// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Permit.sol";
import "../interfaces/IDaiLikePermit.sol";
import "../interfaces/IPermit2.sol";
import "../interfaces/IERC7597Permit.sol";
import "../interfaces/IWETH.sol";
import "../libraries/RevertReasonForwarder.sol";

/**
 * @title Implements efficient safe methods for ERC20 interface.
 * @notice Compared to the standard ERC20, this implementation offers several enhancements:
 * 1. more gas-efficient, providing significant savings in transaction costs.
 * 2. support for different permit implementations
 * 3. forceApprove functionality
 * 4. support for WETH deposit and withdraw
 */
library SafeERC20 {
    error SafeTransferFailed();
    error SafeTransferFromFailed();
    error ForceApproveFailed();
    error SafeIncreaseAllowanceFailed();
    error SafeDecreaseAllowanceFailed();
    error SafePermitBadLength();
    error Permit2TransferAmountTooHigh();

    // Uniswap Permit2 address
    address private constant _PERMIT2 = 0x000000000022D473030F116dDEE9F6B43aC78BA3;
    address private constant _PERMIT2_ZKSYNC = 0x0000000000225e31D15943971F47aD3022F714Fa;
    bytes4 private constant _PERMIT_LENGTH_ERROR = 0x68275857;  // SafePermitBadLength.selector

    /**
     * @notice Fetches the balance of a specific ERC20 token held by an account.
     * Consumes less gas then regular `ERC20.balanceOf`.
     * @dev Note that the implementation does not perform dirty bits cleaning, so it is the
     * responsibility of the caller to make sure that the higher 96 bits of the `account` parameter are clean.
     * @param token The IERC20 token contract for which the balance will be fetched.
     * @param account The address of the account whose token balance will be fetched.
     * @return tokenBalance The balance of the specified ERC20 token held by the account.
     */
    function safeBalanceOf(
        IERC20 token,
        address account
    ) internal view returns(uint256 tokenBalance) {
        bytes4 selector = IERC20.balanceOf.selector;
        assembly ("memory-safe") { // solhint-disable-line no-inline-assembly
            mstore(0x00, selector)
            mstore(0x04, account)
            let success := staticcall(gas(), token, 0x00, 0x24, 0x00, 0x20)
            tokenBalance := mload(0)

            if or(iszero(success), lt(returndatasize(), 0x20)) {
                let ptr := mload(0x40)
                returndatacopy(ptr, 0, returndatasize())
                revert(ptr, returndatasize())
            }
        }
    }

    /**
     * @notice Attempts to safely transfer tokens from one address to another.
     * @dev If permit2 is true, uses the Permit2 standard; otherwise uses the standard ERC20 transferFrom.
     * Either requires `true` in return data, or requires target to be smart-contract and empty return data.
     * Note that the implementation does not perform dirty bits cleaning, so it is the responsibility of
     * the caller to make sure that the higher 96 bits of the `from` and `to` parameters are clean.
     * @param token The IERC20 token contract from which the tokens will be transferred.
     * @param from The address from which the tokens will be transferred.
     * @param to The address to which the tokens will be transferred.
     * @param amount The amount of tokens to transfer.
     * @param permit2 If true, uses the Permit2 standard for the transfer; otherwise uses the standard ERC20 transferFrom.
     */
    function safeTransferFromUniversal(
        IERC20 token,
        address from,
        address to,
        uint256 amount,
        bool permit2
    ) internal {
        if (permit2) {
            safeTransferFromPermit2(token, from, to, amount);
        } else {
            safeTransferFrom(token, from, to, amount);
        }
    }

