Replace wagon/locomotive readiness with yard tracking, assign unassigned bookings from origin-yard fleet, standardize rates on USD with CBE ETB conversion, and update fleet/scheduling UI

apps/edr-freight-api/src/modules/cbe-exchange/cbe-exchange.service.ts

@@ -0,0 +1,115 @@
+import { Injectable, Logger } from '@nestjs/common';
+import { ConfigService } from '@nestjs/config';
+
+@Injectable()
+export class CbeExchangeService {
+  private readonly logger = new Logger(CbeExchangeService.name);
+  private cachedRate: number | null = null;
+  private cacheExpiresAt = 0;
+
+  constructor(private readonly configService: ConfigService) {}
+
+  /**
+   * Returns the current CBE USD→ETB exchange rate.
+   * Fetches live from CBE_EXCHANGE_API_URL, caches for CBE_EXCHANGE_CACHE_TTL_MS,
+   * and falls back to CBE_EXCHANGE_FALLBACK_RATE when the API is unreachable.
+   */
+  async getUsdToEtbRate(): Promise<number> {
+    const now = Date.now();
+
+    if (this.cachedRate !== null && now < this.cacheExpiresAt) {
+      return this.cachedRate;
+    }
+
+    const apiUrl = this.configService.get<string>('app.cbeExchange.apiUrl') ?? '';
+    const fallbackRate = this.configService.get<number>('app.cbeExchange.fallbackRate') ?? 130;
+    const cacheTtlMs = this.configService.get<number>('app.cbeExchange.cacheTtlMs') ?? 3_600_000;
+
+    if (!apiUrl) {
+      this.logger.warn(
+        `CBE_EXCHANGE_API_URL not configured — using fallback rate ${fallbackRate} ETB/USD`,
+      );
+      return fallbackRate;
+    }
+
+    try {
+      const response = await fetch(apiUrl, {
+        signal: AbortSignal.timeout(8_000),
+        headers: { Accept: 'application/json' },
+      });
+
+      if (!response.ok) {
+        throw new Error(`CBE API responded with status ${response.status}`);
+      }
+
+      const json = await response.json();
+      const rate = this.parseRate(json);
+
+      if (!rate || !Number.isFinite(rate) || rate <= 0) {
+        throw new Error(`Invalid rate value parsed from CBE API response: ${rate}`);
+      }
+
+      this.cachedRate = rate;
+      this.cacheExpiresAt = now + cacheTtlMs;
+      this.logger.log(`CBE USD→ETB rate refreshed: ${rate}`);
+      return rate;
+    } catch (err) {
+      this.logger.error(
+        `Failed to fetch CBE exchange rate — using fallback ${fallbackRate} ETB/USD. Error: ${(err as Error).message}`,
+      );
+
+      if (this.cachedRate !== null) {
+        this.logger.warn(`Using previously cached CBE rate: ${this.cachedRate}`);
+        return this.cachedRate;
+      }
+
+      return fallbackRate;
+    }
+  }
+
+  /**
+   * Parses the USD→ETB selling rate from the CBE API JSON response.
+   * CBE API typically returns an array of currency objects.
+   * Adjust this method if the API shape differs.
+   *
+   * Expected shape (one common format):
+   *   [ { currency: "USD", selling: "130.50", ... }, ... ]
+   */
+  private parseRate(json: unknown): number | null {
+    if (Array.isArray(json)) {
+      const usdEntry = json.find(
+        (entry: unknown) =>
+          typeof entry === 'object' &&
+          entry !== null &&
+          (
+            (entry as Record<string, unknown>)['currency'] === 'USD' ||
+            (entry as Record<string, unknown>)['Currency'] === 'USD'
+          ),
+      ) as Record<string, unknown> | undefined;
+
+      if (!usdEntry) return null;
+
+      const selling =
+        usdEntry['selling'] ??
+        usdEntry['Selling'] ??
+        usdEntry['sellingRate'] ??
+        usdEntry['rate'] ??
+        usdEntry['Rate'];
+
+      return selling !== undefined ? Number(selling) : null;
+    }
+
+    if (typeof json === 'object' && json !== null) {
+      const obj = json as Record<string, unknown>;
+      const selling =
+        obj['selling'] ??
+        obj['Selling'] ??
+        obj['sellingRate'] ??
+        obj['usdToEtb'] ??
+        obj['rate'];
+      return selling !== undefined ? Number(selling) : null;
+    }
+
+    return null;
+  }
+}