// SPDX-License-Identifier: MIT

pragma solidity =0.8.18;

import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/draft-ERC20PermitUpgradeable.sol";

/**
 * @title SOMA Swap Pair contract.
 * @author SOMA.finance
 * @notice Interface for the {SomaSwapPair} contract.
 */
interface ISomaSwapPair is IERC20Upgradeable, IERC20PermitUpgradeable {
    /**
     * @notice Emitted when `sender` adds liquidity of `amount0` token0 and `amount1` token1.
     * @param sender The address of the message sender.
     * @param amount0 The amount of amount0 added as liquidity.
     * @param amount1 The amount of amount1 added as liquidity.
     */
    event Mint(address indexed sender, uint256 amount0, uint256 amount1);

    /**
     * @notice Emitted when `sender` removes liquidity of `amount0` token0 and `amount1` token1.
     * @param sender The address of the message sender.
     * @param amount0 The address of amount0 removed as liquidity.
     * @param amount1 The address of amount1 removed as liquidity.
     * @param to The address where the underlying liquidity gets sent to.
     */
    event Burn(address indexed sender, uint256 amount0, uint256 amount1, address indexed to);

    /**
     * @notice Emitted when `sender` swaps `amount0Out` token0 and `amount1Out` token1.
     * @param sender The address of the message sender.
     * @param amount0In The amount of token0 sent into the contract from message sender.
     * @param amount1In The amount of token1 sent into the contract from message sender.
     * @param amount0Out The amount of token0 received by the message sender.
     * @param amount1Out The amount of token1 received by the message sender.
     * @param to The address receiving the swapped tokens.
     */
    event Swap(
        address indexed sender,
        uint256 amount0In,
        uint256 amount1In,
        uint256 amount0Out,
        uint256 amount1Out,
        address indexed to
    );

    /**
     * @notice Emitted when the reserves are set to match the balances of the contract.
     * @param reserve0 The updated amount of reserve0.
     * @param reserve1 The updated amount of reserve1.
     */
    event Sync(uint112 reserve0, uint112 reserve1);

    /**
     * @notice Returns the minimum liquidity for the pair.
     * @dev Returns `10**3`.
     */
    function MINIMUM_LIQUIDITY() external pure returns (uint256);

    /**
     * @notice Returns the address of the SOMA Swap Factory.
     */
    function factory() external view returns (address);

    /**
     * @notice Returns the address of token0 of the pair.
     */
    function token0() external view returns (address);

    /**
     * @notice Returns the address of token1 of the pair.
     */
    function token1() external view returns (address);

    /**
     * @notice Returns the reserves of token0 and token1, and the block timestamp from the latest pair interaction.
     * @return _reserve0 The reserve of token0.
     * @return _reserve1 The reserve of token1.
     * @return _blockTimestampLast The latest block timestamp of a pair interaction.
     */
    function getReserves() external view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast);

    /**
     * @notice Returns the price of token0 denominated in token1.
     */
    function price0CumulativeLast() external view returns (uint256);

    /**
     * @notice Returns the price of token1 denominated in token0.
     */
    function price1CumulativeLast() external view returns (uint256);

    /**
     * @notice Returns product of the reserves as of the latest liquidity event.
     */
    function kLast() external view returns (uint256);

    /**
     * @notice Creates pool tokens.
     * @param to The address to receive the minted tokens.
     * @custom:emits Mint
     * @custom:requirement The liquidity of `token0` and `token1`  must both be greater than zero.
     * @custom:requirement SomaSwap must not be locked.
     * @return liquidity The liquidity of the pair.
     */
    function mint(address to) external returns (uint256 liquidity);

    /**
     * @notice Burns pool tokens.
     * @param to The address to receive the underlying liquidity.
     * @custom:emits Burn
     * @custom:requirement The liquidity of `token0` and `token1` must both be greater than zero.
     * @custom:requirement SomaSwap must not be locked.
     * @return amount0 The amount of liquidity in token0 redeemed.
     * @return amount1 The amount of liquidity in token1 redeemed.
     */
    function burn(address to) external returns (uint256 amount0, uint256 amount1);

    /**
     * @notice Tries to perform a swap.
     * @param amount0Out The amount  of token0 to be swapped.
     * @param amount1Out The amount of token1 to be swapped.
     * @param to The address to receive the swapped tokens.
     * @param data Miscalaneous data associated with the swap.
     * @custom:requirement `amount0Out` and `amount1In` must be greater than zero.
     * @custom:requirement `amount0Out` must be less than `reserve0`.
     * @custom:requirement `amount1In` must be less than `reserve1`.
     * @custom:requirement `to` must not be equal to `token0` or `token1`.
     * @custom:requirement SomaSwap must not be locked.
     * @custom:requirement The function caller must have the required privileges to swap.
     */
    function swap(uint256 amount0Out, uint256 amount1Out, address to, bytes calldata data) external;

    /**
     * @notice Transfers the difference between the reserves and the balance of the contract to `to`.
     * @param to The address to receive the skimmed tokens.
     * @custom:emits Skim
     * @custom:requirement SomaSwap must not be locked.
     */
    function skim(address to) external;

    /**
     * @notice Syncing the reserves to the current balances of token0 and token1.
     * @custom:emits Sync
     * @custom:requirement SomaSwap must not be locked.
     */
    function sync() external;

    /**
     * @notice Initializer for the contract.
     * @param _token0 The address of token0.
     * @param _token1 The address of token1.
     */
    function initialize(address _token0, address _token1) external;
}