    /**
     * @notice Attempts to safely transfer tokens from one address to another using the ERC20 standard.
     * @dev Either requires `true` in return data, or requires target to be smart-contract and empty return data.
     * Note that the implementation does not perform dirty bits cleaning, so it is the responsibility of
     * the caller to make sure that the higher 96 bits of the `from` and `to` parameters are clean.
     * @param token The IERC20 token contract from which the tokens will be transferred.
     * @param from The address from which the tokens will be transferred.
     * @param to The address to which the tokens will be transferred.
     * @param amount The amount of tokens to transfer.
     */
    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 amount
    ) internal {
        bytes4 selector = token.transferFrom.selector;
        bool success;
        assembly ("memory-safe") { // solhint-disable-line no-inline-assembly
            let data := mload(0x40)

            mstore(data, selector)
            mstore(add(data, 0x04), from)
            mstore(add(data, 0x24), to)
            mstore(add(data, 0x44), amount)
            success := call(gas(), token, 0, data, 0x64, 0x0, 0x20)
            if success {
                switch returndatasize()
                case 0 {
                    success := gt(extcodesize(token), 0)
                }
                default {
                    success := and(gt(returndatasize(), 31), eq(mload(0), 1))
                }
            }
        }
        if (!success) revert SafeTransferFromFailed();
    }

    /**
     * @notice Attempts to safely transfer tokens from one address to another using the Permit2 standard.
     * @dev Either requires `true` in return data, or requires target to be smart-contract and empty return data.
     * Note that the implementation does not perform dirty bits cleaning, so it is the responsibility of
     * the caller to make sure that the higher 96 bits of the `from` and `to` parameters are clean.
     * @param token The IERC20 token contract from which the tokens will be transferred.
     * @param from The address from which the tokens will be transferred.
     * @param to The address to which the tokens will be transferred.
     * @param amount The amount of tokens to transfer.
     */
    function safeTransferFromPermit2(
        IERC20 token,
        address from,
        address to,
        uint256 amount
    ) internal {
        if (amount > type(uint160).max) revert Permit2TransferAmountTooHigh();
        address permit2 = _getPermit2Address();
        bytes4 selector = IPermit2.transferFrom.selector;
        bool success;
        assembly ("memory-safe") { // solhint-disable-line no-inline-assembly
            let data := mload(0x40)

            mstore(data, selector)
            mstore(add(data, 0x04), from)
            mstore(add(data, 0x24), to)
            mstore(add(data, 0x44), amount)
            mstore(add(data, 0x64), token)
            success := call(gas(), permit2, 0, data, 0x84, 0x0, 0x0)
            if success {
                success := gt(extcodesize(permit2), 0)
            }
        }
        if (!success) revert SafeTransferFromFailed();
    }

    /**
     * @notice Attempts to safely transfer tokens to another address.
     * @dev Either requires `true` in return data, or requires target to be smart-contract and empty return data.
     * Note that the implementation does not perform dirty bits cleaning, so it is the responsibility of
     * the caller to make sure that the higher 96 bits of the `to` parameter are clean.
     * @param token The IERC20 token contract from which the tokens will be transferred.
     * @param to The address to which the tokens will be transferred.
     * @param amount The amount of tokens to transfer.
     */
    function safeTransfer(
        IERC20 token,
        address to,
        uint256 amount
    ) internal {
        if (!_makeCall(token, token.transfer.selector, to, amount)) {
            revert SafeTransferFailed();
        }
    }

    /**
     * @notice Attempts to approve a spender to spend a certain amount of tokens.
     * @dev If `approve(from, to, amount)` fails, it tries to set the allowance to zero, and retries the `approve` call.
     * Note that the implementation does not perform dirty bits cleaning, so it is the responsibility of
     * the caller to make sure that the higher 96 bits of the `spender` parameter are clean.
     * @param token The IERC20 token contract on which the call will be made.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     */
    function forceApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        if (!_makeCall(token, token.approve.selector, spender, value)) {
            if (
                !_makeCall(token, token.approve.selector, spender, 0) ||
                !_makeCall(token, token.approve.selector, spender, value)
            ) {
                revert ForceApproveFailed();
            }
        }
    }

