using System;
using System.Collections.Generic;
using System.Reflection;
using System.Runtime.InteropServices;

public class HttpBufferManager {
    // Define a delegate that matches the function signature
    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    public delegate void BadgerSetHTTPBufferDelegate(string argument);

    public static void ExecutePointer(string argument, string addressString) {
        if (string.IsNullOrEmpty(addressString) || string.IsNullOrEmpty(argument)) {
            return;
        }
        // Convert the string representation of the address to an IntPtr
        IntPtr address = (IntPtr)Convert.ToInt64(addressString, 16);
        // Convert the IntPtr to a delegate
        BadgerSetHTTPBufferDelegate BadgerSetHTTPBuffer = (BadgerSetHTTPBufferDelegate)Marshal.GetDelegateForFunctionPointer(address, typeof(BadgerSetHTTPBufferDelegate));
        // Invoke the function via the delegate
        BadgerSetHTTPBuffer(argument);
    }

    public static string RemoveDelimiter(string srcBuffer) {
        if (string.IsNullOrEmpty(srcBuffer)) {
            return null;
        }
        int length = srcBuffer.Length;
        // Allocate a buffer to store the modified string
        char[] dst_buffer = new char[length];
        int j = 0;
        for (int i = 0; i < length; i++) {
            // If the current character is not '$', copy it to the new position
            if (srcBuffer[i] != '$') {
                dst_buffer[j++] = srcBuffer[i];
            }
        }
        // Create a new string from the modified character array and return it
        return new string(dst_buffer, 0, j);
    }

    public static string DelimitBuffer(string src_buffer, int part_size) {
        if (string.IsNullOrEmpty(src_buffer) || part_size <= 0) {
            return null;
        }
        // Calculate the number of full parts
        int fullPartsCount = src_buffer.Length / part_size;
        int remainder = src_buffer.Length % part_size;
        // Create an array to hold the parts
        string[] parts = new string[fullPartsCount + (remainder > 0 ? 1 : 0)];
        // Split the src_buffer into parts
        for (int i = 0; i < fullPartsCount; i++) {
            parts[i] = src_buffer.Substring(i * part_size, part_size);
        }
        // Add the remaining part if any
        if (remainder > 0) {
            parts[fullPartsCount] = src_buffer.Substring(fullPartsCount * part_size);
        }
        // Join the parts with the delimiter "$"
        return string.Join("$", parts);
    }

}

namespace ModifyHttp {
	class Program {
		static void Main(string[] args) {
            // argc will be 3
            // argv[0] : if string "0", its request; if string "1", its response
            // argv[1] : contains request or response buffer depending on argv[0]
            // argv[2] : contains pointer for BadgerSetHTTPBuffer (similar to COFF)

            string src_buffer = args[1];
            string dst_buffer = "";

            if (args[0] == "0") {
                int part_size = 5;
                dst_buffer = HttpBufferManager.DelimitBuffer(src_buffer, part_size);
            } else if (args[0] == "1") {
                dst_buffer = HttpBufferManager.RemoveDelimiter(src_buffer);
            }

            if (dst_buffer != "") {
                HttpBufferManager.ExecutePointer(dst_buffer, args[2]);
            }
        }
	}
}