<?php

namespace App\Services\Payment\Stripe;

use App\Enums\PaymentProvider;
use App\Models\ShoppingOrder;
use App\Models\ShoppingPayment;
use App\Models\ShoppingUser;
use App\Models\UserAbo;
use App\Services\CheckoutFunnelTracker;
use App\Services\Payment\DTOs\AboChargeResult;
use App\Services\Payment\Stripe\DTOs\StripeCheckoutSessionResult;
use App\Services\Util;
use Stripe\Checkout\Session;
use Stripe\Exception\ApiErrorException;

/**
 * Stripe-Zahlungsvorgänge (Plan dev/2026-07-08-stripe/, Phase S3 ff.).
 *
 * Einmalzahlung im Checkout = Hosted Checkout Session (Redirect-Flow,
 * Konzept §3.1): Zahlartenwahl und Dateneingabe passieren bei Stripe,
 * "bezahlt" setzt ausschließlich der Webhook (StripeWebhookHandler).
 *
 * Abos (Phase S4): Die Erstzahlung speichert das Zahlungsmittel
 * (setup_future_usage=off_session, Customer wird von Stripe angelegt);
 * Folgeabbuchungen laufen als off-session PaymentIntent über chargeAbo().
 */
class StripePaymentService
{
    public function __construct(private readonly StripeClientWrapper $stripe) {}

    /**
     * Erstellt ShoppingPayment + Checkout Session für eine Einmalzahlung.
     * Die Success-/Cancel-URLs baut der HTTP-Aufrufer (Routen sind
     * domain-abhängig und gehören nicht in die Service-Schicht).
     *
     * Abo-/Recovery-Bestellungen speichern das Zahlungsmittel für künftige
     * off-session Abbuchungen: Stripe legt einen Customer an und blendet
     * automatisch nur wiederverwendbare Zahlarten ein (Dynamic Payment
     * Methods filtern nach setup_future_usage — löst N1, Plan S4.1).
     */
    public function initiateCheckoutPayment(
        ShoppingUser $shoppingUser,
        ShoppingOrder $shoppingOrder,
        int $amountCents,
        string $currency,
        string $reference,
        string $successUrl,
        string $cancelUrl,
    ): StripeCheckoutSessionResult {
        $shoppingPayment = ShoppingPayment::create([
            'shopping_order_id' => $shoppingOrder->id,
            'payment_provider' => PaymentProvider::Stripe->value,
            'clearingtype' => 'stripe',
            'reference' => $reference,
            'amount' => $amountCents,
            'currency' => $currency,
            'is_abo' => (bool) $shoppingOrder->is_abo,
            'abo_interval' => $shoppingOrder->abo_interval ?? 0,
            'identifier' => Util::getUserShopIdentifier(),
            'mode' => $shoppingOrder->mode,
        ]);

        CheckoutFunnelTracker::initiatedPayment(
            shoppingUserId: $shoppingUser->id,
            shoppingOrderId: $shoppingOrder->id,
            shoppingPaymentId: $shoppingPayment->id,
            consultantUserId: $shoppingUser->auth_user_id ?? null,
            paymentMethod: 'stripe',
            amountCents: $amountCents,
        );

        $metadata = [
            'shopping_order_id' => (string) $shoppingOrder->id,
            'shopping_payment_id' => (string) $shoppingPayment->id,
            'reference' => $reference,
            'mode' => (string) $shoppingOrder->mode,
        ];

        $sessionParams = [
            'mode' => 'payment',
            'client_reference_id' => $reference,
            'customer_email' => $shoppingUser->billing_email ?: null,
            'line_items' => [[
                'quantity' => 1,
                'price_data' => [
                    'currency' => strtolower($currency),
                    'unit_amount' => $amountCents,
                    'product_data' => [
                        'name' => __('payment.stripe_order_label', ['reference' => $reference]),
                    ],
                ],
            ]],
            'metadata' => $metadata,
            'payment_intent_data' => ['metadata' => $metadata],
            'success_url' => $successUrl,
            'cancel_url' => $cancelUrl,
        ];

        if ($this->requiresReusablePaymentMethod($shoppingOrder)) {
            $sessionParams['customer_creation'] = 'always';
            $sessionParams['payment_intent_data']['setup_future_usage'] = 'off_session';
        }

