Merge pull request aragon#9 from 1Hive/fees-updater

Added FeesUpdater contract for updating fees using stable coin value.

contracts/court/AragonCourt.sol

@@ -24,7 +24,8 @@ contract AragonCourt is Controller, IArbitrator {
     * @param _governors Array containing:
     *        0. _fundsGovernor Address of the funds governor
     *        1. _configGovernor Address of the config governor
-    *        2. _modulesGovernor Address of the modules governor
+    *        2. _oracle Address of the price oracle
+    *        3. _modulesGovernor Address of the modules governor
     * @param _feeToken Address of the token contract that is used to pay for fees
     * @param _fees Array containing:
     *        0. jurorFee Amount of fee tokens that is paid per juror per dispute
@@ -54,7 +55,7 @@ contract AragonCourt is Controller, IArbitrator {
     */
     constructor(
         uint64[2] memory _termParams,
-        address[3] memory _governors,
+        address[4] memory _governors,
         ERC20 _feeToken,
         uint256[3] memory _fees,
         uint64[5] memory _roundStateDurations,

contracts/court/controller/Controller.sol

@@ -38,6 +38,7 @@ contract Controller is IsContract, CourtClock, CourtConfig {
     struct Governor {
         address funds;      // This address can be unset at any time. It is allowed to recover funds from the ControlledRecoverable modules
         address config;     // This address is meant not to be unset. It is allowed to change the different configurations of the whole system
+        address feesUpdater;// This is a second address that can update the config. It is expected to be used with a price oracle for updating fees
         address modules;    // This address can be unset at any time. It is allowed to plug/unplug modules from the system
     }
 
@@ -50,6 +51,7 @@ contract Controller is IsContract, CourtClock, CourtConfig {
     event ModuleSet(bytes32 id, address addr);
     event FundsGovernorChanged(address previousGovernor, address currentGovernor);
     event ConfigGovernorChanged(address previousGovernor, address currentGovernor);
+    event FeesUpdaterChanged(address previousFeesUpdater, address currentFeesUpdater);
     event ModulesGovernorChanged(address previousGovernor, address currentGovernor);
 
     /**
@@ -61,13 +63,21 @@ contract Controller is IsContract, CourtClock, CourtConfig {
     }
 
     /**
-    * @dev Ensure the msg.sender is the modules governor
+    * @dev Ensure the msg.sender is the config governor
     */
     modifier onlyConfigGovernor {
         require(msg.sender == governor.config, ERROR_SENDER_NOT_GOVERNOR);
         _;
     }
 
+    /**
+    * @dev Ensure the msg.sender is the config governor or the fees updater
+    */
+    modifier onlyConfigGovernorOrFeesUpdater {
+        require(msg.sender == governor.config || msg.sender == governor.feesUpdater, ERROR_SENDER_NOT_GOVERNOR);
+        _;
+    }
+
     /**
     * @dev Ensure the msg.sender is the modules governor
     */
@@ -84,7 +94,8 @@ contract Controller is IsContract, CourtClock, CourtConfig {
     * @param _governors Array containing:
     *        0. _fundsGovernor Address of the funds governor
     *        1. _configGovernor Address of the config governor
-    *        2. _modulesGovernor Address of the modules governor
+    *        2. _feesUpdater Address of the price feesUpdater
+    *        3. _modulesGovernor Address of the modules governor
     * @param _feeToken Address of the token contract that is used to pay for fees
     * @param _fees Array containing:
     *        0. jurorFee Amount of fee tokens that is paid per juror per dispute
@@ -114,7 +125,7 @@ contract Controller is IsContract, CourtClock, CourtConfig {
     */
     constructor(
         uint64[2] memory _termParams,
-        address[3] memory _governors,
+        address[4] memory _governors,
         ERC20 _feeToken,
         uint256[3] memory _fees,
         uint64[5] memory _roundStateDurations,
@@ -129,7 +140,8 @@ contract Controller is IsContract, CourtClock, CourtConfig {
     {
         _setFundsGovernor(_governors[0]);
         _setConfigGovernor(_governors[1]);
-        _setModulesGovernor(_governors[2]);
+        _setFeesUpdater(_governors[2]);
+        _setModulesGovernor(_governors[3]);
     }
 
     /**
@@ -173,7 +185,7 @@ contract Controller is IsContract, CourtClock, CourtConfig {
         uint256[3] calldata _jurorsParams
     )
         external
-        onlyConfigGovernor
+        onlyConfigGovernorOrFeesUpdater
     {
         uint64 currentTermId = _ensureCurrentTerm();
         _setConfig(
@@ -215,6 +227,14 @@ contract Controller is IsContract, CourtClock, CourtConfig {
         _setConfigGovernor(_newConfigGovernor);
     }
 
+    /**
+    * @notice Change fees updater to `_newFeesUpdater`
+    * @param _newFeesUpdater Address of the new fees updater to be set
+    */
+    function changeFeesUpdater(address _newFeesUpdater) external onlyConfigGovernor {
+        _setFeesUpdater(_newFeesUpdater);
+    }
+
     /**
     * @notice Change modules governor address to `_newModulesGovernor`
     * @param _newModulesGovernor Address of the new governor to be set
@@ -345,6 +365,14 @@ contract Controller is IsContract, CourtClock, CourtConfig {
         return governor.config;
     }
 
