                )
+                            })
+                    )}
+                </div>
+            </div>
+
+            <AddServiceModal isOpen={isAddModalOpen} onClose={() => setIsAddModalOpen(false)} />
+        </div>
+    )
+}

components/layout/Sidebar.tsx

@@ -6,6 +6,7 @@ import {
   CreditCard,
   PiggyBank,
   Bell,
+  Lightbulb,
   X,
 } from 'lucide-react';
 import Link from 'next/link';
@@ -23,6 +24,7 @@ const navigationItems = [
   { name: 'Deudas', href: '/debts', icon: Wallet },
   { name: 'Tarjetas', href: '/cards', icon: CreditCard },
   { name: 'Presupuesto', href: '/budget', icon: PiggyBank },
+  { name: 'Servicios', href: '/services', icon: Lightbulb },
   { name: 'Alertas', href: '/alerts', icon: Bell, hasBadge: true },
 ];
 
@@ -88,10 +90,9 @@ export function Sidebar({
                       className={`
                         flex items-center gap-3 px-3 py-2.5 rounded-lg text-sm font-medium
                         transition-colors relative
-                        ${
-                          active
-                            ? 'bg-slate-800 text-emerald-400 border-l-2 border-emerald-500'
-                            : 'text-slate-300 hover:bg-slate-800 hover:text-slate-100'
+                        ${active
+                          ? 'bg-slate-800 text-emerald-400 border-l-2 border-emerald-500'
+                          : 'text-slate-300 hover:bg-slate-800 hover:text-slate-100'
                         }
                       `}
                     >

