<?php

namespace App\Services\ResellerClub;

use App\Models\Domain;
use App\Models\PromoBanner;
use App\Models\RcServiceOrder;
use App\Models\User;
use App\Services\Domain\DomainRegistrarService;
use App\Support\ResellerClubLegacy;
use Carbon\Carbon;
use Illuminate\Contracts\Support\Arrayable;
use Illuminate\Database\Eloquent\Collection as EloquentCollection;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Crypt;
use RuntimeException;

class RcOrderCartService
{
    /**
     * @return array<int, string>
     */
    public function cartStatuses(): array
    {
        return [
            RcServiceOrder::STATUS_CART,
            RcServiceOrder::STATUS_PENDING_PAYMENT,
        ];
    }

    public function cartItemsForUser(User $user): EloquentCollection
    {
        return RcServiceOrder::query()
            ->where('user_id', $user->id)
            ->whereIn('status', $this->cartStatuses())
            ->latest()
            ->get();
    }

    public function cartCountForUser(User $user): int
    {
        return RcServiceOrder::query()
            ->where('user_id', $user->id)
            ->whereIn('status', $this->cartStatuses())
            ->count();
    }

    /**
     * @return array{items: EloquentCollection<int, RcServiceOrder>, count: int, reference: string|null}|null
     */
    public function pendingCheckoutForUser(User $user): ?array
    {
        $items = RcServiceOrder::query()
            ->where('user_id', $user->id)
            ->where('status', RcServiceOrder::STATUS_PENDING_PAYMENT)
            ->latest()
            ->get();

        if ($items->isEmpty()) {
            return null;
        }

        return [
            'items' => $items,
            'count' => $items->count(),
            'reference' => $items->pluck('payment_reference')->filter()->first(),
        ];
    }

    public function recentOrdersForUser(User $user, int $limit = 10): EloquentCollection
    {
        return RcServiceOrder::query()
            ->where('user_id', $user->id)
            ->whereNotIn('status', $this->cartStatuses())
            ->latest()
            ->limit($limit)
            ->get();
    }

    public function addProductOrder(User $user, string $category, array $input, ResellerClubProductService $products): RcServiceOrder
    {
        ResellerClubLegacy::assertNewSaleAllowed();

        $quote = $products->quoteForSelection(
            $category,
            (string) ($input['plan_id'] ?? ''),
            (int) ($input['months'] ?? 0)
        );

        if (! ($quote['success'] ?? false)) {
            throw new RuntimeException($quote['message'] ?? 'This product cannot be added to the cart right now.');
        }

        $currency = strtoupper((string) ($quote['currency'] ?? 'GHS'));
        $this->assertCurrencyCompatibility($user, $currency);

        $domainName = strtolower(trim((string) ($input['domain_name'] ?? $category)));

        return $this->upsertCartItem(
            $user,
            [
                'category' => $category,
                'order_type' => RcServiceOrder::TYPE_SERVICE,
                'domain_name' => $domainName,
                'plan_id' => (string) ($input['plan_id'] ?? ''),
                'plan_name' => (string) ($quote['plan_name'] ?? $products->packageLabel($category, (string) ($input['plan_id'] ?? ''))),
                'amount_minor' => (int) ($quote['amount_minor'] ?? 0),
                'currency' => $currency,
                'term_months' => (int) ($input['months'] ?? 1),
                'term_years' => null,
                'meta' => [
                    'order_input' => $input,
                    'quote' => $quote,
                ],
            ]
        );
    }

    public function addDomainRegistration(User $user, string $domain, DomainRegistrarService $registrar): RcServiceOrder
    {
        ResellerClubLegacy::assertNewSaleAllowed();

        $domainName = strtolower(trim($domain));

        if (Domain::query()->where('host', $domainName)->exists()) {
            throw new RuntimeException('This domain is already registered in our system.');
        }

        $quote = $registrar->quoteDomainRegistration($domainName);
        if (! ($quote['success'] ?? false)) {
            throw new RuntimeException($quote['message'] ?? 'Domain pricing is unavailable right now.');
        }

