using System.IO;
using Newtonsoft.Json;
using Pilz.GeneralEventArgs;

namespace Pilz.Configuration
{
    public static class ConfigurationSerializer
    {
        public static event GettingJsonSerializerEventHandler GettingJsonSerializer;

        public delegate void GettingJsonSerializerEventHandler(object instance, GetValueEventArgs<JsonSerializer> e);

        private static JsonSerializer GetJsonSerializer(SimpleConfiguration instance)
        {
            var args = new GetValueEventArgs<JsonSerializer>(JsonSerializer.CreateDefault());
            GettingJsonSerializer?.Invoke(instance, args);
            return args.Value;
        }

        /// <summary>
        /// Writes the given instance to a string and return it.
        /// </summary>
        /// <param name="instance">The configuration instance that should be serialized.</param>
        /// <returns>The content of the configuration instance as string.</returns>
        public static string WriteToString(SimpleConfiguration instance)
        {
            var tw = new StringWriter();
            GetJsonSerializer(instance).Serialize(tw, instance);
            string txt = tw.ToString();
            tw.Close();
            return txt;
        }

        /// <summary>
        /// Write the given instance to a given stream.
        /// </summary>
        /// <param name="instance">The configuration instance that should be serialized.</param>
        /// <param name="stream">The stream where the content should be written to.</param>
        public static void WriteToStream(SimpleConfiguration instance, Stream stream)
        {
            var sr = new StreamWriter(stream);
            sr.Write(WriteToString(instance));
        }

        /// <summary>
        /// Writes the given instance to the given filePath as text file.
        /// </summary>
        /// <param name="instance">The configuration instance that should be serialized.</param>
        /// <param name="filePath">The file path where the content should be written to. The file will be created or overwritten.</param>
        public static void WriteToFile(SimpleConfiguration instance, string filePath)
        {
            var fs = new FileStream(filePath, FileMode.Create, FileAccess.ReadWrite);
            WriteToStream(instance, fs);
            fs.Close();
        }

        /// <summary>
        /// Reads a configuratin from the given string and returns an instance of it.
        /// </summary>
        /// <typeparam name="T">The type of the configuration class to instance.</typeparam>
        /// <param name="content">The content of the configuration as string.</param>
        /// <returns></returns>
        public static T ReadFromString<T>(string content) where T : SimpleConfiguration
        {
            var sr = new StringReader(content);
            T instance = (T)GetJsonSerializer(null).Deserialize(sr, typeof(T));
            sr.Close();
            return instance;
        }

        /// <summary>
        /// Read a configuration from the given string and put them to the given instance.
        /// </summary>
        /// <param name="instance">The instance to populate with the configuration.</param>
        /// <param name="content">The content of the configuration as string.</param>
        public static void ReadFromString(SimpleConfiguration instance, string content)
        {
            var sr = new StringReader(content);
            GetJsonSerializer(null).Populate(sr, content);
            sr.Close();
        }

        /// <summary>
        /// Reads a configuratin from the given string and returns an instance of it.
        /// </summary>
        /// <typeparam name="T">The type of the configuration class to instance.</typeparam>
        /// <param name="stream">The stream with the content of the configuration.</param>
        /// <returns></returns>
        public static T ReadFromStream<T>(Stream stream) where T : SimpleConfiguration
        {
            return ReadFromString<T>(GetContentOfStream(stream));
        }

        /// <summary>
        /// Read a configuration from the given string and put them to the given instance.
        /// </summary>
        /// <param name="instance">The instance to populate with the configuration.</param>
        /// <param name="stream">The stream with the content of the configuration.</param>
        public static void ReadFromStream(SimpleConfiguration instance, Stream stream)
        {
            ReadFromString(instance, GetContentOfStream(stream));
        }

        /// <summary>
        /// Reads a configuratin from the given string and returns an instance of it.
        /// </summary>
        /// <typeparam name="T">The type of the configuration class to instance.</typeparam>
        /// <param name="filePath">The path to the file with the content of the configuration.</param>
        /// <returns></returns>
        public static T ReadFromFile<T>(string filePath) where T : SimpleConfiguration
        {
            return ReadFromString<T>(GetContentOfFile(filePath));
        }

        /// <summary>
        /// Read a configuration from the given string and put them to the given instance.
        /// </summary>
        /// <param name="instance">The instance to populate with the configuration.</param>
        /// <param name="filePath">The path to the file with the content of the configuration.</param>
        public static void ReadFromFile(SimpleConfiguration instance, string filePath)
        {
            ReadFromString(instance, GetContentOfFile(filePath));
        }

        private static string GetContentOfStream(Stream stream)
        {
            var sr = new StreamReader(stream);
            return sr.ReadToEnd();
        }

        private static string GetContentOfFile(string filePath)
        {
            var fs = new FileStream(filePath, FileMode.Open, FileAccess.Read);
            string content = GetContentOfStream(fs);
            fs.Close();
            return content;
        }
    }
}