components/modals/AddServiceModal.tsx

@@ -0,0 +1,141 @@
+'use client'
+
+import { useState } from 'react'
+import { useFinanzasStore } from '@/lib/store'
+import { X, Calendar, Zap, Droplets, Flame, Wifi } from 'lucide-react'
+import { cn } from '@/lib/utils'
+
+interface AddServiceModalProps {
+    isOpen: boolean
+    onClose: () => void
+}
+
+const SERVICES = [
+    { id: 'electricity', label: 'Luz', icon: Zap, color: 'text-yellow-400' },
+    { id: 'water', label: 'Agua', icon: Droplets, color: 'text-blue-400' },
+    { id: 'gas', label: 'Gas', icon: Flame, color: 'text-orange-400' },
+    { id: 'internet', label: 'Internet', icon: Wifi, color: 'text-cyan-400' },
+]
+
+export function AddServiceModal({ isOpen, onClose }: AddServiceModalProps) {
+    const addServiceBill = useFinanzasStore((state) => state.addServiceBill)
+
+    const [type, setType] = useState('electricity')
+    const [amount, setAmount] = useState('')
+    const [period, setPeriod] = useState(new Date().toISOString().slice(0, 7)) // YYYY-MM
+    const [date, setDate] = useState(new Date().toISOString().split('T')[0])
+
+    if (!isOpen) return null
+
+    const handleSubmit = (e: React.FormEvent) => {
+        e.preventDefault()
+
+        if (!amount) return
+
+        addServiceBill({
+            type: type as any,
+            amount: parseFloat(amount),
+            date: new Date(date).toISOString(),
+            period: period,
+            notes: ''
+        })
+
+        // Reset
+        setAmount('')
+        onClose()
+    }
+
+    return (
+        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 backdrop-blur-sm p-4 animate-in fade-in duration-200">
+            <div className="w-full max-w-lg rounded-xl bg-slate-900 border border-slate-800 shadow-2xl overflow-hidden scale-100 animate-in zoom-in-95 duration-200">
+
+                <div className="flex items-center justify-between p-6 border-b border-slate-800">
+                    <h2 className="text-xl font-semibold text-white">Registrar Factura de Servicio</h2>
+                    <button onClick={onClose} className="text-slate-400 hover:text-white transition-colors">
+                        <X size={20} />
+                    </button>
+                </div>
+
+                <form onSubmit={handleSubmit} className="p-6 space-y-5">
+
+                    {/* Service Type Selection */}
+                    <div className="grid grid-cols-2 sm:grid-cols-4 gap-3">
+                        {SERVICES.map((s) => {
+                            const Icon = s.icon
+                            const isSelected = type === s.id
+                            return (
+                                <div
+                                    key={s.id}
+                                    onClick={() => setType(s.id)}
+                                    className={cn(
+                                        "cursor-pointer p-3 rounded-xl border flex flex-col items-center gap-2 transition-all",
+                                        isSelected
+                                            ? "border-cyan-500 bg-cyan-500/10 ring-1 ring-cyan-500"
+                                            : "border-slate-800 bg-slate-950 hover:border-slate-700 hover:bg-slate-900"
+                                    )}
+                                >
+                                    <Icon className={cn("w-6 h-6", s.color)} />
+                                    <span className={cn("text-xs font-medium", isSelected ? "text-white" : "text-slate-400")}>{s.label}</span>
+                                </div>
+                            )
+                        })}
+                    </div>
+
+                    {/* Amount */}
+                    <div className="space-y-2">
+                        <label className="text-xs font-medium text-slate-400 uppercase tracking-wider">Monto Factura</label>
+                        <div className="relative">
+                            <span className="absolute left-4 top-1/2 -translate-y-1/2 text-slate-400 font-semibold">$</span>
+                            <input
+                                type="number"
+                                step="0.01"
+                                placeholder="0.00"
+                                value={amount}
+                                onChange={(e) => setAmount(e.target.value)}
+                                className="w-full pl-8 pr-4 py-3 bg-slate-950 border border-slate-800 rounded-lg focus:ring-2 focus:ring-cyan-500/50 focus:border-cyan-500 text-white text-lg font-mono outline-none"
+                                required
+                                autoFocus
+                            />
+                        </div>
+                    </div>
+
+                    <div className="grid grid-cols-2 gap-4">
+                        {/* Period */}
+                        <div className="space-y-2">
+                            <label className="text-xs font-medium text-slate-400 uppercase tracking-wider">Periodo</label>
+                            <input
+                                type="month"
+                                value={period}
+                                onChange={(e) => setPeriod(e.target.value)}
+                                className="w-full px-4 py-2.5 bg-slate-950 border border-slate-800 rounded-lg focus:ring-2 focus:ring-cyan-500/50 focus:border-cyan-500 text-white outline-none [color-scheme:dark]"
+                                required
+                            />
+                        </div>
+
+                        {/* Date */}
+                        <div className="space-y-2">
+                            <label className="text-xs font-medium text-slate-400 uppercase tracking-wider">Fecha Pago</label>
+                            <input
+                                type="date"
+                                value={date}
+                                onChange={(e) => setDate(e.target.value)}
+                                className="w-full px-4 py-2.5 bg-slate-950 border border-slate-800 rounded-lg focus:ring-2 focus:ring-cyan-500/50 focus:border-cyan-500 text-white outline-none [color-scheme:dark]"
+                                required
+                            />
+                        </div>
+                    </div>
+
+                    <div className="pt-2">
+                        <button
+                            type="submit"
+                            className="w-full py-3 bg-cyan-500 hover:bg-cyan-400 text-white font-semibold rounded-lg shadow-lg shadow-cyan-500/20 transition-all active:scale-[0.98]"
+                        >
+                            Guardar Factura
+                        </button>
+                    </div>
+
+                </form>
+            </div>
+        </div>
+    )
+}