        $session = $this->stripe->client()->checkout->sessions->create($sessionParams);

        $shoppingPayment->external_reference = $session->id;
        $shoppingPayment->save();

        StripeTransactionRecorder::recordFromStripeObject(
            $shoppingPayment,
            'checkout.session.created',
            $session->toArray(),
        );

        return new StripeCheckoutSessionResult(
            sessionId: $session->id,
            url: (string) $session->url,
            reference: $reference,
            shoppingPayment: $shoppingPayment,
        );
    }

    /**
     * Abo-/Recovery-Bestellungen brauchen ein wiederverwendbares Zahlungsmittel
     * (Erstzahlung eines neuen Abos bzw. Nachholzahlung, die das Abo auf
     * Stripe umzieht — §7.2 Nr. 3).
     */
    private function requiresReusablePaymentMethod(ShoppingOrder $shoppingOrder): bool
    {
        return (bool) $shoppingOrder->is_abo || ! empty($shoppingOrder->recovery_user_abo_id);
    }

    /**
     * Wiederkehrende Abo-Abbuchung (Plan S4.3): off-session PaymentIntent mit
     * dem am Abo gespeicherten Customer/PaymentMethod. Der Idempotency-Key
     * pro Abo+Bestellung schützt gegen Doppel-Abbuchung bei Netzwerk-Retries.
     * "Bezahlt" (Order, Rechnung, Mails) setzt auch hier erst der Webhook.
     */
    public function chargeAbo(
        UserAbo $userAbo,
        ShoppingOrder $shoppingOrder,
        ShoppingUser $shoppingUser,
        int $amountCents,
        string $currency,
    ): AboChargeResult {
        if (empty($userAbo->stripe_customer_id) || empty($userAbo->stripe_payment_method_id)) {
            return new AboChargeResult(
                provider: PaymentProvider::Stripe,
                success: false,
                status: 'ERROR',
                rawResponse: [],
                errorMessage: 'Stripe-Abo ohne Customer-/PaymentMethod-ID (user_abo '.$userAbo->id.')',
                customerMessage: __('payment.stripe_abo_payment_method_missing'),
            );
        }

        $shoppingPayment = ShoppingPayment::create([
            'shopping_order_id' => $shoppingOrder->id,
            'payment_provider' => PaymentProvider::Stripe->value,
            'clearingtype' => 'stripe',
            'reference' => substr(uniqid('m', false), 0, 16),
            'amount' => $amountCents,
            'currency' => $currency,
            'is_abo' => true,
            'abo_interval' => $userAbo->abo_interval ?? 0,
            'mode' => $shoppingOrder->mode,
            'user_abo_id' => $userAbo->id,
            'stripe_customer_id' => $userAbo->stripe_customer_id,
            'stripe_payment_method_id' => $userAbo->stripe_payment_method_id,
        ]);

        $metadata = [
            'shopping_order_id' => (string) $shoppingOrder->id,
            'shopping_payment_id' => (string) $shoppingPayment->id,
            'user_abo_id' => (string) $userAbo->id,
            'reference' => (string) $shoppingPayment->reference,
            'mode' => (string) $shoppingOrder->mode,
        ];

        try {
            $paymentIntent = $this->stripe->client()->paymentIntents->create([
                'amount' => $amountCents,
                'currency' => strtolower($currency),
                'customer' => $userAbo->stripe_customer_id,
                'payment_method' => $userAbo->stripe_payment_method_id,
                'off_session' => true,
                'confirm' => true,
                'metadata' => $metadata,
            ], [
                'idempotency_key' => 'abo-'.$userAbo->id.'-order-'.$shoppingOrder->id,
            ]);
        } catch (ApiErrorException $e) {
            // Deckt auch CardException ab (Declines wie card_declined,
            // insufficient_funds, authentication_required bei off_session).
            return $this->aboChargeError($shoppingPayment, $e);
        }

        $shoppingPayment->external_reference = $paymentIntent->id;
        $shoppingPayment->save();

