Telegram Notification Bot for Supplier Price Changes

Developing a Telegram Bot for Supplier Price Change Notifications

The bot monitors supplier prices (via API, scraping, or price list uploads) and immediately notifies those responsible of changes requiring action: price increase, deficit items appearing, condition changes.

Monitoring Logic

class SupplierPriceMonitor
{
    public function checkChanges(Supplier $supplier): void
    {
        $newPrices = $this->fetchPrices($supplier);

        foreach ($newPrices as $sku => $newPrice) {
            $oldPrice = SupplierPrice::where([
                'supplier_id' => $supplier->id,
                'sku'         => $sku,
            ])->value('price');

            if ($oldPrice === null) continue;  // new position — don't notify

            $changePercent = abs($newPrice - $oldPrice) / $oldPrice * 100;

            if ($changePercent >= config('suppliers.notify_threshold_percent', 5)) {
                $this->notify($supplier, $sku, $oldPrice, $newPrice, $changePercent);
            }

            SupplierPrice::updateOrCreate(
                ['supplier_id' => $supplier->id, 'sku' => $sku],
                ['price' => $newPrice, 'checked_at' => now()]
            );
        }
    }

    private function notify(Supplier $supplier, string $sku, float $old, float $new, float $pct): void
    {
        $arrow     = $new > $old ? '📈' : '📉';
        $direction = $new > $old ? 'increased' : 'decreased';

        $message = "{$arrow} <b>Price {$direction}</b>\n\n" .
                   "Supplier: {$supplier->name}\n" .
                   "SKU: <code>{$sku}</code>\n" .
                   "Was: " . number_format($old, 2) . " ₽\n" .
                   "Now: " . number_format($new, 2) . " ₽\n" .
                   "Change: <b>" . round($pct, 1) . "%</b>";

        $this->telegram->sendToChannel(config('telegram.pricing_channel'), $message);
    }
}

Notification threshold (5% by default) is configured. Check runs by schedule via Cron/Celery Beat.

Timeline: 2–3 business days.