Feat: Implementado cálculo de ISR en nóminas

- Agregado campo isr_table_id en tabla months para seleccionar tabla ISR por mes
- Creado servicio IsrCalculator para calcular ISR mensual y quincenal
- Modificado CommissionCalculator para descontar ISR del total a pagar
- Agregado selector de tabla ISR en formulario de crear/editar mes
- Actualizada vista de meses para mostrar tabla ISR asignada
- Actualizados reportes mensual y quincenal para mostrar ISR descontado

app/Http/Controllers/MonthController.php

@@ -2,6 +2,7 @@
 
 namespace App\Http\Controllers;
 
+use App\Models\IsrTable;
 use App\Models\Month;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Auth;
@@ -16,6 +17,7 @@ class MonthController extends Controller
         $user = Auth::user();
         
         $months = $user->months()
+            ->with('isrTable')
             ->orderBy('year', 'desc')
             ->orderByRaw("FIELD(name, 'Diciembre', 'Noviembre', 'Octubre', 'Septiembre', 'Agosto', 'Julio', 'Junio', 'Mayo', 'Abril', 'Marzo', 'Febrero', 'Enero')")
             ->paginate(12);
@@ -28,7 +30,8 @@ class MonthController extends Controller
      */
     public function create()
     {
-        return view('months.create');
+        $isrTables = IsrTable::with('brackets')->orderBy('year', 'desc')->get();
+        return view('months.create', compact('isrTables'));
     }
 
     /**
@@ -41,6 +44,7 @@ class MonthController extends Controller
         $validated = $request->validate([
             'name' => ['required', 'string', 'max:50'],
             'year' => ['required', 'integer', 'min:2020', 'max:2100'],
+            'isr_table_id' => ['nullable', 'exists:isr_tables,id'],
         ]);
 
         // Verificar que no exista ya el mes para el usuario
@@ -59,6 +63,7 @@ class MonthController extends Controller
             'name' => $validated['name'],
             'year' => $validated['year'],
             'status' => 'open',
+            'isr_table_id' => $validated['isr_table_id'] ?? null,
         ]);
 
         return redirect()->route('months.index')
@@ -92,7 +97,8 @@ class MonthController extends Controller
             abort(403);
         }
 
-        return view('months.edit', compact('month'));
+        $isrTables = IsrTable::with('brackets')->orderBy('year', 'desc')->get();
+        return view('months.edit', compact('month', 'isrTables'));
     }
 
     /**
@@ -110,6 +116,7 @@ class MonthController extends Controller
             'name' => ['required', 'string', 'max:50'],
             'year' => ['required', 'integer', 'min:2020', 'max:2100'],
             'status' => ['required', 'in:open,closed,paid'],
+            'isr_table_id' => ['nullable', 'exists:isr_tables,id'],
         ]);
 
         $month->update($validated);

app/Models/Month.php

@@ -8,7 +8,7 @@ use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 
-#[Fillable(['user_id', 'name', 'year', 'status'])]
+#[Fillable(['user_id', 'name', 'year', 'status', 'isr_table_id'])]
 class Month extends Model
 {
     use HasFactory;
@@ -25,6 +25,7 @@ class Month extends Model
         'name',
         'year',
         'status',
+        'isr_table_id',
     ];
 
     /**
@@ -63,6 +64,14 @@ class Month extends Model
         return $this->hasMany(Expense::class);
     }
 
+    /**
+     * Relación con tabla ISR
+     */
+    public function isrTable(): BelongsTo
+    {
+        return $this->belongsTo(IsrTable::class);
+    }
+
     /**
      * Obtener el nombre del mes con formato
      */

app/Services/CommissionCalculator.php

@@ -4,6 +4,7 @@ namespace App\Services;
 
 use App\Models\DailySale;
 use App\Models\Expense;
+use App\Models\IsrTable;
 use App\Models\Month;
 use App\Models\User;
 use Illuminate\Support\Facades\DB;
@@ -38,8 +39,15 @@ class CommissionCalculator
         // Calcular comisión basada en ventas del sistema (ventas consolidadas)
         $commission = ($totalSystemSales * $commissionPercentage) / 100;
         
