using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

namespace F4SD.Gamification.Services
{
    internal static class PersistenceService
    {
        private static readonly string _databaseName = "F4SD-gmfc.txt";
        private static readonly string _directory = $@"{Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData)}\Consulting4IT GmbH\C4IT First Aid Service Desk";

        private static string GetConnectionString()
        {
            return Path.Combine(_directory, _databaseName);
        }

        internal static void Persist(CockpitAction action)
        {
            Initialize();

            using var writer = File.AppendText(GetConnectionString());
            string actionLine = $"{DateTime.UtcNow},{action}";
            string base64 = Convert.ToBase64String(Encoding.UTF8.GetBytes(actionLine));
            writer.WriteLine(base64);
        }

        internal static void Initialize()
        {
            Directory.CreateDirectory(_directory);

            if (!File.Exists(GetConnectionString()))
            {
                FileStream createdFile = File.Create(GetConnectionString());
                File.SetAttributes(GetConnectionString(), FileAttributes.Hidden);
                createdFile.Close();
            }
        }

        internal static IEnumerable<(DateTime Time, CockpitAction Action)> GetActions()
        {
            using StreamReader reader = new(GetConnectionString());

            string line;
            while ((line = reader.ReadLine()) != null)
            {
                string encodedLine = string.Empty;

                try { encodedLine = Encoding.UTF8.GetString(Convert.FromBase64String(line)); }
                catch { continue; }

                if (string.IsNullOrWhiteSpace(encodedLine))
                    continue;

                string[] splittedLine = encodedLine.Split(',');

                if (splittedLine.Length < 2)
                    continue;

                if (!DateTime.TryParse(splittedLine[0], out var date))
                    continue;

                if (!(Enum.TryParse(splittedLine[1], out CockpitAction action)))
                    continue;

                yield return new(date, action);
            }
        }
    }
}