<?php

namespace App\Services\Shopify;

use App\Exceptions\ShopifyApiException;
use App\Models\Client;
use App\Models\User;
use App\Services\Shopify\Models\ShopifyModel;
use Illuminate\Support\Collection;
use Illuminate\Support\Str;
use Osiset\BasicShopifyAPI\ResponseAccess;

class ShopifyApiResponse extends ResponseAccess
{
    protected array $resourceClassMap = [
        'customer'          => \App\Services\Shopify\Models\Customer::class,
        'fulfillment'       => \App\Services\Shopify\Models\Fulfillment::class,
        'image'             => \App\Services\Shopify\Models\Image::class,
        'metafield'         => \App\Services\Shopify\Models\Metafield::class,
        'order'             => \App\Services\Shopify\Models\Order::class,
        'draft_order'       => \App\Services\Shopify\Models\DraftOrder::class,
        'product'           => \App\Services\Shopify\Models\Product::class,
        'custom_collection' => \App\Services\Shopify\Models\CustomCollection::class,
        'collect'           => \App\Services\Shopify\Models\Collect::class,
        'inventory_level'   => \App\Services\Shopify\Models\InventoryLevel::class,
        'inventory_item'    => \App\Services\Shopify\Models\InventoryItem::class,
        'shop'              => \App\Services\Shopify\Models\Shop::class,
        'transaction'       => \App\Services\Shopify\Models\Transaction::class,
        'variant'           => \App\Services\Shopify\Models\Variant::class,
        'webhook'           => \App\Services\Shopify\Models\Webhook::class,
    ];

    /**
     * Get all possible keys for a resource (singular, plural)
     *
     * Shopify uses a singular or plural key based on the resource:
     * - Resource "/orders/123456" = key "order" (singular)
     * - Resource "/orders/123456/fulfillments" = key "fulfillments" (plural)
     *
     * @param string $resource
     *
     * @return array
     */
    protected function getPossibleResourceKeys(string $resource): array
    {
        $resource = ShopifyApiService::fixResource($resource);

        $base = pathinfo($resource, PATHINFO_FILENAME);

        if (is_numeric($base)) {
            // e.g. /admin/products/123456.json
            return static::getPossibleResourceKeys(dirname($resource));
        }

        return array_values(array_unique([
            $base,
            Str::singular($base),
            Str::plural($base),
        ]));
    }

    /**
     * Return the object(s) from the response that pertains to the resource's calculated key.
     *
     * The response object(s) are mapped to resource-specific models (e.g. \App\Services\Shopify\Models\Product)
     *
     * The response is either a single model instance, a Collection of model instances,
     * or an integer (for count requests)
     *
     * Shopify returns the resource's data in a top-level key that is named after the resource.
     * For example, the "orders" resource returns...
     *   Single order: {"order": {...}}
     *   Multiple orders: {"orders": [{...}, {...}, ...]}
     * If none of the known keys are found, an exception is thrown
     *
     * @param string $resource
     * @param Client|User $owner
     *
     * @return Collection|ShopifyModel|ShopifyModel[]|int|null
     * @throws ShopifyApiException
     */
    public function forResource(string $resource, $owner)
    {
        foreach ($this->getPossibleResourceKeys($resource) as $key) {
            if ($this->offsetExists($key)) {
                $value = $this->offsetGet($key);

                return is_numeric($value)
                    ? $value
                    : $this->toModel($key, new self($value->toArray()), $owner);
            }
        }

        throw new ShopifyApiException("Unable to identify the correct response key for resource '$resource'", $owner);
    }

    /**
     * Map the response to a Shopify model (if single result)
     * or a Collection of Shopify models (if multiple results)
     *
     * @param string $resource
     * @param ShopifyApiResponse $response
     * @param Client|User $owner
     *
     * @return Collection|ShopifyModel[]|ShopifyModel
     * @throws ShopifyApiException
     */
    protected function toModel(string $resource, self $response, $owner)
    {
        $resource = Str::singular($resource);

        if (! isset($this->resourceClassMap[$resource])) {
            throw new ShopifyApiException("Model class is not known for resource '$resource'", $owner);
        }

        $class = $this->resourceClassMap[$resource];

        return call_user_func([$class, 'createFromResponse'], $response, $owner);
    }
}