// File: contracts/risk/CoverageDataProvider.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity 0.8.6;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

import "../interfaces/risk/ICoverageDataProvider.sol";
import "../interfaces/utils/IRegistry.sol";
import "../interfaces/ISOLACE.sol";
import "../interfaces/utils/Aave/IAavePriceOracle.sol";
import "../interfaces/utils/Sushiswap/ISushiswapLPToken.sol";
import "../utils/Governable.sol";

/**
 * @title  CoverageDataProvider
 * @author solace.fi
 * @notice Holds underwriting pool amounts in `USD`. Provides information to the [**Risk Manager**](./RiskManager.sol) that is the maximum amount of cover that `Solace` protocol can sell as a coverage.
*/
contract CoverageDataProvider is ICoverageDataProvider, Governable {

    /***************************************
     STATE VARIABLES
    ***************************************/

    /// @notice The balance of underwriting pool in usd.
    mapping(string => uint256) private _uwpBalanceOf;

    /// @notice The index to underwriting pool.
    mapping(uint256 => string) private _indexToUwp;

    /// @notice The underwriting pool to index.
    mapping(string => uint256) private _uwpToIndex;

    /// @notice The underwriting pool count
    uint256 public numOfPools;

    /// @notice The pool updater.
    address private _uwpUpdater;

    modifier canUpdate() {
      require(msg.sender == super.governance() || msg.sender == _uwpUpdater, "!governance");
      _;
    }

    /**
     * @notice Constructs the `CoverageDataProvider` contract.
     * @param governance The address of the [governor](/docs/protocol/governance).
    */
    // solhint-disable-next-line no-empty-blocks
    constructor(address governance) Governable(governance) {}

    /***************************************
     MUTUATOR FUNCTIONS
    ***************************************/
   
    /**
      * @notice Resets the underwriting pool balances.
      * @param uwpNames The underwriting pool values to set.
      * @param amounts The underwriting pool balances in `USD`.
    */
    function reset(string[] calldata uwpNames, uint256[] calldata amounts) external override canUpdate {
      require(uwpNames.length == amounts.length, "length mismatch");
      // delete current underwriting pools
      uint256 poolCount = numOfPools;
      for (uint256 i = poolCount; i > 0; i--) {
        string memory uwpName = _indexToUwp[i];
        delete _uwpToIndex[uwpName];
        delete _indexToUwp[i];
        delete _uwpBalanceOf[uwpName];
        emit UnderwritingPoolRemoved(uwpName);
      }

      // set new underwriting pools
      numOfPools = 0;
      for (uint256 i = 0; i < uwpNames.length; i++) {
        set(uwpNames[i], amounts[i]);
      }
    }

    /**
     * @notice Sets the balance of the given underwriting pool.
     * @param uwpName The underwriting pool name to set balance.
     * @param amount The balance of the underwriting pool in `USD`.
    */
    function set(string calldata uwpName, uint256 amount) public override canUpdate {
      require(bytes(uwpName).length > 0, "empty underwriting pool name");
     
      _uwpBalanceOf[uwpName] = amount;
      if (_uwpToIndex[uwpName] == 0) {
        uint256 index = numOfPools;
        _uwpToIndex[uwpName] = ++index;
        _indexToUwp[index] = uwpName;
        numOfPools = index;
      }
      emit UnderwritingPoolSet(uwpName, amount);
    }

    /**
     * @notice Removes the given underwriting pool.
     * @param uwpName The underwriting pool name to remove.
    */
    function remove(string calldata uwpName) external override canUpdate {
      uint256 index = _uwpToIndex[uwpName];
      if (index == 0) return;

      uint256 poolCount = numOfPools;
      if (poolCount == 0) return;

      if (index != poolCount) {
        string memory lastPool = _indexToUwp[poolCount];
        _uwpToIndex[lastPool] = index;
        _indexToUwp[index] = lastPool;
      }

      delete _uwpToIndex[uwpName];
      delete _indexToUwp[poolCount];
      delete _uwpBalanceOf[uwpName];
      numOfPools -= 1;
      emit UnderwritingPoolRemoved(uwpName);
    }

