// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;
pragma experimental ABIEncoderV2;

import {SafeMath} from '../../dependencies/openzeppelin/contracts/SafeMath.sol';
import {VersionedInitializable} from '../../tools/upgradeability/VersionedInitializable.sol';
import {IProxy} from '../../tools/upgradeability/IProxy.sol';
import {ReserveConfiguration} from '../libraries/configuration/ReserveConfiguration.sol';
import {IMarketAccessController} from '../../access/interfaces/IMarketAccessController.sol';
import {MarketAccessBitmask} from '../../access/MarketAccessBitmask.sol';
import {ILendingPool} from '../../interfaces/ILendingPool.sol';
import {IERC20Detailed} from '../../dependencies/openzeppelin/contracts/IERC20Detailed.sol';
import {Errors} from '../libraries/helpers/Errors.sol';
import {PercentageMath} from '../../tools/math/PercentageMath.sol';
import {DataTypes} from '../libraries/types/DataTypes.sol';
import {IInitializablePoolToken} from '../tokenization/interfaces/IInitializablePoolToken.sol';
import {PoolTokenConfig} from '../tokenization/interfaces/PoolTokenConfig.sol';
import {IBalanceHook} from '../../interfaces/IBalanceHook.sol';
import {ILendingPoolConfigurator} from '../../interfaces/ILendingPoolConfigurator.sol';

/**
 * @title LendingPoolConfigurator contract
 * @dev Implements the configuration methods for the protocol
 **/

contract LendingPoolConfigurator is
  VersionedInitializable,
  MarketAccessBitmask,
  ILendingPoolConfigurator
{
  using SafeMath for uint256;
  using PercentageMath for uint256;
  using ReserveConfiguration for DataTypes.ReserveConfigurationMap;

  ILendingPool internal pool;

  uint256 private constant CONFIGURATOR_REVISION = 0x1;

  function getRevision() internal pure virtual override returns (uint256) {
    return CONFIGURATOR_REVISION;
  }

  function initialize(IMarketAccessController provider)
    public
    initializerRunAlways(CONFIGURATOR_REVISION)
  {
    _remoteAcl = provider;
    pool = ILendingPool(provider.getLendingPool());
  }

  /**
   * @dev Initializes reserves in batch
   **/
  function batchInitReserve(InitReserveInput[] calldata input) external onlyPoolAdmin {
    ILendingPool cachedPool = pool;
    for (uint256 i = 0; i < input.length; i++) {
      _initReserve(cachedPool, input[i]);
    }
  }

  function _initReserve(ILendingPool pool_, InitReserveInput calldata input) internal {
    PoolTokenConfig memory config =
      PoolTokenConfig({
        pool: pool_,
        treasury: input.treasury,
        underlyingAsset: input.underlyingAsset
      });

    address aTokenProxyAddress =
      _initTokenWithProxy(
        input.aTokenImpl,
        abi.encodeWithSelector(
          IInitializablePoolToken.initialize.selector,
          config,
          input.aTokenName,
          input.aTokenSymbol,
          input.underlyingAssetDecimals,
          input.params
        )
      );

    address stableDebtTokenProxyAddress =
      _initTokenWithProxy(
        input.stableDebtTokenImpl,
        abi.encodeWithSelector(
          IInitializablePoolToken.initialize.selector,
          config,
          input.stableDebtTokenName,
          input.stableDebtTokenSymbol,
          input.underlyingAssetDecimals,
          input.params
        )
      );

    address variableDebtTokenProxyAddress =
      _initTokenWithProxy(
        input.variableDebtTokenImpl,
        abi.encodeWithSelector(
          IInitializablePoolToken.initialize.selector,
          config,
          input.variableDebtTokenName,
          input.variableDebtTokenSymbol,
          input.underlyingAssetDecimals,
          input.params
        )
      );

    pool.initReserve(
      input.underlyingAsset,
      aTokenProxyAddress,
      stableDebtTokenProxyAddress,
      variableDebtTokenProxyAddress,
      input.interestRateStrategyAddress
    );

