Merge pull request #316 from near/issue-298

Add account balance to account state (#298)

src/account.ts

@@ -32,10 +32,17 @@ function sleep(millis: number): Promise<any> {
 }
 
 export interface AccountState {
-    account_id: string;
     amount: string;
-    staked: string;
     code_hash: string;
+    storage_usage: number;
+    locked: string;
+}
+
+export interface AccountBalance {
+    total: string;
+    stateStaked: string;
+    staked: string;
+    available: string;
 }
 
 /**
@@ -324,4 +331,26 @@ export class Account {
         });
         return result;
     }
+
+    /**
+     * Returns calculated account balance
+     * @returns {Promise<AccountBalance>}
+     */
+    async getAccountBalance(): Promise<AccountBalance> {
+        const genesisConfig = await this.connection.provider.experimental_genesisConfig();
+        const state = await this.state();
+
+        const costPerByte = new BN(genesisConfig.runtime_config.storage_amount_per_byte);
+        const stateStaked = new BN(state.storage_usage).mul(costPerByte);
+        const staked = new BN(state.locked);
+        const totalBalance = new BN(state.amount).add(staked);
+        const availableBalance = totalBalance.sub(staked).sub(stateStaked);
+
+        return {
+            total: totalBalance.toString(),
+            stateStaked: stateStaked.toString(),
+            staked: staked.toString(),
+            available: availableBalance.toString()
+        };
+    }
 }

src/providers/json-rpc-provider.ts

@@ -1,6 +1,7 @@
 import {
     Provider, FinalExecutionOutcome, NodeStatusResult, BlockId,
-    BlockResult, ChunkId, ChunkResult, adaptTransactionResult, EpochValidatorInfo
+    BlockResult, ChunkId, ChunkResult, adaptTransactionResult, EpochValidatorInfo,
+    GenesisConfig
 } from './provider';
 import { Network } from '../utils/network';
 import { ConnectionInfo, fetchJson } from '../utils/web';
@@ -106,6 +107,14 @@ export class JsonRpcProvider extends Provider {
         return this.sendJsonRpc('validators', [blockId]);
     }
 
+    /**
+     * Gets EXPERIMENTAL_genesis_config from RPC
+     * @returns {Promise<GenesisConfig>}
+     */
+    async experimental_genesisConfig(): Promise<GenesisConfig> {
+        return await this.sendJsonRpc('EXPERIMENTAL_genesis_config', []);
+    }
+
     /**
      * Directly call the RPC specifying the method and params
      * @param method RPC method

src/providers/provider.ts

@@ -156,6 +156,14 @@ export interface ValidatorStakeView {
     stake: string;
 }
 
+export interface GenesisConfig {
+    runtime_config: RuntimeConfig;
+}
+
+export interface RuntimeConfig {
+    storage_amount_per_byte: string;
+}
+
 export interface EpochValidatorInfo {
     // Validators for the current epoch.
     next_validators: NextEpochValidatorInfo[];
@@ -183,6 +191,7 @@ export abstract class Provider {
     abstract async block(blockId: BlockId): Promise<BlockResult>;
     abstract async chunk(chunkId: ChunkId): Promise<ChunkResult>;
     abstract async validators(blockId: BlockId): Promise<EpochValidatorInfo>;
+    abstract async experimental_genesisConfig(): Promise<GenesisConfig>;
 }
 
 export function getTransactionLastResult(txResult: FinalExecutionOutcome): any {