<?php

namespace App\Http\Controllers\Checkout;

use App\Http\Controllers\Controller;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Validator;
use Illuminate\Validation\Rule;
use Illuminate\View\View;
use Lunar\Facades\ShippingManifest;
use Lunar\Models\Cart;
use Lunar\Models\Country;
use Lunar\Models\State;
use Modules\Core\Cart\Services\CartService;
use Modules\Core\Checkout\Exceptions\InvalidShippingOptionException;
use Modules\Core\Checkout\Services\CheckoutService;

/**
 * The checkout page — one page, sections (contact / billing / shipping /
 * shipping method), reviewed against boboko-core's CheckoutService. Stops
 * short of payment for this slice (see project memory).
 *
 * The address form and the shipping-method radios **autosave** — no submit
 * buttons. `saveAddress()` / `selectShippingOption()` are called by
 * bbk-checkout-form (debounced fetch) and return a JSON envelope of
 * server-rendered fragments (shipping options + order summary) plus any
 * field errors, rather than redirecting. Address validation is deliberately
 * lenient — nothing is rejected mid-typing; required-field enforcement is the
 * job of the (not-yet-built) "Continue to payment" gate.
 *
 * Guest-only for now — the Contact section's login tab is UI only.
 *
 * Single-country store: STORE_COUNTRY_ISO3 fixes the country to Greece (hidden
 * field, forced server-side). Set it to null for the full country picker (the
 * portable path for a multi-country boboko store).
 */
class CheckoutController extends Controller
{
    private const STORE_COUNTRY_ISO3 = 'GRC';

    public function __construct(
        private readonly CartService $cart,
        private readonly CheckoutService $checkout,
    ) {}

    public function show(string $locale): View
    {
        $cart = $this->cart->current();
        $lines = $cart ? $this->cart->activeLines($cart) : collect();
        $storeCountry = $this->storeCountry();

        $shippingOptions = collect();

        if ($cart?->shippingAddress) {
            $this->resetShippingManifest($cart);
            $shippingOptions = $this->syncShipping($cart);
            $cart->refresh();
        }

        return view('checkout::page', [
            'cart' => $cart,
            'lines' => $lines,
            'billingAddress' => $cart?->billingAddress,
            'shippingAddress' => $cart?->shippingAddress,
            'shippingOptions' => $shippingOptions,
            'shipToBilling' => (bool) data_get($cart, 'meta.ship_to_billing', true),
            'storeCountry' => $storeCountry,
            'countries' => $storeCountry
                ? collect()
                : Country::orderBy('name')->get(['id', 'name']),
            'regions' => $storeCountry
                ? State::where('country_id', $storeCountry->id)->orderBy('name')->get(['id', 'name'])
                : collect(),
        ]);
    }

    public function saveAddress(string $locale, Request $request): JsonResponse
    {
        $storeCountry = $this->storeCountry();
        $sameAsBilling = $request->boolean('same_as_billing');

        // Only the fields shipping rates resolve against — if none of these
        // changed (shopper edited their name, phone, email, …) there's no point
        // re-quoting shipping or re-rendering the summary.
        $rateKeyBefore = $this->cart->current()?->shippingAddress?->only(['postcode', 'state', 'country_id']);

        $stateRule = $storeCountry
            ? ['nullable', 'string', Rule::exists((new State)->getTable(), 'name')->where('country_id', $storeCountry->id)]
            : ['nullable', 'string', 'max:255'];
        $countryRule = $storeCountry
            ? ['nullable']
            : ['nullable', 'integer', 'exists:'.(new Country)->getTable().',id'];

        // Lenient — only format checks. Anything that fails is simply left out
        // of what gets persisted, and reported back for inline display.
        $validator = Validator::make($request->all(), [
            'contact_email' => ['nullable', 'email'],