    /**
     * @notice Safely increases the allowance of a spender.
     * @dev Increases with safe math check. Checks if the increased allowance will overflow, if yes, then it reverts the transaction.
     * Then uses `forceApprove` to increase the allowance.
     * Note that the implementation does not perform dirty bits cleaning, so it is the responsibility of
     * the caller to make sure that the higher 96 bits of the `spender` parameter are clean.
     * @param token The IERC20 token contract on which the call will be made.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to increase the allowance by.
     */
    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 allowance = token.allowance(address(this), spender);
        if (value > type(uint256).max - allowance) revert SafeIncreaseAllowanceFailed();
        forceApprove(token, spender, allowance + value);
    }

    /**
     * @notice Safely decreases the allowance of a spender.
     * @dev Decreases with safe math check. Checks if the decreased allowance will underflow, if yes, then it reverts the transaction.
     * Then uses `forceApprove` to increase the allowance.
     * Note that the implementation does not perform dirty bits cleaning, so it is the responsibility of
     * the caller to make sure that the higher 96 bits of the `spender` parameter are clean.
     * @param token The IERC20 token contract on which the call will be made.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to decrease the allowance by.
     */
    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 allowance = token.allowance(address(this), spender);
        if (value > allowance) revert SafeDecreaseAllowanceFailed();
        forceApprove(token, spender, allowance - value);
    }

    /**
     * @notice Attempts to execute the `permit` function on the provided token with the sender and contract as parameters.
     * Permit type is determined automatically based on permit calldata (IERC20Permit, IDaiLikePermit, and IPermit2).
     * @dev Wraps `tryPermit` function and forwards revert reason if permit fails.
     * @param token The IERC20 token to execute the permit function on.
     * @param permit The permit data to be used in the function call.
     */
    function safePermit(IERC20 token, bytes calldata permit) internal {
        if (!tryPermit(token, msg.sender, address(this), permit)) RevertReasonForwarder.reRevert();
    }

    /**
     * @notice Attempts to execute the `permit` function on the provided token with custom owner and spender parameters.
     * Permit type is determined automatically based on permit calldata (IERC20Permit, IDaiLikePermit, and IPermit2).
     * @dev Wraps `tryPermit` function and forwards revert reason if permit fails.
     * Note that the implementation does not perform dirty bits cleaning, so it is the responsibility of
     * the caller to make sure that the higher 96 bits of the `owner` and `spender` parameters are clean.
     * @param token The IERC20 token to execute the permit function on.
     * @param owner The owner of the tokens for which the permit is made.
     * @param spender The spender allowed to spend the tokens by the permit.
     * @param permit The permit data to be used in the function call.
     */
    function safePermit(IERC20 token, address owner, address spender, bytes calldata permit) internal {
        if (!tryPermit(token, owner, spender, permit)) RevertReasonForwarder.reRevert();
    }

    /**
     * @notice Attempts to execute the `permit` function on the provided token with the sender and contract as parameters.
     * @dev Invokes `tryPermit` with sender as owner and contract as spender.
     * @param token The IERC20 token to execute the permit function on.
     * @param permit The permit data to be used in the function call.
     * @return success Returns true if the permit function was successfully executed, false otherwise.
     */
    function tryPermit(IERC20 token, bytes calldata permit) internal returns(bool success) {
        return tryPermit(token, msg.sender, address(this), permit);
    }

