WhatsApp Desktop Client Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public class ProtocolTreeNode
{
    public string tag;
    public IEnumerable<KeyValue> attributeHash;
    public IEnumerable<ProtocolTreeNode> children;
    public byte[] data;

    public ProtocolTreeNode(string tag, IEnumerable<KeyValue> attributeHash, IEnumerable<ProtocolTreeNode> children = null,  byte[] data = null)
    {
        this.tag = tag ?? "";
        this.attributeHash = attributeHash ?? new KeyValue[0];
        this.children = children ?? new ProtocolTreeNode[0];
        this.data = new byte[0];
        if (data != null)
            this.data = data;
    }

    public ProtocolTreeNode(string tag, IEnumerable<KeyValue> attributeHash, ProtocolTreeNode children = null)
    {
        this.tag = tag ?? "";
        this.attributeHash = attributeHash ?? new KeyValue[0];
        this.children = children != null ? new ProtocolTreeNode[] { children } : new ProtocolTreeNode[0];
        this.data = new byte[0];
    }

    public ProtocolTreeNode(string tag, IEnumerable<KeyValue> attributeHash, byte[] data = null)  : this(tag, attributeHash, new ProtocolTreeNode[0], data)
    { 
    }

    public ProtocolTreeNode(string tag, IEnumerable<KeyValue> attributeHash) : this(tag, attributeHash, new ProtocolTreeNode[0], null)
    {
    }

    public string NodeString(string indent = "")
    {
        string ret = "\n" + indent + "<" + this.tag;
        if (this.attributeHash != null)
        {
            foreach (var item in this.attributeHash)
            {
                ret += string.Format(" {0}=\"{1}\"", item.Key, item.Value);
            }
        }
        ret += ">";
        if (this.data.Length > 0)
        {
            ret += Encoding.UTF8.GetString(this.data);
        }
        if (this.children != null && this.children.Count() > 0)
        {
            foreach (var item in this.children)
            {
                ret += item.NodeString(indent + "  ");
            }
            ret += "\n" + indent;
        }
        ret += "</" + this.tag + ">";
        return ret;
    }

    public string GetAttribute(string attribute)
    {
        var ret = this.attributeHash.FirstOrDefault(x => x.Key.Equals(attribute));
        return (ret == null) ? null : ret.Value;
    }

    public ProtocolTreeNode GetChild(string tag)
    {
        if (this.children != null && this.children.Any())
        {
            foreach (var item in this.children)
            {
                if (tag.Equals(item.tag, StringComparison.InvariantCultureIgnoreCase))
                {
                    return item;
                }
                ProtocolTreeNode ret = item.GetChild(tag);
                if (ret != null)
                {
                    return ret;
                }
            }
        }
        return null;
    }

    public IEnumerable<ProtocolTreeNode> GetAllChildren(string tag)
    {
        var tmpReturn = new List<ProtocolTreeNode>();
        if (this.children != null && this.children.Any())
        {
            foreach (var item in this.children)
            {
                if (tag.Equals(item.tag, StringComparison.InvariantCultureIgnoreCase))
                {
                    tmpReturn.Add(item);
                }
                tmpReturn.AddRange(item.GetAllChildren(tag));
            }
        }
        return tmpReturn.ToArray();
    }

    public IEnumerable<ProtocolTreeNode> GetAllChildren()
    {
        return this.children.ToArray();
    }

    public byte[] GetData()
    {
        return this.data;
    }

    public static bool TagEquals(ProtocolTreeNode node, string _string)
    {
        return (((node != null) && (node.tag != null)) && node.tag.Equals(_string, StringComparison.OrdinalIgnoreCase));
    }
}