+    /**
+    * @dev Tell the address of the fees updater
+    * @return Address of the fees updater
+    */
+    function getFeesUpdater() external view returns (address) {
+        return governor.feesUpdater;
+    }
+
     /**
     * @dev Tell the address of the modules governor
     * @return Address of the modules governor
@@ -428,6 +456,15 @@ contract Controller is IsContract, CourtClock, CourtConfig {
         governor.config = _newConfigGovernor;
     }
 
+    /**
+    * @dev Internal function to set the address of the fees updater
+    * @param _newFeesUpdater Address of the new fees updater to be set
+    */
+    function _setFeesUpdater(address _newFeesUpdater) internal {
+        emit FeesUpdaterChanged(governor.feesUpdater, _newFeesUpdater);
+        governor.feesUpdater = _newFeesUpdater;
+    }
+
     /**
     * @dev Internal function to set the address of the modules governor
     * @param _newModulesGovernor Address of the new modules governor to be set

contracts/feesUpdater/FeesUpdater.sol

@@ -0,0 +1,58 @@
+pragma solidity ^0.5.8;
+
+import "../court/AragonCourt.sol";
+import "./IPriceOracle.sol";
+import "../lib/os/ERC20.sol";
+
+contract FeesUpdater {
+
+    IPriceOracle public priceOracle;
+    AragonCourt public court;
+    address public courtStableToken;
+    uint256[3] public courtStableValueFees;
+
+    constructor(
+        IPriceOracle _priceOracle,
+        AragonCourt _court,
+        address _courtStableToken,
+        uint256[3] memory _courtStableValueFees
+    ) public {
+        priceOracle = _priceOracle;
+        court = _court;
+        courtStableToken = _courtStableToken;
+        courtStableValueFees = _courtStableValueFees;
+    }
+
+    function getStableFees() external view returns (uint256[3] memory) {
+        return courtStableValueFees;
+    }
+
+    /**
+    * @notice Convert the court fees from their stable value to the fee token value and update the court config from the
+    *   next term with them. This function can be called any number of times during a court term, the closer to the
+    *   start of the following term the more accurate the configured fees will be.
+    */
+    function updateCourtFees() external {
+        uint64 currentTerm = court.ensureCurrentTerm();
+
+        // We use the latest possible term to ensure that if the config has been updated by an account other
+        // than this oracle, the config fetched will be the updated one. However, this does mean that a config update
+        // that is scheduled for a future term will be scheduled for the next term instead.
+        uint64 latestPossibleTerm = uint64(-1);
+        (ERC20 feeToken,,
+        uint64[5] memory roundStateDurations,
+        uint16[2] memory pcts,
+        uint64[4] memory roundParams,
+        uint256[2] memory appealCollateralParams,
+        uint256[3] memory jurorsParams
+        ) = court.getConfig(latestPossibleTerm);
+
+        uint256[3] memory convertedFees;
+        convertedFees[0] = priceOracle.consult(courtStableToken, courtStableValueFees[0], address(feeToken));
+        convertedFees[1] = priceOracle.consult(courtStableToken, courtStableValueFees[1], address(feeToken));
+        convertedFees[2] = priceOracle.consult(courtStableToken, courtStableValueFees[2], address(feeToken));
+
+        court.setConfig(currentTerm + 1, feeToken, convertedFees, roundStateDurations, pcts, roundParams,
+            appealCollateralParams, jurorsParams);
+    }
+}

contracts/feesUpdater/IPriceOracle.sol

@@ -0,0 +1,5 @@
+pragma solidity ^0.5.8;
+
+contract IPriceOracle {
+    function consult(address tokenIn, uint256 amountIn, address tokenOut) external view returns (uint256 amountOut);
+}

contracts/test/court/AragonCourtMock.sol

@@ -10,7 +10,7 @@ contract AragonCourtMock is AragonCourt, TimeHelpersMock {
 
     constructor(
         uint64[2] memory _termParams,
-        address[3] memory _governors,
+        address[4] memory _governors,
         ERC20 _feeToken,
         uint256[3] memory _fees,
         uint64[5] memory _roundStateDurations,

contracts/test/feesUpdater/MockPriceOracle.sol

@@ -0,0 +1,16 @@
+pragma solidity ^0.5.8;
+
+import "../../feesUpdater/IPriceOracle.sol";
+
+contract MockPriceOracle is IPriceOracle {
+
+    uint256 public feeTokenPriceInStableToken;
+
+    constructor(uint256 _feeTokenPriceInStableToken) public {
+        feeTokenPriceInStableToken = _feeTokenPriceInStableToken;
+    }
+
+    function consult(address tokenIn, uint256 amountIn, address tokenOut) external view returns (uint256 amountOut) {
+        return amountIn / feeTokenPriceInStableToken;
+    }
+}