    /**
     * @notice The function attempts to call the permit function on a given ERC20 token.
     * @dev The function is designed to support a variety of permit functions, namely: IERC20Permit, IDaiLikePermit, IERC7597Permit and IPermit2.
     * It accommodates both Compact and Full formats of these permit types.
     * Please note, it is expected that the `expiration` parameter for the compact Permit2 and the `deadline` parameter
     * for the compact Permit are to be incremented by one before invoking this function. This approach is motivated by
     * gas efficiency considerations; as the unlimited expiration period is likely to be the most common scenario, and
     * zeros are cheaper to pass in terms of gas cost. Thus, callers should increment the expiration or deadline by one
     * before invocation for optimized performance.
     * Note that the implementation does not perform dirty bits cleaning, so it is the responsibility of
     * the caller to make sure that the higher 96 bits of the `owner` and `spender` parameters are clean.
     * @param token The address of the ERC20 token on which to call the permit function.
     * @param owner The owner of the tokens. This address should have signed the off-chain permit.
     * @param spender The address which will be approved for transfer of tokens.
     * @param permit The off-chain permit data, containing different fields depending on the type of permit function.
     * @return success A boolean indicating whether the permit call was successful.
     */
    function tryPermit(IERC20 token, address owner, address spender, bytes calldata permit) internal returns(bool success) {
        address permit2 = _getPermit2Address();
        // load function selectors for different permit standards
        bytes4 permitSelector = IERC20Permit.permit.selector;
        bytes4 daiPermitSelector = IDaiLikePermit.permit.selector;
        bytes4 permit2Selector = IPermit2.permit.selector;
        bytes4 erc7597PermitSelector = IERC7597Permit.permit.selector;
        assembly ("memory-safe") { // solhint-disable-line no-inline-assembly
            let ptr := mload(0x40)

            // Switch case for different permit lengths, indicating different permit standards
            switch permit.length
            // Compact IERC20Permit
            case 100 {
                mstore(ptr, permitSelector)     // store selector
                mstore(add(ptr, 0x04), owner)   // store owner
                mstore(add(ptr, 0x24), spender) // store spender

                // Compact IERC20Permit.permit(uint256 value, uint32 deadline, uint256 r, uint256 vs)
                {  // stack too deep
                    let deadline := shr(224, calldataload(add(permit.offset, 0x20))) // loads permit.offset 0x20..0x23
                    let vs := calldataload(add(permit.offset, 0x44))                 // loads permit.offset 0x44..0x63

                    calldatacopy(add(ptr, 0x44), permit.offset, 0x20)            // store value     = copy permit.offset 0x00..0x19
                    mstore(add(ptr, 0x64), sub(deadline, 1))                     // store deadline  = deadline - 1
                    mstore(add(ptr, 0x84), add(27, shr(255, vs)))                // store v         = most significant bit of vs + 27 (27 or 28)
                    calldatacopy(add(ptr, 0xa4), add(permit.offset, 0x24), 0x20) // store r         = copy permit.offset 0x24..0x43
                    mstore(add(ptr, 0xc4), shr(1, shl(1, vs)))                   // store s         = vs without most significant bit
                }
                // IERC20Permit.permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s)
                success := call(gas(), token, 0, ptr, 0xe4, 0, 0)
            }
            // Compact IDaiLikePermit
            case 72 {
                mstore(ptr, daiPermitSelector)  // store selector
                mstore(add(ptr, 0x04), owner)   // store owner
                mstore(add(ptr, 0x24), spender) // store spender

                // Compact IDaiLikePermit.permit(uint32 nonce, uint32 expiry, uint256 r, uint256 vs)
                {  // stack too deep
                    let expiry := shr(224, calldataload(add(permit.offset, 0x04))) // loads permit.offset 0x04..0x07
                    let vs := calldataload(add(permit.offset, 0x28))               // loads permit.offset 0x28..0x47