-        // Calcular percepción total (salario + comisión - gastos)
-        $totalEarning = $monthlySalary + $commission - $totalExpenses;
+        // Calcular ISR sobre (salario + comisión)
+        // Los gastos personales NO son deducibles del ISR
+        $incomeForIsr = $monthlySalary + $commission;
+        $isrTable = $month->isrTable;
+        $isrResult = IsrCalculator::calculateMonthly($incomeForIsr, $isrTable);
+        $isrAmount = $isrResult['isr'];
+        
+        // Calcular percepción total con ISR (salario + comisión - gastos - ISR)
+        $totalEarning = $monthlySalary + $commission - $totalExpenses - $isrAmount;
 
         return [
             'user_id' => $user->id,
@@ -51,6 +59,8 @@ class CommissionCalculator
             'monthly_salary' => round($monthlySalary, 2),
             'commission_percentage' => round($commissionPercentage, 2),
             'commission_amount' => round($commission, 2),
+            'isr_amount' => round($isrAmount, 2),
+            'isr_details' => $isrResult,
             'total_earning' => round($totalEarning, 2),
             'has_difference' => ($totalUserSales !== $totalSystemSales),
             'sales_difference' => round($totalUserSales - $totalSystemSales, 2),
@@ -60,8 +70,8 @@ class CommissionCalculator
     /**
      * Calcular quincena (primera o segunda)
      * 
-     * QUINCENA 1 (ANTICIPO): mitad salary + comisiones del MES completo
-     * QUINCENA 2 (LIQUIDACIÓN): mitad salary - gastos de la segunda quincena
+     * QUINCENA 1 (ANTICIPO): mitad salary + comisiones del MES completo - ISR quincenal
+     * QUINCENA 2 (LIQUIDACIÓN): mitad salary - gastos de la segunda quincena - ISR quincenal
      */
     public static function calculateBiweekly(User $user, Month $month, int $biweekly): array
     {
@@ -78,13 +88,20 @@ class CommissionCalculator
         $year = $month->year;
         $lastDay = self::getLastDayOfMonth($month->name, $year);
         
+        // Calcular ISR mensual completo (salario + comisión)
+        $totalSystemSales = $month->dailySales()->sum('system_sales');
+        $commission = ($totalSystemSales * $commissionPercentage) / 100;
+        $incomeForIsr = $monthlySalary + $commission;
+        $isrTable = $month->isrTable;
+        $isrResult = IsrCalculator::calculateMonthly($incomeForIsr, $isrTable);
+        $isrMonthlyAmount = $isrResult['isr'];
+        $isrBiweekly = IsrCalculator::calculateBiweekly($isrMonthlyAmount);
+        
         if ($biweekly === 1) {
             // =====================
             // QUINCENA 1 - ANTICIPO
             // =====================
-            // Anticipo = mitad del sueldo + comisiones del MES completo
-            $totalSystemSales = $month->dailySales()->sum('system_sales');
-            $commission = ($totalSystemSales * $commissionPercentage) / 100;
+            // Anticipo = mitad del sueldo + comisiones del MES completo - ISR quincenal
             
             // Gastos: q1 completo + mensual/2
             $expensesQ1Amount = $month->expenses()
@@ -97,7 +114,7 @@ class CommissionCalculator
                     return $e->expense_type === 'mensual' ? $e->amount / 2 : $e->amount;
                 });
             
-            $totalEarning = $biweeklySalary + $commission - $expensesQ1Amount;
+            $totalEarning = $biweeklySalary + $commission - $expensesQ1Amount - $isrBiweekly;
             
