using System;
using System.Collections.Generic;
using System.IO;
using System.Text.Json;
using Project_Periodensystem.Model;

namespace Project_Periodensystem.Persistence
{
    /// <summary>
    /// Erweiterte Persistenz - Speichern/Laden von JSON-Dateien
    /// </summary>
    public static class DataManager
    {
        private static readonly string DataDirectory = Path.Combine(
            Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
            "Periodensystem");
        
        private static readonly string ElementsFile = Path.Combine(DataDirectory, "elements.json");
        private static readonly string SettingsFile = Path.Combine(DataDirectory, "settings.json");

        /// <summary>
        /// Speichert Elemente als JSON
        /// </summary>
        public static void SaveElements(List<Element> elements)
        {
            try
            {
                Directory.CreateDirectory(DataDirectory);
                var json = JsonSerializer.Serialize(elements, new JsonSerializerOptions { WriteIndented = true });
                File.WriteAllText(ElementsFile, json);
                Logger.Log($"Elemente gespeichert: {elements.Count} Einträge");
            }
            catch (Exception ex)
            {
                Logger.LogException(ex, "SaveElements");
            }
        }

        /// <summary>
        /// Lädt Elemente aus JSON oder Fallback zu eingebauten Daten
        /// </summary>
        public static List<Element> LoadElements()
        {
            try
            {
                if (File.Exists(ElementsFile))
                {
                    var json = File.ReadAllText(ElementsFile);
                    var elements = JsonSerializer.Deserialize<List<Element>>(json);
                    if (elements != null && elements.Count > 0)
                    {
                        Logger.Log($"Elemente aus Datei geladen: {elements.Count}");
                        return elements;
                    }
                }
            }
            catch (Exception ex)
            {
                Logger.LogException(ex, "LoadElements");
            }

            // Fallback zu eingebauten Daten
            Logger.Log("Fallback zu eingebauten Element-Daten");
            return PeriodicTableData.Elements;
        }

        /// <summary>
        /// Speichert Benutzereinstellungen
        /// </summary>
        public static void SaveSettings(AppSettings settings)
        {
            try
            {
                Directory.CreateDirectory(DataDirectory);
                var json = JsonSerializer.Serialize(settings, new JsonSerializerOptions { WriteIndented = true });
                File.WriteAllText(SettingsFile, json);
            }
            catch (Exception ex)
            {
                Logger.LogException(ex, "SaveSettings");
            }
        }

        /// <summary>
        /// Lädt Benutzereinstellungen
        /// </summary>
        public static AppSettings LoadSettings()
        {
            try
            {
                if (File.Exists(SettingsFile))
                {
                    var json = File.ReadAllText(SettingsFile);
                    var settings = JsonSerializer.Deserialize<AppSettings>(json);
                    return settings ?? new AppSettings();
                }
            }
            catch (Exception ex)
            {
                Logger.LogException(ex, "LoadSettings");
            }

            return new AppSettings();
        }
    }

    /// <summary>
    /// Benutzereinstellungen für Persistenz
    /// </summary>
    public class AppSettings
    {
        public string LastTheme { get; set; } = "Dark";
        public DateTime LastUsed { get; set; } = DateTime.Now;
        public string PreferredLanguage { get; set; } = "German";
    }
}