using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml.Serialization;

namespace Tango.Serialization
{
    /// <summary>
    /// Represents a data serializer for serializing data using standard xml serializer.
    /// </summary>
    public class XmlDataSerializer : IDataSerializer
    {

        /// <summary>
        /// Serialize object to a file.
        /// </summary>
        /// <typeparam name="T">Type of specified object.</typeparam>
        /// <param name="obj">The specified object.</param>
        /// <param name="filePath">The full path to the file to write.</param>
        public void SerializeToFile<T>(T obj, string filePath)
        {
            using (FileStream fs = new FileStream(filePath, FileMode.Create))
            {
                SerializeToStream<T>(obj, fs);
            }
        }

        /// <summary>
        /// Serialize object to encrypted file.
        /// </summary>
        /// <typeparam name="T">Type of specified object.</typeparam>
        /// <param name="obj">The specified object.</param>
        /// <param name="filePath">The full path to the file to write.</param>
        public void SerializeToEncryptedFile<T>(T obj, string filePath)
        {
            var plainText = SerializeToString(obj);
            var cypherText = CryptographyHelper.Encrypt(plainText);
            File.WriteAllText(filePath, cypherText);
        }

        /// <summary>
        /// Serialize object to encrypted string.
        /// </summary>
        /// <typeparam name="T">Type of specified object.</typeparam>
        /// <param name="obj">The specified object.</param>
        public String SerializeToEncryptedString<T>(T obj)
        {
            var plainText = SerializeToString(obj);
            var cypherText = CryptographyHelper.Encrypt(plainText);
            return cypherText;
        }

        /// <summary>
        /// Deserialize object from encrypted file.
        /// </summary>
        /// <typeparam name="T">Type of object to deserialize.</typeparam>
        /// <param name="filePath">The full path of the data file.</param>
        /// <returns>The resulting object.</returns>
        public T DeserializeFromEncryptedFile<T>(string filePath)
        {
            var cypherText = File.ReadAllText(filePath);
            var plainText = CryptographyHelper.Decrypt(cypherText);
            return DeserializeFromString<T>(plainText);
        }

        /// <summary>
        /// Deserialize object from encrypted string.
        /// </summary>
        /// <typeparam name="T">Type of object to deserialize.</typeparam>
        /// <returns>The resulting object.</returns>
        public T DeserializeFromEncryptedString<T>(string encyptedString)
        {
            var plainText = CryptographyHelper.Decrypt(encyptedString);
            return DeserializeFromString<T>(plainText);
        }

        /// <summary>
        /// Deserialize object from a file.
        /// </summary>
        /// <typeparam name="T">Type of object to deserialize.</typeparam>
        /// <param name="filePath">The full path of the data file.</param>
        /// <returns>The resulting object.</returns>
        public T DeserializeFromFile<T>(string filePath)
        {
            using (FileStream fs = new FileStream(filePath, FileMode.Open))
            {
                return DeserializeFromStream<T>(fs);
            }
        }


        /// <summary>
        /// Serialize object to stream.
        /// </summary>
        /// <typeparam name="T">Type of specified object.</typeparam>
        /// <param name="obj">The specified object.</param>
        /// <param name="st">The stream to write.</param>
        public void SerializeToStream<T>(T obj, Stream st)
        {
            XmlSerializer f = XmlSerializer.FromTypes(new[] { typeof(T) })[0]; //Microsoft bug workaround.
            f.Serialize(st, obj);
        }

        /// <summary>
        /// Serialize object to string.
        /// </summary>
        /// <typeparam name="T">Type of specified object.</typeparam>
        /// <param name="obj">The specified object.</param>
        /// <returns></returns>
        public String SerializeToString<T>(T obj)
        {
            XmlSerializer f = XmlSerializer.FromTypes(new[] { typeof(T) })[0]; //Microsoft bug workaround.

            using (StringWriter textWriter = new StringWriter())
            {
                f.Serialize(textWriter, obj);
                return textWriter.ToString();
            }
        }

        /// <summary>
        /// Deserialize object from stream.
        /// </summary>
        /// <typeparam name="T">Type of object to deserialize.</typeparam>
        /// <param name="st">Stream to read from.</param>
        /// <returns>The resulting object.</returns>
        public T DeserializeFromStream<T>(Stream st)
        {
            XmlSerializer f = XmlSerializer.FromTypes(new[] { typeof(T) })[0]; //Microsoft bug workaround.
            return (T)f.Deserialize(st);
        }

        /// <summary>
        /// Deserialize object from string.
        /// </summary>
        /// <typeparam name="T">Type of specified object.</typeparam>
        /// <param name="obj">The specified object.</param>
        /// <returns></returns>
        public T DeserializeFromString<T>(String str)
        {
            XmlSerializer f = XmlSerializer.FromTypes(new[] { typeof(T) })[0]; //Microsoft bug workaround.
            using (TextReader reader = new StringReader(str))
            {
                return (T)f.Deserialize(reader);
            }
        }

        /// <summary>
        /// Returns the serializer full name.
        /// </summary>
        /// <returns></returns>
        public override string ToString()
        {
            return SerializationHelper.GetSerializerName(this);
        }

    }
}