        $currency = strtoupper((string) ($quote['currency'] ?? 'GHS'));
        $this->assertCurrencyCompatibility($user, $currency);

        return $this->upsertCartItem(
            $user,
            [
                'category' => 'domain-registration',
                'order_type' => RcServiceOrder::TYPE_DOMAIN_REGISTRATION,
                'domain_name' => $domainName,
                'plan_id' => null,
                'plan_name' => '1 year registration',
                'amount_minor' => (int) ($quote['amount_minor'] ?? 0),
                'currency' => $currency,
                'term_months' => null,
                'term_years' => 1,
                'meta' => [
                    'quote' => $quote,
                ],
            ]
        );
    }

    public function addDomainTransfer(User $user, string $domain, ?string $authCode, DomainRegistrarService $registrar): RcServiceOrder
    {
        ResellerClubLegacy::assertNewSaleAllowed();

        $domainName = strtolower(trim($domain));
        $quote = $registrar->quoteDomainTransfer($domainName);

        if (! ($quote['success'] ?? false)) {
            throw new RuntimeException($quote['message'] ?? 'This domain cannot be transferred right now.');
        }

        $currency = strtoupper((string) ($quote['currency'] ?? 'GHS'));
        $this->assertCurrencyCompatibility($user, $currency);

        $meta = [
            'quote' => $quote,
        ];

        $authCode = trim((string) $authCode);
        if ($authCode !== '') {
            $meta['transfer_auth_code_encrypted'] = Crypt::encryptString($authCode);
        }

        return $this->upsertCartItem(
            $user,
            [
                'category' => 'domain-transfer',
                'order_type' => RcServiceOrder::TYPE_DOMAIN_TRANSFER,
                'domain_name' => $domainName,
                'plan_id' => null,
                'plan_name' => 'Domain transfer',
                'amount_minor' => (int) ($quote['amount_minor'] ?? 0),
                'currency' => $currency,
                'term_months' => null,
                'term_years' => 1,
                'meta' => $meta,
            ]
        );
    }

    public function addServiceRenewal(
        User $user,
        RcServiceOrder $existingOrder,
        int $months,
        ResellerClubProductService $products
    ): RcServiceOrder {
        ResellerClubLegacy::assertRenewalsAllowed();

        if ((int) $existingOrder->user_id !== (int) $user->id) {
            throw new RuntimeException('You can only renew your own services.');
        }

        if (! filled($existingOrder->rc_order_id)) {
            throw new RuntimeException('This service cannot be renewed online yet. Please contact support.');
        }

        if (! $products->supportsCategory($existingOrder->category)) {
            throw new RuntimeException('Renewals are not available for this product type.');
        }

        $months = max(1, min(120, $months));
        $planId = (string) ($existingOrder->plan_id ?? '');

        $quote = $products->quoteRenewal($existingOrder->category, $planId, $months);
        if (! ($quote['success'] ?? false)) {
            throw new RuntimeException($quote['message'] ?? 'Renewal pricing is unavailable right now.');
        }

        $currency = strtoupper((string) ($quote['currency'] ?? 'GHS'));
        $this->assertCurrencyCompatibility($user, $currency);

        return $this->upsertCartItem(
            $user,
            [
                'category' => $existingOrder->category,
                'order_type' => RcServiceOrder::TYPE_RENEWAL,
                'domain_name' => $existingOrder->domain_name,
                'plan_id' => $planId !== '' ? $planId : null,
                'plan_name' => (string) ($quote['plan_name'] ?? $existingOrder->plan_name ?? 'Service renewal'),
                'amount_minor' => (int) ($quote['amount_minor'] ?? 0),
                'currency' => $currency,
                'term_months' => $months,
                'term_years' => null,
                'meta' => [
                    'is_renewal' => true,
                    'renew_rc_order_id' => (string) $existingOrder->rc_order_id,
                    'renew_source_order_id' => $existingOrder->id,
                    'quote' => $quote,
                ],
            ]
        );
    }

    public function addDomainRenewal(
        User $user,
        string $domain,
        int $years,
        DomainRegistrarService $registrar
    ): RcServiceOrder {
        ResellerClubLegacy::assertRenewalsAllowed();