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@1hive/celeste",
-  "version": "0.1.1",
+  "version": "0.1.2",
   "description": "Celeste Oracle",
   "author": "Aragon Association",
   "license": "GPL-3.0",
@@ -16,6 +16,7 @@
     "test:controller": "buidler test test/court/controller/*",
     "test:subscriptions": "buidler test test/subscriptions/*",
     "test:disputes": "buidler test test/disputes/*",
+    "test:feesupdater": "buidler test test/feesUpdater/*",
     "test:registry": "buidler test test/registry/*",
     "test:voting": "buidler test test/voting/*"
   },

test/court/controller/controller-config.js

@@ -8,7 +8,7 @@ const { assertConfig, buildNewConfig } = require('../../helpers/utils/config')(a
 const { assertEvent, assertAmountOfEvents } = require('../../helpers/asserts/assertEvent')
 const { CLOCK_ERRORS, CONFIG_ERRORS, CONTROLLER_ERRORS } = require('../../helpers/utils/errors')
 
-contract('Controller', ([_, configGovernor, someone, drafter, appealMaker, appealTaker, juror500, juror1000, juror3000]) => {
+contract('Controller', ([_, configGovernor, feesUpdater, someone, drafter, appealMaker, appealTaker, juror500, juror1000, juror3000]) => {
   let courtHelper, controller
 
   let initialConfig, feeToken
@@ -154,7 +154,7 @@ contract('Controller', ([_, configGovernor, someone, drafter, appealMaker, appea
     let newConfig
 
     beforeEach('deploy controller and build new config', async () => {
-      controller = await courtHelper.deploy({ ...initialConfig, configGovernor })
+      controller = await courtHelper.deploy({ ...initialConfig, configGovernor, feesUpdater })
       newConfig = await buildNewConfig(initialConfig)
     })
 
@@ -444,6 +444,13 @@ contract('Controller', ([_, configGovernor, someone, drafter, appealMaker, appea
       })
     })
 
+    context('when the sender is the fees updater', () => {
+      it('updates the config', async () => {
+        const receipt = await courtHelper.setConfig(0, newConfig, { from: feesUpdater })
+        assertAmountOfEvents(receipt, CONFIG_EVENTS.CONFIG_CHANGED)
+      })
+    })
+
     context('when the sender is not the governor', () => {
       const from = someone
 

test/court/controller/controller-modules.js

@@ -9,11 +9,11 @@ const Controlled = artifacts.require('Controlled')
 
 const ZERO_ADDRESS = '0x0000000000000000000000000000000000000000'
 
-contract('Controller', ([_, fundsGovernor, configGovernor, modulesGovernor, someone]) => {
+contract('Controller', ([_, fundsGovernor, configGovernor, feesUpdater, modulesGovernor, someone]) => {
   let controller
 
   beforeEach('create controller', async () => {
-    controller = await buildHelper().deploy({ fundsGovernor, configGovernor, modulesGovernor })
+    controller = await buildHelper().deploy({ fundsGovernor, configGovernor, feesUpdater, modulesGovernor })
   })
 
   describe('getFundsGovernor', () => {
@@ -28,6 +28,12 @@ contract('Controller', ([_, fundsGovernor, configGovernor, modulesGovernor, some
     })
   })
 
+  describe('getFeesUpdater', () => {
+    it('tells the fees updater', async () => {
+      assert.equal(await controller.getFeesUpdater(), feesUpdater, 'fees updater does not match')
+    })
+  })
+
   describe('getModulesGovernor', () => {
     it('tells the expected governor', async () => {
       assert.equal(await controller.getModulesGovernor(), modulesGovernor, 'modules governor does not match')
@@ -118,6 +124,37 @@ contract('Controller', ([_, fundsGovernor, configGovernor, modulesGovernor, some
     })
   })
 
+  describe('changeFeesUpdater', () => {
+    context('when the sender is the config governor', () => {
+      const from = configGovernor
+      const newFeesUpdater = someone
+
+      it('changes the fee updater', async () => {
+        await controller.changeFeesUpdater(newFeesUpdater, { from })
+
+        assert.equal(await controller.getFeesUpdater(), newFeesUpdater, 'fees updater does not match')
+      })
+
+      it('emits an event', async () => {
+        const receipt = await controller.changeFeesUpdater(newFeesUpdater, { from })
+
+        assertAmountOfEvents(receipt, 'FeesUpdaterChanged')
+        assertEvent(receipt, 'FeesUpdaterChanged', {
+          previousFeesUpdater: feesUpdater,
+          currentFeesUpdater: newFeesUpdater
+        })
+      })
+    })
+
+    context('when the sender is not the config governor', () => {
+      const from = feesUpdater
+
+      it('reverts', async () => {
+        await assertRevert(controller.changeFeesUpdater(someone, { from }), CONTROLLER_ERRORS.SENDER_NOT_GOVERNOR)
+      })
+    })
+  })
+
   describe('changeModulesGovernor', () => {
     context('when the sender is the modules governor', () => {
       const from = modulesGovernor