    /***************************************
     VIEW FUNCTIONS
    ***************************************/

    /**
     * @notice Returns the maximum amount of cover in `USD` that Solace as a whole can sell.
     * @return cover The max amount of cover in `USD`.
    */
    function maxCover() external view override returns (uint256 cover) {
      // get pool balance
      uint256 pools = numOfPools;
      for (uint256 i = pools; i > 0; i--) {
        cover += balanceOf(_indexToUwp[i]);
      }
    }
   
    /**
     * @notice Returns the balance of the underwriting pool in `USD`.
     * @param uwpName The underwriting pool name to get balance.
     * @return amount The balance of the underwriting pool in `USD`.
    */
    function balanceOf(string memory uwpName) public view override returns (uint256 amount) {
      return _uwpBalanceOf[uwpName];
    }

    /**
     * @notice Returns underwriting pool name for given index.
     * @param index The underwriting pool index to get.
     * @return uwpName The underwriting pool name.
    */
    function poolOf(uint256 index) external view override returns (string memory uwpName) {
      return _indexToUwp[index];
    }

    /**
     * @notice Returns the underwriting pool bot updater address.
     * @return uwpUpdater The bot address.
    */
    function getUwpUpdater() external view override returns (address uwpUpdater) {
      return _uwpUpdater;
    }

    /***************************************
     GOVERNANCE FUNCTIONS
    ***************************************/
    
    /**
     * @notice Sets the underwriting pool bot updater.
     * @param uwpUpdater The bot address to set.
    */
    function setUwpUpdater(address uwpUpdater) external override onlyGovernance {
      require(uwpUpdater != address(0x0), "zero address uwp updater");
      _uwpUpdater = uwpUpdater;
      emit UwpUpdaterSet(uwpUpdater);
    }
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        unchecked {
            _approve(sender, _msgSender(), currentAllowance - amount);
        }

        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(_msgSender(), spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[sender] = senderBalance - amount;
        }
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);

        _afterTokenTransfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

// File: contracts/interfaces/risk/ICoverageDataProvider.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity 0.8.6;

/**
 * @title ICoverageDataProvider
 * @author solace.fi
 * @notice Holds underwriting pool amounts in `USD`. Provides information to the [**Risk Manager**](./RiskManager.sol) that is the maximum amount of cover that `Solace` protocol can sell as a coverage.
*/
interface ICoverageDataProvider {
    /***************************************
     EVENTS
    ***************************************/

    /// @notice Emitted when the underwriting pool is set.
    event UnderwritingPoolSet(string uwpName, uint256 amount);

    /// @notice Emitted when underwriting pool is removed.
    event UnderwritingPoolRemoved(string uwpName);

    /// @notice Emitted when underwriting pool updater is set.
    event UwpUpdaterSet(address uwpUpdater);

    /***************************************
     MUTUATOR FUNCTIONS
    ***************************************/

    /**
      * @notice Resets the underwriting pool balances.
      * @param uwpNames The underwriting pool values to set.
      * @param amounts The underwriting pool balances.
    */
    function reset(string[] calldata uwpNames, uint256[] calldata amounts) external;

    /**
     * @notice Sets the balance of the given underwriting pool.
     * @param uwpName The underwriting pool name to set balance.
     * @param amount The balance of the underwriting pool in `USD`.
    */
    function set(string calldata uwpName, uint256 amount) external;

    /**
     * @notice Removes the given underwriting pool.
     * @param uwpName The underwriting pool name to remove.
    */
    function remove(string calldata uwpName) external;

    /***************************************
     VIEW FUNCTIONS
    ***************************************/

    /**
     * @notice The maximum amount of cover in `USD` that Solace as a whole can sell.
     * @return cover The max amount of cover in `USD`.
    */
    function maxCover() external view returns (uint256 cover);

    /**
     * @notice Returns the balance of the underwriting pool in `USD`.
     * @param uwpName The underwriting pool name to get balance.
     * @return amount The balance of the underwriting pool in `USD`.
    */
    function balanceOf(string memory uwpName) external view returns (uint256 amount); 

    /**
     * @notice Returns underwriting pool name for given index.
     * @param index The underwriting pool index to get.
     * @return uwpName The underwriting pool name.
    */
    function poolOf(uint256 index) external view returns (string memory uwpName);

    /**
     * @notice Returns the underwriting pool bot updater address.
     * @return uwpUpdater The bot address.
    */
    function getUwpUpdater() external view returns (address uwpUpdater);