        $piArray = $paymentIntent->toArray();
        StripeTransactionRecorder::recordFromStripeObject($shoppingPayment, 'authorization', $piArray);

        [$status, $errorMessage, $customerMessage] = match ($paymentIntent->status) {
            'succeeded' => ['APPROVED', null, null],
            'processing' => ['PENDING', null, null],
            'requires_action', 'requires_confirmation' => [
                'ERROR',
                'authentication_required (PaymentIntent '.$paymentIntent->id.')',
                __('payment.stripe_abo_authentication_required'),
            ],
            default => [
                'ERROR',
                'Unerwarteter PaymentIntent-Status "'.$paymentIntent->status.'" ('.$paymentIntent->id.')',
                __('payment.payment_error_reasons.general'),
            ],
        };

        return new AboChargeResult(
            provider: PaymentProvider::Stripe,
            success: $status === 'APPROVED',
            status: $status,
            rawResponse: StripeTransactionRecorder::redactPayload($piArray),
            transactionId: $paymentIntent->id,
            errorMessage: $errorMessage,
            customerMessage: $customerMessage,
            shoppingPayment: $shoppingPayment,
        );
    }

    /**
     * "Zahlungsart ändern" (Plan S5.1): Hosted Checkout Session im Setup-Modus —
     * der Abo-Inhaber wählt bei Stripe frei eine neue, wiederverwendbare
     * Zahlart; es wird NICHTS abgebucht. Verankert wird die Methode nach
     * Erfolg über den Return-Pfad bzw. den setup_intent.succeeded-Webhook.
     */
    public function createPaymentMethodChangeSession(
        UserAbo $userAbo,
        string $successUrl,
        string $cancelUrl,
        ?string $source = null,
    ): Session {
        $customerId = $this->ensureAboStripeCustomer($userAbo);

        $metadata = [
            'user_abo_id' => (string) $userAbo->id,
            'source' => (string) ($source ?? ''),
        ];

        return $this->stripe->client()->checkout->sessions->create([
            'mode' => 'setup',
            // Pflicht im Setup-Modus mit dynamischen Zahlarten: Währung der
            // künftigen Abbuchungen (Abos laufen fest in EUR, Plan §1 E).
            'currency' => 'eur',
            'customer' => $customerId,
            'metadata' => $metadata,
            'setup_intent_data' => ['metadata' => $metadata],
            'success_url' => $successUrl,
            'cancel_url' => $cancelUrl,
        ]);
    }

    /**
     * Stripe-Customer des Abos — bei PAYONE-Bestandsabos wird er hier erstmalig
     * angelegt und sofort am Abo persistiert (wiederverwendbar bei erneutem
     * Versuch; der Provider des Abos bleibt unverändert, bis die neue
     * Zahlungsart tatsächlich verankert ist).
     */
    private function ensureAboStripeCustomer(UserAbo $userAbo): string
    {
        if (! empty($userAbo->stripe_customer_id)) {
            return $userAbo->stripe_customer_id;
        }

        $shoppingUser = $userAbo->shopping_user;
        $customer = $this->stripe->client()->customers->create([
            'email' => $userAbo->email ?: null,
            'name' => $shoppingUser
                ? (trim(($shoppingUser->billing_firstname ?? '').' '.($shoppingUser->billing_lastname ?? '')) ?: null)
                : null,
            'metadata' => ['mivita_type' => 'user_abo', 'mivita_id' => (string) $userAbo->id],
        ]);

        $userAbo->forceFill(['stripe_customer_id' => $customer->id])->save();

        return $customer->id;
    }

    /**
     * Anzeige-Summary einer PaymentMethod (Struktur wie
     * StripeWebhookHandler::paymentMethodSummary, aber aus dem
     * PaymentMethod-Objekt statt aus Charge-Details). Best effort — null,
     * wenn die API nicht erreichbar ist.
     *
     * @return array<string, mixed>|null
     */
    public function retrievePaymentMethodSummary(string $paymentMethodId): ?array
    {
        try {
            $paymentMethod = $this->stripe->client()->paymentMethods->retrieve($paymentMethodId);
        } catch (\Throwable $e) {
            \Log::channel('stripe')->warning('PaymentMethod-Summary nicht abrufbar: '.$e->getMessage(), [
                'payment_method' => $paymentMethodId,
            ]);

