Merge Lightning backend into Mempool backend

backend/src/api/lightning/lightning-api-abstract-factory.ts

@@ -0,0 +1,7 @@
+import { ILightningApi } from './lightning-api.interface';
+
+export interface AbstractLightningApi {
+  $getNetworkInfo(): Promise<ILightningApi.NetworkInfo>;
+  $getNetworkGraph(): Promise<ILightningApi.NetworkGraph>;
+  $getChanInfo(id: string): Promise<ILightningApi.Channel>;
+}

backend/src/api/lightning/lightning-api-factory.ts

@@ -0,0 +1,13 @@
+import config from '../../config';
+import { AbstractLightningApi } from './lightning-api-abstract-factory';
+import LndApi from './lnd/lnd-api';
+
+function lightningApiFactory(): AbstractLightningApi {
+  switch (config.LIGHTNING.BACKEND) {
+    case 'lnd':
+    default:
+      return new LndApi();
+  }
+}
+
+export default lightningApiFactory();

backend/src/api/lightning/lightning-api.interface.ts

@@ -0,0 +1,53 @@
+export namespace ILightningApi {
+  export interface NetworkInfo {
+    average_channel_size: number;
+    channel_count: number;
+    max_channel_size: number;
+    median_channel_size: number;
+    min_channel_size: number;
+    node_count: number;
+    not_recently_updated_policy_count: number;
+    total_capacity: number;
+  }
+
+  export interface NetworkGraph {
+    channels: Channel[];
+    nodes: Node[];
+  }
+
+  export interface Channel {
+    id: string;
+    capacity: number;
+    policies: Policy[];
+    transaction_id: string;
+    transaction_vout: number;
+    updated_at: string;
+  }
+
+  interface Policy {
+    public_key: string;
+    base_fee_mtokens?: number;
+    cltv_delta?: number;
+    fee_rate?: number;
+    is_disabled?: boolean;
+    max_htlc_mtokens?: number;
+    min_htlc_mtokens?: number;
+    updated_at?: string;
+  }
+
+  export interface Node {
+    alias: string;
+    color: string;
+    features: Feature[];
+    public_key: string;
+    sockets: string[];
+    updated_at: string;
+  }
+
+  interface Feature {
+    bit: number;
+    is_known: boolean;
+    is_required: boolean;
+    type: string;
+  }
+}

backend/src/api/lightning/lnd/lnd-api.ts

@@ -0,0 +1,44 @@
+import { AbstractLightningApi } from '../lightning-api-abstract-factory';
+import { ILightningApi } from '../lightning-api.interface';
+import * as fs from 'fs';
+import * as lnService from 'ln-service';
+import config from '../../../config';
+import logger from '../../../logger';
+
+class LndApi implements AbstractLightningApi {
+  private lnd: any;
+  constructor() {
+    if (!config.LIGHTNING.ENABLED) {
+      return;
+    }
+    try {
+      const tls = fs.readFileSync(config.LND_NODE_AUTH.TLS_CERT_PATH).toString('base64');
+      const macaroon = fs.readFileSync(config.LND_NODE_AUTH.MACAROON_PATH).toString('base64');
+
+      const { lnd } = lnService.authenticatedLndGrpc({
+        cert: tls,
+        macaroon: macaroon,
+        socket: config.LND_NODE_AUTH.SOCKET,
+      });
+
+      this.lnd = lnd;
+    } catch (e) {
+      logger.err('Could not initiate the LND service handler: ' + (e instanceof Error ? e.message : e));
+      process.exit(1);
+    }
+  }
+
+  async $getNetworkInfo(): Promise<ILightningApi.NetworkInfo> {
+    return await lnService.getNetworkInfo({ lnd: this.lnd });
+  }
+
+  async $getNetworkGraph(): Promise<ILightningApi.NetworkGraph> {
+    return await lnService.getNetworkGraph({ lnd: this.lnd });
+  }
+
+  async $getChanInfo(id: string): Promise<ILightningApi.Channel> {
+    return await lnService.getChannel({ lnd: this.lnd, id });
+  }
+}
+
+export default LndApi;