From f7985fb57c15f469f1be5115fd3112267cdbc4f3 Mon Sep 17 00:00:00 2001
From: Richard Ramos <info@richardramos.me>
Date: Tue, 26 Jun 2018 16:34:28 -0400
Subject: [PATCH] Added quadratic voting

---
 contracts/polls/SingleChoice.sol | 24 ++++++++++++++++++++++++
 test/votingdapp.js               | 25 ++++++++++++++++---------
 2 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/contracts/polls/SingleChoice.sol b/contracts/polls/SingleChoice.sol
index ab5b250..3ba2230 100644
--- a/contracts/polls/SingleChoice.sol
+++ b/contracts/polls/SingleChoice.sol
@@ -27,7 +27,10 @@ contract SingleChoice is Controlled {
 
     string public question;
     string[] public choices;
+
     int[] public result;
+    int[] public qvResult;
+
     bytes32 uid;
 
     function SingleChoice(address _controller, bytes _rlpDefinition, uint salt) {
@@ -55,6 +58,7 @@ contract SingleChoice is Controlled {
         }
 
         result.length = choices.length; 
+        qvResult.length = choices.length; 
     }
 
     function pollType() public constant returns (bytes32) {
@@ -71,7 +75,18 @@ contract SingleChoice is Controlled {
     function deltaVote(int _amount, bytes32 _ballot) onlyController returns (bool _succes) {
         if (!isValid(_ballot)) return false;
         uint v = uint(_ballot) / (2**248);
+        
         result[v] += _amount;
+
+        int qv;
+        if (_amount < 0) {
+            qv = -sqrt(-_amount);
+        } else {
+            qv = sqrt(_amount);
+        }
+
+        qvResult[v] += qv;
+        
         return true;
     }
 
@@ -82,6 +97,15 @@ contract SingleChoice is Controlled {
     function getBallot(uint _option) constant returns(bytes32) {
         return bytes32((_option * (2**248)) + (uint(keccak256(uid, _option)) & (2**248 -1)));
     }
+
+    function sqrt(int256 x) public pure returns (int256 y) {
+        int256 z = (x + 1) / 2;
+        y = x;
+        while (z < y) {
+            y = z;
+            z = (x / z + z) / 2;
+        }
+    }
 }
 
 
diff --git a/test/votingdapp.js b/test/votingdapp.js
index 04e79b7..e9105e3 100644
--- a/test/votingdapp.js
+++ b/test/votingdapp.js
@@ -59,13 +59,13 @@ describe("VotingDapp", function () {
         
         web3.eth.getAccounts().then((acc) => { 
             accounts = acc; 
-            return SNT.methods.generateTokens(accounts[0], 123456).send()
+            return SNT.methods.generateTokens(accounts[0], 6).send()
         }).then((receipt) => { 
-            return SNT.methods.generateTokens(accounts[1], 789012).send()
+            return SNT.methods.generateTokens(accounts[1], 12).send()
         }).then((receipt) => { 
-            return SNT.methods.generateTokens(accounts[2], 345678).send()
+            return SNT.methods.generateTokens(accounts[2], 10).send()
         }).then((receipt) => { 
-            return SNT.methods.generateTokens(accounts[3], 901234).send()
+            return SNT.methods.generateTokens(accounts[3], 7).send()
         }).then((receipt) => {
             done(); 
         });
@@ -148,18 +148,25 @@ describe("VotingDapp", function () {
         poll = await PollManager.methods.poll(pollId).call();
         let votersByBallotYES = await PollManager.methods.getVotesByBallot(pollId, Yes).call();
         let tokenVotesByBallotYES = await pollContract.methods.result(0).call(); // 0 == Yes (because it is the initial option )
-        
-        // console.dir(poll); // Will contain state of the poll
-        // console.log(tokenVotesByBallotYES); // Contains how many votes has a ballot
-        // console.log(votersByBallotYES); // Contains how many voters voted for that option
+        let quadraticVotesByBallotYES = await pollContract.methods.qvResult(0).call(); // 0 == Yes (because it is the initial option )
 
+        // Will contain state of the poll
+        // console.dir(poll);
+
+        // Contains how many votes has a ballot
+        // console.log(tokenVotesByBallotYES); 
+
+        // Contains how many votes has a ballot using quadratic voting
+        //console.log(quadraticVotesByBallotYES);
+
+        // Contains how many voters voted for that option
+        // console.log(votersByBallotYES); 
 
         // ===================================================
         // Unvote
         receipt = await PollManager.methods.unvote(pollId).send({from: accounts[0]});
         assert.equal(!!receipt.events.Unvote, true, "Unvote not triggered");
 
-
     });
 
 });