<?php

namespace Modules\Core\Checkout\Services;

use Lunar\Exceptions\FingerprintMismatchException;
use Lunar\Exceptions\Carts\CartException;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Event;
use Lunar\Base\Addressable;
use Lunar\DataTypes\ShippingOption;
use Lunar\Facades\ShippingManifest;
use Lunar\Models\Cart;
use Lunar\Shipping\Models\ShippingMethod;
use Modules\Core\Cart\Services\CartService;
use Modules\Core\Checkout\Events\BillingAddressSet;
use Modules\Core\Checkout\Events\PaymentMethodSelected;
use Modules\Core\Checkout\Events\RecoveryConsentSet;
use Modules\Core\Checkout\Events\ShippingAddressSet;
use Modules\Core\Checkout\Events\ShippingOptionSelected;
use Modules\Core\Checkout\Exceptions\InvalidShippingOptionException;
use Modules\Core\Checkout\Exceptions\NoShippingAddressException;
use Modules\Core\Checkout\Exceptions\TermsNotAcceptedException;
use Modules\Core\Checkout\Exceptions\UnknownPaymentTypeException;
use Modules\Core\Payment\Contracts\RequiresFulfillmentType;
use Modules\Core\Payment\DTOs\PaymentResult;
use Modules\Core\Payment\Models\PaymentMethod;
use Modules\Core\Payment\Services\PaymentDriverRegistry;
use Modules\Core\Payment\Services\PaymentMethodCache;
use Modules\Core\Shipping\Support\FulfillmentType;

/**
 * Storefront-facing checkout operations, mirroring
 * Modules\Core\Cart\Services\CartService's shape — one boboko-owned API a
 * storefront calls, keeping Lunar's own Cart/ShippingManifest primitives an
 * implementation detail. See docs/checkout.md for the full design —
 * Checkout is the middle of a three-stage lifecycle (Cart → Checkout →
 * Order): it owns the placement moment itself (address, shipping selection,
 * ensuring a draft Order exists) and hands off to Payment the instant that
 * draft exists — see initiatePayment(). What happens to that Order
 * afterward (status transitions, fulfillment) is deliberately out of
 * scope here — see docs/payments.md and Checkout\Events\OrderPlaced's
 * docblock for where that now lives.
 *
 * Depends on CartService for cart access rather than reaching into
 * Lunar\Facades\CartSession directly a second time, so Checkout stays
 * layered on top of Cart's own service boundary instead of duplicating it.
 */
class CheckoutService
{
    public function __construct(
        private readonly CartService $cart,
        private readonly PaymentDriverRegistry $paymentDrivers,
        private readonly PaymentMethodCache $paymentMethods,
    ) {}

    /**
     * Lunar\Actions\Carts\AddAddress (behind Cart::setShippingAddress())
     * always deletes the cart's existing shipping address row and inserts
     * a brand new one — it has no notion of "update in place." Every field
     * on the new row therefore starts blank, including `meta`, which is
     * where selectBoxNowLocker() stores the shopper's chosen locker. Since
     * the checkout page autosaves the address form on every field change
     * (not just once), any edit made after picking a locker — even an
     * unrelated one, like delivery instructions — silently wiped the
     * locker choice by recreating the row out from under it.
     *
     * Carries the previous row's box_now_locker forward onto the new one
     * so the two features don't stomp on each other, without needing
     * Lunar's own AddAddress action to change. The old row's meta is read
     * BEFORE Lunar deletes it, since afterward there's nothing left to
     * read.
     */
    public function setShippingAddress(array|Addressable $address): Cart
    {
        $cartBefore = $this->cart->currentOrCreate();
        $boxNowLocker = $cartBefore->shippingAddress?->meta['box_now_locker'] ?? null;

        $cart = $cartBefore->setShippingAddress($address);

        if ($boxNowLocker !== null) {
            $newAddress = $cart->shippingAddress;
            $newAddress->meta = [...($newAddress->meta?->toArray() ?? []), 'box_now_locker' => $boxNowLocker];
            $newAddress->save();
        }

        Event::dispatch(new ShippingAddressSet($cart, $address));

        return $cart;
    }

    public function setBillingAddress(array|Addressable $address): Cart
    {
        $cart = $this->cart->currentOrCreate()->setBillingAddress($address);

