// SPDX-License-Identifier: MIT

pragma solidity 0.8.19;
import "../interfaces/IPropelBase.sol";

/*
 * Base contract for TroveManager, BorrowerOperations and StabilityPool. Contains global system constants and
 * common functions.
 */
contract PropelBase is IPropelBase {
	uint256 public constant override DECIMAL_PRECISION = 1e18;

	// Critical system collateral ratio. If the system's total collateral ratio (TCR) falls below the CCR, Recovery Mode is triggered.
	uint256 public constant override CCR = 1500000000000000000; // 150%

	// Amount of debt to be locked in gas pool on opening troves
	uint256 public immutable override DEBT_GAS_COMPENSATION;

	uint256 public constant override PERCENT_DIVISOR = 200; // dividing by 200 yields 0.5%

	constructor(uint256 _gasCompensation) {
		DEBT_GAS_COMPENSATION = _gasCompensation;
	}

	// --- Gas compensation functions ---

	// Returns the composite debt (drawn debt + gas compensation) of a trove, for the purpose of ICR calculation
	function _getCompositeDebt(uint256 _debt) internal view returns (uint256) {
		return _debt + DEBT_GAS_COMPENSATION;
	}

	function _getNetDebt(uint256 _debt) internal view returns (uint256) {
		return _debt - DEBT_GAS_COMPENSATION;
	}

	// Return the amount of collateral to be drawn from a trove's collateral and sent as gas compensation.
	function _getCollGasCompensation(uint256 _entireColl) internal pure returns (uint256) {
		return _entireColl / PERCENT_DIVISOR;
	}

	function _requireUserAcceptsFee(uint256 _fee, uint256 _amount, uint256 _maxFeePercentage) internal pure {
		uint256 feePercentage = (_fee * DECIMAL_PRECISION) / _amount;
		require(feePercentage <= _maxFeePercentage, "Fee exceeded provided maximum");
	}
}