            'billing_first_name' => ['nullable', 'string', 'max:255'],
            'billing_last_name' => ['nullable', 'string', 'max:255'],
            'billing_company_name' => ['nullable', 'string', 'max:255'],
            'billing_tax_identifier' => ['nullable', 'string', 'max:255'],
            'billing_line_one' => ['nullable', 'string', 'max:255'],
            'billing_line_two' => ['nullable', 'string', 'max:255'],
            'billing_city' => ['nullable', 'string', 'max:255'],
            'billing_state' => $stateRule,
            'billing_postcode' => ['nullable', 'string', 'max:20'],
            'billing_country_id' => $countryRule,
            'billing_contact_phone' => ['nullable', 'string', 'max:50'],

            'shipping_first_name' => ['nullable', 'string', 'max:255'],
            'shipping_last_name' => ['nullable', 'string', 'max:255'],
            'shipping_company_name' => ['nullable', 'string', 'max:255'],
            'shipping_line_one' => ['nullable', 'string', 'max:255'],
            'shipping_line_two' => ['nullable', 'string', 'max:255'],
            'shipping_city' => ['nullable', 'string', 'max:255'],
            'shipping_state' => $stateRule,
            'shipping_postcode' => ['nullable', 'string', 'max:20'],
            'shipping_country_id' => $countryRule,
            'shipping_contact_phone' => ['nullable', 'string', 'max:50'],
            'shipping_delivery_instructions' => ['nullable', 'string', 'max:1000'],
        ]);

        $errors = $validator->errors()->toArray();
        $data = $validator->valid();

        $billingCountryId = $storeCountry?->id ?? ($data['billing_country_id'] ?? null);
        $shippingCountryId = $storeCountry?->id ?? ($data['shipping_country_id'] ?? $billingCountryId);

        $billing = [
            'first_name' => $data['billing_first_name'] ?? null,
            'last_name' => $data['billing_last_name'] ?? null,
            'company_name' => $data['billing_company_name'] ?? null,
            'tax_identifier' => $data['billing_tax_identifier'] ?? null,
            'line_one' => $data['billing_line_one'] ?? null,
            'line_two' => $data['billing_line_two'] ?? null,
            'city' => $data['billing_city'] ?? null,
            'state' => $data['billing_state'] ?? null,
            'postcode' => $data['billing_postcode'] ?? null,
            'country_id' => $billingCountryId,
            'contact_email' => $data['contact_email'] ?? null,
            'contact_phone' => $data['billing_contact_phone'] ?? null,
        ];

        $shipping = $sameAsBilling
            ? [...$billing, 'delivery_instructions' => $data['shipping_delivery_instructions'] ?? null]
            : [
                'first_name' => $data['shipping_first_name'] ?? null,
                'last_name' => $data['shipping_last_name'] ?? null,
                'company_name' => $data['shipping_company_name'] ?? null,
                'line_one' => $data['shipping_line_one'] ?? null,
                'line_two' => $data['shipping_line_two'] ?? null,
                'city' => $data['shipping_city'] ?? null,
                'state' => $data['shipping_state'] ?? null,
                'postcode' => $data['shipping_postcode'] ?? null,
                'country_id' => $shippingCountryId,
                'contact_email' => $data['contact_email'] ?? null,
                'contact_phone' => $data['shipping_contact_phone'] ?? null,
                'delivery_instructions' => $data['shipping_delivery_instructions'] ?? null,
            ];

        $this->checkout->setBillingAddress($billing);
        $cart = $this->checkout->setShippingAddress($shipping);

        $cart->meta = [...($cart->meta?->toArray() ?? []), 'ship_to_billing' => $sameAsBilling];
        $cart->save();

        // Abandoned-cart-recovery opt-in — boboko-core owns the record (bool +
        // timestamp + policy version on Cart::meta, RecoveryConsentSet event).
        // Deliberately its own scope, not merged with any future newsletter opt-in.
        $this->checkout->setRecoveryConsent($request->boolean('recovery_consent'));