            return null;
        }

        $summary = ['type' => $paymentMethod->type];

        if ($paymentMethod->type === 'card' && $paymentMethod->card) {
            $summary['brand'] = $paymentMethod->card->brand ?? null;
            $summary['last4'] = $paymentMethod->card->last4 ?? null;
            $summary['wallet'] = $paymentMethod->card->wallet->type ?? null;
            $summary['exp'] = isset($paymentMethod->card->exp_month, $paymentMethod->card->exp_year)
                ? sprintf('%02d/%d', $paymentMethod->card->exp_month, $paymentMethod->card->exp_year)
                : null;
        }

        if ($paymentMethod->type === 'sepa_debit' && $paymentMethod->sepa_debit) {
            $summary['last4'] = $paymentMethod->sepa_debit->last4 ?? null;
        }

        return $summary;
    }

    /**
     * Setup-Session für den Return-Pfad nachladen (inkl. SetupIntent).
     */
    public function retrieveSetupSession(string $sessionId): Session
    {
        return $this->stripe->client()->checkout->sessions->retrieve($sessionId, [
            'expand' => ['setup_intent'],
        ]);
    }

    /**
     * Alte PaymentMethod nach erfolgreichem Wechsel am Customer lösen —
     * best effort, ein Fehler darf den Wechsel nie kippen.
     */
    public function detachPaymentMethod(string $paymentMethodId): void
    {
        try {
            $this->stripe->client()->paymentMethods->detach($paymentMethodId);
        } catch (\Throwable $e) {
            \Log::channel('stripe')->warning('Alte PaymentMethod konnte nicht detached werden: '.$e->getMessage(), [
                'payment_method' => $paymentMethodId,
            ]);
        }
    }

    /**
     * Fehler-Mapping (Plan S4.5): Stripe-Declines werden protokolliert und als
     * ERROR-Ergebnis zurückgegeben — der Cron setzt damit denselben
     * Abo-Fehlerstatus (3) wie bei PAYONE-Declines inkl. Pay-now-Mail.
     */
    private function aboChargeError(ShoppingPayment $shoppingPayment, ApiErrorException $e): AboChargeResult
    {
        $stripeError = $e->getError();
        $errorObject = $e->getJsonBody()['error'] ?? ['message' => $e->getMessage()];

        if (! empty($stripeError?->payment_intent)) {
            $shoppingPayment->external_reference = $stripeError->payment_intent->id;
            $shoppingPayment->save();
        }

        StripeTransactionRecorder::recordFromStripeObject($shoppingPayment, 'authorization', [
            'id' => $stripeError?->payment_intent->id ?? '',
            'status' => 'failed',
            'last_payment_error' => [
                'code' => $stripeError?->code ?? $e->getStripeCode(),
                'message' => $stripeError?->message ?? $e->getMessage(),
            ],
            'decline_code' => $stripeError?->decline_code ?? null,
        ]);

        return new AboChargeResult(
            provider: PaymentProvider::Stripe,
            success: false,
            status: 'ERROR',
            rawResponse: is_array($errorObject) ? $errorObject : [],
            transactionId: $stripeError?->payment_intent->id ?? '',
            errorMessage: trim(($stripeError?->code ?? (string) $e->getStripeCode()).': '.($stripeError?->message ?? $e->getMessage()), ': '),
            customerMessage: $this->customerMessageForDecline($stripeError?->code ?? (string) $e->getStripeCode()),
            shoppingPayment: $shoppingPayment,
        );
    }

    private function customerMessageForDecline(?string $code): string
    {
        return match ($code) {
            'expired_card' => __('payment.payment_error_reasons.card_expired'),
            'card_declined' => __('payment.payment_error_reasons.card_declined'),
            'insufficient_funds' => __('payment.payment_error_reasons.insufficient_funds'),
            'incorrect_cvc' => __('payment.payment_error_reasons.cvv_invalid'),
            'authentication_required' => __('payment.stripe_abo_authentication_required'),
            default => __('payment.payment_error_reasons.general'),
        };
    }
}