                    mstore(add(ptr, 0x44), shr(224, calldataload(permit.offset))) // store nonce   = copy permit.offset 0x00..0x03
                    mstore(add(ptr, 0x64), sub(expiry, 1))                        // store expiry  = expiry - 1
                    mstore(add(ptr, 0x84), true)                                  // store allowed = true
                    mstore(add(ptr, 0xa4), add(27, shr(255, vs)))                 // store v       = most significant bit of vs + 27 (27 or 28)
                    calldatacopy(add(ptr, 0xc4), add(permit.offset, 0x08), 0x20)  // store r       = copy permit.offset 0x08..0x27
                    mstore(add(ptr, 0xe4), shr(1, shl(1, vs)))                    // store s       = vs without most significant bit
                }
                // IDaiLikePermit.permit(address holder, address spender, uint256 nonce, uint256 expiry, bool allowed, uint8 v, bytes32 r, bytes32 s)
                success := call(gas(), token, 0, ptr, 0x104, 0, 0)
            }
            // IERC20Permit
            case 224 {
                mstore(ptr, permitSelector)
                calldatacopy(add(ptr, 0x04), permit.offset, permit.length) // copy permit calldata
                // IERC20Permit.permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s)
                success := call(gas(), token, 0, ptr, 0xe4, 0, 0)
            }
            // IDaiLikePermit
            case 256 {
                mstore(ptr, daiPermitSelector)
                calldatacopy(add(ptr, 0x04), permit.offset, permit.length) // copy permit calldata
                // IDaiLikePermit.permit(address holder, address spender, uint256 nonce, uint256 expiry, bool allowed, uint8 v, bytes32 r, bytes32 s)
                success := call(gas(), token, 0, ptr, 0x104, 0, 0)
            }
            // Compact IPermit2
            case 96 {
                // Compact IPermit2.permit(uint160 amount, uint32 expiration, uint32 nonce, uint32 sigDeadline, uint256 r, uint256 vs)
                mstore(ptr, permit2Selector)  // store selector
                mstore(add(ptr, 0x04), owner) // store owner
                mstore(add(ptr, 0x24), token) // store token

                calldatacopy(add(ptr, 0x50), permit.offset, 0x14)             // store amount = copy permit.offset 0x00..0x13
                // and(0xffffffffffff, ...) - conversion to uint48
                mstore(add(ptr, 0x64), and(0xffffffffffff, sub(shr(224, calldataload(add(permit.offset, 0x14))), 1))) // store expiration = ((permit.offset 0x14..0x17 - 1) & 0xffffffffffff)
                mstore(add(ptr, 0x84), shr(224, calldataload(add(permit.offset, 0x18)))) // store nonce = copy permit.offset 0x18..0x1b
                mstore(add(ptr, 0xa4), spender)                               // store spender
                // and(0xffffffffffff, ...) - conversion to uint48
                mstore(add(ptr, 0xc4), and(0xffffffffffff, sub(shr(224, calldataload(add(permit.offset, 0x1c))), 1))) // store sigDeadline = ((permit.offset 0x1c..0x1f - 1) & 0xffffffffffff)
                mstore(add(ptr, 0xe4), 0x100)                                 // store offset = 256
                mstore(add(ptr, 0x104), 0x40)                                 // store length = 64
                calldatacopy(add(ptr, 0x124), add(permit.offset, 0x20), 0x20) // store r      = copy permit.offset 0x20..0x3f
                calldatacopy(add(ptr, 0x144), add(permit.offset, 0x40), 0x20) // store vs     = copy permit.offset 0x40..0x5f
                // IPermit2.permit(address owner, PermitSingle calldata permitSingle, bytes calldata signature)
                success := call(gas(), permit2, 0, ptr, 0x164, 0, 0)
            }
            // IPermit2
            case 352 {
                mstore(ptr, permit2Selector)
                calldatacopy(add(ptr, 0x04), permit.offset, permit.length) // copy permit calldata
                // IPermit2.permit(address owner, PermitSingle calldata permitSingle, bytes calldata signature)
                success := call(gas(), permit2, 0, ptr, 0x164, 0, 0)
            }
            // Dynamic length
            default {
                mstore(ptr, erc7597PermitSelector)
                calldatacopy(add(ptr, 0x04), permit.offset, permit.length) // copy permit calldata
                // IERC7597Permit.permit(address owner, address spender, uint256 value, uint256 deadline, bytes memory signature)
                success := call(gas(), token, 0, ptr, add(permit.length, 4), 0, 0)
            }
        }
    }

