Merge pull request #1010 from mempool/simon/liquid-icons-api

Liquid icons api

backend/src/api/liquid/icons.ts

@@ -0,0 +1,39 @@
+import * as fs from 'fs';
+import config from '../../config';
+import logger from '../../logger';
+
+class Icons {
+  private static FILE_NAME = './icons.json';
+  private iconIds: string[] = [];
+  private icons: { [assetId: string]: string; } = {};
+
+  constructor() {}
+
+  public loadIcons() {
+    if (!fs.existsSync(Icons.FILE_NAME)) {
+      logger.warn(`${Icons.FILE_NAME} does not exist. No Liquid icons loaded.`);
+      return;
+    }
+    const cacheData = fs.readFileSync(Icons.FILE_NAME, 'utf8');
+    this.icons = JSON.parse(cacheData);
+
+    for (const i in this.icons) {
+      this.iconIds.push(i);
+    }
+    logger.debug(`Liquid icons has been loaded.`);
+  }
+
+  public getIconByAssetId(assetId: string): Buffer | undefined {
+    const icon = this.icons[assetId];
+    if (icon) {
+      return Buffer.from(icon, 'base64');
+    }
+  }
+
+  public getAllIconIds() {
+    return this.iconIds;
+  }
+
+}
+
+export default new Icons();

backend/src/config.ts

@@ -16,6 +16,7 @@ interface IConfig {
     MEMPOOL_BLOCKS_AMOUNT: number;
     PRICE_FEED_UPDATE_INTERVAL: number;
     USE_SECOND_NODE_FOR_MINFEE: boolean;
+    EXTERNAL_ASSETS: string[];
   };
   ESPLORA: {
     REST_API_URL: string;
@@ -78,6 +79,7 @@ const defaults: IConfig = {
     'MEMPOOL_BLOCKS_AMOUNT': 8,
     'PRICE_FEED_UPDATE_INTERVAL': 3600,
     'USE_SECOND_NODE_FOR_MINFEE': false,
+    'EXTERNAL_ASSETS': [],
   },
   'ESPLORA': {
     'REST_API_URL': 'http://127.0.0.1:3000',

backend/src/index.ts

@@ -21,6 +21,8 @@ import backendInfo from './api/backend-info';
 import loadingIndicators from './api/loading-indicators';
 import mempool from './api/mempool';
 import elementsParser from './api/liquid/elements-parser';
+import syncAssets from './sync-assets';
+import icons from './api/liquid/icons';
 
 class Server {
   private wss: WebSocket.Server | undefined;
@@ -77,6 +79,7 @@ class Server {
 
     this.setUpWebsocketHandling();
 
+    await syncAssets.syncAssets();
     diskCache.loadMempoolCache();
 
     if (config.DATABASE.ENABLED) {
@@ -87,6 +90,10 @@ class Server {
       statistics.startStatistics();
     }
 
+    if (config.MEMPOOL.NETWORK === 'liquid') {
+      icons.loadIcons();
+    }
+
     fiatConversion.startService();
 
     this.setUpHttpApiRoutes();
@@ -270,6 +277,13 @@ class Server {
       ;
     }
 
+    if (config.MEMPOOL.NETWORK === 'liquid') {
+      this.app
+        .get(config.MEMPOOL.API_URL_PREFIX + 'assets/icons', routes.getAllLiquidIcon)
+        .get(config.MEMPOOL.API_URL_PREFIX + 'asset/:assetId/icon', routes.getLiquidIcon)
+      ;
+    }
+
     if (config.MEMPOOL.NETWORK === 'liquid' && config.DATABASE.ENABLED) {
       this.app
         .get(config.MEMPOOL.API_URL_PREFIX + 'liquid/pegs/month', routes.$getElementsPegsByMonth)

backend/src/routes.ts

@@ -19,6 +19,7 @@ import loadingIndicators from './api/loading-indicators';
 import { Common } from './api/common';
 import bitcoinClient from './api/bitcoin/bitcoin-client';
 import elementsParser from './api/liquid/elements-parser';
+import icons from './api/liquid/icons';
 
 class Routes {
   constructor() {}
@@ -807,6 +808,26 @@ class Routes {
         : (e.message || 'Error'));
     }
   }
+
+  public getLiquidIcon(req: Request, res: Response) {
+    const result = icons.getIconByAssetId(req.params.assetId);
+    if (result) {
+      res.setHeader('content-type', 'image/png');
+      res.setHeader('content-length', result.length);
+      res.send(result);
+    } else {
+      res.status(404).send('Asset icon not found');
+    }
+  }
+
+  public getAllLiquidIcon(req: Request, res: Response) {
+    const result = icons.getAllIconIds();
+    if (result) {
+      res.json(result);
+    } else {
+      res.status(404).send('Asset icons not found');
+    }
+  }
 }
 
 export default new Routes();

backend/src/sync-assets.ts

@@ -0,0 +1,32 @@
+import axios from 'axios';
+import * as fs from 'fs';
+const fsPromises = fs.promises;
+import config from './config';
+import logger from './logger';
+
+const PATH = './';
+
+class SyncAssets {
+  constructor() { }
+
+  public async syncAssets() {
+    for (const url of config.MEMPOOL.EXTERNAL_ASSETS) {
+      await this.downloadFile(url);
+    }
+  }
+
+  private async downloadFile(url: string) {
+    const fileName = url.split('/').slice(-1)[0];
+    logger.info(`Downloading external asset: ${fileName}...`);
+    try {
+      const response = await axios.get(url, {
+        responseType: 'stream', timeout: 30000
+      });
+      await fsPromises.writeFile(PATH + fileName, response.data);
+    } catch (e: any) {
+      throw new Error(`Failed to download external asset. ` + e);
+    }
+  }
+}
+
+export default new SyncAssets();