             return [
                 'user_id' => $user->id,
@@ -105,11 +122,12 @@ class CommissionCalculator
                 'month_name' => $month->name . ' ' . $year,
                 'biweekly' => $biweekly,
                 'period' => '1ra Quincena (1-15) - ANTICIPO',
-                'description' => 'Mitad del sueldo + comisiones del mes completo',
+                'description' => 'Mitad del sueldo + comisiones del mes completo - ISR',
                 'biweekly_salary' => round($biweeklySalary, 2),
                 'total_system_sales' => round($totalSystemSales, 2),
                 'commission_percentage' => round($commissionPercentage, 2),
                 'commission_amount' => round($commission, 2),
+                'isr_amount' => round($isrBiweekly, 2),
                 'total_expenses_month' => 0,
                 'expenses_q1' => round($expensesQ1Amount, 2),
                 'expenses_q2' => 0,
@@ -120,7 +138,7 @@ class CommissionCalculator
             // =====================
             // QUINCENA 2 - LIQUIDACIÓN
             // =====================
-            // Liquidación = mitad del sueldo - gastos de Q2
+            // Liquidación = mitad del sueldo - gastos de Q2 - ISR quincenal
             
             // Gastos: q2 completo + mensual/2
             $expensesQ2Amount = $month->expenses()
@@ -134,7 +152,7 @@ class CommissionCalculator
                 });
             
             // Total a pagar en liquidacion
-            $totalEarning = $biweeklySalary - $expensesQ2Amount;
+            $totalEarning = $biweeklySalary - $expensesQ2Amount - $isrBiweekly;
             
             return [
                 'user_id' => $user->id,
@@ -142,9 +160,10 @@ class CommissionCalculator
                 'month_name' => $month->name . ' ' . $year,
                 'biweekly' => $biweekly,
                 'period' => "2da Quincena (16-$lastDay) - LIQUIDACIÓN",
-                'description' => 'Mitad del sueldo - mitad de gastos del mes',
+                'description' => 'Mitad del sueldo - mitad de gastos del mes - ISR',
                 'biweekly_salary' => round($biweeklySalary, 2),
                 'total_system_sales' => 0,
+                'isr_amount' => round($isrBiweekly, 2),
                 'expenses_q2' => round($expensesQ2Amount, 2),
                 'total_earning' => round($totalEarning, 2),
                 'type' => 'liquidacion',

app/Services/IsrCalculator.php

@@ -0,0 +1,65 @@
+<?php
+
+namespace App\Services;
+
+use App\Models\IsrBracket;
+use App\Models\IsrTable;
+
+class IsrCalculator
+{
+    /**
+     * Calcular ISR mensual dado un ingreso base
+     * Retorna: ['isr' => float, 'bracket' => array|null, 'effective_rate' => float]
+     */
+    public static function calculateMonthly(float $baseIncome, ?IsrTable $isrTable): array
+    {
+        if (!$isrTable || $baseIncome <= 0) {
+            return [
+                'isr' => 0,
+                'bracket' => null,
+                'effective_rate' => 0,
+                'taxable_income' => 0,
+            ];
+        }
+
+        $brackets = $isrTable->brackets()->orderBy('lower_limit')->get();
+        
+        foreach ($brackets as $bracket) {
+            $upperLimit = $bracket->upper_limit;
+            
+            // Si es el último bracket (upper_limit es null = "En adelante")
+            if ($upperLimit === null || $baseIncome <= $upperLimit) {
+                // Calcular ISR: Cuota Fija + (Excedente × Tasa)
+                $excedent = $baseIncome - $bracket->lower_limit;
+                $isr = $bracket->fixed_fee + ($excedent * $bracket->rate / 100);
+                
+                return [
+                    'isr' => round($isr, 2),
+                    'bracket' => [
+                        'lower_limit' => $bracket->lower_limit,
+                        'upper_limit' => $bracket->upper_limit,
+                        'fixed_fee' => $bracket->fixed_fee,
+                        'rate' => $bracket->rate,
+                    ],
+                    'effective_rate' => round(($isr / $baseIncome) * 100, 2),
+                    'taxable_income' => round($baseIncome, 2),
+                ];
+            }
+        }
+        
+        return [
+            'isr' => 0,
+            'bracket' => null,
+            'effective_rate' => 0,
+            'taxable_income' => 0,
+        ];
+    }
+    
+    /**
+     * Calcular ISR quincenal = ISR mensual / 2
+     */
+    public static function calculateBiweekly(float $monthlyIsr): float
+    {
+        return round($monthlyIsr / 2, 2);
+    }
+}