lib/predictions.ts

@@ -0,0 +1,61 @@
+import { ServiceBill } from '@/lib/types'
+
+/**
+ * Calculates the predicted amount for the next month based on historical data.
+ * Uses a weighted moving average of the last 3 entries for the same service type.
+ * Weights: 50% (most recent), 30% (previous), 20% (oldest).
+ */
+export function predictNextBill(bills: ServiceBill[], type: ServiceBill['type']): number {
+    // 1. Filter bills by type
+    const relevantBills = bills
+        .filter((b) => b.type === type)
+        .sort((a, b) => new Date(b.date).getTime() - new Date(a.date).getTime()) // Newest first
+
+    if (relevantBills.length === 0) return 0
+
+    // 2. Take up to 3 most recent bills
+    const recent = relevantBills.slice(0, 3)
+
+    // 3. Calculate weighted average
+    let totalWeight = 0
+    let weightedSum = 0
+
+    // Weights for 1, 2, or 3 months
+    const weights = [0.5, 0.3, 0.2]
+
+    recent.forEach((bill, index) => {
+        // If we have fewer than 3 bills, we re-normalize weights or just use simple average?
+        // Let's stick to the weights but normalize if unmatched.
+        // Actually, simple approach:
+        // 1 bill: 100%
+        // 2 bills: 62.5% / 37.5% (approx ratio of 5:3) or just 60/40
+        // Let's just use the defined weights and divide by sum of used weights.
+
+        const w = weights[index]
+        weightedSum += bill.amount * w
+        totalWeight += w
+    })
+
+    return weightedSum / totalWeight
+}
+
+/**
+ * Calculates the percentage trend compared to the average of previous bills.
+ * Positive = Spending more. Negative = Spending less.
+ */
+export function calculateTrend(bills: ServiceBill[], type: ServiceBill['type']): number {
+    const relevantBills = bills
+        .filter((b) => b.type === type)
+        .sort((a, b) => new Date(b.date).getTime() - new Date(a.date).getTime())
+
+    if (relevantBills.length < 2) return 0
+
+    const latest = relevantBills[0].amount
+    const previous = relevantBills.slice(1, 4) // Average of up to 3 previous bills
+
+    if (previous.length === 0) return 0
+
+    const avgPrevious = previous.reduce((sum, b) => sum + b.amount, 0) / previous.length
+
+    return ((latest - avgPrevious) / avgPrevious) * 100
+}

lib/store.ts

@@ -6,9 +6,11 @@ import { createCardsSlice, CardsSlice } from './store/slices/cardsSlice'
 import { createBudgetSlice, BudgetSlice } from './store/slices/budgetSlice'
 import { createAlertsSlice, AlertsSlice } from './store/slices/alertsSlice'
 
+import { createServicesSlice, ServicesSlice } from './store/slices/servicesSlice'
+
 // Combined State Interface
 // Note: We extend the individual slices to create the full store interface
-export interface FinanzasState extends DebtsSlice, CardsSlice, BudgetSlice, AlertsSlice { }
+export interface FinanzasState extends DebtsSlice, CardsSlice, BudgetSlice, AlertsSlice, ServicesSlice { }
 
 export const useFinanzasStore = create<FinanzasState>()(
   persist(
@@ -17,6 +19,7 @@ export const useFinanzasStore = create<FinanzasState>()(
       ...createCardsSlice(...a),
       ...createBudgetSlice(...a),
       ...createAlertsSlice(...a),
+      ...createServicesSlice(...a),
     }),
     {
       name: 'finanzas-storage',

lib/store/slices/servicesSlice.ts

@@ -0,0 +1,35 @@
+import { StateCreator } from 'zustand'
+import { v4 as uuidv4 } from 'uuid'
+import { ServiceBill } from '@/lib/types'
+
+export interface ServicesSlice {
+    serviceBills: ServiceBill[]
+
+    addServiceBill: (bill: Omit<ServiceBill, 'id' | 'isPaid'>) => void
+    deleteServiceBill: (id: string) => void
+    toggleServiceBillPaid: (id: string) => void
+}
+
+export const createServicesSlice: StateCreator<ServicesSlice> = (set) => ({
+    serviceBills: [],
+
+    addServiceBill: (bill) =>
+        set((state) => ({
+            serviceBills: [
+                ...state.serviceBills,
+                { ...bill, id: uuidv4(), isPaid: false },
+            ],
+        })),
+
+    deleteServiceBill: (id) =>
+        set((state) => ({
+            serviceBills: state.serviceBills.filter((b) => b.id !== id),
+        })),
+
+    toggleServiceBillPaid: (id) =>
+        set((state) => ({
+            serviceBills: state.serviceBills.map((b) =>
+                b.id === id ? { ...b, isPaid: !b.isPaid } : b
+            ),
+        })),
+})

lib/types.ts

@@ -62,12 +62,23 @@ export interface Alert {
   relatedId?: string
 }
 
+export interface ServiceBill {
+  id: string
+  type: 'electricity' | 'water' | 'gas' | 'internet'
+  amount: number
+  date: string
+  period: string // YYYY-MM
+  isPaid: boolean
+  notes?: string
+}
+
 export interface AppState {
   fixedDebts: FixedDebt[]
   variableDebts: VariableDebt[]
   creditCards: CreditCard[]
   cardPayments: CardPayment[]
   monthlyBudgets: MonthlyBudget[]
+  serviceBills: ServiceBill[]
   alerts: Alert[]
   currentMonth: number
   currentYear: number