        $domainName = strtolower(trim($domain));
        $years = max(1, min(10, $years));

        $quote = $registrar->quoteDomainRenewal($domainName, $years);
        if (! ($quote['success'] ?? false)) {
            throw new RuntimeException($quote['message'] ?? 'Domain renewal pricing is unavailable right now.');
        }

        $currency = strtoupper((string) ($quote['currency'] ?? 'GHS'));
        $this->assertCurrencyCompatibility($user, $currency);

        return $this->upsertCartItem(
            $user,
            [
                'category' => 'domain-renewal',
                'order_type' => RcServiceOrder::TYPE_RENEWAL,
                'domain_name' => $domainName,
                'plan_id' => null,
                'plan_name' => $years === 1 ? '1 year renewal' : "{$years} year renewal",
                'amount_minor' => (int) ($quote['amount_minor'] ?? 0),
                'currency' => $currency,
                'term_months' => null,
                'term_years' => $years,
                'meta' => [
                    'is_renewal' => true,
                    'renew_rc_order_id' => (string) ($quote['rc_order_id'] ?? ''),
                    'quote' => $quote,
                ],
            ]
        );
    }

    /**
     * @return array{items: EloquentCollection<int, RcServiceOrder>, total_minor: int, currency: string, subtotal_minor: int, discount_minor: int, applied_promos: array, promo_name: string|null}
     */
    public function checkoutSummaryForUser(User $user): array
    {
        $items = $this->cartItemsForUser($user);
        ResellerClubLegacy::assertCartCheckoutAllowed($items);

        $currency = strtoupper((string) $items->first()->currency);

        if ($items->contains(fn (RcServiceOrder $item) => strtoupper((string) $item->currency) !== $currency)) {
            throw new RuntimeException('Your cart contains items in more than one currency. Clear it and try again with a single currency.');
        }

        $subtotalMinor = (int) $items->sum('amount_minor');

        // Get all active promos with discounts
        $activePromos = PromoBanner::active()
            ->whereNotNull('discount_percent')
            ->where('discount_percent', '>', 0)
            ->get();

        // Calculate per-item discounts based on product-specific promos
        $appliedPromos = [];
        $totalDiscountMinor = 0;

        foreach ($items as $item) {
            $itemPromo = $this->findMatchingPromoForItem($item, $activePromos);

            if ($itemPromo) {
                $discountPercent = (int) $itemPromo->discount_percent;
                $itemDiscount = (int) round($item->amount_minor * ($discountPercent / 100));
                $totalDiscountMinor += $itemDiscount;

                // Track applied promos for display
                $promoKey = $itemPromo->id;
                if (!isset($appliedPromos[$promoKey])) {
                    $appliedPromos[$promoKey] = [
                        'id' => $itemPromo->id,
                        'name' => $itemPromo->name,
                        'title' => $itemPromo->title ?: $itemPromo->name,
                        'product_type' => $itemPromo->product_type,
                        'discount_percent' => $discountPercent,
                        'discount_minor' => 0,
                        'items' => [],
                    ];
                }
                $appliedPromos[$promoKey]['discount_minor'] += $itemDiscount;
                $appliedPromos[$promoKey]['items'][] = [
                    'id' => $item->id,
                    'domain_name' => $item->domain_name,
                    'category' => $item->category,
                    'original_amount' => $item->amount_minor,
                    'discount_amount' => $itemDiscount,
                ];
            }
        }

        $totalMinor = max(0, $subtotalMinor - $totalDiscountMinor);

        // For backward compatibility, provide a single promo name if only one promo applied
        $promoName = count($appliedPromos) === 1 ? array_values($appliedPromos)[0]['name'] : null;
        $discountPercent = count($appliedPromos) === 1 ? array_values($appliedPromos)[0]['discount_percent'] : null;

        return [
            'items' => $items,
            'currency' => $currency,
            'subtotal_minor' => $subtotalMinor,
            'discount_minor' => $totalDiscountMinor,
            'discount_percent' => $discountPercent,
            'promo_name' => $promoName,
            'applied_promos' => array_values($appliedPromos),
            'total_minor' => $totalMinor,
        ];
    }