    DataTypes.ReserveConfigurationMap memory currentConfig =
      pool.getConfiguration(input.underlyingAsset);

    currentConfig.setDecimals(input.underlyingAssetDecimals);

    currentConfig.setActive(true);
    currentConfig.setFrozen(false);

    pool.setConfiguration(input.underlyingAsset, currentConfig.data);

    emit ReserveInitialized(
      input.underlyingAsset,
      aTokenProxyAddress,
      stableDebtTokenProxyAddress,
      variableDebtTokenProxyAddress,
      input.interestRateStrategyAddress
    );
  }

  /**
   * @dev Updates DepositToken implementation for the reserve
   **/
  function updateDepositToken(UpdateDepositTokenInput calldata input) external onlyPoolAdmin {
    ILendingPool cachedPool = pool;

    DataTypes.ReserveData memory reserveData = cachedPool.getReserveData(input.asset);

    (, , , uint256 decimals, ) = cachedPool.getConfiguration(input.asset).getParamsMemory();

    PoolTokenConfig memory config =
      PoolTokenConfig({pool: cachedPool, treasury: input.treasury, underlyingAsset: input.asset});

    bytes memory encodedCall =
      abi.encodeWithSelector(
        IInitializablePoolToken.initialize.selector,
        config,
        input.name,
        input.symbol,
        decimals,
        input.params
      );

    _upgradeTokenImplementation(reserveData.aTokenAddress, input.implementation, encodedCall);

    emit DepositTokenUpgraded(input.asset, reserveData.aTokenAddress, input.implementation);
  }

  /**
   * @dev Updates the stable debt token implementation for the reserve
   **/
  function updateStableDebtToken(UpdateDebtTokenInput calldata input) external onlyPoolAdmin {
    ILendingPool cachedPool = pool;

    DataTypes.ReserveData memory reserveData = cachedPool.getReserveData(input.asset);

    (, , , uint256 decimals, ) = cachedPool.getConfiguration(input.asset).getParamsMemory();

    PoolTokenConfig memory config =
      PoolTokenConfig({pool: cachedPool, treasury: address(0), underlyingAsset: input.asset});

    bytes memory encodedCall =
      abi.encodeWithSelector(
        IInitializablePoolToken.initialize.selector,
        config,
        input.name,
        input.symbol,
        decimals,
        input.params
      );

    _upgradeTokenImplementation(
      reserveData.stableDebtTokenAddress,
      input.implementation,
      encodedCall
    );

    emit StableDebtTokenUpgraded(
      input.asset,
      reserveData.stableDebtTokenAddress,
      input.implementation
    );
  }

  /**
   * @dev Updates the variable debt token implementation for the asset
   **/
  function updateVariableDebtToken(UpdateDebtTokenInput calldata input) external onlyPoolAdmin {
    ILendingPool cachedPool = pool;

    DataTypes.ReserveData memory reserveData = cachedPool.getReserveData(input.asset);

    (, , , uint256 decimals, ) = cachedPool.getConfiguration(input.asset).getParamsMemory();

    PoolTokenConfig memory config =
      PoolTokenConfig({pool: cachedPool, treasury: address(0), underlyingAsset: input.asset});

    bytes memory encodedCall =
      abi.encodeWithSelector(
        IInitializablePoolToken.initialize.selector,
        config,
        input.name,
        input.symbol,
        decimals,
        input.params
      );

    _upgradeTokenImplementation(
      reserveData.variableDebtTokenAddress,
      input.implementation,
      encodedCall
    );

    emit VariableDebtTokenUpgraded(
      input.asset,
      reserveData.variableDebtTokenAddress,
      input.implementation
    );
  }

