Mimante/Mimante/Services/SessionManager.cs

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
using System.Text.Json;
using AutoBidder.Models;

namespace AutoBidder.Services
{
    /// <summary>
    /// Gestore persistenza sessione Bidoo
    /// Salva in modo sicuro il cookie di autenticazione per riutilizzo
    /// </summary>
    public class SessionManager
    {
        private static readonly string SessionFilePath = Path.Combine(
            Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
            "AutoBidder",
            "session.dat"
        );
        
        private static readonly byte[] Entropy = Encoding.UTF8.GetBytes("AutoBidder_V1_2025");
        
        /// <summary>
        /// Salva la sessione in modo sicuro (crittografata con DPAPI)
        /// </summary>
        public static bool SaveSession(BidooSession session)
        {
            try
            {
                // Crea directory se non esiste
                var directory = Path.GetDirectoryName(SessionFilePath);
                if (!string.IsNullOrEmpty(directory) && !Directory.Exists(directory))
                {
                    Directory.CreateDirectory(directory);
                }
                
                // Serializza sessione in JSON
                var json = JsonSerializer.Serialize(session, new JsonSerializerOptions 
                { 
                    WriteIndented = true 
                });
                
                // Cripta usando DPAPI (Windows Data Protection API)
                var plainBytes = Encoding.UTF8.GetBytes(json);
                var encryptedBytes = ProtectedData.Protect(plainBytes, Entropy, DataProtectionScope.CurrentUser);
                
                // Salva su file
                File.WriteAllBytes(SessionFilePath, encryptedBytes);
                
                Console.WriteLine($"[SESSION] Saved to: {SessionFilePath}");
                return true;
            }
            catch (Exception ex)
            {
                Console.WriteLine($"[SESSION ERROR] Failed to save: {ex.Message}");
                return false;
            }
        }
        
        /// <summary>
        /// Carica la sessione salvata (decripta con DPAPI)
        /// </summary>
        public static BidooSession? LoadSession()
        {
            try
            {
                if (!File.Exists(SessionFilePath))
                {
                    Console.WriteLine($"[SESSION] No saved session found");
                    return null;
                }
                
                // Leggi file crittografato
                var encryptedBytes = File.ReadAllBytes(SessionFilePath);
                
                // Decripta usando DPAPI
                var plainBytes = ProtectedData.Unprotect(encryptedBytes, Entropy, DataProtectionScope.CurrentUser);
                var json = Encoding.UTF8.GetString(plainBytes);
                
                // Deserializza JSON
                var session = JsonSerializer.Deserialize<BidooSession>(json);
                
                if (session != null && session.IsValid)
                {
                    Console.WriteLine($"[SESSION] Loaded from: {SessionFilePath}");
                    Console.WriteLine($"[SESSION] Username: {session.Username}");
                    return session;
                }
                
                Console.WriteLine($"[SESSION] Loaded session is invalid");
                return null;
            }
            catch (Exception ex)
            {
                Console.WriteLine($"[SESSION ERROR] Failed to load: {ex.Message}");
                return null;
            }
        }
        
        /// <summary>
        /// Elimina la sessione salvata
        /// </summary>
        public static bool ClearSession()
        {
            try
            {
                if (File.Exists(SessionFilePath))
                {
                    File.Delete(SessionFilePath);
                    Console.WriteLine($"[SESSION] Cleared: {SessionFilePath}");
                }
                return true;
            }
            catch (Exception ex)
            {
                Console.WriteLine($"[SESSION ERROR] Failed to clear: {ex.Message}");
                return false;
            }
        }
        
        /// <summary>
        /// Verifica se esiste una sessione salvata
        /// </summary>
        public static bool HasSavedSession()
        {
            return File.Exists(SessionFilePath);
        }
        
        /// <summary>
        /// Ottiene informazioni sulla sessione salvata senza caricarla
        /// </summary>
        public static (bool exists, DateTime? lastModified) GetSessionInfo()
        {
            if (File.Exists(SessionFilePath))
            {
                var fileInfo = new FileInfo(SessionFilePath);
                return (true, fileInfo.LastWriteTime);
            }
            return (false, null);
        }
    }
}