// SPDX-License-Identifier: MIT
// File @openzeppelin/contracts/utils/Context.sol@v4.1.0
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) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

// File @openzeppelin/contracts/access/Ownable.sol@v4.1.0

pragma solidity ^0.8.0;

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File contracts/interfaces/IOracle.sol

pragma solidity 0.8.4;
pragma experimental ABIEncoderV2;

interface IOracle {
    function consult() external view returns (uint256);
}

// File contracts/interfaces/IPairOracle.sol

pragma solidity 0.8.4;

interface IPairOracle {
    function consult(address token, uint256 amountIn) external view returns (uint256 amountOut);

    function update() external;
}

// File contracts/oracle/DollarOracle.sol

pragma solidity 0.8.4;

contract DollarOracle is Ownable, IOracle {
    address public oracleDollarToken;
    address public oracleToken;
    address public dollar;

    uint256 private constant PRICE_PRECISION = 1e6;

    constructor(
        address _dollar,
        address _oracleDollarToken,
        address _oracleToken
    ) {
        dollar = _dollar;
        oracleDollarToken = _oracleDollarToken;
        oracleToken = _oracleToken;
    }

    function consult() external view override returns (uint256) {
        uint256 _priceDollarToToken = IPairOracle(oracleDollarToken).consult(dollar, PRICE_PRECISION);
        uint256 _priceTokenToUsd = IOracle(oracleToken).consult();
        return _priceDollarToToken * _priceTokenToUsd / PRICE_PRECISION;
    }

    function setOracleDollarToken(address _oracleDollarToken) external onlyOwner {
        oracleDollarToken = _oracleDollarToken;
    }

    function setOracleToken(address _oracleToken) external onlyOwner {
        oracleToken = _oracleToken;
    }
    
}