  /**
   * @dev Enables borrowing on a reserve
   * @param asset The address of the underlying asset of the reserve
   * @param stableBorrowRateEnabled True if stable borrow rate needs to be enabled by default on this reserve
   **/
  function enableBorrowingOnReserve(address asset, bool stableBorrowRateEnabled)
    external
    onlyPoolAdmin
  {
    DataTypes.ReserveConfigurationMap memory currentConfig = pool.getConfiguration(asset);

    currentConfig.setBorrowingEnabled(true);
    currentConfig.setStableRateBorrowingEnabled(stableBorrowRateEnabled);

    pool.setConfiguration(asset, currentConfig.data);

    emit BorrowingEnabledOnReserve(asset, stableBorrowRateEnabled);
  }

  /**
   * @dev Disables borrowing on a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  function disableBorrowingOnReserve(address asset) external onlyPoolAdmin {
    DataTypes.ReserveConfigurationMap memory currentConfig = pool.getConfiguration(asset);

    currentConfig.setBorrowingEnabled(false);

    pool.setConfiguration(asset, currentConfig.data);
    emit BorrowingDisabledOnReserve(asset);
  }

  /**
   * @dev Configures the reserve collateralization parameters
   * all the values are expressed in percentages with two decimals of precision. A valid value is 10000, which means 100.00%
   * @param asset The address of the underlying asset of the reserve
   * @param ltv The loan to value of the asset when used as collateral
   * @param liquidationThreshold The threshold at which loans using this asset as collateral will be considered undercollateralized
   * @param liquidationBonus The bonus liquidators receive to liquidate this asset. The values is always above 100%. A value of 105%
   * means the liquidator will receive a 5% bonus
   **/
  function configureReserveAsCollateral(
    address asset,
    uint256 ltv,
    uint256 liquidationThreshold,
    uint256 liquidationBonus
  ) external onlyPoolAdmin {
    DataTypes.ReserveConfigurationMap memory currentConfig = pool.getConfiguration(asset);

    //validation of the parameters: the LTV can
    //only be lower or equal than the liquidation threshold
    //(otherwise a loan against the asset would cause instantaneous liquidation)
    require(ltv <= liquidationThreshold, Errors.LPC_INVALID_CONFIGURATION);

    if (liquidationThreshold != 0) {
      //liquidation bonus must be bigger than 100.00%, otherwise the liquidator would receive less
      //collateral than needed to cover the debt
      require(
        liquidationBonus > PercentageMath.PERCENTAGE_FACTOR,
        Errors.LPC_INVALID_CONFIGURATION
      );

      //if threshold * bonus is less than PERCENTAGE_FACTOR, it's guaranteed that at the moment
      //a loan is taken there is enough collateral available to cover the liquidation bonus
      require(
        liquidationThreshold.percentMul(liquidationBonus) <= PercentageMath.PERCENTAGE_FACTOR,
        Errors.LPC_INVALID_CONFIGURATION
      );
    } else {
      require(liquidationBonus == 0, Errors.LPC_INVALID_CONFIGURATION);
      //if the liquidation threshold is being set to 0,
      // the reserve is being disabled as collateral. To do so,
      //we need to ensure no liquidity is deposited
      _checkNoLiquidity(asset);
    }

    currentConfig.setLtv(ltv);
    currentConfig.setLiquidationThreshold(liquidationThreshold);
    currentConfig.setLiquidationBonus(liquidationBonus);

    pool.setConfiguration(asset, currentConfig.data);

    emit CollateralConfigurationChanged(asset, ltv, liquidationThreshold, liquidationBonus);
  }

  /**
   * @dev Enable stable rate borrowing on a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  function enableReserveStableRate(address asset) external onlyPoolAdmin {
    DataTypes.ReserveConfigurationMap memory currentConfig = pool.getConfiguration(asset);

    currentConfig.setStableRateBorrowingEnabled(true);

    pool.setConfiguration(asset, currentConfig.data);

    emit StableRateEnabledOnReserve(asset);
  }

  /**
   * @dev Disable stable rate borrowing on a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  function disableReserveStableRate(address asset) external onlyPoolAdmin {
    DataTypes.ReserveConfigurationMap memory currentConfig = pool.getConfiguration(asset);

    currentConfig.setStableRateBorrowingEnabled(false);

    pool.setConfiguration(asset, currentConfig.data);

    emit StableRateDisabledOnReserve(asset);
  }

  /**
   * @dev Activates a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  function activateReserve(address asset) external onlyPoolAdmin {
    DataTypes.ReserveConfigurationMap memory currentConfig = pool.getConfiguration(asset);

    currentConfig.setActive(true);

    pool.setConfiguration(asset, currentConfig.data);

    emit ReserveActivated(asset);
  }

  /**
   * @dev Deactivates a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  function deactivateReserve(address asset) external onlyPoolAdmin {
    _checkNoLiquidity(asset);

