<?php

namespace App\Services;

use App\Http\Controllers\Admin\ProductController;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Cache;

class PriceBroadcastService
{
    private const LAST_HASH_KEY = 'price_broadcast:last_hash';

    private const LIST_HASH_KEY = 'price_broadcast:list_hash';

    /**
     * برادکست SSE — payload کامل last/list وقتی داده عوض شود.
     *
     * @param array<string, mixed>|null $lastPayload
     */
    public function broadcastAfterPriceUpdate(?array $lastPayload = null, bool $force = false): void
    {
        $stream = app(PriceStreamService::class);
        if (! $stream->isEnabled()) {
            return;
        }

        if ($lastPayload === null) {
            $cache = app(LivePriceCacheService::class);
            $lastPayload = $cache->get() ?? $cache->buildFromDatabase();
        }

        if ($force) {
            if (is_array($lastPayload) && $lastPayload !== []) {
                $stream->publish('last', $lastPayload);
            }

            $listPayload = $this->buildProductListPayload();
            if ($listPayload !== null) {
                $stream->publish('list', $listPayload);
            }

            return;
        }

        $lastChanged = is_array($lastPayload) && $lastPayload !== []
            && $this->rememberHashIfChanged(self::LAST_HASH_KEY, $lastPayload);

        $this->publishListIfChanged();

        if ($lastChanged && is_array($lastPayload)) {
            $stream->publish('last', $lastPayload);
        }
    }

    public function broadcastLastIfChanged(?array $lastPayload): void
    {
        $stream = app(PriceStreamService::class);
        if (! $stream->isEnabled()) {
            return;
        }

        if (! is_array($lastPayload) || $lastPayload === []) {
            return;
        }

        if (! $this->rememberHashIfChanged(self::LAST_HASH_KEY, $lastPayload)) {
            return;
        }

        $stream->publish('last', $lastPayload);
    }

    public function broadcastListIfChanged(): bool
    {
        $stream = app(PriceStreamService::class);
        if (! $stream->isEnabled()) {
            return false;
        }

        return $this->publishListIfChanged();
    }

    private function publishListIfChanged(): bool
    {
        $listPayload = $this->buildProductListPayload();
        if ($listPayload === null) {
            return false;
        }

        if (! $this->rememberHashIfChanged(self::LIST_HASH_KEY, $listPayload)) {
            return false;
        }

        app(PriceStreamService::class)->publish('list', $listPayload);

        return true;
    }

    /**
     * @param array<string, mixed>|array<int, mixed> $payload
     */
    private function rememberHashIfChanged(string $cacheKey, array $payload): bool
    {
        $hash = md5(json_encode($payload, JSON_UNESCAPED_UNICODE));
        if (Cache::get($cacheKey) === $hash) {
            return false;
        }

        Cache::put($cacheKey, $hash, now()->addHour());

        return true;
    }

    /**
     * @return array<int, mixed>|null
     */
    private function buildProductListPayload(): ?array
    {
        $request = Request::create('/customer/product/list', 'GET');
        app()->instance('request', $request);

        $response = app(ProductController::class)->listProduct();
        $decoded = json_decode($response->getContent(), true);

        return is_array($decoded) ? $decoded : null;
    }
}