using System;
using System.IO;
using System.Text.Json;
using System.Threading.Tasks;
using BetterEN5.Services;

namespace BetterEN5
{
    public class InkAutoSaveService
    {
        private static readonly string SettingsPath = Path.Combine(
            Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
            "BetterEN5", "ink-settings.json");

        public async Task StartAsync()
        {
            while (true)
            {
                try
                {
                    var settings = LoadSettings();
                    if (settings != null && settings.AutoSaveEnabled)
                    {
                        var dir = settings.SaveDirectory;
                        if (!string.IsNullOrEmpty(dir))
                        {
                            if (!Directory.Exists(dir))
                                Directory.CreateDirectory(dir);
                            var timestamp = DateTime.Now.ToString("yyyyMMdd-HHmmss");
                            var filePath = Path.Combine(dir, $"ink-auto-{timestamp}.ink.json");
                            var inkService = new InkService();
                            await inkService.ExportInkAsync(filePath);

                            var retentionMinutes = settings.AutoSaveIntervalMinutes * 2;
                            CleanOldFiles(dir, TimeSpan.FromMinutes(retentionMinutes > 0 ? retentionMinutes : 10));
                        }
                    }
                }
                catch { }

                var intervalMinutes = LoadSettings()?.AutoSaveIntervalMinutes ?? 5;
                await Task.Delay(TimeSpan.FromMinutes(Math.Max(1, intervalMinutes)));
            }
        }

        private static InkAutoSaveSettings? LoadSettings()
        {
            try
            {
                if (File.Exists(SettingsPath))
                {
                    var json = File.ReadAllText(SettingsPath);
                    return JsonSerializer.Deserialize<InkAutoSaveSettings>(json);
                }
            }
            catch { }
            return null;
        }

        private static void CleanOldFiles(string dir, TimeSpan maxAge)
        {
            try
            {
                if (!Directory.Exists(dir)) return;
                foreach (var file in Directory.GetFiles(dir, "ink-auto-*.ink.json"))
                {
                    try
                    {
                        if (DateTime.Now - File.GetCreationTime(file) > maxAge)
                            File.Delete(file);
                    }
                    catch { }
                }
            }
            catch { }
        }
    }

    public class InkAutoSaveSettings
    {
        public bool AutoSaveEnabled { get; set; }
        public int AutoSaveIntervalMinutes { get; set; } = 5;
        public string SaveDirectory { get; set; } = "";
    }
}