    /**
     * Find the best matching promo for a cart item based on product type.
     */
    private function findMatchingPromoForItem(RcServiceOrder $item, $promos): ?PromoBanner
    {
        $itemProductType = $this->mapItemToProductType($item);

        // First, try to find a product-specific promo
        $specificPromo = $promos->first(function (PromoBanner $promo) use ($itemProductType) {
            return $promo->product_type && $promo->product_type === $itemProductType;
        });

        if ($specificPromo) {
            return $specificPromo;
        }

        // Fall back to general promos (no product_type set or product_type is 'general')
        return $promos->first(function (PromoBanner $promo) {
            return !$promo->product_type || $promo->product_type === PromoBanner::TYPE_GENERAL;
        });
    }

    /**
     * Map a cart item to a promo product type.
     */
    private function mapItemToProductType(RcServiceOrder $item): string
    {
        // Domain orders
        if (in_array($item->order_type, [RcServiceOrder::TYPE_DOMAIN_REGISTRATION, RcServiceOrder::TYPE_DOMAIN_TRANSFER, RcServiceOrder::TYPE_RENEWAL], true)
            && str_contains((string) $item->category, 'domain')) {
            return PromoBanner::TYPE_DOMAINS;
        }

        // Map category to product type
        $categoryMap = [
            'domain-registration' => PromoBanner::TYPE_DOMAINS,
            'domain-transfer' => PromoBanner::TYPE_DOMAINS,
            'single-domain-hosting' => PromoBanner::TYPE_HOSTING,
            'multi-domain-hosting' => PromoBanner::TYPE_HOSTING,
            'reseller-hosting' => PromoBanner::TYPE_HOSTING,
            'cloud-hosting' => PromoBanner::TYPE_HOSTING,
            'vps' => PromoBanner::TYPE_VPS,
            'dedicated-server' => PromoBanner::TYPE_DEDICATED,
            'email' => PromoBanner::TYPE_EMAIL,
        ];

        return $categoryMap[$item->category] ?? PromoBanner::TYPE_GENERAL;
    }

    /**
     * @param  Collection<int, RcServiceOrder>|EloquentCollection<int, RcServiceOrder>  $items
     */
    public function markCheckoutPending(iterable $items, string $reference): void
    {
        foreach ($items as $item) {
            $item->forceFill([
                'status' => RcServiceOrder::STATUS_PENDING_PAYMENT,
                'payment_status' => RcServiceOrder::PAYMENT_STATUS_PENDING,
                'fulfillment_status' => RcServiceOrder::FULFILLMENT_PAYMENT_PENDING,
                'payment_reference' => $reference,
            ])->save();
        }
    }

    /**
     * @return EloquentCollection<int, RcServiceOrder>
     */
    public function markPaymentSuccessful(array $metadata, string $reference, ?Carbon $paidAt = null): EloquentCollection
    {
        $orders = $this->ordersForPaymentMetadata($metadata, $reference);
        $transitioned = new EloquentCollection();

        foreach ($orders as $order) {
            if ($order->payment_status === RcServiceOrder::PAYMENT_STATUS_PAID) {
                continue;
            }

            $order->forceFill([
                'status' => RcServiceOrder::STATUS_PROCESSING,
                'payment_status' => RcServiceOrder::PAYMENT_STATUS_PAID,
                'fulfillment_status' => RcServiceOrder::FULFILLMENT_PAYMENT_RECEIVED,
                'payment_reference' => $reference,
                'paid_at' => $paidAt ?: now(),
            ])->save();

            $transitioned->push($order->fresh());
        }

        return $transitioned;
    }

    public function markPaymentFailed(array $metadata, string $reference): void
    {
        $orders = $this->ordersForPaymentMetadata($metadata, $reference);

        foreach ($orders as $order) {
            if ($order->payment_status === RcServiceOrder::PAYMENT_STATUS_PAID) {
                continue;
            }

