<?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';

    private const LIST_SNAPSHOT_KEY = 'price_broadcast:list_snapshot';

    private const LIST_SNAPSHOT_SECONDS = 8;

    /**
     * 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 !== []
            && $this->rememberHashIfChanged(self::LAST_HASH_KEY, self::lastPriceIdentity($lastPayload));

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

    /**
     * @param array<string, mixed> $payload
     * @return array<string, int|bool>
     */
    public static function lastPriceIdentity(array $payload): array
    {
        return [
            'sell' => (int) ($payload['sell'] ?? 0),
            'buy' => (int) ($payload['buy'] ?? 0),
            'price_last' => (int) ($payload['price_last'] ?? 0),
            'price' => (int) ($payload['price'] ?? 0),
            'closed' => (bool) ($payload['closed'] ?? false),
            'main_product' => (int) ($payload['main_product'] ?? 0),
            'montzar' => (int) ($payload['montzar'] ?? 0),
            'zaarbox' => (int) ($payload['zaarbox'] ?? 0),
        ];
    }

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

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

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

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

    public function buildListPayload(bool $allowCached = false): ?array
    {
        if ($allowCached) {
            $cached = Cache::get(self::LIST_SNAPSHOT_KEY);
            if (
                is_array($cached)
                && is_array($cached['body'] ?? null)
                && isset($cached['stored_at'])
                && now()->diffInSeconds($cached['stored_at']) <= self::LIST_SNAPSHOT_SECONDS
            ) {
                return $cached['body'];
            }
        }

        $body = $this->buildProductListPayload();
        if ($body !== null && $body !== []) {
            Cache::put(self::LIST_SNAPSHOT_KEY, [
                'body' => $body,
                'stored_at' => now(),
            ], now()->addSeconds(self::LIST_SNAPSHOT_SECONDS + 5));
        }

        return $body;
    }

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

        return $this->publishListIfChanged($force);
    }

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

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

        if ($force) {
            $this->rememberHashIfChanged(self::LIST_HASH_KEY, self::listIdentity($listPayload));
        }

        Cache::forget(self::LIST_SNAPSHOT_KEY);
        app(PriceStreamService::class)->publish('list', $listPayload);

        return true;
    }

    /**
     * @param array<int, array<string, mixed>> $listPayload
     * @return array<int, array<string, int|bool>>
     */
    public static function listIdentity(array $listPayload): array
    {
        $identity = [];

        foreach ($listPayload as $product) {
            if (! is_array($product)) {
                continue;
            }

            $identity[] = [
                'id' => (int) ($product['id'] ?? 0),
                'price' => (int) ($product['price'] ?? 0),
                'price_profit' => (int) ($product['price_profit'] ?? 0),
                'show' => (bool) ($product['show'] ?? true),
                'active' => (bool) ($product['active'] ?? true),
                'reference_provider_active' => (bool) ($product['reference_provider_active'] ?? false),
            ];
        }

        return $identity;
    }

    /**
     * @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
    {
        if (app(ConfigService::class)->isStore()) {
            return app(ProductController::class)->customerStoreProductListPayload();
        }

        $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;
    }
}