<?php

namespace App\Http\Controllers\App;

use App\Http\Controllers\Controller;
use App\Models\Client;
use App\Models\Sale;
use Illuminate\Http\Request;
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
use PhpOffice\PhpSpreadsheet\Style\Border;
use PhpOffice\PhpSpreadsheet\Style\Fill;
use PhpOffice\PhpSpreadsheet\Style\Alignment;
use Carbon\Carbon;

class ExcelController extends Controller
{
    /**
     * Generar reporte Excel de descuentos a clientes
     */
    public function clientDiscountsReport(Request $request)
    {
        // 1. VALIDACIÓN Y OBTENCIÓN DE DATOS
        $request->validate([
            'fecha_inicio' => 'required|date',
            'fecha_fin' => 'required|date|after_or_equal:fecha_inicio',
            'tier_id' => 'nullable|exists:client_tiers,id',
        ]);

        $fechaInicio = Carbon::parse($request->fecha_inicio)->startOfDay();
        $fechaFin = Carbon::parse($request->fecha_fin)->endOfDay();
        $tierId = $request->tier_id;

        // 2. OBTENER DATOS DE CLIENTES CON DESCUENTOS
        $clients = Client::whereNotNull('tier_id')
            ->with('tier:id,tier_name,discount_percentage')
            ->whereHas('sales', function($q) use ($fechaInicio, $fechaFin) {
                $q->where('discount_amount', '>', 0)
                  ->whereBetween('created_at', [$fechaInicio, $fechaFin]);
            })
            ->when($tierId, function($query) use ($tierId) {
                $query->where('tier_id', $tierId);
            })
            ->get();

        if ($clients->isEmpty()) {
            return response()->json(['message' => 'No se encontraron registros en el periodo especificado'], 404);
        }

        // 3. MAPEO DE DATOS
        $data = $clients->map(function($client) use ($fechaInicio, $fechaFin) {
            $sales = $client->sales()
                ->where('discount_amount', '>', 0)
                ->whereBetween('created_at', [$fechaInicio, $fechaFin])
                ->get();

            return [
                'numero' => $client->client_number,
                'nombre' => $client->name,
                'email' => $client->email ?? 'N/A',
                'telefono' => $client->phone ?? 'N/A',
                'tier' => $client->tier?->tier_name ?? 'N/A',
                'descuento_porcentaje' => $client->tier?->discount_percentage ?? 0,
                'total_compras' => $client->total_purchases,
                'ventas_con_descuento' => $sales->count(),
                'descuentos_recibidos' => $sales->sum('discount_amount'),
                'promedio_descuento' => $sales->count() > 0 ? $sales->avg('discount_amount') : 0,
            ];
        });

        // 4. CONFIGURACIÓN EXCEL Y ESTILOS
        $fileName = 'Reporte_Descuentos_Clientes_' . $fechaInicio->format('Ymd') . '.xlsx';
        $filePath = storage_path('app/temp/' . $fileName);
        if (!file_exists(dirname($filePath))) mkdir(dirname($filePath), 0755, true);

        $spreadsheet = new Spreadsheet();
        $sheet = $spreadsheet->getActiveSheet();

        // Fuente Global
        $sheet->getParent()->getDefaultStyle()->getFont()->setName('Arial');
        $sheet->getParent()->getDefaultStyle()->getFont()->setSize(10);

        // Estilos Comunes
        $styleBox = [
            'borders' => ['allBorders' => ['borderStyle' => Border::BORDER_THIN, 'color' => ['rgb' => '000000']]],
            'alignment' => ['horizontal' => Alignment::HORIZONTAL_CENTER, 'vertical' => Alignment::VERTICAL_CENTER]
        ];
        $styleLabel = [
            'font' => ['size' => 12, 'bold' => true],
            'alignment' => ['horizontal' => Alignment::HORIZONTAL_RIGHT, 'vertical' => Alignment::VERTICAL_CENTER]
        ];
        $styleTableHeader = [
            'font' => ['bold' => true, 'size' => 10, 'color' => ['rgb' => 'FFFFFF']],
            'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => ['rgb' => '4472C4']],
            'alignment' => ['horizontal' => Alignment::HORIZONTAL_CENTER, 'vertical' => Alignment::VERTICAL_CENTER, 'wrapText' => true],
            'borders' => ['allBorders' => ['borderStyle' => Border::BORDER_THIN]]
        ];

        // --- ESTRUCTURA DEL DOCUMENTO ---
        $sheet->getRowDimension(2)->setRowHeight(10);
        $sheet->getRowDimension(3)->setRowHeight(25);
        $sheet->getRowDimension(5)->setRowHeight(30);

        // --- TÍTULO PRINCIPAL ---
        $sheet->mergeCells('A3:J3');
        $sheet->setCellValue('A3', 'REPORTE DE DESCUENTOS A CLIENTES');
        $sheet->getStyle('A3')->applyFromArray([
            'font' => ['bold' => true, 'size' => 16, 'color' => ['rgb' => '000000']],
            'alignment' => ['horizontal' => Alignment::HORIZONTAL_CENTER, 'vertical' => Alignment::VERTICAL_CENTER],
        ]);

        // --- INFORMACIÓN DEL PERIODO ---
        Carbon::setLocale('es');
        if ($fechaInicio->format('m/Y') === $fechaFin->format('m/Y')) {
            $periodoTexto = 'del ' . $fechaInicio->format('d') . ' al ' . $fechaFin->format('d') . ' de ' . $fechaFin->translatedFormat('F \d\e Y');
        } else {
            $periodoTexto = 'del ' . $fechaInicio->format('d/m/Y') . ' al ' . $fechaFin->format('d/m/Y');
        }

