> For the complete documentation index, see [llms.txt](https://smartscenarios.pirichain.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://smartscenarios.pirichain.com/psce-functions/examples/deposit-withdraw-from-foreign-chain-bsc-and-add-order-buy-and-sell-token-just-a-277-code-lines.md). # Deposit/Withdraw from Foreign Chain (BSC) and Add Order , Buy and Sell Token, Just a 277 Code Lines! Below sample explained how to build a simple exchange operation using with PSce The provided code is an example of a trading and order management system designed to operate on the **Pirichain Smart Scenario** platform. It handles the swap of **BNB** and **PIRI coins**, and includes functions for liquidity management, placing and removing orders, and checking wallet balances. #### Key Features * **Transaction Initialization and Status Check:**\ The `swapInitialize` function initializes the order books (asks and bids) and price data for a specific trading pair (`BNB_PIRI`). * **Wallet Balance Check:**\ Functions like `checkMyBNBDeposit` and `depositToken` check the balances of BNB and PIRI tokens in the user’s wallet and, if sufficient, add liquidity to the pool. * **Wallet Blocking:**\ The `blockWallet` and `unBlockWallet` functions allow the blocking and unblocking of wallet addresses based on specific conditions. * **Buy/Sell Orders:**\ The `buyToken` and `sellToken` functions search for orders with a given timestamp (ask or bid), check if the user has enough balance, and if so, execute the buy or sell order. * **Order Management:**\ Users can create and remove buy (`addBid`) and sell (`addAsk`) orders. These functions also handle order removal (`removeMyBid`, `removeMyAsk`). * **Withdrawal of Liquidity:**\ The `withdrawBnbWallet` and `withdrawToken` functions allow users to withdraw their BNB or PIRI token balances from the platform to their own wallets. #### Usage * **Liquidity Management in Exchanges:**\ This system can be applied in decentralized exchanges (DEX) or liquidity pools to manage the liquidity for BNB and PIRI tokens. * **Wallet Status and Security:**\ Security mechanisms, such as blocking wallets and suspending transactions, are integrated into the system. #### Example Use Cases 1. **Initializing Trading for a BNB and PIRI Pair:**\ Users can call the `swapInitialize` function to set up the liquidity and order books for BNB and PIRI coins. 2. **Placing and Removing Orders:**\ Users can place bids and asks at a specific level (`level`) and quantity (`quantity`), or remove them if needed. 3. **Withdrawing Liquidity:**\ Users can withdraw their available BNB or PIRI token balances from the system using `withdrawBnbWallet` or `withdrawToken` functions. This structure can be used to build a DEX protocol on **Pirichain**, or enhance existing exchange integrations by providing automated, blockchain-based trading and liquidity management. {% code lineNumbers="true" %} ```javascript // PIRICHAIN SWAP INTEGRATION FOR BNB CHAIN BNB COIN const parity='BNB_PIRI'; const slippage=0.15; async function swapInitialize() { PSDATA[parity]={}; PSDATA[parity].asks=[]; PSDATA[parity].bids=[]; PSDATA['lastPrice']=0; PSDATA['volumeDaily']=[]; PSDATA['slippageFeeCrypto']=0; PSDATA['slippageFeeToken']=0; const result= await Map.saveMap(JSON.stringify(PSDATA)); return result; } async function checkMyBNBDeposit() { const myBalanceObj=await getBnbWalletBalance(); const myBalance=parseFloat(myBalanceObj.data); const hasTx=await Transaction.checkPoolTransaction(EXECUTER_ADDRESS); if (hasTx.data) return {error:1,message:'There is a transaction processing... System cannot start a new transaction..'}; if (myBalance>0) { let withdrawalResultForPSCE={}; checkWalletInitialization(); if (ORIGINFLAG) { const scenarioWeb3WalletAddress=await createPSceBnbWallet(); withdrawalResultForPSCE=await withdrawBnbWallet(scenarioWeb3WalletAddress.data); } PSDATA[EXECUTER_ADDRESS].liquidityCrypto+=myBalance; const depositLiqResult=await Map.saveMap(JSON.stringify(PSDATA)); return {depositLiqResult:depositLiqResult,withdrawalResultForPSCE:withdrawalResultForPSCE}; } else return {error:1,message:'There is no BNB at your address'}; } async function depositToken() { if (isNaN(ASSETID)) return {error:-1,message:'AssetID Must be declared,cannot be NAN!'