        // ShippingManifest is a request-lifetime singleton whose getOptions()
        // appends without ever clearing, and addOption() keeps the FIRST entry
        // per identifier. The setBillingAddress() recalc above ran ApplyShipping
        // against the still-stale shipping address, so an option resolved for
        // the old region can shadow the correct one for the new region (a
        // carrier priced differently across two matching zones). Reset it and
        // recompute totals from a clean slate before we read anything back.
        $this->resetShippingManifest($cart);

        $rateKeyAfter = $cart->shippingAddress?->only(['postcode', 'state', 'country_id']);

        // Nothing rate-relevant moved — persist and acknowledge, no re-render.
        if ($rateKeyAfter == $rateKeyBefore) {
            return $this->fragments($cart, null, $errors);
        }

        return $this->fragments($cart, $this->syncShipping($cart), $errors);
    }

    public function selectShippingOption(string $locale, Request $request): JsonResponse
    {
        $identifier = (string) $request->input('shipping_option');

        if ($cart = $this->cart->current()) {
            $this->resetShippingManifest($cart);
        }

        try {
            $this->checkout->selectShippingOption($identifier);
        } catch (InvalidShippingOptionException) {
            // Re-render with whatever is currently valid; no hard error surfaced.
        }

        $cart = $this->cart->current();
        $options = $cart?->shippingAddress
            ? $this->checkout->getShippingOptions()
            : collect();

        return $this->fragments($cart, $options);
    }

    /**
     * Re-resolve shipping options for the cart's current address and keep the
     * selection sane: auto-select when exactly one resolves, and drop a
     * previously-picked option that no longer applies (e.g. region changed).
     *
     * @return Collection<int, \Lunar\DataTypes\ShippingOption>
     */
    private function syncShipping(Cart $cart): Collection
    {
        $address = $cart->shippingAddress;

        if (! $address) {
            return collect();
        }

        $options = $this->checkout->getShippingOptions();
        $current = $address->shipping_option;

        if ($options->count() === 1) {
            $only = $options->first();

            if ($current !== $only->identifier) {
                try {
                    $this->checkout->selectShippingOption($only->identifier);
                } catch (InvalidShippingOptionException) {
                    // nothing to select against — leave as is
                }
            }
        } elseif ($current !== null && ! $options->contains(fn ($option) => $option->identifier === $current)) {
            $address->update(['shipping_option' => null]);
            $cart->calculate();
        }

        return $options;
    }

    /**
     * $options === null means "nothing money-relevant changed" — acknowledge the
     * save (and any field errors) without re-rendering the shipping options or
     * the order summary, so a plain name/phone edit is a cheap round-trip.
     */
    private function fragments(?Cart $cart, ?Collection $options, array $errors = []): JsonResponse
    {
        return response()->json([
            'errors' => collect($errors)
                ->map(fn ($messages) => is_array($messages) ? ($messages[0] ?? null) : $messages)
                ->all(),
            'shippingOptionsHtml' => $options === null ? null : view('checkout::partials.shipping-options', [
                'shippingAddress' => $cart?->shippingAddress,
                'shippingOptions' => $options,
            ])->render(),
            // Composer (CheckoutModuleServiceProvider) fills $cart / $lines.
            'summaryHtml' => $options === null ? null : view('checkout::partials.cart-body')->render(),
        ]);
    }

    /**
     * Wipe the request-lifetime ShippingManifest singleton and recompute the
     * cart's totals, so both the options list and the cart's shippingTotal are
     * resolved against the current address rather than an accumulation of
     * every resolution that ran earlier in the request. See saveAddress().
     */
    private function resetShippingManifest(Cart $cart): void
    {
        ShippingManifest::clearOptions();
        $cart->calculate();
    }

    private function storeCountry(): ?Country
    {
        if (self::STORE_COUNTRY_ISO3 === null) {
            return null;
        }

        return Country::where('iso3', self::STORE_COUNTRY_ISO3)->first();
    }
}