package com.ruoyi.fuzhou.utils.watermodbus;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;

public class FloatInverseWaterParser {

    public static void main(String[] args) {
        // 示例输入：8位十六进制字符串（FloatInverse格式）
        String hexString = "0005"; // 反转后的字节顺序，表示浮点数 3.14
        byte[] bytes = FloatInverseWaterParser.hexStringToByteArray(hexString);
        byte[] reversedBytes = FloatInverseWaterParser.reverseByteArray(bytes);
        float floatValue = FloatInverseWaterParser.parseAsFloat(reversedBytes, ByteOrder.LITTLE_ENDIAN);
        System.out.println("3值为" + floatValue);
    }

    /**
     * 将十六进制字符串转换为字节数组
     */
    public static byte[] hexStringToByteArray(String s) {
        int len = s.length();
        if (len % 2 != 0) {
            throw new IllegalArgumentException("十六进制字符串长度必须为偶数。");
        }
        byte[] data = new byte[len / 2];
        for (int i = 0; i < len; i += 2) {
            int high = Character.digit(s.charAt(i), 16) << 4;
            int low = Character.digit(s.charAt(i + 1), 16);
            if (high == -1 || low == -1) {
                throw new IllegalArgumentException("包含无效的十六进制字符: " + s);
            }
            data[i / 2] = (byte) (high + low);
        }
        return data;
    }

    /**
     * 反转字节数组
     */
    public static byte[] reverseByteArray(byte[] bytes) {
        byte[] reversed = new byte[bytes.length];
        for (int i = 0; i < bytes.length; i++) {
            reversed[i] = bytes[bytes.length - 1 - i];
        }
        return reversed;
    }

    /**
     * 将字节数组解析为浮点数
     *
     * @param bytes 字节数组（必须为4字节）
     * @param order 字节顺序（大端或小端）
     */
    public static float parseAsFloat(byte[] bytes, ByteOrder order) {
        if (bytes.length != 4) {
            throw new IllegalArgumentException("字节数组长度必须为4字节。");
        }
        ByteBuffer buffer = ByteBuffer.wrap(bytes).order(order);
        return buffer.getFloat();
    }
}