// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./IFYToken.sol";
import "./IOracle.sol";
import "./DataTypes.sol";

interface ICauldron {
    /// @dev Variable rate lending oracle for an underlying
    function lendingOracles(bytes6 baseId) external view returns (IOracle);

    /// @dev An user can own one or more Vaults, with each vault being able to borrow from a single series.
    function vaults(bytes12 vault)
        external
        view
        returns (DataTypes.Vault memory);

    /// @dev Series available in Cauldron.
    function series(bytes6 seriesId)
        external
        view
        returns (DataTypes.Series memory);

    /// @dev Assets available in Cauldron.
    function assets(bytes6 assetsId) external view returns (address);

    /// @dev Each vault records debt and collateral balances_.
    function balances(bytes12 vault)
        external
        view
        returns (DataTypes.Balances memory);


    // @dev Assets that are approved as collateral for a series
    function ilks(bytes6 seriesId, bytes6 assetId)
        external
        view
        returns (bool);

    /// @dev Max, min and sum of debt per underlying and collateral.
    function debt(bytes6 baseId, bytes6 ilkId)
        external
        view
        returns (DataTypes.Debt memory);

    // @dev Spot price oracle addresses and collateralization ratios
    function spotOracles(bytes6 baseId, bytes6 ilkId)
        external
        view
        returns (DataTypes.SpotOracle memory);

    /// @dev Create a new vault, linked to a series (and therefore underlying) and up to 5 collateral types
    function build(
        address owner,
        bytes12 vaultId,
        bytes6 seriesId,
        bytes6 ilkId
    ) external returns (DataTypes.Vault memory);

    /// @dev Destroy an empty vault. Used to recover gas costs.
    function destroy(bytes12 vault) external;

    /// @dev Change a vault series and/or collateral types.
    function tweak(
        bytes12 vaultId,
        bytes6 seriesId,
        bytes6 ilkId
    ) external returns (DataTypes.Vault memory);

    /// @dev Give a vault to another user.
    function give(bytes12 vaultId, address receiver)
        external
        returns (DataTypes.Vault memory);

    /// @dev Move collateral and debt between vaults.
    function stir(
        bytes12 from,
        bytes12 to,
        uint128 ink,
        uint128 art
    ) external returns (DataTypes.Balances memory, DataTypes.Balances memory);

    /// @dev Manipulate a vault debt and collateral.
    function pour(
        bytes12 vaultId,
        int128 ink,
        int128 art
    ) external returns (DataTypes.Balances memory);

    /// @dev Change series and debt of a vault.
    /// The module calling this function also needs to buy underlying in the pool for the new series, and sell it in pool for the old series.
    function roll(
        bytes12 vaultId,
        bytes6 seriesId,
        int128 art
    ) external returns (DataTypes.Vault memory, DataTypes.Balances memory);

    /// @dev Reduce debt and collateral from a vault, ignoring collateralization checks.
    function slurp(
        bytes12 vaultId,
        uint128 ink,
        uint128 art
    ) external returns (DataTypes.Balances memory);

    // ==== Helpers ====

    /// @dev Convert a debt amount for a series from base to fyToken terms.
    /// @notice Think about rounding if using, since we are dividing.
    function debtFromBase(bytes6 seriesId, uint128 base)
        external
        returns (uint128 art);

    /// @dev Convert a debt amount for a series from fyToken to base terms
    function debtToBase(bytes6 seriesId, uint128 art)
        external
        returns (uint128 base);

    // ==== Accounting ====

    /// @dev Record the borrowing rate at maturity for a series
    function mature(bytes6 seriesId) external;

    /// @dev Retrieve the rate accrual since maturity, maturing if necessary.
    function accrual(bytes6 seriesId) external returns (uint256);

    /// @dev Return the collateralization level of a vault. It will be negative if undercollateralized.
    function level(bytes12 vaultId) external returns (int256);
}