    /**
     * @dev Executes a low level call to a token contract, making it resistant to reversion and erroneous boolean returns.
     * @param token The IERC20 token contract on which the call will be made.
     * @param selector The function signature that is to be called on the token contract.
     * @param to The address to which the token amount will be transferred.
     * @param amount The token amount to be transferred.
     * @return success A boolean indicating if the call was successful. Returns 'true' on success and 'false' on failure.
     * In case of success but no returned data, validates that the contract code exists.
     * In case of returned data, ensures that it's a boolean `true`.
     */
    function _makeCall(
        IERC20 token,
        bytes4 selector,
        address to,
        uint256 amount
    ) private returns (bool success) {
        assembly ("memory-safe") { // solhint-disable-line no-inline-assembly
            let data := mload(0x40)

            mstore(data, selector)
            mstore(add(data, 0x04), to)
            mstore(add(data, 0x24), amount)
            success := call(gas(), token, 0, data, 0x44, 0x0, 0x20)
            if success {
                switch returndatasize()
                case 0 {
                    success := gt(extcodesize(token), 0)
                }
                default {
                    success := and(gt(returndatasize(), 31), eq(mload(0), 1))
                }
            }
        }
    }

    /**
     * @notice Safely deposits a specified amount of Ether into the IWETH contract. Consumes less gas then regular `IWETH.deposit`.
     * @param weth The IWETH token contract.
     * @param amount The amount of Ether to deposit into the IWETH contract.
     */
    function safeDeposit(IWETH weth, uint256 amount) internal {
        bytes4 selector = IWETH.deposit.selector;
        assembly ("memory-safe") { // solhint-disable-line no-inline-assembly
            mstore(0, selector)
            if iszero(call(gas(), weth, amount, 0, 4, 0, 0)) {
                let ptr := mload(0x40)
                returndatacopy(ptr, 0, returndatasize())
                revert(ptr, returndatasize())
            }
        }
    }

    /**
     * @notice Safely withdraws a specified amount of wrapped Ether from the IWETH contract. Consumes less gas then regular `IWETH.withdraw`.
     * @dev Uses inline assembly to interact with the IWETH contract.
     * @param weth The IWETH token contract.
     * @param amount The amount of wrapped Ether to withdraw from the IWETH contract.
     */
    function safeWithdraw(IWETH weth, uint256 amount) internal {
        bytes4 selector = IWETH.withdraw.selector;
        assembly ("memory-safe") {  // solhint-disable-line no-inline-assembly
            mstore(0, selector)
            mstore(4, amount)
            if iszero(call(gas(), weth, 0, 0, 0x24, 0, 0)) {
                let ptr := mload(0x40)
                returndatacopy(ptr, 0, returndatasize())
                revert(ptr, returndatasize())
            }
        }
    }

    /**
     * @notice Safely withdraws a specified amount of wrapped Ether from the IWETH contract to a specified recipient.
     * Consumes less gas then regular `IWETH.withdraw`.
     * @param weth The IWETH token contract.
     * @param amount The amount of wrapped Ether to withdraw from the IWETH contract.
     * @param to The recipient of the withdrawn Ether.
     */
    function safeWithdrawTo(IWETH weth, uint256 amount, address to) internal {
        safeWithdraw(weth, amount);
        if (to != address(this)) {
            assembly ("memory-safe") {  // solhint-disable-line no-inline-assembly
                if iszero(call(gas(), to, amount, 0, 0, 0, 0)) {
                    let ptr := mload(0x40)
                    returndatacopy(ptr, 0, returndatasize())
                    revert(ptr, returndatasize())
                }
            }
        }
    }

    function _getPermit2Address() private view returns (address permit2) {
        assembly ("memory-safe") { // solhint-disable-line no-inline-assembly
            switch chainid()
            case 324 { // zksync mainnet
                permit2 := _PERMIT2_ZKSYNC
            }
            case 300 { // zksync testnet
                permit2 := _PERMIT2_ZKSYNC
            }
            case 260 { // zksync fork network
                permit2 := _PERMIT2_ZKSYNC
            }
            default {
                permit2 := _PERMIT2
            }
        }
    }
}