/// Copyright (c) 2021 Iiro Iivanainen, Harri Linna, Jere Pakkanen, Riikka Vilavaara
/// 
/// Permission is hereby granted, free of charge, to any person obtaining
/// a copy of this software and associated documentation files (the
/// "Software"), to deal in the Software without restriction, including
/// without limitation the rights to use, copy, modify, merge, publish,
/// distribute, sublicense, and/or sell copies of the Software, and to
/// permit persons to whom the Software is furnished to do so, subject to
/// the following conditions:
/// 
/// The above copyright notice and this permission notice shall be included
/// in all copies or substantial portions of the Software.
/// 
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
/// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
/// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
/// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
/// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
/// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
/// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
/// 
/// @created 07.03.2021
/// @version 24.04.2021, JSON
/// @version 25.04.2021, Standard library Vector3

using System;
using System.IO;
using System.Text.Json;
using System.Threading.Tasks;

namespace CoreLibrary
{
    /// <summary>
    /// Exception class for image reading
    /// </summary>
    public class SaveException : Exception
    {
        public SaveException(string message) : base(message)
        {
        }
    }

    /// <summary>
    /// Exception class for stack writing
    /// </summary>
    public class LoadException : Exception
    {
        public LoadException(string message) : base(message)
        {
        }
    }
    /// <summary>Operations for reading text files, especially CSV files.</summary>
    public static class FileManager
    {
        /// <summary>
        /// Synchronous non generic deserializer. Deserializes sample from json
        /// file.
        /// </summary>
        /// <param name="filepath">Path to JSON file</param>
        /// <returns>Sample made from the JSON file</returns>
        /// <exception cref="SaveException">Thrown when failed to write stack</exception>
        public static Sample Dezerialize(string filepath)
        {
            try
            {
                FileStream filestream = File.OpenRead(filepath);
                if (!File.Exists(filepath)) return new Sample();
                string contents;
                var sr = new StreamReader(filestream);
                contents = sr.ReadToEnd();
                filestream.Close();
                sr.Close();
                return JsonSerializer.Deserialize<Sample>(contents, options);
            }
            catch (IOException e)
            {
                throw new SaveException("Failed to save sample. Problems with IO operations: " 
                                            + e.Message);
            }
            catch (JsonException e)
            {
                throw new SaveException("Failed to save sample. Problems with Json serialization: " 
                                            + e.Message);
            }
            
        }

        /// <summary>
        /// Synchronous non generic serialization of sample. Writes 
        /// JSON string representing the sample into a file.
        /// </summary>
        /// <param name="samp">Sample to serialize into JSON</param>
        /// <param name="filepath">Filepath to the written JSON file</param>
        /// <exception cref="LoadException">Thrown when failed to write stack</exception>
        public static void SerializeSync(Sample samp, string filepath)
        {
            try
            {
                string info = JsonSerializer.Serialize(samp, options);
                StreamWriter writer = new(filepath);
                writer.Write(info);
                writer.Close();
            }
            catch(IOException e)
            {
                throw new SaveException("Failed to load sample. Problems with IO operations: "
                                            + e.Message);
            }
            
        }

        /// <summary>
        /// JSON object contains public properties as well.
        /// </summary>
        private static readonly JsonSerializerOptions options 
            = new() { IncludeFields = true,
                                            Converters = {new Vector3JSONConverter()}
            };
    }
}