package com.ruoyi.test;

import java.io.*;

public class ShpDebug3 {
    public static void main(String[] args) throws Exception {
        String shpPath = "d:\\Web\\PlatformModel\\ruoyi-admin\\uploads\\models\\geojson\\8aa64945328e428d97923165c8b8cf31\\流域.shp";
        
        FileInputStream fis = new FileInputStream(shpPath);
        fis.skip(100); // Skip header
        
        byte[] recordHeader = new byte[8];
        fis.read(recordHeader);
        
        int contentLengthWords = readIntBE(recordHeader, 4);
        int contentLength = contentLengthWords * 2;
        
        byte[] recordContent = new byte[contentLength];
        fis.read(recordContent);
        
        System.out.println("Content Length: " + contentLength);
        
        System.out.println("\n--- Polygon Structure ---");
        System.out.println("Offset 0-3: Shape type = " + recordContent[0]);
        
        System.out.println("\n--- Bounding Box (8 bytes each) ---");
        System.out.println("Offset 4-11 (Xmin): " + readDoubleLE(recordContent, 4));
        System.out.println("Offset 12-19 (Ymin): " + readDoubleLE(recordContent, 12));
        System.out.println("Offset 20-27 (Xmax): " + readDoubleLE(recordContent, 20));
        System.out.println("Offset 28-35 (Ymax): " + readDoubleLE(recordContent, 28));
        
        System.out.println("\n--- After Bounding Box ---");
        System.out.println("Offset 36-39 (numParts): " + readIntLE(recordContent, 36));
        System.out.println("Offset 40-43 (numPoints): " + readIntLE(recordContent, 40));
        
        fis.close();
    }
    
    static int readIntBE(byte[] data, int offset) {
        return ((data[offset] & 0xFF) << 24) |
               ((data[offset + 1] & 0xFF) << 16) |
               ((data[offset + 2] & 0xFF) << 8) |
               (data[offset + 3] & 0xFF);
    }
    
    static int readIntLE(byte[] data, int offset) {
        return (data[offset] & 0xFF) |
               ((data[offset + 1] & 0xFF) << 8) |
               ((data[offset + 2] & 0xFF) << 16) |
               ((data[offset + 3] & 0xFF) << 24);
    }
    
    static double readDoubleLE(byte[] data, int offset) {
        long bits = (data[offset] & 0xFFL) |
               ((data[offset + 1] & 0xFFL) << 8) |
               ((data[offset + 2] & 0xFFL) << 16) |
               ((data[offset + 3] & 0xFFL) << 24) |
               ((data[offset + 4] & 0xFFL) << 32) |
               ((data[offset + 5] & 0xFFL) << 40) |
               ((data[offset + 6] & 0xFFL) << 48) |
               ((data[offset + 7] & 0xFFL) << 56);
        return Double.longBitsToDouble(bits);
    }
}