<?php

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;

class CommissionCalculator
{
    /**
     * Calcular comisión para un usuario en un mes específico
     */
    public static function calculateForMonth(User $user, Month $month): array
    {
        // Verificar que el mes pertenece al usuario
        if ($month->user_id !== $user->id) {
            throw new \InvalidArgumentException('El mes no pertenece al usuario');
        }

        // Total de ventas del usuario
        $totalUserSales = $month->dailySales()->sum('user_sales');
        
        // Total de ventas del sistema
        $totalSystemSales = $month->dailySales()->sum('system_sales');
        
        // Total de gastos
        $totalExpenses = $month->expenses()->sum('amount');
        
        // Salario base
        $monthlySalary = $user->monthly_salary;
        
        // Porcentaje de comisión
        $commissionPercentage = $user->commission_percentage;
        
        // Calcular comisión basada en ventas del sistema (ventas consolidadas)
        $commission = ($totalSystemSales * $commissionPercentage) / 100;
        
        // 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,
            'month_id' => $month->id,
            'month_name' => $month->name . ' ' . $month->year,
            'total_user_sales' => round($totalUserSales, 2),
            'total_system_sales' => round($totalSystemSales, 2),
            'total_expenses' => round($totalExpenses, 2),
            '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),
        ];
    }

    /**
     * Calcular quincena (primera o segunda)
     * 
     * 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 $biweekly): array
    {
        if ($month->user_id !== $user->id) {
            throw new \InvalidArgumentException('El mes no pertenece al usuario');
        }

        $monthlySalary = $user->monthly_salary;
        $biweeklySalary = $monthlySalary / 2; // Mitad del sueldo
        $commissionPercentage = $user->commission_percentage;
        
        // Get month number
        $monthNumber = self::getMonthNumber($month->name);
        $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 - ISR quincenal
            
            // Gastos: q1 completo + mensual/2
            $expensesQ1Amount = $month->expenses()
                ->where(function($q) {
                    $q->where('expense_type', 'q1')
                      ->orWhere('expense_type', 'mensual');
                })
                ->get()
                ->sum(function($e) {
                    return $e->expense_type === 'mensual' ? $e->amount / 2 : $e->amount;
                });
            
            $totalEarning = $biweeklySalary + $commission - $expensesQ1Amount - $isrBiweekly;
            
            return [
                'user_id' => $user->id,
                'month_id' => $month->id,
                'month_name' => $month->name . ' ' . $year,
                'biweekly' => $biweekly,
                'period' => '1ra Quincena (1-15) - ANTICIPO',
                'description' => 'Mitad del sueldo + comisiones del mes completo - ISR',
                'biweekly_salary' => round($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($expensesQ1Amount, 2),
                'expenses_q2' => 0,
                'total_earning' => round($totalEarning, 2),
                'type' => 'anticipo',
            ];
        } else {
            // =====================
            // QUINCENA 2 - LIQUIDACIÓN
            // =====================
            // Liquidación = mitad del sueldo - gastos de Q2 - ISR quincenal
            
            // Gastos: q2 completo + mensual/2
            $expensesQ2Amount = $month->expenses()
                ->where(function($q) {
                    $q->where('expense_type', 'q2')
                      ->orWhere('expense_type', 'mensual');
                })
                ->get()
                ->sum(function($e) {
                    return $e->expense_type === 'mensual' ? $e->amount / 2 : $e->amount;
                });
            
            // Total a pagar en liquidacion
            $totalEarning = $biweeklySalary - $expensesQ2Amount - $isrBiweekly;
            
            return [
                'user_id' => $user->id,
                'month_id' => $month->id,
                'month_name' => $month->name . ' ' . $year,
                'biweekly' => $biweekly,
                'period' => "2da Quincena (16-$lastDay) - LIQUIDACIÓN",
                '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',
            ];
        }
    }

    /**
     * Resumen anual del usuario
     */
    public static function calculateYearly(User $user, int $year): array
    {
        $months = $user->months()->where('year', $year)->get();

        $totalUserSales = 0;
        $totalSystemSales = 0;
        $totalExpenses = 0;
        $totalSalary = 0;
        $totalCommission = 0;

        foreach ($months as $month) {
            $totalUserSales += $month->dailySales()->sum('user_sales');
            $totalSystemSales += $month->dailySales()->sum('system_sales');
            $totalExpenses += $month->expenses()->sum('amount');
            $totalSalary += $user->monthly_salary;
            $totalCommission += ($month->dailySales()->sum('system_sales') * $user->commission_percentage) / 100;
        }

        return [
            'user_id' => $user->id,
            'year' => $year,
            'months_count' => $months->count(),
            'total_user_sales' => round($totalUserSales, 2),
            'total_system_sales' => round($totalSystemSales, 2),
            'total_expenses' => round($totalExpenses, 2),
            'total_salary' => round($totalSalary, 2),
            'total_commission' => round($totalCommission, 2),
            'total_earning' => round($totalSalary + $totalCommission - $totalExpenses, 2),
        ];
    }

    /**
     * Obtener número del mes por nombre
     */
    private static function getMonthNumber(string $monthName): int
    {
        $months = [
            'Enero' => 1, 'Febrero' => 2, 'Marzo' => 3, 'Abril' => 4,
            'Mayo' => 5, 'Junio' => 6, 'Julio' => 7, 'Agosto' => 8,
            'Septiembre' => 9, 'Octubre' => 10, 'Noviembre' => 11, 'Diciembre' => 12
        ];
        
        return $months[$monthName] ?? 1;
    }

    /**
     * Obtener último día del mes
     */
    private static function getLastDayOfMonth(string $monthName, int $year): int
    {
        $monthNumber = self::getMonthNumber($monthName);
        return (int) date('t', mktime(0, 0, 0, $monthNumber, 1, $year));
    }
}