Add reduce tx

package.json

@@ -26,6 +26,7 @@
     "@types/graphql-depth-limit": "^1.1.3",
     "@types/ioredis": "^4.28.10",
     "@types/jest": "^28.1.8",
+    "@types/json-bigint": "^1.0.4",
     "@types/lodash": "^4.14.191",
     "@types/node": "^18.13.0",
     "@types/validator": "^13.7.12",
@@ -47,10 +48,12 @@
     "axios": "^1.4.0",
     "class-validator": "^0.14.0",
     "dotenv": "^16.0.3",
+    "ergo-lib-wasm-nodejs": "^0.26.0",
     "graphql": "^15.8.0",
     "graphql-depth-limit": "^1.1.0",
     "graphql-type-json": "^0.3.2",
     "ioredis": "5.3.1",
+    "json-bigint": "^1.0.0",
     "lodash": "^4.17.21",
     "pg": "^8.11.0",
     "reflect-metadata": "^0.1.13",

src/graphql/input-types/transaction.ts

@@ -20,3 +20,15 @@ export class SignedTransactionInput {
   @Field({ nullable: true })
   size?: number;
 }
+
+@InputType("UnsignedTransaction")
+export class UnsignedTransactionInput {
+  @Field(() => String)
+  unsignedTransaction!: string;
+
+  @Field(() => [String])
+  inputBoxes!: string[];
+
+  @Field(() => [String])
+  dataInputBoxes!: string[];
+}

src/graphql/resolvers/transaction-resolver.ts

@@ -1,10 +1,24 @@
 import { GraphQLResolveInfo } from "graphql";
-import { Args, ArgsType, Ctx, Field, Info, Int, Query, Resolver } from "type-graphql";
+import {
+  Arg,
+  Args,
+  ArgsType,
+  Ctx,
+  Field,
+  Info,
+  Int,
+  Mutation,
+  Query,
+  Resolver
+} from "type-graphql";
 import { Transaction } from "../objects/transaction";
 import { removeUndefined } from "../../utils";
 import { GraphQLContext } from "../context-type";
 import { PaginationArguments } from "./pagination-arguments";
 import { ArrayMaxSize } from "class-validator";
+import { UnsignedTransactionInput } from "../input-types";
+import * as wasm from "ergo-lib-wasm-nodejs";
+import { nodeService } from "../../services";
 
 @ArgsType()
 class TransactionArguments {
@@ -72,4 +86,24 @@
       take
     });
   }
+
+  @Mutation(() => String)
+  async reduceTransaction(@Arg("transaction") transaction: UnsignedTransactionInput) {
+    try {
+      const ctx = await nodeService.getStateContext();
+      const tx = wasm.UnsignedTransaction.from_json(transaction.unsignedTransaction);
+      const ergoBoxes = wasm.ErgoBoxes.from_boxes_json(transaction.inputBoxes);
+      const dataInputBoxes = wasm.ErgoBoxes.from_boxes_json([]);
+      const reducedTx = wasm.ReducedTransaction.from_unsigned_tx(
+        tx,
+        ergoBoxes,
+        dataInputBoxes,
+        ctx
+      );
+      return reducedTx.sigma_serialize_bytes().toString();
+    } catch (e: any) {
+      console.error(e);
+      throw new Error(`Failed to reduce transaction! ${e}`);
+    }
+  }
 }

src/graphql/schema.graphql

@@ -218,6 +218,7 @@ type Mempool {
 
 type Mutation {
   checkTransaction(signedTransaction: SignedTransaction!): String!
+  reduceTransaction(transaction: UnsignedTransaction!): String!
   submitTransaction(signedTransaction: SignedTransaction!): String!
 }
 
@@ -369,3 +370,9 @@ type UnconfirmedTransaction implements ITransaction {
   timestamp: String!
   transactionId: String!
 }
+
+input UnsignedTransaction {
+  dataInputBoxes: [String!]!
+  inputBoxes: [String!]!
+  unsignedTransaction: String!
+}

src/services/node-service.ts

@@ -1,5 +1,7 @@
 import axios from "axios";
 import { SignedTransactionInput } from "../graphql/input-types";
+import * as wasm from "ergo-lib-wasm-nodejs";
+import { JsonBI } from "../utils";
 
 const HTTP_PREFIX_PATTERN = /^http(s?):\/\//;
 
@@ -30,6 +32,23 @@
   public getNodeInfo() {
     return axios.get(this._baseUrl + "/info");
   }
+
+  public getStateContext = async () => {
+    try {
+      const lastHeaderResponse = await axios.get(this._baseUrl + "/blocks/lastHeaders/10");
+      const lastBlocks = lastHeaderResponse.data as any[];
+      const lastBlocksStrings = lastBlocks.map((header) => JsonBI.stringify(header));
+      const lastBlocksHeaders = wasm.BlockHeaders.from_json(lastBlocksStrings);
+      const lastBlockPreHeader = wasm.PreHeader.from_block_header(lastBlocksHeaders.get(0));
+
+      const stateContext = new wasm.ErgoStateContext(lastBlockPreHeader, lastBlocksHeaders);
+
+      return stateContext;
+    } catch (e) {
+      console.error(e);
+      throw new Error("Failed to get state context");
+    }
+  };
 }
 
 export const nodeService = new NodeService();

src/utils.ts

@@ -1,3 +1,5 @@
+import JSONBigInt from "json-bigint";
+
 export function removeUndefined(value: Record<string, unknown>) {
   const result: Record<string, unknown> = {};
   for (const key in value) {
@@ -9,3 +11,8 @@ export function removeUndefined(value: Record<string, unknown>) {
 
   return result;
 }
+
+export const JsonBI = JSONBigInt({
+  useNativeBigInt: true,
+  alwaysParseAsBig: true
+});