Feat/eng 382 unbond function

contracts/ProviderPool.sol

@@ -17,7 +17,6 @@ contract ProviderPool is Ownable {
     return providerPool.contains(_provider);
   }
 
-  // TODO: Add default value in the main constructor
   function setMaxNumberOfProviders(uint _maxNumber) external onlyOwner {
     providerPool.setMaxSize(_maxNumber);
   }

contracts/RoundManager.sol

@@ -1,8 +1,9 @@
 pragma solidity ^0.4.24;
 
 import "zeppelin-solidity/contracts/math/SafeMath.sol";
+import "zeppelin-solidity/contracts/ownership/Ownable.sol";
 
-contract RoundManager {
+contract RoundManager is Ownable {
   using SafeMath for uint;
 
   // Round number of the last round
@@ -12,15 +13,24 @@ contract RoundManager {
 
   uint public electionPeriodLength;
   uint public rateLockDeadline;
+  // The time (in number of blocks) that a Delegator has to wait before he can withdraw() his tokens
+  uint public unbondingPeriod;
 
   modifier onlyBeforeActiveRoundIsLocked() {
     require(block.number.sub(startOfCurrentRound) < electionPeriodLength.sub(rateLockDeadline));
     _;
   }
 
-  constructor() public {
-    electionPeriodLength = 20;
-    rateLockDeadline = 5;
+  function setElectionPeriodLength(uint _electionPeriodLength) public onlyOwner {
+    electionPeriodLength = _electionPeriodLength;
+  }
+
+  function setRateLockDeadline(uint _rateLockDeadline) public onlyOwner {
+    rateLockDeadline = _rateLockDeadline;
+  }
+
+  function setUnbondingPeriod(uint _unbondingPeriod) public onlyOwner {
+    unbondingPeriod = _unbondingPeriod;
   }
 
   function initializeRound() external {

contracts/TransmuteDPOS.sol

@@ -6,6 +6,18 @@ import "./ProviderPool.sol";
 
 contract TransmuteDPOS is TransmuteToken, RoundManager, ProviderPool {
 
+  event DelegatorBonded(
+    address indexed _delegator,
+    address indexed _provider,
+    uint _amount
+  );
+
+  event DelegatorUnbonded(
+    address indexed _delegator,
+    address indexed _provider,
+    uint _amount
+  );
+
   event ProviderAdded (
     address indexed _provider,
     uint _pricePerStorageMineral,
@@ -26,8 +38,11 @@ contract TransmuteDPOS is TransmuteToken, RoundManager, ProviderPool {
     address indexed _provider
   );
 
+  enum DelegatorStatus { Unbonded, UnbondedWithTokensToWithdraw, Bonded }
+
   struct Delegator {
     address delegateAddress;
+    // TODO: rename variable
     uint amountBonded;
   }
 
@@ -48,6 +63,16 @@ contract TransmuteDPOS is TransmuteToken, RoundManager, ProviderPool {
   uint public numberOfProviders;
   mapping(address => Provider) public providers;
 
+  mapping (address => uint) public withdrawBlocks;
+
+  // FIXME: Those are temporary values
+  constructor() public {
+    // Set constants from RoundManager
+    electionPeriodLength = 20;
+    rateLockDeadline = 5;
+    unbondingPeriod = 10;
+  }
+
   function provider(uint _pricePerStorageMineral, uint _pricePerComputeMineral, uint _blockRewardCut, uint _feeShare)
     external onlyBeforeActiveRoundIsLocked
   {
@@ -92,5 +117,42 @@ contract TransmuteDPOS is TransmuteToken, RoundManager, ProviderPool {
     if (p.status == ProviderStatus.Registered) {
       updateProvider(_provider, p.totalAmountBonded);
     }
+    emit DelegatorBonded(msg.sender, _provider, _amount);
+  }
+
+  function unbond() external {
+    // Only Bonded Delegators can call the function
+    require(delegatorStatus(msg.sender) == DelegatorStatus.Bonded);
+    // TODO: What if a Provider calls unbond() on himself ?
+    // Should he resign ?
+    // What about the tokens of the Delegators that bonded to him ?
+    // For now we prevent providers from calling this function
+    require(providers[msg.sender].status == ProviderStatus.Unregistered);
+
+    Delegator storage d = delegators[msg.sender];
+    Provider storage p = providers[d.delegateAddress];
+    // Sets the block number from which the Delegator will be able to withdraw() his tokens
+    withdrawBlocks[msg.sender] = block.number.add(unbondingPeriod);
+    // Decrease the totalAmountBonded parameter of the provider
+    p.totalAmountBonded = p.totalAmountBonded.sub(d.amountBonded);
+    updateProvider(d.delegateAddress, p.totalAmountBonded);
+    emit DelegatorUnbonded(msg.sender, d.delegateAddress, d.amountBonded);
+    // Remove delegator from the list. He is no longer in the the Bonded State
+    delete delegators[msg.sender];
+  }
+
+  // TODO: Create the same function for Providers
+  // This will remove the need for ProviderStatus inside the Provider Struct
+  function delegatorStatus(address _delegator) public view returns (DelegatorStatus) {
+    if (delegators[_delegator].amountBonded != 0) {
+      // If _delegator is in the mapping, he is Bonded
+      return DelegatorStatus.Bonded;
+    } else if (withdrawBlocks[_delegator] != 0) {
+      // Else if _delegator has a withdrawBlock, he just called unbond() and didn't withdraw() yet
+      return DelegatorStatus.UnbondedWithTokensToWithdraw;
+    } else {
+      // Else he is Unbonded: either he didn't call bond() or he called bond() unbond() and withdraw()
+      return DelegatorStatus.Unbonded;
+    }
   }
 }

test/TestRoundManager.spec.js

@@ -3,13 +3,18 @@ const { blockMiner, assertFail } = require('./utils.js');
 
 contract('RoundManager', accounts => {
 
-  let rm, electionPeriodLength;
+  let rm;
+  const electionPeriodLength = 20;
+  const rateLockDeadline = 5;
+  const unbondingPeriod = 10;
 
   describe('initializeRound', () => {
 
     before(async () => {
       rm = await RoundManager.deployed();
-      electionPeriodLength = await rm.electionPeriodLength.call();
+      await rm.setElectionPeriodLength(electionPeriodLength);
+      await rm.setRateLockDeadline(rateLockDeadline);
+      await rm.setUnbondingPeriod(unbondingPeriod);
       await blockMiner.mineUntilEndOfElectionPeriod(rm);
       assert.equal(0, (web3.eth.blockNumber + 1) % electionPeriodLength);
     });