<?php

namespace App\Services;

use App\Enums\ShipmentType;
use App\Models\Country;
use App\Models\DiscountCode;
use App\Models\SystemSetting;
use InvalidArgumentException;

class PriceCalculatorService
{
    public function calculate(array $data): array
    {
        $type = ShipmentType::from($data['type']);
        $direction = $data['direction'] === 'Outbound' ? 'export' : 'import';
        $chargeableWeight = max($data['weight'], $data['volumetric_weight']);

        $country = Country::where('iso_code', $data['country_iso'])->firstOrFail();

        $zone = match (true) {
            $type === ShipmentType::Parcel && $direction === 'export' => $country->export_zone_parcel,
            $type === ShipmentType::Parcel && $direction === 'import' => $country->import_zone_parcel,
            $type !== ShipmentType::Parcel && $direction === 'export' => $country->export_zone_doc,
            $type !== ShipmentType::Parcel && $direction === 'import' => $country->import_zone_doc,
        };

        $rate = $this->lookupRate($direction, $type, $chargeableWeight, $zone);

        $profitMargin = (float) SystemSetting::get('profit_margin', 1.25);
        $aedToIrr = (float) SystemSetting::get('aed_to_irr', 455000);
        $vatRate = (float) SystemSetting::get('vat_rate', 0.09);
        $packingCostDefault = (float) SystemSetting::get('packing_cost_default', 100000);

        $netDirham = $rate * $profitMargin;
        $netRial = $netDirham * $aedToIrr;

        $extraService = (float) ($data['extra_service'] ?? 0);
        $packingCost = (float) ($data['packing_cost'] ?? $packingCostDefault);
        $domesticPickup = (float) ($data['domestic_pickup'] ?? 0);
        $domesticDelivery = (float) ($data['domestic_delivery'] ?? 0);
        $warehousingCost = (float) ($data['warehousing_cost'] ?? 0);
        
        // متغیر $discount را از آرایه داده‌ها دریافت می‌کنیم (اگر وجود داشته باشد)
        // اما در اینجا ما از کد تخفیف استفاده می‌کنیم، پس این خط را حذف یا اصلاح می‌کنیم
        // $discount = (float) ($data['discount'] ?? 0);

        // محاسبه قیمت اولیه قبل از تخفیف کد
        $subtotal = $netRial + $extraService + $packingCost + $domesticPickup + $domesticDelivery + $warehousingCost;

        // اعمال کد تخفیف (در صورت وجود)
        $discountCode = $data['discount_code'] ?? null;
        $discountResult = $this->applyDiscount($subtotal, $discountCode);

        if ($discountResult['success']) {
            $finalPrice = $discountResult['final_price'];
            // افزایش شمارنده استفاده از کد تخفیف
            $discount = DiscountCode::where('code', $discountResult['discount_code'])->first();
            if ($discount) {
                $discount->increment('used_count');
            }
        } else {
            $finalPrice = $subtotal;
        }

        $totalFee = $finalPrice * (1 + $vatRate);
        $vatAmount = $totalFee - $finalPrice;

        return [
            'base_price' => $rate,
            'net_dirham' => $netDirham,
            'net_rial' => $netRial,
            'extra_service' => $extraService,
            'packing_cost' => $packingCost,
            'domestic_pickup' => $domesticPickup,
            'domestic_delivery' => $domesticDelivery,
            'warehousing_cost' => $warehousingCost,
            'discount_applied' => $discountResult['success'],
            'discount_amount' => $discountResult['discount_amount'],
            'discount_message' => $discountResult['message'],
            'vat_amount' => $vatAmount,
            'total_fee' => $totalFee,
            'zone' => $zone,
            'chargeable_weight' => $chargeableWeight,
        ];
    }

    /**
     * اعمال کد تخفیف روی قیمت نهایی
     *
     * @param float $totalPrice قیمت کل قبل از تخفیف
     * @param string|null $code کد تخفیف وارد شده توسط کاربر
     * @return array ['success' => bool, 'message' => string, 'discount_amount' => float, 'final_price' => float]
     */
    public function applyDiscount(float $totalPrice, ?string $code): array
    {
        if (empty($code)) {
            return [
                'success' => false,
                'message' => 'کد تخفیف وارد نشده است.',
                'discount_amount' => 0,
                'final_price' => $totalPrice,
            ];
        }

        $discount = DiscountCode::where('code', $code)->first();

        // 1. بررسی وجود کد
        if (!$discount) {
            return [
                'success' => false,
                'message' => 'کد تخفیف نامعتبر است.',
                'discount_amount' => 0,
                'final_price' => $totalPrice,
            ];
        }

        // 2. بررسی فعال بودن کد
        if (!$discount->is_active) {
            return [
                'success' => false,
                'message' => 'این کد تخفیف غیرفعال شده است.',
                'discount_amount' => 0,
                'final_price' => $totalPrice,
            ];
        }

        // 3. بررسی تاریخ انقضا
        if ($discount->expires_at && $discount->expires_at->isPast()) {
            return [
                'success' => false,
                'message' => 'این کد تخفیف منقضی شده است.',
                'discount_amount' => 0,
                'final_price' => $totalPrice,
            ];
        }

        // 4. بررسی حداقل مبلغ سفارش
        if ($discount->min_order_amount > 0 && $totalPrice < $discount->min_order_amount) {
            return [
                'success' => false,
                'message' => "حداقل مبلغ سفارش برای استفاده از این کد " . number_format($discount->min_order_amount) . " ریال است.",
                'discount_amount' => 0,
                'final_price' => $totalPrice,
            ];
        }

        // 5. بررسی محدودیت استفاده
        if ($discount->usage_limit && $discount->used_count >= $discount->usage_limit) {
            return [
                'success' => false,
                'message' => 'ظرفیت استفاده از این کد تخفیف به پایان رسیده است.',
                'discount_amount' => 0,
                'final_price' => $totalPrice,
            ];
        }

        // محاسبه مبلغ تخفیف
        $discountAmount = 0;

        if ($discount->type === 'percentage') {
            $discountAmount = ($totalPrice * $discount->value) / 100;
        } elseif ($discount->type === 'fixed') {
            $discountAmount = $discount->value;
        }

        // اطمینان از اینکه تخفیف بیشتر از مبلغ کل نشود
        $discountAmount = min($discountAmount, $totalPrice);
        $finalPrice = $totalPrice - $discountAmount;

        return [
            'success' => true,
            'message' => 'کد تخفیف با موفقیت اعمال شد.',
            'discount_amount' => $discountAmount,
            'final_price' => $finalPrice,
            'discount_code' => $discount->code, // برای ذخیره در سفارش
        ];
    }

    private function lookupRate(string $direction, ShipmentType $type, float $weight, int $zone): float
    {
        $zoneColumn = 'zone_' . $zone;

        $rate = \App\Models\ShippingRate::query()
            ->where('direction', $direction)
            ->where('type', $type->value)
            ->where('weight', '<=', $weight)
            ->where($zoneColumn, '>', 0)
            ->orderByDesc('weight')
            ->value($zoneColumn);

        if ($rate === null) {
            throw new InvalidArgumentException('No rate found for the given parameters.');
        }

        return (float) $rate;
    }
}