        Event::dispatch(new BillingAddressSet($cart, $address));

        return $cart;
    }

    /**
     * The shopper's promotional/abandoned-cart-recovery opt-in — a
     * cart-level decision, deliberately independent of setShippingAddress()/
     * setBillingAddress(): consent is given once, and must NOT be reset or
     * re-asked just because the shopper later changes which address is on
     * the cart (a different Addressable being set is not a withdrawal of
     * consent). Only an explicit call to THIS method — the checkbox itself
     * being submitted, checked or unchecked — ever changes it; calling it
     * again with false is exactly how a later opt-out is recorded.
     *
     * Stored on Cart::meta (interim, per the legal design this implements —
     * a real column/consent record is the eventual target) as
     * recovery_consent (bool), recovery_consent_at (ISO 8601 timestamp,
     * null when $consent is false), and recovery_consent_policy_version
     * (config('legal.privacy_policy_version') at the moment of consent —
     * so a later dispute is answered from what was actually agreed to,
     * not whatever the policy says today). Separate from any future
     * newsletter opt-in — recovery consent is its own scope, never merged
     * with marketing-newsletter consent.
     *
     * Deliberately does not merge with the meta-writing pattern
     * selectPaymentMethod() uses (read-merge-save in two separate
     * statements) — this writes both meta keys in one save, since there's
     * no dependency between recovery_consent and anything else needing to
     * be persisted first.
     */
    public function setRecoveryConsent(bool $consent): Cart
    {
        $cart = $this->cart->currentOrCreate();

        $cart->meta = [
            ...($cart->meta?->toArray() ?? []),
            'recovery_consent' => $consent,
            'recovery_consent_at' => $consent ? now()->toIso8601String() : null,
            'recovery_consent_policy_version' => $consent ? config('legal.privacy_policy_version') : null,
        ];
        $cart->save();

        Event::dispatch(new RecoveryConsentSet($cart, $consent));

        return $cart;
    }

    /**
     * Every shipping option currently available for the cart — already
     * fully backed by the merged Shipping-Carriers work: this runs every
     * registered Lunar\Shipping\Interfaces\ShippingRateInterface driver
     * (ACS/Box Now live-rate quoting alongside table-rate-shipping's own
     * flat-rate/free-shipping/collection drivers) through
     * ShippingManifest's pipeline. No rate-resolution logic lives here —
     * this is a thin pass-through.
     *
     * @return Collection<int, ShippingOption>
     */
    public function getShippingOptions(): Collection
    {
        return ShippingManifest::getOptions($this->cart->currentOrCreate());
    }

    /**
     * @throws InvalidShippingOptionException if $identifier doesn't resolve
     *   to a real, currently-available option for the cart
     */
    public function selectShippingOption(string $identifier): Cart
    {
        $cartBefore = $this->cart->currentOrCreate();
        $option = ShippingManifest::getOption($cartBefore, $identifier);

        if ($option === null) {
            throw new InvalidShippingOptionException($identifier);
        }

        $cart = $cartBefore->setShippingOption($option);

        // Switching away from Box Now leaves a stale box_now_locker on the
        // address's meta (see setShippingAddress()'s own docblock for why
        // it survives address-row recreation) — irrelevant while a
        // different method is selected, but wrong if the shopper later
        // switches BACK to Box Now and it resurfaces as if still chosen,
        // possibly for a locker that no longer exists/fits. Cleared here,
        // the one place that knows the method just changed.
        if ($identifier !== 'box-now') {
            $address = $cart->shippingAddress;

            if ($address && isset($address->meta['box_now_locker'])) {
                $meta = $address->meta->toArray();
                unset($meta['box_now_locker']);
                $address->meta = $meta;
                $address->save();
            }
        }

        Event::dispatch(new ShippingOptionSelected($cart, $option));

        return $cart;
    }

    /**
     * Records the shopper's chosen Box Now locker on the cart's shipping
     * address (Cart\Addresses::shippingAddress()->meta['box_now_locker']),
     * not on the cart itself — Lunar\Pipelines\Order\Creation\
     * CreateOrderAddresses copies every cart address's full attributes
     * (meta included) onto the new order address when the order is placed,
     * so this is what Modules\Core\Shipping\Carriers\BoxNow\
     * BoxNowFulfillmentService and Modules\Core\Shipping\Extensions\
     * OrderViewExtension already expect to find at
     * $order->shippingAddress->meta['box_now_locker']['locationId'].
     *
     * No validation against Box Now's own /destinations list here — this
     * mirrors setShippingAddress()'s leniency (see its own docblock/the
     * class-level note on required-field enforcement happening at the
     * payment gate, not mid-checkout). An invalid/stale locationId still
     * surfaces later, at BoxNowFulfillmentService::createShipment() time.
     *
     * @throws NoShippingAddressException if the cart has no shipping
     *   address yet
     */
    public function selectBoxNowLocker(array $locker): Cart
    {
        $cart = $this->cart->currentOrCreate();
        $address = $cart->shippingAddress;