            $order->forceFill([
                'status' => RcServiceOrder::STATUS_CART,
                'payment_status' => RcServiceOrder::PAYMENT_STATUS_FAILED,
                'fulfillment_status' => RcServiceOrder::FULFILLMENT_CART,
                'payment_reference' => null,
            ])->save();
        }
    }

    public function returnPendingCheckoutToCart(User $user): int
    {
        return RcServiceOrder::query()
            ->where('user_id', $user->id)
            ->where('status', RcServiceOrder::STATUS_PENDING_PAYMENT)
            ->update([
                'status' => RcServiceOrder::STATUS_CART,
                'payment_status' => RcServiceOrder::PAYMENT_STATUS_UNPAID,
                'fulfillment_status' => RcServiceOrder::FULFILLMENT_CART,
                'payment_reference' => null,
            ]);
    }

    public function removeCartItem(User $user, RcServiceOrder $order): void
    {
        if ((int) $order->user_id !== (int) $user->id || ! in_array($order->status, $this->cartStatuses(), true)) {
            throw new RuntimeException('This cart item cannot be removed.');
        }

        $order->delete();
    }

    public function clearCart(User $user): int
    {
        return RcServiceOrder::query()
            ->where('user_id', $user->id)
            ->whereIn('status', $this->cartStatuses())
            ->delete();
    }

    /**
     * @param  array<string, mixed>  $attributes
     */
    private function upsertCartItem(User $user, array $attributes): RcServiceOrder
    {
        $query = RcServiceOrder::query()
            ->where('user_id', $user->id)
            ->where('order_type', (string) $attributes['order_type'])
            ->where('category', (string) $attributes['category'])
            ->where('domain_name', (string) $attributes['domain_name'])
            ->whereIn('status', $this->cartStatuses());

        if (isset($attributes['plan_id']) && $attributes['plan_id'] !== null) {
            $query->where('plan_id', (string) $attributes['plan_id']);
        } else {
            $query->whereNull('plan_id');
        }

        if (isset($attributes['term_months']) && $attributes['term_months'] !== null) {
            $query->where('term_months', (int) $attributes['term_months']);
        } else {
            $query->whereNull('term_months');
        }

        $existing = $query->latest('id')->first();

        $payload = array_merge($attributes, [
            'user_id' => $user->id,
            'status' => RcServiceOrder::STATUS_CART,
            'payment_status' => RcServiceOrder::PAYMENT_STATUS_UNPAID,
            'fulfillment_status' => RcServiceOrder::FULFILLMENT_CART,
            'payment_reference' => null,
            'paid_at' => null,
            'submitted_at' => null,
            'last_synced_at' => null,
        ]);

        if ($existing) {
            $existing->forceFill($payload)->save();

            return $existing->fresh();
        }

        return RcServiceOrder::query()->create($payload);
    }

    /**
     * @param  array<string, mixed>  $metadata
     * @return EloquentCollection<int, RcServiceOrder>
     */
    private function ordersForPaymentMetadata(array $metadata, string $reference): EloquentCollection
    {
        $ids = collect($metadata['rc_service_order_ids'] ?? [])
            ->map(fn ($value) => (int) $value)
            ->filter()
            ->values();

        if ($ids->isNotEmpty()) {
            return RcServiceOrder::query()
                ->whereIn('id', $ids->all())
                ->get();
        }

        return RcServiceOrder::query()
            ->where('payment_reference', $reference)
            ->get();
    }

    private function assertCurrencyCompatibility(User $user, string $currency): void
    {
        $cartCurrency = RcServiceOrder::query()
            ->where('user_id', $user->id)
            ->whereIn('status', $this->cartStatuses())
            ->value('currency');

        if ($cartCurrency && strtoupper((string) $cartCurrency) !== strtoupper($currency)) {
            throw new RuntimeException(sprintf(
                'Your cart already contains %s items. Complete or clear that checkout before adding a %s item.',
                strtoupper((string) $cartCurrency),
                strtoupper($currency)
            ));
        }
    }
}