    /***************************************
     GOVERNANCE FUNCTIONS
    ***************************************/
    
    /**
     * @notice Sets the underwriting pool bot updater.
     * @param uwpUpdater The bot address to set.
    */
    function setUwpUpdater(address uwpUpdater) external;
}

// File: contracts/interfaces/utils/IRegistry.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity 0.8.6;


/**
 * @title IRegistry
 * @author solace.fi
 * @notice Tracks the contracts of the Solaverse.
 *
 * [**Governance**](/docs/protocol/governance) can set the contract addresses and anyone can look them up.
 *
 * A key is a unique identifier for each contract. Use [`get(key)`](#get) or [`tryGet(key)`](#tryget) to get the address of the contract. Enumerate the keys with [`length()`](#length) and [`getKey(index)`](#getkey).
 */
interface IRegistry {

    /***************************************
    EVENTS
    ***************************************/

    /// @notice Emitted when a record is set.
    event RecordSet(string indexed key, address indexed value);

    /***************************************
    VIEW FUNCTIONS
    ***************************************/

    /// @notice The number of unique keys.
    function length() external view returns (uint256);

    /**
     * @notice Gets the `value` of a given `key`.
     * Reverts if the key is not in the mapping.
     * @param key The key to query.
     * @param value The value of the key.
     */
    function get(string calldata key) external view returns (address value);

    /**
     * @notice Gets the `value` of a given `key`.
     * Fails gracefully if the key is not in the mapping.
     * @param key The key to query.
     * @param success True if the key was found, false otherwise.
     * @param value The value of the key or zero if it was not found.
     */
    function tryGet(string calldata key) external view returns (bool success, address value);

    /**
     * @notice Gets the `key` of a given `index`.
     * @dev Iterable [1,length].
     * @param index The index to query.
     * @return key The key at that index.
     */
    function getKey(uint256 index) external view returns (string memory key);

    /***************************************
    GOVERNANCE FUNCTIONS
    ***************************************/

    /**
     * @notice Sets keys and values.
     * Can only be called by the current [**governor**](/docs/protocol/governance).
     * @param keys The keys to set.
     * @param values The values to set.
     */
    function set(string[] calldata keys, address[] calldata values) external;
}

// File: contracts/interfaces/ISOLACE.sol



// SPDX-License-Identifier: GPL-3.0-or-later

pragma solidity 0.8.6;

import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";

/**
 * @title Solace Token (SOLACE)
 * @author solace.fi
 * @notice The native governance token of the Solace Coverage Protocol.
 */
interface ISOLACE is IERC20Metadata {

    /***************************************
    EVENTS
    ***************************************/

    /// @notice Emitted when a minter is added.
    event MinterAdded(address indexed minter);
    /// @notice Emitted when a minter is removed.
    event MinterRemoved(address indexed minter);

    /***************************************
    MINT FUNCTIONS
    ***************************************/

    /**
     * @notice Returns true if `account` is authorized to mint [**SOLACE**](../SOLACE).
     * @param account Account to query.
     * @return status True if `account` can mint, false otherwise.
     */
    function isMinter(address account) external view returns (bool status);

    /**
     * @notice Mints new [**SOLACE**](../SOLACE) to the receiver account.
     * Can only be called by authorized minters.
     * @param account The receiver of new tokens.
     * @param amount The number of new tokens.
     */
    function mint(address account, uint256 amount) external;

    /**
     * @notice Burns [**SOLACE**](../SOLACE) from msg.sender.
     * @param amount Amount to burn.
     */
    function burn(uint256 amount) external;

    /**
     * @notice Adds a new minter.
     * Can only be called by the current [**governor**](/docs/protocol/governance).
     * @param minter The new minter.
     */
    function addMinter(address minter) external;

    /**
     * @notice Removes a minter.
     * Can only be called by the current [**governor**](/docs/protocol/governance).
     * @param minter The minter to remove.
     */
    function removeMinter(address minter) external;
}

// File: contracts/interfaces/utils/Aave/IAavePriceOracle.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity 0.8.6;

/**
 * @title IAavePriceOracle
 * @author solace.fi
 * @notice The smart contract that returns the asset prices in `ETH`.
*/
interface IAavePriceOracle {
    function getAssetPrice(address _asset) external view returns (uint256);
}
// File: contracts/interfaces/utils/Sushiswap/ISushiswapLPToken.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity 0.8.6;

interface ISushiswapLPToken {
 
  /**
   * @notice Returns the address of `SushiFactory`.
   * @return factory The address of the factory.
   */
  function factory() external view returns (address factory);
  
