// SPDX-License-Identifier: AGPL-3.0

pragma solidity ^0.8.11;

import "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";

library PriceConverter {
    function getDerivedPrice(
        address _base,
        address _quote,
        uint8 _decimals
    ) public view returns (int256) {
        require(
            _decimals > uint8(0) && _decimals <= uint8(18),
            "Invalid _decimals"
        );
        int256 decimals = int256(10**uint256(_decimals));
        (, int256 basePrice, , , ) = AggregatorV3Interface(_base)
            .latestRoundData();
        uint8 baseDecimals = AggregatorV3Interface(_base).decimals();
        basePrice = scalePrice(basePrice, baseDecimals, _decimals);

        (, int256 quotePrice, , , ) = AggregatorV3Interface(_quote)
            .latestRoundData();
        uint8 quoteDecimals = AggregatorV3Interface(_quote).decimals();
        quotePrice = scalePrice(quotePrice, quoteDecimals, _decimals);

        return (basePrice * decimals) / quotePrice;
    }

    function scalePrice(
        int256 _price,
        uint8 _priceDecimals,
        uint8 _decimals
    ) internal pure returns (int256) {
        if (_priceDecimals < _decimals) {
            return _price * int256(10**uint256(_decimals - _priceDecimals));
        } else if (_priceDecimals > _decimals) {
            return _price / int256(10**uint256(_priceDecimals - _decimals));
        }
        return _price;
    }
}