using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Terminal.Gui;
using YamlDotNet.Serialization;

namespace Akari.Provider.WaveshareUART.Users
{
    public class UsersManager
    {
        public const string UsersFilePath = "users.yaml";

        private readonly List<User> _users;
        private IDeserializer _deserializer;
        private ISerializer _serializer;

        public int Count => _users.Count;

        public UsersManager()
        {
            _serializer = new SerializerBuilder().Build();
            _deserializer = new DeserializerBuilder().Build();

            try
            {
                if (!File.Exists(UsersFilePath))
                {
                    _users = new List<User>();
                }
                else
                {
                    _users = _deserializer.Deserialize<List<User>>(File.ReadAllText(UsersFilePath));
                }
            }
            catch (Exception e)
            {
                Console.WriteLine($"Can't load users: {e.Message}");
                Console.WriteLine(e.StackTrace);
            }
        }

        public User this[string name] => _users.FirstOrDefault(u => u.Name.Equals(name, StringComparison.OrdinalIgnoreCase));

        public void Add(User user)
        {
            _users.Add(user);

            Save();
        }

        public IReadOnlyCollection<User> GetAll()
        {
            return _users.AsReadOnly();
        }

        public void Remove(User user)
        {
            _users.Remove(user);

            Save();
        }

        public void Clear()
        {
            _users.Clear();

            Save();
        }

        private void Save()
        {
            try
            {
                File.WriteAllText(UsersFilePath, _serializer.Serialize(_users));
            }
            catch (Exception e)
            {
                Console.WriteLine($"Can't save users: {e.Message}");
                Console.WriteLine(e.StackTrace);

                MessageBox.ErrorQuery("Users", $"Can't save users: {e.Message}");
            }
        }
    }
}