}; if (ASSETID!==-1) return {error:-1,message:'AssetID Must be -1 for PIRI Coin!'}; if (isNaN(AMOUNT)) return {error:-1,message:'Amount Must be declared,cannot be NAN!'}; if (AMOUNT<=0) return {error:-1,message:'Amount Must be declared, cannot be zero or negative!'}; checkWalletInitialization(); PSDATA[EXECUTER_ADDRESS].liquidityToken+=AMOUNT; const depositTokenResult=await Map.saveMap(JSON.stringify(PSDATA)); return depositTokenResult; } async function getMyDepositWallet() { return await createBnbWallet(); } async function checkWalletInitialization() { if (PSDATA[EXECUTER_ADDRESS]==undefined) { PSDATA[EXECUTER_ADDRESS]={}; PSDATA[EXECUTER_ADDRESS].bids=[]; PSDATA[EXECUTER_ADDRESS].asks=[]; PSDATA[EXECUTER_ADDRESS].volume=0; PSDATA[EXECUTER_ADDRESS].liquidityCrypto=0; PSDATA[EXECUTER_ADDRESS].liquidityToken=0; } } async function blockWallet(walletAddress,reason) { if (OWNER_ADDRESS!==EXECUTER_ADDRESS) return {error:1,message:'This function must be run by authorized!'}; if (PSDATA['blockedAddress']==undefined) PSDATA['blockedAddress']=[]; PSDATA['blockedAddress'].push({wallet:walletAddress,reason:reason}); const blockedAddresses=await Map.saveMap(JSON.stringify(PSDATA)); return blockedAddresses; } async function unBlockWallet(walletAddress) { if (OWNER_ADDRESS!==EXECUTER_ADDRESS) return {error:1,message:'This function must be run by authorized!'}; if (PSDATA['blockedAddress']==undefined) return {error:1,message:'There is no blocked addresses'}; PSDATA['blockedAddress']=PSDATA['blockedAddress'].filter(e=>e.wallet===walletAddress); const blockedAddresses=await Map.saveMap(JSON.stringify(PSDATA)); return blockedAddresses; } async function buyToken(timeStamp) { if (PSDATA['blockedAddress']!=undefined) { if (PSDATA['blockedAddress'].find(r=>r.wallet===EXECUTER_ADDRESS)) return {error:1,message:'Your wallet has been blocked!'}; } const currentAsk=PSDATA[parity].asks.find(r=>r.dateTime===timeStamp); if (!currentAsk) return {error:1,message:'There is no asks table record by your given timeStamp!'}; else { if (PSDATA[EXECUTER_ADDRESS].liquidityCryptof.dateTime!==timeStamp); PSDATA[currentAsk.wallet].asks=PSDATA[currentAsk.wallet].asks.filter(f=>f.dateTime!==timeStamp); PSDATA[currentAsk.wallet].liquidityToken-=currentAsk.quantity; PSDATA[currentAsk.wallet].liquidityCrypto+=currentAsk.quantity*currentAsk.level*(1-slippage); PSDATA['slippageFeeCrypto']+=currentAsk.quantity*currentAsk.level*(slippage); PSDATA[EXECUTER_ADDRESS].liquidityToken+=currentAsk.quantity*(1-slippage); PSDATA['slippageFeeToken']+=currentAsk.quantity*slippage; PSDATA[EXECUTER_ADDRESS].liquidityCrypto-=currentAsk.quantity*currentAsk.level; const buyTokenResult=await Map.saveMap(JSON.stringify(PSDATA)); return buyTokenResult; } } async function sellToken(timeStamp) { if (PSDATA['blockedAddress']!=undefined) { if (PSDATA['blockedAddress'].find(r=>r.wallet===EXECUTER_ADDRESS)) return {error:1,message:'Your wallet has been blocked!'}; } const currentBids=PSDATA[parity].bids.find(r=>r.dateTime===timeStamp); if (!currentBids) return {error:1,message:'There is no asks table record by your given timeStamp!'}; else { if (PSDATA[EXECUTER_ADDRESS].liquidityTokenf.dateTime!==timeStamp); PSDATA[currentBids.wallet].bids=PSDATA[currentBids.wallet].bids.filter(f=>f.dateTime!==timeStamp); PSDATA[currentBids.wallet].liquidityToken+=currentBids.quantity*(1-slippage); PSDATA['slippageFeeToken']+=currentBids.quantity*slippage; PSDATA[currentBids.wallet].liquidityCrypto-=currentBids.quantity*currentBids.level; PSDATA[EXECUTER_ADDRESS].liquidityToken-=currentBids.quantity; PSDATA[EXECUTER_ADDRESS].liquidityCrypto+=currentBids.quantity*currentBids.level*(1-slippage); PSDATA['slippageFeeCrypto']+=currentBids.quantity*currentBids.level*(slippage); const buyTokenResult=await Map.saveMap(JSON.stringify(PSDATA)); return buyTokenResult; } } async function removeMyBid(timeStamp) { checkWalletInitialization(); const currentRecord=PSDATA[EXECUTER_ADDRESS].bids.find(r=>r.dateTime===timeStamp); if (currentRecord) { PSDATA[EXECUTER_ADDRESS].bids=PSDATA[EXECUTER_ADDRESS].bids.filter(f=>f.dateTime!