  /**
   * @notice Returns the first pair token.
   * @return token The address of the first pair token.
   */
  function token0() external view returns (address token);

  /**
   * @notice Returns the second pair token.
   * @return token The address of the second pair token.
   */
  function token1() external view returns (address token);

  /**
   * @notice Returns the symbol of the token.
   * @return symbol The token symbol.
   */
  function symbol() external view returns (string memory symbol);

  /**
   * @notice Returns the name of the token.
   * @return name The token name.
   */
  function name() external view returns (string memory name);

  /**
   * @notice Returns total token supply.
   * @return totalSupply The total supply.
   */
  function totalSupply() external view returns (uint256 totalSupply);

  /**
   * @notice Returns account's balance.
   * @param account The address of the user.
   * @return balance The amount tokens user have.
   */
  function balanceOf(address account) external view returns (uint256 balance);

  /**
  * @notice Returns the decimals value.
  * @return decimals The decimals value.
  */
  function decimals() external view returns (uint256);

  /**
   * @notice Returns LP token reserves.
   * @return _reserve0
   * @return _reserve1
   * @return _blockTimestampLast 
  */
  function getReserves() external view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast);
}
// File: contracts/utils/Governable.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity 0.8.6;

import "./../interfaces/utils/IGovernable.sol";

/**
 * @title Governable
 * @author solace.fi
 * @notice Enforces access control for important functions to [**governor**](/docs/protocol/governance).
 *
 * Many contracts contain functionality that should only be accessible to a privileged user. The most common access control pattern is [OpenZeppelin's `Ownable`](https://docs.openzeppelin.com/contracts/4.x/access-control#ownership-and-ownable). We instead use `Governable` with a few key differences:
   * - Transferring the governance role is a two step process. The current governance must [`setPendingGovernance(pendingGovernance_)`](#setpendinggovernance) then the new governance must [`acceptGovernance()`](#acceptgovernance). This is to safeguard against accidentally setting ownership to the wrong address and locking yourself out of your contract.
 * - `governance` is a constructor argument instead of `msg.sender`. This is especially useful when deploying contracts via a [`SingletonFactory`](./../interfaces/utils/ISingletonFactory).
 * - We use `lockGovernance()` instead of `renounceOwnership()`. `renounceOwnership()` is a prerequisite for the reinitialization bug because it sets `owner = address(0x0)`. We also use the `governanceIsLocked()` flag.
 */
contract Governable is IGovernable {

    /***************************************
    GLOBAL VARIABLES
    ***************************************/

    // Governor.
    address private _governance;

    // governance to take over.
    address private _pendingGovernance;

    bool private _locked;

    /**
     * @notice Constructs the governable contract.
     * @param governance_ The address of the [governor](/docs/protocol/governance).
     */
    constructor(address governance_) {
        require(governance_ != address(0x0), "zero address governance");
        _governance = governance_;
        _pendingGovernance = address(0x0);
        _locked = false;
    }

    /***************************************
    MODIFIERS
    ***************************************/

    // can only be called by governor
    // can only be called while unlocked
    modifier onlyGovernance() {
        require(!_locked, "governance locked");
        require(msg.sender == _governance, "!governance");
        _;
    }

    // can only be called by pending governor
    // can only be called while unlocked
    modifier onlyPendingGovernance() {
        require(!_locked, "governance locked");
        require(msg.sender == _pendingGovernance, "!pending governance");
        _;
    }

    /***************************************
    VIEW FUNCTIONS
    ***************************************/

    /// @notice Address of the current governor.
    function governance() public view override returns (address) {
        return _governance;
    }

    /// @notice Address of the governor to take over.
    function pendingGovernance() external view override returns (address) {
        return _pendingGovernance;
    }

    /// @notice Returns true if governance is locked.
    function governanceIsLocked() external view override returns (bool) {
        return _locked;
    }

    /***************************************
    MUTATOR FUNCTIONS
    ***************************************/

    /**
     * @notice Initiates transfer of the governance role to a new governor.
     * Transfer is not complete until the new governor accepts the role.
     * Can only be called by the current [**governor**](/docs/protocol/governance).
     * @param pendingGovernance_ The new governor.
     */
    function setPendingGovernance(address pendingGovernance_) external override onlyGovernance {
        _pendingGovernance = pendingGovernance_;
        emit GovernancePending(pendingGovernance_);
    }