        if (! $address) {
            throw new NoShippingAddressException();
        }

        $address->meta = [
            ...($address->meta?->toArray() ?? []),
            'box_now_locker' => $locker,
        ];
        $address->save();

        return $cart;
    }

    /**
     * Every payment method currently offered to the storefront, ordered by
     * Modules\Core\Payment\Models\PaymentMethod::position — a row is
     * offered only when ALL four checks pass, each meaning something
     * different to an admin diagnosing why a method isn't showing up (see
     * docs/payments.md):
     *   1. `enabled` — an admin turned it on.
     *   2. its `driver` still resolves via PaymentDriverRegistry — the
     *      driver class hasn't been removed (see the `payment:sync-drivers`
     *      command, which sets `driver_missing_at` when this fails; a row
     *      with that set is excluded here regardless of `enabled`, so a
     *      vanished driver can never silently look "available").
     *   3. the resolved driver reports Configurable::isConfigured() — its
     *      own runtime requirements (e.g. an API key) are met.
     *   4. its driver's RequiresFulfillmentType (if it declares one)
     *      agrees with the cart's currently selected shipping method's own
     *      fulfillment type (Modules\Core\Shipping\Support\
     *      FulfillmentType::resolve()) — "Pay in store" offered alongside
     *      a courier delivery makes no sense (no staff member present at
     *      handoff to take cash), and cash-on-delivery alongside store
     *      pickup is equally meaningless (OfflinePaymentDriver already
     *      covers that in-person moment). A cart with no shipping option
     *      selected yet imposes no constraint here — every method is
     *      offered until a fulfillment type is actually known, the same
     *      leniency setShippingAddress()'s own docblock describes for
     *      required-field enforcement happening at the payment gate, not
     *      mid-checkout.
     *
     * @return Collection<int, PaymentMethod>
     */
    public function getPaymentMethods(): Collection
    {
        $fulfillmentType = $this->currentFulfillmentType();

        return $this->paymentMethods->all()
            ->filter(fn (PaymentMethod $method) => $method->enabled && $method->driver_missing_at === null)
            ->filter(function (PaymentMethod $method) use ($fulfillmentType) {
                $driver = $this->paymentDrivers->resolve($method->driver);

                if (! $driver?->isConfigured()) {
                    return false;
                }

                if ($fulfillmentType === null || ! $driver instanceof RequiresFulfillmentType) {
                    return true;
                }

                return $driver->requiredFulfillmentType() === $fulfillmentType;
            })
            ->values();
    }

    /**
     * @return 'carrier'|'store_pickup'|null null when the cart has no
     *   shipping option selected yet
     */
    private function currentFulfillmentType(): ?string
    {
        $identifier = $this->cart->currentOrCreate()->shippingAddress?->shipping_option;

        if ($identifier === null) {
            return null;
        }

        $method = ShippingMethod::where('code', $identifier)->first();

        return $method ? FulfillmentType::resolve($method) : null;
    }

    /**
     * Records which payment type the shopper picked (Cart::meta
     * ['payment_method']) — read by Modules\Core\Payment\Pipelines\
     * Cart\ApplyPaymentMethodFee to add that method's own `data.fee` (if
     * any) before recalculation.
     *
     * Also snapshots Cart::fingerprint() into meta, *after* saving the
     * chosen type — the fingerprint has to reflect the final total
     * including any payment-method-specific fee, which only exists once
     * payment_method is set and the cart recalculates. Captured here,
     * server-side, rather than asked of the storefront: this is the last
     * moment before initiatePayment() that the shopper's reviewed total is
     * known, and initiatePayment() reads it back internally instead of
     * taking a fingerprint parameter — a storefront should never need to
     * know Cart::fingerprint() exists.
     *
     * Does not itself call a payment driver — selecting a method and
     * initiating payment against it are deliberately separate steps, same
     * as selecting a shipping option happens before placing the order.
     *
     * @throws UnknownPaymentTypeException if $type isn't currently offered
     *   — see getPaymentMethods() for what that means
     */
    public function selectPaymentMethod(string $type): Cart
    {
        if (! $this->getPaymentMethods()->contains('type', $type)) {
            throw new UnknownPaymentTypeException($type);
        }

        $cart = $this->cart->currentOrCreate();
        $cart->meta = [...($cart->meta?->toArray() ?? []), 'payment_method' => $type];
        $cart->save();