        $sheet->mergeCells('A5:B5');
        $sheet->setCellValue('A5', 'PERÍODO:');
        $sheet->getStyle('A5')->applyFromArray($styleLabel);

        $sheet->mergeCells('C5:J5');
        $sheet->setCellValue('C5', $periodoTexto);
        $sheet->getStyle('C5:J5')->applyFromArray($styleBox);
        $sheet->getStyle('C5')->getFont()->setSize(12);

        // --- RESUMEN DE TOTALES ---
        $totalClientes = $data->count();
        $totalVentas = $data->sum('ventas_con_descuento');
        $totalDescuentos = $data->sum('descuentos_recibidos');

        $row = 7;
        $sheet->setCellValue('A' . $row, 'TOTAL CLIENTES CON DESCUENTOS:');
        $sheet->setCellValue('C' . $row, $totalClientes);
        $sheet->setCellValue('E' . $row, 'TOTAL VENTAS:');
        $sheet->setCellValue('G' . $row, $totalVentas);
        $sheet->setCellValue('I' . $row, 'TOTAL DESCUENTOS:');
        $sheet->setCellValue('J' . $row, '$' . number_format($totalDescuentos, 2));

        $sheet->getStyle('A' . $row . ':J' . $row)->getFont()->setBold(true);
        $sheet->getStyle('C' . $row)->getFont()->setSize(12)->getColor()->setRGB('4472C4');
        $sheet->getStyle('G' . $row)->getFont()->setSize(12)->getColor()->setRGB('4472C4');
        $sheet->getStyle('J' . $row)->getFont()->setSize(12)->getColor()->setRGB('008000');

        // --- ENCABEZADOS DE TABLA ---
        $h = 9;
        $headers = [
            'A' => 'No.',
            'B' => "NÚMERO\nCLIENTE",
            'C' => 'NOMBRE',
            'D' => 'EMAIL',
            'E' => 'TELÉFONO',
            'F' => 'TIER',
            'G' => "DESCUENTO\n(%)",
            'H' => "VENTAS CON\nDESCUENTO",
            'I' => "DESCUENTOS\nRECIBIDOS",
            'J' => "PROMEDIO\nDESCUENTO"
        ];

        foreach ($headers as $col => $text) {
            $sheet->setCellValue("{$col}{$h}", $text);
        }

        $sheet->getStyle("A{$h}:J{$h}")->applyFromArray($styleTableHeader);
        $sheet->getRowDimension($h)->setRowHeight(35);

        // --- LLENADO DE DATOS ---
        $row = 10;
        $i = 1;

        foreach ($data as $item) {
            $sheet->setCellValue('A' . $row, $i);
            $sheet->setCellValue('B' . $row, $item['numero']);
            $sheet->setCellValue('C' . $row, $item['nombre']);
            $sheet->setCellValue('D' . $row, $item['email']);
            $sheet->setCellValue('E' . $row, $item['telefono']);
            $sheet->setCellValue('F' . $row, $item['tier']);
            $sheet->setCellValue('G' . $row, $item['descuento_porcentaje'] . '%');
            $sheet->setCellValue('H' . $row, $item['ventas_con_descuento']);
            $sheet->setCellValue('I' . $row, '$' . number_format($item['descuentos_recibidos'], 2));
            $sheet->setCellValue('J' . $row, '$' . number_format($item['promedio_descuento'], 2));

            // Estilos de fila
            $sheet->getStyle("A{$row}:J{$row}")->applyFromArray([
                'borders' => ['allBorders' => ['borderStyle' => Border::BORDER_THIN]],
                'alignment' => ['vertical' => Alignment::VERTICAL_CENTER],
                'font' => ['size' => 10]
            ]);

            // Centrados
            $sheet->getStyle("A{$row}")->getAlignment()->setHorizontal(Alignment::HORIZONTAL_CENTER);
            $sheet->getStyle("B{$row}")->getAlignment()->setHorizontal(Alignment::HORIZONTAL_CENTER);
            $sheet->getStyle("G{$row}")->getAlignment()->setHorizontal(Alignment::HORIZONTAL_CENTER);
            $sheet->getStyle("H{$row}")->getAlignment()->setHorizontal(Alignment::HORIZONTAL_CENTER);

            // Color alterno de filas
            if ($i % 2 == 0) {
                $sheet->getStyle("A{$row}:J{$row}")->getFill()
                    ->setFillType(Fill::FILL_SOLID)
                    ->getStartColor()->setRGB('F2F2F2');
            }

            $row++;
            $i++;
        }

        // --- ANCHOS DE COLUMNA ---
        $sheet->getColumnDimension('A')->setWidth(5);
        $sheet->getColumnDimension('B')->setWidth(15);
        $sheet->getColumnDimension('C')->setWidth(25);
        $sheet->getColumnDimension('D')->setWidth(25);
        $sheet->getColumnDimension('E')->setWidth(15);
        $sheet->getColumnDimension('F')->setWidth(12);
        $sheet->getColumnDimension('G')->setWidth(12);
        $sheet->getColumnDimension('H')->setWidth(15);
        $sheet->getColumnDimension('I')->setWidth(18);
        $sheet->getColumnDimension('J')->setWidth(18);

        $writer = new Xlsx($spreadsheet);
        $writer->save($filePath);

        return response()->download($filePath, $fileName)->deleteFileAfterSend(true);
    }
}