using System;
using System.IO;
using System.IO.Compression;
using System.Text;
using System.Xml;
using System.Xml.Serialization;
using XmlDocument = BWP.ABCClient.Businesses.XmlDocument;

namespace BWP.ABCClient
{
	public class MsgUtil
	{
		public class BareXmlTextWriter : XmlTextWriter
		{
			public BareXmlTextWriter(TextWriter writer) : base(writer) {}

			public override void WriteStartDocument() {}

			public override void WriteStartDocument(bool bare) {}

			public override void WriteEndElement()
			{
				WriteFullEndElement();
			}
		}

		public static string MsgToBareXml(object obj)
		{
			return MsgToBareXml(obj, Formatting.None, char.MinValue);
		}

		public static string MsgToBareXml(object obj, Formatting formatting, char indentChar)
		{
			StringBuilder sb = new StringBuilder();
			using (var stringWriter = new StringWriter(sb)) {
				using (BareXmlTextWriter writer = new BareXmlTextWriter(stringWriter)) {
					writer.Formatting = formatting;
					writer.IndentChar = indentChar;
					var ns = new XmlSerializerNamespaces();
					ns.Add(string.Empty, string.Empty);
					new XmlSerializer(obj.GetType()).Serialize(writer, obj, ns);
				}
			}
			return sb.ToString();
		}

		public static T ParseXmlToMsg<T>(string xml)
		{
			using (TextReader reader = new StringReader(xml)) {
				return (T)new XmlSerializer(typeof(T)).Deserialize(reader);
			}
		}

		public static string GetInnerXml(string xml, string xpath)
		{
			var aMessage = new XmlDocument(xml);
			return aMessage.GetValueNoNull(xpath); 
		}

		public static string Compress(string uncompressedString)
		{
			byte[] byteData = Encoding.GetEncoding("GB18030").GetBytes(uncompressedString);
			using (MemoryStream srcStream = new MemoryStream(byteData)) {
				using (var destStream = new MemoryStream()) {
					using (GZipStream compress = new GZipStream(destStream, CompressionMode.Compress)) {
						srcStream.CopyTo(compress);
					}
					return Convert.ToBase64String(destStream.ToArray());
				}
			}
		}

		public static string DeCompress(string comppressedString)
		{
			byte[] byteInput = Convert.FromBase64String(comppressedString);
			using (var srcStream = new MemoryStream(byteInput)) {
				using (var destStream = new MemoryStream()) {
					using (GZipStream decompress = new GZipStream(srcStream, CompressionMode.Decompress)) {
						decompress.CopyTo(destStream);
						var resultBytes = destStream.ToArray();
						return Encoding.GetEncoding("GB18030").GetString(resultBytes, 0, resultBytes.Length);
					}
				}
			}
		}

		public static string[] GetMultiInnerXml(string xml, string xpath)
		{
			var xmlDoc = new System.Xml.XmlDocument();
			xmlDoc.LoadXml(xml);
			var nodes = xmlDoc.SelectNodes(xpath);
			if (nodes == null) {
				return null;
			}
			var result = new string[nodes.Count];
			for (int i = 0; i < result.Length; i++) {
				result[i] = nodes[i].InnerXml;
			}
			return result;
		}

		public static string FromBase64StringToXml(string msg)
		{
			byte[] bytes = Convert.FromBase64String(msg);
			return Encoding.GetEncoding("gb2312").GetString(bytes, 0, bytes.Length);
		}
	}
}