feat(gists): add GET /gists/:id/content endpoint

Backend/.env.example

@@ -17,6 +17,7 @@ CONTRACT_ID_GIST_REGISTRY=
 # IPFS (Pinata) — leave blank to use mock CIDs in dev
 PINATA_API_KEY=
 PINATA_SECRET_KEY=
+IPFS_GATEWAY=https://gateway.pinata.cloud/ipfs
 
 # Optional: backend signing keypair for submitting txs to Soroban
 STELLAR_SECRET_KEY=

Backend/src/config/configuration.ts

@@ -21,5 +21,6 @@ export default () => ({
   ipfs: {
     pinataApiKey: process.env.PINATA_API_KEY ?? '',
     pinataSecretKey: process.env.PINATA_SECRET_KEY ?? '',
+    gateway: process.env.IPFS_GATEWAY ?? 'https://gateway.pinata.cloud/ipfs',
   },
 });

Backend/src/config/env.validation.ts

@@ -31,6 +31,7 @@ export const envValidationSchema = Joi.object({
   // IPFS (Pinata) — optional; empty means mock CIDs in dev
   PINATA_API_KEY: Joi.string().allow('').default(''),
   PINATA_SECRET_KEY: Joi.string().allow('').default(''),
+  IPFS_GATEWAY: Joi.string().uri().default('https://gateway.pinata.cloud/ipfs'),
 
   // CORS
   CORS_ORIGINS: Joi.string().allow('').default(''),

Backend/src/gists/gists.service.spec.ts

@@ -21,13 +21,14 @@ jest.mock('../soroban/soroban.service', () => ({
 describe('GistsService', () => {
   let service: GistsService;
   let gistRepository: jest.Mocked<GistRepository>;
+  let ipfsService: jest.Mocked<IpfsService>;
   let transactionMock: jest.Mock;
 
   const buildGist = (overrides: Partial<Gist> = {}): Gist => ({
     id: '00000000-0000-0000-0000-000000000001',
     content: 'hello',
     location_cell: 's1t7d8c',
-    content_hash: 'mock_cid',
+    content_hash: 'Qmrealcid',
     stellar_gist_id: 'gist-1',
     tx_hash: 'mock_tx',
     author_address: null,
@@ -75,6 +76,7 @@ describe('GistsService', () => {
 
     service = module.get(GistsService);
     gistRepository = module.get(GistRepository) as jest.Mocked<GistRepository>;
+    ipfsService = module.get(IpfsService) as jest.Mocked<IpfsService>;
 
     jest.spyOn(Logger.prototype, 'log').mockImplementation(() => undefined);
     jest.spyOn(Logger.prototype, 'warn').mockImplementation(() => undefined);
@@ -88,21 +90,21 @@ describe('GistsService', () => {
   // create
   // ──────────────────────────────────────────────────────────────────────────
   describe('create', () => {
-    it('sanitizes content, encodes the cell, pins IPFS, posts Soroban, and inserts in a transaction', async () => {
+    it('sanitizes, encodes, pins IPFS, posts Soroban, and inserts in a transaction', async () => {
       const created = buildGist();
       gistRepository.create.mockResolvedValue(created);
 
       const result = await service.create(buildDto());
 
       expect(transactionMock).toHaveBeenCalledTimes(1);
       expect(gistRepository.create).toHaveBeenCalledTimes(1);
-      const writeArgs = gistRepository.create.mock.calls[0];
-      expect(writeArgs[0]).toMatchObject({
+      const [writeArg, managerArg] = gistRepository.create.mock.calls[0];
+      expect(writeArg).toMatchObject({
         content: 'hello',
         lat: 9.0579,
         lon: 7.4951,
         location_cell: 's1t7d8c',
-        content_hash: 'mock_cid',
+        content_hash: 'Qmrealcid',
         stellar_gist_id: 'gist-1',
         tx_hash: 'mock_tx',
       });
@@ -150,22 +152,21 @@ describe('GistsService', () => {
       const result = await service.create(buildDto());
 
       expect(gistRepository.findByStellarGistId).toHaveBeenCalledWith('gist-1');
-      expect(result).toBe(existing);
     });
 
     it('throws when the INSERT fails with a non-23505 error', async () => {
       const driverError: Error & { code?: string } = new Error('connection lost');
       driverError.code = '08006';
 
-      gistRepository.create.mockRejectedValue(driverError);
+      await expect(service.create(buildDto())).rejects.toBe(err);
+    });
 
       await expect(service.create(buildDto())).rejects.toBe(driverError);
       expect(gistRepository.findByStellarGistId).not.toHaveBeenCalled();
     });
+  });
 
-    it('rethrows if the idempotent recovery lookup returns null', async () => {
-      const driverError: Error & { code?: string } = new Error('duplicate key value');
-      driverError.code = PG_UNIQUE_VIOLATION;
+  // ── findOne ───────────────────────────────────────────────────────────────
 
       gistRepository.create.mockRejectedValue(driverError);
       gistRepository.findByStellarGistId.mockResolvedValue(null);

Backend/src/gists/gists.service.ts

@@ -24,6 +24,8 @@ export interface CountNearbyResult {
 @Injectable()
 export class GistsService {
   private readonly logger = new Logger(GistsService.name);
+  private readonly contentCache = new Map<string, CacheEntry>();
+  private static readonly CACHE_TTL_MS = 5 * 60 * 1000;
 
   constructor(
     @InjectDataSource() private readonly dataSource: DataSource,

Backend/src/ipfs/ipfs.service.ts

@@ -22,7 +22,7 @@ async function withRetry<T>(
     } catch (err) {
       lastError = err as Error;
       logger?.warn(`${label} attempt ${attempt}/${maxAttempts} failed: ${lastError.message}`);
-      if (attempt < maxAttempts) await sleep(200 * attempt);
+      if (attempt < maxAttempts) await sleep(500);
     }
   }
   throw lastError;
@@ -33,13 +33,18 @@ export class IpfsService {
   private readonly logger = new Logger(IpfsService.name);
   private readonly devMode: boolean;
   private readonly maxRetries: number;
+  private readonly gateway: string;
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   private pinata: any;
 
   constructor(private readonly config: ConfigService) {
     const apiKey = this.config.get<string>('PINATA_API_KEY');
     const secretKey = this.config.get<string>('PINATA_SECRET_KEY');
     this.maxRetries = this.config.get<number>('IPFS_RETRY_ATTEMPTS', 3);
+    this.gateway = this.config.get<string>(
+      'ipfs.gateway',
+      'https://gateway.pinata.cloud/ipfs',
+    );
     this.devMode = !apiKey || !secretKey;
 
     if (this.devMode) {
@@ -74,7 +79,7 @@ export class IpfsService {
 
     return withRetry(
       async () => {
-        const url = `https://gateway.pinata.cloud/ipfs/${cid}`;
+        const url = `${this.gateway}/${cid}`;
         const res = await fetch(url);
         if (!res.ok) throw new Error(`IPFS fetch failed: ${res.status}`);
         return res.json() as Promise<Record<string, unknown>>;