    DataTypes.ReserveConfigurationMap memory currentConfig = pool.getConfiguration(asset);

    currentConfig.setActive(false);

    pool.setConfiguration(asset, currentConfig.data);

    emit ReserveDeactivated(asset);
  }

  /**
   * @dev Freezes a reserve. A frozen reserve doesn't allow any new deposit, borrow or rate swap
   *  but allows repayments, liquidations, rate rebalances and withdrawals
   * @param asset The address of the underlying asset of the reserve
   **/
  function freezeReserve(address asset) external onlyPoolAdmin {
    DataTypes.ReserveConfigurationMap memory currentConfig = pool.getConfiguration(asset);

    currentConfig.setFrozen(true);

    pool.setConfiguration(asset, currentConfig.data);

    emit ReserveFrozen(asset);
  }

  /**
   * @dev Unfreezes a reserve
   * @param asset The address of the underlying asset of the reserve
   **/
  function unfreezeReserve(address asset) external onlyPoolAdmin {
    DataTypes.ReserveConfigurationMap memory currentConfig = pool.getConfiguration(asset);

    currentConfig.setFrozen(false);

    pool.setConfiguration(asset, currentConfig.data);

    emit ReserveUnfrozen(asset);
  }

  /**
   * @dev Updates the reserve factor of a reserve
   * @param asset The address of the underlying asset of the reserve
   * @param reserveFactor The new reserve factor of the reserve
   **/
  function setReserveFactor(address asset, uint256 reserveFactor) external onlyPoolAdmin {
    DataTypes.ReserveConfigurationMap memory currentConfig = pool.getConfiguration(asset);

    currentConfig.setReserveFactor(reserveFactor);

    pool.setConfiguration(asset, currentConfig.data);

    emit ReserveFactorChanged(asset, reserveFactor);
  }

  /**
   * @dev Sets the interest rate strategy of a reserve
   * @param asset The address of the underlying asset of the reserve
   * @param rateStrategyAddress The new address of the interest strategy contract
   **/
  function setReserveInterestRateStrategyAddress(address asset, address rateStrategyAddress)
    external
    onlyPoolAdmin
  {
    pool.setReserveInterestRateStrategyAddress(asset, rateStrategyAddress);
    emit ReserveInterestRateStrategyChanged(asset, rateStrategyAddress);
  }

  /**
   * @dev pauses or unpauses all the actions of the protocol, including aToken transfers. Deprecated, call the pool directly. Used by tests.
   * @param val true if protocol needs to be paused, false otherwise
   **/
  function setPoolPause(bool val) external onlyEmergencyAdmin {
    pool.setPaused(val);
  }

  function _initTokenWithProxy(address impl, bytes memory initParams) internal returns (address) {
    return address(_remoteAcl.createProxy(address(this), impl, initParams));
  }

  function _upgradeTokenImplementation(
    address proxyAddress,
    address implementation,
    bytes memory initParams
  ) internal {
    IProxy(proxyAddress).upgradeToAndCall(implementation, initParams);
  }

  function _checkNoLiquidity(address asset) internal view {
    DataTypes.ReserveData memory reserveData = pool.getReserveData(asset);

    uint256 availableLiquidity = IERC20Detailed(asset).balanceOf(reserveData.aTokenAddress);

    require(
      availableLiquidity == 0 && reserveData.currentLiquidityRate == 0,
      Errors.LPC_RESERVE_LIQUIDITY_NOT_0
    );
  }
}