        // Cart::calculate() no-ops if this cart instance was already
        // calculated earlier in the request (Cart::isCalculated()) — which
        // it will have been if the shopper switches payment method after
        // the checkout page's first render already calculated it. Without
        // recalculate() forcing a fresh run, the just-saved payment_method
        // (and any fee tied to it, see ApplyPaymentMethodFee) would never
        // be reflected — the summary would keep showing whichever method
        // was calculated first.
        $cart = $cart->recalculate();
        $cart->meta = [...($cart->meta?->toArray() ?? []), 'checkout_fingerprint' => $cart->fingerprint()];
        $cart->save();

        Event::dispatch(new PaymentMethodSelected($cart, $type));

        return $cart;
    }

    /**
     * The one storefront-facing "place this order and pay for it" call —
     * the point where Checkout hands off to Payment. Ensures a draft
     * Order exists (Cart::createOrder() — confirmed idempotent against a
     * cart's own pre-existing, not-yet-placed-at draft; see
     * vendor/lunarphp/core/src/Actions/Carts/CreateOrder.php), then
     * resolves the payment method selected by selectPaymentMethod() and
     * calls pay() or authorize() on its driver, per that method's own
     * `capture_mode` column.
     *
     * Returns the driver's own PaymentResult UNCHANGED — this method does
     * not wait for or resolve anything past what pay()/authorize() itself
     * returns synchronously. A Pending result (an async gateway like
     * Stripe requiring 3-D Secure/a redirect) is a normal, expected
     * outcome, not an error — the caller (a storefront controller) is
     * responsible for whatever the gateway needs next.
     *
     * The draft order's own $order->total (not the Cart's) is what gets
     * passed as $amount — Order::$total is Lunar's own Price-cast
     * attribute, already resolving the correct Currency via the order's
     * own currency_code, and is the authoritative total once the draft
     * row exists.
     *
     * $context passed to the driver is {cart_id, order_id} — the exact
     * keys Modules\Core\Payment\Drivers\StripePaymentDriver::
     * rememberIntent() already reads.
     *
     * Same fingerprint precondition the old placeOrder() had: mandatory,
     * not optional, checked before the draft is created.
     *
     * $termsAccepted is likewise mandatory, not optional data a caller
     * might omit — an Order is a consumer contract, and its acceptance
     * must be refused (TermsNotAcceptedException, before createOrder() is
     * ever called — the order is never created-then-flagged) rather than
     * assumed. $policyVersion is recorded alongside it on the created
     * Order's own meta (terms_accepted, terms_accepted_at,
     * terms_accepted_policy_version) — the order-level equivalent of
     * setRecoveryConsent()'s cart-level record, and the durable audit
     * trail for a later "what did the shopper actually agree to"
     * dispute. Written directly here (not via a separate event/listener)
     * since the Order row this attaches to doesn't exist before
     * createOrder() runs, and nothing else needs to react to this
     * specific write independently of the order simply existing.
     *
     * @param  array<string, mixed>  $data  passed through untouched to
     *   the driver's pay()/authorize() — e.g. Stripe's payment_method
     *   token.
     *
     * @throws UnknownPaymentTypeException if the cart's selected
     *   payment_method (from selectPaymentMethod()) is no longer offered
     *   — re-checked here, not just at selection time, since a method
     *   could be disabled (or its driver removed) in between
     * @throws TermsNotAcceptedException if $termsAccepted is false
     * @throws FingerprintMismatchException
     * @throws CartException
     */
    public function initiatePayment(string $fingerprint, bool $termsAccepted, string $policyVersion, array $data = []): PaymentResult
    {
        if (! $termsAccepted) {
            throw new TermsNotAcceptedException;
        }

        $cart = $this->cart->currentOrCreate();
        $cart->checkFingerprint($fingerprint);

        $type = $cart->meta['payment_method'] ?? null;
        $method = $type !== null ? $this->getPaymentMethods()->firstWhere('type', $type) : null;

        if ($method === null) {
            throw new UnknownPaymentTypeException((string) $type);
        }

        $order = $cart->createOrder();

        $order->meta = [
            ...($order->meta?->toArray() ?? []),
            'payment_method' => $type,
            'terms_accepted' => true,
            'terms_accepted_at' => now()->toIso8601String(),
            'terms_accepted_policy_version' => $policyVersion,
        ];
        $order->save();

        $driver = $this->paymentDrivers->resolve($method->driver);
        $context = ['cart_id' => $cart->id, 'order_id' => $order->id];

        return $method->capture_mode === 'authorize'
            ? $driver->authorize($type, $order->total, $data, $context)
            : $driver->pay($type, $order->total, $data, $context);
    }
}