    /**
     * @notice Accepts the governance role.
     * Can only be called by the pending governor.
     */
    function acceptGovernance() external override onlyPendingGovernance {
        // sanity check against transferring governance to the zero address
        // if someone figures out how to sign transactions from the zero address
        // consider the entirety of ethereum to be rekt
        require(_pendingGovernance != address(0x0), "zero governance");
        address oldGovernance = _governance;
        _governance = _pendingGovernance;
        _pendingGovernance = address(0x0);
        emit GovernanceTransferred(oldGovernance, _governance);
    }

    /**
     * @notice Permanently locks this contract's governance role and any of its functions that require the role.
     * This action cannot be reversed.
     * Before you call it, ask yourself:
     *   - Is the contract self-sustaining?
     *   - Is there a chance you will need governance privileges in the future?
     * Can only be called by the current [**governor**](/docs/protocol/governance).
     */
    function lockGovernance() external override onlyGovernance {
        _locked = true;
        // intentionally not using address(0x0), see re-initialization exploit
        _governance = address(0xFFfFfFffFFfffFFfFFfFFFFFffFFFffffFfFFFfF);
        _pendingGovernance = address(0xFFfFfFffFFfffFFfFFfFFFFFffFFFffffFfFFFfF);
        emit GovernanceTransferred(msg.sender, address(0xFFfFfFffFFfffFFfFFfFFFFFffFFFffffFfFFFfF));
        emit GovernanceLocked();
    }
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: contracts/interfaces/utils/IGovernable.sol



// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity 0.8.6;

/**
 * @title IGovernable
 * @author solace.fi
 * @notice Enforces access control for important functions to [**governor**](/docs/protocol/governance).
 *
 * Many contracts contain functionality that should only be accessible to a privileged user. The most common access control pattern is [OpenZeppelin's `Ownable`](https://docs.openzeppelin.com/contracts/4.x/access-control#ownership-and-ownable). We instead use `Governable` with a few key differences:
 * - Transferring the governance role is a two step process. The current governance must [`setPendingGovernance(pendingGovernance_)`](#setpendinggovernance) then the new governance must [`acceptGovernance()`](#acceptgovernance). This is to safeguard against accidentally setting ownership to the wrong address and locking yourself out of your contract.
 * - `governance` is a constructor argument instead of `msg.sender`. This is especially useful when deploying contracts via a [`SingletonFactory`](./ISingletonFactory).
 * - We use `lockGovernance()` instead of `renounceOwnership()`. `renounceOwnership()` is a prerequisite for the reinitialization bug because it sets `owner = address(0x0)`. We also use the `governanceIsLocked()` flag.
 */
interface IGovernable {

    /***************************************
    EVENTS
    ***************************************/

    /// @notice Emitted when pending Governance is set.
    event GovernancePending(address pendingGovernance);
    /// @notice Emitted when Governance is set.
    event GovernanceTransferred(address oldGovernance, address newGovernance);
    /// @notice Emitted when Governance is locked.
    event GovernanceLocked();

    /***************************************
    VIEW FUNCTIONS
    ***************************************/

    /// @notice Address of the current governor.
    function governance() external view returns (address);

    /// @notice Address of the governor to take over.
    function pendingGovernance() external view returns (address);

    /// @notice Returns true if governance is locked.
    function governanceIsLocked() external view returns (bool);

    /***************************************
    MUTATORS
    ***************************************/

    /**
     * @notice Initiates transfer of the governance role to a new governor.
     * Transfer is not complete until the new governor accepts the role.
     * Can only be called by the current [**governor**](/docs/protocol/governance).
     * @param pendingGovernance_ The new governor.
     */
    function setPendingGovernance(address pendingGovernance_) external;

    /**
     * @notice Accepts the governance role.
     * Can only be called by the new governor.
     */
    function acceptGovernance() external;

    /**
     * @notice Permanently locks this contract's governance role and any of its functions that require the role.
     * This action cannot be reversed.
     * Before you call it, ask yourself:
     *   - Is the contract self-sustaining?
     *   - Is there a chance you will need governance privileges in the future?
     * Can only be called by the current [**governor**](/docs/protocol/governance).
     */
    function lockGovernance() external;
}