cac payemnt integration and cbe rate exchange webscrabing

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

@@ -1,6 +1,12 @@
 import { Injectable, Logger } from '@nestjs/common';
 import { ConfigService } from '@nestjs/config';
 
+const DEFAULT_SCRAPE_URL = 'https://ethio.forex/bank/CBET';
+
+/** Matches USD buying/selling embedded in ethio.forex CBET page HTML (after entity unescape). */
+const USD_RATE_REGEX =
+  /currency_code":\[0,"USD"\],"currency_name":\[0,"US DOLLAR"\],"buying":\[0,([\d.]+)\],"selling":\[0,([\d.]+)\]/;
+
 @Injectable()
 export class CbeExchangeService {
   private readonly logger = new Logger(CbeExchangeService.name);
@@ -10,9 +16,8 @@ export class CbeExchangeService {
   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.
+   * Returns the current CBE USD→ETB **selling** rate scraped from ethio.forex.
+   * Cached for CBE_EXCHANGE_CACHE_TTL_MS; falls back to CBE_EXCHANGE_FALLBACK_RATE on failure.
    */
   async getUsdToEtbRate(): Promise<number> {
     const now = Date.now();
@@ -21,41 +26,43 @@ export class CbeExchangeService {
       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;
-    }
+    const scrapeUrl = this.getScrapeUrl();
+    const fallbackRate =
+      this.configService.get<number>('app.cbeExchange.fallbackRate') ?? 130;
+    const cacheTtlMs =
+      this.configService.get<number>('app.cbeExchange.cacheTtlMs') ?? 3_600_000;
 
     try {
-      const response = await fetch(apiUrl, {
+      const response = await fetch(scrapeUrl, {
         signal: AbortSignal.timeout(8_000),
-        headers: { Accept: 'application/json' },
+        headers: { 'User-Agent': 'Mozilla/5.0' },
       });
 
       if (!response.ok) {
-        throw new Error(`CBE API responded with status ${response.status}`);
+        throw new Error(`CBE scrape responded with status ${response.status}`);
       }
 
-      const json = await response.json();
-      const rate = this.parseRate(json);
+      const html = await response.text();
+      const rates = this.parseScrapedRates(html);
 
-      if (!rate || !Number.isFinite(rate) || rate <= 0) {
-        throw new Error(`Invalid rate value parsed from CBE API response: ${rate}`);
+      if (!rates) {
+        throw new Error('USD rate not found in ethio.forex page HTML');
+      }
+
+      const rate = rates.selling;
+      if (!Number.isFinite(rate) || rate <= 0) {
+        throw new Error(`Invalid selling rate parsed: ${rate}`);
       }
 
       this.cachedRate = rate;
       this.cacheExpiresAt = now + cacheTtlMs;
-      this.logger.log(`CBE USD→ETB rate refreshed: ${rate}`);
+      this.logger.log(
+        `CBE USD→ETB rate refreshed from ethio.forex — buying=${rates.buying} selling=${rate}`,
+      );
       return rate;
     } catch (err) {
       this.logger.error(
-        `Failed to fetch CBE exchange rate — using fallback ${fallbackRate} ETB/USD. Error: ${(err as Error).message}`,
+        `Failed to scrape CBE exchange rate — using fallback ${fallbackRate} ETB/USD. Error: ${(err as Error).message}`,
       );
 
       if (this.cachedRate !== null) {
@@ -67,49 +74,33 @@ export class CbeExchangeService {
     }
   }
 
-  /**
-   * 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;
+  private getScrapeUrl(): string {
+    const configured =
+      this.configService.get<string>('app.cbeExchange.scrapeUrl') ??
+      this.configService.get<string>('app.cbeExchange.apiUrl');
+    return configured?.trim() || DEFAULT_SCRAPE_URL;
+  }
 
-      if (!usdEntry) return null;
+  private parseScrapedRates(
+    html: string,
+  ): { buying: number; selling: number } | null {
+    const decoded = this.unescapeHtml(html);
+    const match = USD_RATE_REGEX.exec(decoded);
+    if (!match) return null;
 
-      const selling =
-        usdEntry['selling'] ??
-        usdEntry['Selling'] ??
-        usdEntry['sellingRate'] ??
-        usdEntry['rate'] ??
-        usdEntry['Rate'];
+    const buying = Number(match[1]);
+    const selling = Number(match[2]);
+    if (!Number.isFinite(buying) || !Number.isFinite(selling)) return null;
 
-      return selling !== undefined ? Number(selling) : null;
-    }
+    return { buying, selling };
+  }
 
-    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;
+  private unescapeHtml(html: string): string {
+    return html
+      .replace(/&quot;/g, '"')
+      .replace(/&#34;/g, '"')
+      .replace(/&amp;/g, '&')
+      .replace(/&lt;/g, '<')
+      .replace(/&gt;/g, '>');
   }
 }