// File: ./contracts/global/SynthRegistryV2.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.5.16;
pragma experimental ABIEncoderV2;

import {Ownable} from "../lib/Ownable.sol";

import {ISyntheticToken} from "../token/ISyntheticToken.sol";
import {IERC20} from "../token/IERC20.sol";

contract SynthRegistryV2 is Ownable {

    // Available Synths which can be used with the system
    address[] public availableSynths;

    // Synth address (proxy) to synthetic token
    mapping(address => address) public synths;

    /* ========== Events ========== */

    event SynthAdded(address proxy, address synth);
    event SynthRemoved(address proxy, address synth);

    /* ========== View Functions ========== */

    function getAllSynths()
        public
        view
        returns (address[] memory)
    {
        return availableSynths;
    }

    /* ========== Mutative Functions ========== */

    /**
     * @dev Add a new synth to the registry.
     *
     * @param core The address of the core proxy contract
     * @param synthetic The address of the synthetic token proxy address
     */
    function addSynth(
        address core,
        address synthetic
    )
        external
        onlyOwner
    {
        require(
            synths[core] == address(0),
            "Synth already exists"
        );

        availableSynths.push(synthetic);
        synths[core] = synthetic;

        emit SynthAdded(core, synthetic);
    }


    /**
     * @dev Remove a new synth from registry.
     *
     * @param core The address of the core proxy contract
     */
    function removeSynth(
        address core
    )
        external
        onlyOwner
    {
        require(
            address(synths[core]) != address(0),
            "Synth does not exist"
        );

        // Save the address we're removing for emitting the event at the end.
        address syntheticToRemove = synths[core];

        // Remove the synth from the availableSynths array.
        for (uint i = 0; i < availableSynths.length; i++) {
            if (address(availableSynths[i]) == core) {
                delete availableSynths[i];
                availableSynths[i] = availableSynths[availableSynths.length - 1];
                availableSynths.length--;

                break;
            }
        }

        // And remove it from the synths mapping
        delete synths[core];

        emit SynthRemoved(core, syntheticToRemove);
    }
}

// File: ./contracts/lib/Ownable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.5.16;

/**
 * @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.
 */
contract Ownable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () internal {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), msg.sender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == msg.sender, "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 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 onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// File: ./contracts/token/ISyntheticToken.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.5.16;
pragma experimental ABIEncoderV2;

import {Amount} from "../lib/Amount.sol";

interface ISyntheticToken {

    function symbolKey()
        external
        view
        returns (bytes32);

    function mint(
        address to,
        uint256 value
    )
        external;

    function burn(
        address to,
        uint256 value
    )
        external;

    function transferCollateral(
        address token,
        address to,
        uint256 value
    )
        external
        returns (bool);

    function getMinterIssued(
        address _minter
    )
        external
        view
        returns (Amount.Principal memory);

    function getMinterLimit(
        address _minter
    )
        external
        view
        returns (uint256);

}

// File: ./contracts/lib/Amount.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.5.16;
pragma experimental ABIEncoderV2;

import {SafeMath} from "../lib/SafeMath.sol";
import {Math} from "../lib/Math.sol";

library Amount {

    using Math for uint256;
    using SafeMath for uint256;

    // ============ Constants ============

    uint256 constant BASE = 10**18;

    // A Principal Amount is an amount that's been adjusted by an index

    struct Principal {
        bool sign; // true if positive
        uint256 value;
    }

    function zero()
        internal
        pure
        returns (Principal memory)
    {
        return Principal({
            sign: false,
            value: 0
        });
    }

    function sub(
        Principal memory a,
        Principal memory b
    )
        internal
        pure
        returns (Principal memory)
    {
        return add(a, negative(b));
    }

    function add(
        Principal memory a,
        Principal memory b
    )
        internal
        pure
        returns (Principal memory)
    {
        Principal memory result;

        if (a.sign == b.sign) {
            result.sign = a.sign;
            result.value = SafeMath.add(a.value, b.value);
        } else {
            if (a.value >= b.value) {
                result.sign = a.sign;
                result.value = SafeMath.sub(a.value, b.value);
            } else {
                result.sign = b.sign;
                result.value = SafeMath.sub(b.value, a.value);
            }
        }
        return result;
    }

    function equals(
        Principal memory a,
        Principal memory b
    )
        internal
        pure
        returns (bool)
    {
        if (a.value == b.value) {
            if (a.value == 0) {
                return true;
            }
            return a.sign == b.sign;
        }
        return false;
    }

    function negative(
        Principal memory a
    )
        internal
        pure
        returns (Principal memory)
    {
        return Principal({
            sign: !a.sign,
            value: a.value
        });
    }

    function calculateAdjusted(
        Principal memory a,
        uint256 index
    )
        internal
        pure
        returns (uint256)
    {
        return Math.getPartial(a.value, index, BASE);
    }

    function calculatePrincipal(
        uint256 value,
        uint256 index,
        bool sign
    )
        internal
        pure
        returns (Principal memory)
    {
        return Principal({
            sign: sign,
            value: Math.getPartial(value, BASE, index)
        });
    }

}

// File: ./contracts/lib/SafeMath.sol




pragma solidity ^0.5.16;

library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {

        require(b > 0, "SafeMath: division by zero");
        uint256 c = a / b;

        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        uint256 c = a - b;

        return c;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }
}

// File: ./contracts/lib/Math.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.5.16;
pragma experimental ABIEncoderV2;

import {SafeMath} from "./SafeMath.sol";

/**
 * @title Math
 *
 * Library for non-standard Math functions
 */
library Math {
    using SafeMath for uint256;

    // ============ Library Functions ============

    /*
     * Return target * (numerator / denominator).
     */
    function getPartial(
        uint256 target,
        uint256 numerator,
        uint256 denominator
    )
        internal
        pure
        returns (uint256)
    {
        return target.mul(numerator).div(denominator);
    }

    function to128(
        uint256 number
    )
        internal
        pure
        returns (uint128)
    {
        uint128 result = uint128(number);
        require(
            result == number,
            "Math: Unsafe cast to uint128"
        );
        return result;
    }

    function min(
        uint256 a,
        uint256 b
    )
        internal
        pure
        returns (uint256)
    {
        return a < b ? a : b;
    }

    function max(
        uint256 a,
        uint256 b
    )
        internal
        pure
        returns (uint256)
    {
        return a > b ? a : b;
    }
}

// File: ./contracts/token/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.5.16;

/**
 * @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
    );
}