Merge pull request #934 from Jaybee020/Jaybee-Bronze-Submission

Jaybee bronze bonus

Author: ChoiceCoin

Bronze_Badges/Jaybee020_Bash/app.js

@@ -0,0 +1,103 @@
+//importing the neccesary modules
+const express=require("express")
+const app=express()
+const server = require('http').createServer(app);
+const { Server } = require("socket.io");
+const io = new Server(server);
+
+const algosdk=require('algosdk');
+
+//This helps in connecting the client with the algorand network
+const algoServer='https://testnet-algorand.api.purestake.io/ps2'
+const algoPort='';
+const token = {
+    'X-API-Key': 'Xy8NsXxfJg2cQ2YQ4pax6aLrTcj55jZ9mbsNCM30 '
+ }
+let algoClient = new algosdk.Algodv2(token, algoServer, algoPort);
+const CHOICE_ASSET_ID = 21364625;
+const choice_per_vote=1;//this constant can be changed 
+const button_address=""//wallet address of sender
+const button_mnemonic=""//25 word pattern of address of sender
+const red_address=""//address of candidate 1
+const blue_address=""//address of candidate 2
+const escrow_key = algosdk.mnemonicToSecretKey(button_mnemonic)['sk'];//generating the secret key from the 25 word pattern
+app.use(express.static(__dirname+"/public"))//setting the public directory you want to use
+
+app.get("/",function(req,res){
+    res.render("vote.ejs")
+})
+
+
+//the socet io module for real time communication between backend and frontend
+io.on("connection",(socket)=>{
+    console.log("Websocket connected")
+    //waits for vote event from front end to occur and receives data from this event 
+    socket.on('vote',async (data)=>{
+        let enc=new TextEncoder()
+        const note=enc.encode("Voting using Choice Coin")
+        //red address maps to 0 and blue address maps to 1 in this data sent from frontend
+        const voter_input=data.voted_for
+        console.log(voter_input)
+        //if else statements that sends to selected addresses
+        if(Number(voter_input)==0){
+            const params=await algoClient.getTransactionParams().do();//getting the parameter objects for the transaction
+            let txn=algosdk.makeAssetTransferTxnWithSuggestedParams(button_address,red_address,undefined,undefined,choice_per_vote,note,CHOICE_ASSET_ID,params)//Sending the specified asset to the address zero
+            let signedtxn=txn.signTxn(escrow_key)//authenticatiing the transaction with the secret key
+            await algoClient.sendRawTransaction(signedtxn).do()//sending the signed transaction to the algorand network for confirmation
+            // Wait for confirmation
+            let txId = txn.txID().toString();
+            let confirmedTxn = await waitForConfirmation(algoClient, txId,4);//awaiting results from the blockchain 
+            socket.emit("voted",`Voted for red with txID ${txId}`)
+            console.log("Signed transaction with txID: %s", txId);
+        }else if (Number(voter_input)==1){
+            const params=await algoClient.getTransactionParams().do();//getting the parameter objects for the transaction
+            let txn=algosdk.makeAssetTransferTxnWithSuggestedParams(button_address,blue_address,undefined,undefined,choice_per_vote,note,CHOICE_ASSET_ID,params) //Sending the specified asset to the address zero
+            let signedtxn=txn.signTxn(escrow_key)//authenticatiing the transaction with the secret key
+            await algoClient.sendRawTransaction(signedtxn).do()//sending the signed transaction to the algorand network for confirmation
+            // Wait for confirmation
+            let txId = txn.txID().toString();
+            let confirmedTxn = await waitForConfirmation(algoClient, txId,4);//awaiting results from the blockchain 
+            socket.emit("voted",`Voted for blue with txID ${txId}`)
+            console.log("Signed transaction with txID: %s", txId);
+        }
+    })
+})
+
+
+//Function to await confirmation results from blockchain
+const waitForConfirmation = async function (algodalgoClient, txId, timeout) {
+    if (algodalgoClient == null || txId == null || timeout < 0) {
+        throw new Error("Bad arguments");
+    }
+
+    const status = (await algodalgoClient.status().do());
+    if (status === undefined) {
+        throw new Error("Unable to get node status");
+    }
+
+    const startround = status["last-round"] + 1;
+    let currentround = startround;
+
+    while (currentround < (startround + timeout)) {
+        const pendingInfo = await algodalgoClient.pendingTransactionInformation(txId).do();
+        if (pendingInfo !== undefined) {
+            if (pendingInfo["confirmed-round"] !== null && pendingInfo["confirmed-round"] > 0) {
+                //Got the completed Transaction
+                return pendingInfo;
+            } else {
+                if (pendingInfo["pool-error"] != null && pendingInfo["pool-error"].length > 0) {
+                    // If there was a pool error, then the transaction has been rejected!
+                    throw new Error("Transaction " + txId + " rejected - pool error: " + pendingInfo["pool-error"]);
+                }
+            }
+        }
+        await algodalgoClient.statusAfterBlock(currentround).do();
+        currentround++;
+    }
+
+    throw new Error("Transaction " + txId + " not confirmed after " + timeout + " rounds!");
+}
+
+server.listen("8000",function(){
+    console.log("Server now listening on port 8000")
+})