==timeStamp); PSDATA[EXECUTER_ADDRESS].liquidityCrypto+=currentRecord.quantity*currentRecord.level; PSDATA[parity].bids=PSDATA[parity].bids.filter(f=>f.dateTime!==timeStamp); const removingBidResult=await Map.saveMap(JSON.stringify(PSDATA)); return removingBidResult; } } async function listMyRecord() { return PSDATA[EXECUTER_ADDRESS]; } async function listTables() { return { bids:PSDATA[parity].bids, asks:PSDATA[parity].asks } } async function removeMyAsk(timeStamp) { checkWalletInitialization(); const currentRecord=PSDATA[EXECUTER_ADDRESS].asks.find(r=>r.dateTime===timeStamp); if (currentRecord) { PSDATA[EXECUTER_ADDRESS].asks=PSDATA[EXECUTER_ADDRESS].asks.filter(f=>f.dateTime!==timeStamp); PSDATA[parity].asks=PSDATA[parity].asks.filter(f=>f.dateTime!==timeStamp); PSDATA[EXECUTER_ADDRESS].liquidityToken+=currentRecord.quantity; const removingAskResult=await Map.saveMap(JSON.stringify(PSDATA)); return removingAskResult; } } async function addBid(quantity,level) { if (PSDATA[EXECUTER_ADDRESS].liquidityCrypto>=quantity*level) { checkWalletInitialization(); PSDATA[EXECUTER_ADDRESS].bids.push({quantity:quantity,level:level,dateTime:new Date().getTime()}); PSDATA[parity].bids.push({wallet:EXECUTER_ADDRESS, quantity:quantity,level:level,dateTime:new Date().getTime()}); PSDATA[EXECUTER_ADDRESS].liquidityCrypto-=quantity*level; const addingBidResult=await Map.saveMap(JSON.stringify(PSDATA)); return addingBidResult; } else return {error:1,message:'Insufficent BNB Balance'}; } async function addAsk(quantity,level) { if (PSDATA[EXECUTER_ADDRESS].liquidityToken>=quantity) { checkWalletInitialization(); PSDATA[EXECUTER_ADDRESS].asks.push({quantity:quantity,level:level,dateTime:new Date().getTime()}); PSDATA[parity].asks.push({wallet:EXECUTER_ADDRESS,quantity:quantity,level:level,dateTime:new Date().getTime()}); PSDATA[EXECUTER_ADDRESS].liquidityToken-=quantity; const addingBidResult=await Map.saveMap(JSON.stringify(PSDATA)); return addingBidResult; } else return {error:1,message:'Insufficent Token'}; } async function withdrawBnbWallet(withdrawalAddress) { const hasTx=await Transaction.checkPoolTransaction(EXECUTER_ADDRESS); if (hasTx.data) return {error:1,message:'There is a transaction processing... System cannot start a new transaction..'}; if (!withdrawalAddress) return {error:1,message:'Wrong Format! Please Fix It'}; if (withdrawalAddress==='') return {error:1,message:'Wrong Format! Please Fix It'}; if (withdrawalAddress.length!=42) return {error:1,message:'Wrong Format! Please Fix It'}; if (PSDATA[EXECUTER_ADDRESS].liquidityCrypto<=0) return {error:1,message:'Insufficient Balance!'}; if (Validator.isHex(withdrawalAddress.substr(2,withdrawalAddress.length-2))) { let withdrawResult={} if (ORIGIN_FLAG) { withdrawResult= await withdrawBnbPSceWallet(withdrawalAddress); } PSDATA[EXECUTER_ADDRESS].liquidityCrypto=0; const wResult=await Map.saveMap(JSON.stringify(PSDATA)); return {addingBidResult:addingBidResult,withdrawResult:wResult}; } else return {error:1,message:'Malformed BNB Address Format!'}; } async function withdrawToken() { const hasTx=await Transaction.checkPoolTransaction(EXECUTER_ADDRESS); if (hasTx.data) return {error:1,message:'There is a transaction processing... System cannot start a new transaction..'}; if (PSDATA[EXECUTER_ADDRESS].liquidityToken<=0) return {error:1,message:'Insufficient Balance!'}; const transferResult=await Transaction.sendPIRI(EXECUTER_ADDRESS,parseFloat(PSDATA[EXECUTER_ADDRESS].liquidityToken)); PSDATA[EXECUTER_ADDRESS].liquidityToken=0; const wResult=await Map.saveMap(JSON.stringify(PSDATA)); return {wResult:wResult,transferResult:transferResult}; } ``` {% endcode %}