feat: refactor exchange rate handling by integrating new ExchangeService and removing CbeExchangeService

packages/api-common/src/services/exchange/exchange.module.ts

@@ -0,0 +1,52 @@
+import { DynamicModule, Module, Provider } from "@nestjs/common";
+
+import {
+  EXCHANGE_OPTIONS,
+  ExchangeAsyncOptions,
+  ExchangeOptions,
+} from "./exchange.options";
+import { ExchangeService } from "./exchange.service";
+
+/**
+ * Provides {@link ExchangeService} (currency conversion, currently CBE-backed).
+ *
+ * Register once in the app root, then inject `ExchangeService` anywhere:
+ *
+ * ```ts
+ * // static config
+ * ExchangeModule.forRoot({ fallbackRate: 135 })
+ *
+ * // config resolved from ConfigService
+ * ExchangeModule.forRootAsync({
+ *   inject: [ConfigService],
+ *   useFactory: (config: ConfigService) => config.get('app.exchange'),
+ * })
+ * ```
+ */
+@Module({})
+export class ExchangeModule {
+  static forRoot(options: ExchangeOptions = {}): DynamicModule {
+    return {
+      module: ExchangeModule,
+      providers: [
+        { provide: EXCHANGE_OPTIONS, useValue: options },
+        ExchangeService,
+      ],
+      exports: [ExchangeService],
+    };
+  }
+
+  static forRootAsync(options: ExchangeAsyncOptions): DynamicModule {
+    const optionsProvider: Provider = {
+      provide: EXCHANGE_OPTIONS,
+      useFactory: options.useFactory,
+      inject: (options.inject ?? []) as never[],
+    };
+
+    return {
+      module: ExchangeModule,
+      providers: [optionsProvider, ExchangeService],
+      exports: [ExchangeService],
+    };
+  }
+}