using System;
using System.IO;
using System.Xml.Linq;
using System.Xml.Serialization;
using JD.Core.Logging;

namespace JD.Core
{
    public static class XmlExtensions
    {
        public static bool Deserialize<T>(string filePath, out T destObject, Type expectedType = null)
            where T : class
        {
            expectedType = expectedType ?? typeof (T);

            try
            {
                var element = XElement.Load(filePath);
                var serializer = new XmlSerializer(expectedType);
                destObject = (T)serializer.Deserialize(element.CreateReader());
                return true;
            }
            catch (Exception ex)
            {
                var log = LogExtensions.GetLog();
                if (log != null)
                {
                    log.Error(LogCategories.Get("Xml"), "Failed to deserialize file \"{0}\" to an object of type {1}. ", filePath, typeof(T).Name);
                    log.Exception(ex);
                }

                destObject = null;
                return false;
            }
        }

        public static bool Deserialize<T>(Stream stream, out T destObject)
            where T : class
        {
            try
            {
                var element = XElement.Load(stream);
                var serializer = new XmlSerializer(typeof(T));
                destObject = (T)serializer.Deserialize(element.CreateReader());
                return true;
            }
            catch (Exception ex)
            {
                var log = LogExtensions.GetLog();
                if (log != null)
                {
                    log.Error(LogCategories.Get("Xml"), "Failed to deserialize a stream to an object of type {0}. ", typeof(T).Name);
                    log.Exception(ex);
                }

                destObject = default(T);
                return false;
            }
        }

        public static XElement ToXml<T>(this T objectToSerialize)
        {
            try
            {
                using (var memoryStream = new MemoryStream())
                {
                    using (TextWriter streamWriter = new StreamWriter(memoryStream, System.Text.Encoding.Default))
                    {
                        var serializer = new XmlSerializer(objectToSerialize.GetType());
                        serializer.Serialize(streamWriter, objectToSerialize);
                        return XElement.Parse(System.Text.Encoding.Default.GetString(memoryStream.ToArray()));
                    }
                }
            }
            catch (Exception ex)
            {
                var log = LogExtensions.GetLog();
                if (log != null)
                {
                    log.Error(LogCategories.Get("Xml"), "Failed to convert an object of type {0} to xml. ", typeof(T).Name);
                    log.Exception(ex);
                }
                
                return null;
            }
        }

        public static bool Serialize<T>(this T objectToSerialize, string filePath)
        {
            try
            {
                XElement element = objectToSerialize.ToXml();
                if (element == null)
                    return false;

                using (TextWriter tw = new StreamWriter(filePath))
                {
                    element.Save(tw);
                    return true;
                }
            }
            catch (Exception ex)
            {
                var log = LogExtensions.GetLog();
                if (log != null)
                {
                    log.Error(LogCategories.Get("Xml"), "Failed to serialize an object of type {0} to the file \"{1}\". ", typeof(T).Name, filePath);
                    log.Exception(ex);
                }

                return false;
            }
        }

        public static bool Serialize<T>(this T objectToSerialize, Stream destStream)
        {
            try
            {
                XElement element = objectToSerialize.ToXml();
                if (element == null)
                    return false;

                using (TextWriter tw = new StreamWriter(destStream))
                {
                    element.Save(tw);
                    return true;
                }
            }
            catch (Exception ex)
            {
                var log = LogExtensions.GetLog();
                if (log != null)
                {
                    log.Error(LogCategories.Get("Xml"), "Failed to serialize an object of type {0} to a stream. ", typeof(T).Name);
                    log.Exception(ex);
                }

                return false;
            }
        }

        public static string GetAttributeValue(this XElement element, XName name, string defaultValue = null)
        {
            var attribute = element.Attribute(name);
            
            if (attribute == null)
                return defaultValue;
            else
                return attribute.Value;
        }
    }
}