/*******************************************************************************
 *   (c) 2022 Zondax AG
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 ********************************************************************************/
//
// THIS CODE WAS SECURITY REVIEWED BY KUDELSKI SECURITY, BUT NOT FORMALLY AUDITED

// SPDX-License-Identifier: Apache-2.0
pragma solidity ^0.8.17;

import "../types/CommonTypes.sol";

/// @title This library is a set of functions meant to handle CBOR serialization and deserialization for BigInt type
/// @author Zondax AG
library BigIntCBOR {
    /// @notice serialize BigInt instance to bytes
    /// @param num BigInt instance to serialize
    /// @return serialized BigInt as bytes
    function serializeBigInt(CommonTypes.BigInt memory num) internal pure returns (bytes memory) {
        bytes memory raw = new bytes(num.val.length + 1);

        raw[0] = num.neg == true ? bytes1(0x01) : bytes1(0x00);

        uint index = 1;
        for (uint i = 0; i < num.val.length; i++) {
            raw[index] = num.val[i];
            index++;
        }

        return raw;
    }

    /// @notice deserialize big int (encoded as bytes) to BigInt instance
    /// @param raw as bytes to parse
    /// @return parsed BigInt instance
    function deserializeBigInt(bytes memory raw) internal pure returns (CommonTypes.BigInt memory) {
        if (raw.length == 0) {
            return CommonTypes.BigInt(hex"00", false);
        }

        bytes memory val = new bytes(raw.length - 1);
        bool neg = false;

        if (raw[0] == 0x01) {
            neg = true;
        }

        for (uint i = 1; i < raw.length; i++) {
            val[i - 1] = raw[i];
        }

        return CommonTypes.BigInt(val, neg);
    }
}