Directional RFID Dock Gate Portals & Custom WMS

interface TransitRecord {
  gateId: string;
  facing: "OUTSIDE" | "INSIDE";
  timestamp: number;
}

const activeTransitCache = new Map<string, TransitRecord>();
const cooldownCache = new Map<string, number>();

export class DirectionalPortalGateEngine {
  /**
   * Processes raw tag bursts from physical antenna banks.
   * Compares millisecond timestamps to deduce transit trajectory.
   */
  static async processTransit(
    companyId: string,
    gateId: string,
    facing: "OUTSIDE" | "INSIDE",
    tags: string[]
  ): Promise<{ inbound: string[]; outbound: string[] }> {
    const now = Date.now();
    const inbound: string[] = [];
    const outbound: string[] = [];

    for (const epc of tags) {
      const key = `${companyId}_${gateId}_${epc}`;
      const cooldownKey = `${companyId}_${epc}`;

      // 1. Skip tag if within active cooldown (prevents stationary jitter)
      if (cooldownCache.has(cooldownKey) && cooldownCache.get(cooldownKey)! > now) {
        continue;
      }

      const prev = activeTransitCache.get(key);
      if (!prev) {
        // First detection on either bank
        activeTransitCache.set(key, { gateId, facing, timestamp: now });
      } else {
        const delta = now - prev.timestamp;
        // Require opposite facing within a 5-second transit envelope
        if (delta < 5000 && prev.facing !== facing) {
          if (prev.facing === "OUTSIDE" && facing === "INSIDE") {
            inbound.push(epc);
          } else if (prev.facing === "INSIDE" && facing === "OUTSIDE") {
            outbound.push(epc);
          }

          // Apply 15-second debounce cooldown
          cooldownCache.set(cooldownKey, now + 15000);
          activeTransitCache.delete(key);
        }
      }
    }

    return { inbound, outbound };
  }
}