#include "us/Crypto_Basic.hpp"

namespace qing {
	std::string Crypto_Basic::bytes_to_hex(const std::vector<unsigned char>& data) {
		static const char hex_chars[] = "0123456789abcdef";
		std::string hex_string;
		hex_string.reserve(data.size() * 2);

		for (unsigned char byte: data) {
			hex_string.push_back(hex_chars[byte >> 4]);	// 高4位
			hex_string.push_back(hex_chars[byte & 0x0F]);	// 低4位
		}

		return hex_string;
	
	}

	std::vector<unsigned char> Crypto_Basic::hex_to_bytes(const std::string &hex) {
		// 检查长度是否为偶数
		if (hex.size() % 2 != 0) {
			throw std::invalid_argument("十六进制字符串长度必须为偶数");
		}

		std::vector<unsigned char> bytes;
		bytes.reserve(hex.size() / 2);

		auto char_to_nibble = [](char c) -> unsigned char {
			if (c >= '0' && c <= '9') return c - '0';
			if (c >= 'a' && c <= 'f') return 10 + (c - 'a');
			if (c >= 'A' && c <= 'F') return 10 + (c - 'A');
			throw std::invalid_argument("无效的十六进制字符：" + std::string(1, c));
		};

		for (size_t i = 0; i < hex.size(); i += 2) {
			unsigned char high = char_to_nibble(hex[i]);
			unsigned char low = char_to_nibble(hex[i + 1]);
			bytes.push_back((high << 4) | low);
		}

		return bytes;
	}
}