feat: enrich ledger events with logo metadata

src/tbank/instrument-metadata.service.ts

@@ -0,0 +1,86 @@
+import { Injectable } from '@nestjs/common';
+import { LRUCache } from 'lru-cache';
+import { StructuredLogger } from '../common/logging/structured-logger.service';
+import { TbankClient, type TbankInstrument } from './tbank.client';
+
+const metadataForMs = 86_400_000;
+const maxCachedInstruments = 500;
+const missingInstrument = Symbol('missingInstrument');
+
+@Injectable()
+export class InstrumentMetadataService {
+  private readonly metadata = new LRUCache<
+    string,
+    TbankInstrument | typeof missingInstrument
+  >({
+    max: maxCachedInstruments,
+    ttl: metadataForMs,
+  });
+  private readonly pending = new Map<string, Promise<TbankInstrument | null>>();
+
+  constructor(
+    private readonly tbank: TbankClient,
+    private readonly logger: StructuredLogger,
+  ) {}
+
+  async resolve(
+    token: string,
+    instrumentUid: string | null | undefined,
+    figi: string | null | undefined,
+  ): Promise<TbankInstrument | null> {
+    const uid = instrumentUid?.trim();
+    if (uid) {
+      const byUid = await this.lookup(`uid:${uid}`, () =>
+        this.tbank.getInstrumentByUid(token, uid),
+      );
+      if (byUid) return byUid;
+    }
+    const instrumentFigi = figi?.trim();
+    return instrumentFigi
+      ? this.lookup(`figi:${instrumentFigi}`, () =>
+          this.tbank.getInstrumentByFigi(token, instrumentFigi),
+        )
+      : null;
+  }
+
+  private async lookup(
+    key: string,
+    fetch: () => Promise<TbankInstrument | null>,
+  ): Promise<TbankInstrument | null> {
+    const cached = this.metadata.get(key);
+    if (cached !== undefined)
+      return cached === missingInstrument ? null : cached;
+    const pending = this.pending.get(key);
+    if (pending) return pending;
+    const request = this.fetch(key, fetch);
+    this.pending.set(key, request);
+    try {
+      return await request;
+    } finally {
+      this.pending.delete(key);
+    }
+  }
+
+  private async fetch(
+    key: string,
+    request: () => Promise<TbankInstrument | null>,
+  ): Promise<TbankInstrument | null> {
+    try {
+      const value = await request();
+      this.metadata.set(key, value ?? missingInstrument);
+      this.logger.event('debug', 'instrument-metadata.resolved', {
+        found: Boolean(value?.name?.trim() || value?.ticker?.trim()),
+      });
+      return value;
+    } catch (error) {
+      this.logger.event('warn', 'instrument-metadata.failed', {
+        code:
+          error instanceof Error && 'response' in error
+            ? ((error as { response?: { code?: string } }).response?.code ??
+              'UNKNOWN')
+            : 'UNKNOWN',
+      });
+      return null;
+    }
+  }
+}