feat: implement and type-safe DriftTradingService for Solana/Drift trading (Node 20+)

lib/drift-trading.ts

@@ -0,0 +1,121 @@
+import { Connection, Keypair } from '@solana/web3.js'
+import { 
+  DriftClient, 
+  Wallet,
+  OrderType,
+  PositionDirection,
+  MarketType,
+  convertToNumber,
+  BASE_PRECISION,
+  PRICE_PRECISION,
+  BN,
+  type PerpPosition
+} from '@drift-labs/sdk'
+
+export interface TradeParams {
+  symbol: string
+  side: 'BUY' | 'SELL'
+  amount: number // USD amount
+  orderType?: 'MARKET' | 'LIMIT'
+  price?: number
+}
+
+export interface TradeResult {
+  success: boolean
+  txId?: string
+  error?: string
+  executedPrice?: number
+  executedAmount?: number
+}
+
+export interface Position {
+  symbol: string
+  side: 'LONG' | 'SHORT'
+  size: number
+  entryPrice: number
+  unrealizedPnl: number
+}
+
+export class DriftTradingService {
+  private connection: Connection
+  private wallet: Wallet
+  private driftClient: DriftClient
+
+  constructor() {
+    const rpcUrl = process.env.SOLANA_RPC_URL || 'https://api.mainnet-beta.solana.com'
+    const secret = process.env.SOLANA_PRIVATE_KEY
+    if (!secret) throw new Error('Missing SOLANA_PRIVATE_KEY in env')
+    const keypair = Keypair.fromSecretKey(Buffer.from(JSON.parse(secret)))
+    this.connection = new Connection(rpcUrl, 'confirmed')
+    this.wallet = new Wallet(keypair)
+    this.driftClient = new DriftClient({
+      connection: this.connection,
+      wallet: this.wallet,
+      env: 'mainnet-beta',
+      opts: { commitment: 'confirmed' }
+    })
+  }
+
+  async executeTrade(params: TradeParams): Promise<TradeResult> {
+    try {
+      await this.driftClient.subscribe()
+      const marketIndex = await this.getMarketIndex(params.symbol)
+      const direction = params.side === 'BUY' ? PositionDirection.LONG : PositionDirection.SHORT
+      const orderType = params.orderType === 'LIMIT' ? OrderType.LIMIT : OrderType.MARKET
+      const price = params.price ? new BN(Math.round(params.price * PRICE_PRECISION.toNumber())) : undefined
+      const baseAmount = new BN(Math.round(params.amount * BASE_PRECISION.toNumber()))
+      const txSig = await this.driftClient.placeAndTakePerpOrder({
+        marketIndex,
+        direction,
+        baseAssetAmount: baseAmount,
+        orderType,
+        price,
+        marketType: MarketType.PERP
+      })
+      // Fetch fill price and amount (simplified)
+      return { success: true, txId: txSig }
+    } catch (e: any) {
+      return { success: false, error: e.message }
+    } finally {
+      await this.driftClient.unsubscribe()
+    }
+  }
+
+  async getPositions(): Promise<Position[]> {
+    await this.driftClient.subscribe()
+    const user = this.driftClient.getUser()
+    // Example: check first 10 market indices (should be replaced with actual market list)
+    const positions: Position[] = []
+    for (let marketIndex = 0; marketIndex < 10; marketIndex++) {
+      const p = user.getPerpPosition(marketIndex)
+      if (!p || p.baseAssetAmount.isZero()) continue
+      // TODO: Calculate unrealizedPnl if SDK exposes it
+      positions.push({
+        symbol: this.getSymbolFromMarketIndex(marketIndex),
+        side: p.baseAssetAmount.gt(new BN(0)) ? 'LONG' : 'SHORT',
+        size: convertToNumber(p.baseAssetAmount, BASE_PRECISION),
+        entryPrice: convertToNumber(p.quoteEntryAmount, PRICE_PRECISION),
+        unrealizedPnl: 0
+      })
+    }
+    await this.driftClient.unsubscribe()
+    return positions
+  }
+
+  // Helper: map symbol to market index (stub, should use Drift markets config)
+  private async getMarketIndex(symbol: string): Promise<number> {
+    // TODO: Replace with real mapping
+    if (symbol === 'BTCUSD') return 0
+    if (symbol === 'ETHUSD') return 1
+    throw new Error('Unknown symbol: ' + symbol)
+  }
+
+  // Helper: map market index to symbol (stub)
+  private getSymbolFromMarketIndex(index: number): string {
+    if (index === 0) return 'BTCUSD'
+    if (index === 1) return 'ETHUSD'
+    return 'UNKNOWN'
+  }
+}
+
+export const driftTradingService = new DriftTradingService()