using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using MotoresArgentinosV2.Core.Interfaces;
using MotoresArgentinosV2.Infrastructure.Data;
using MotoresArgentinosV2.Core.Entities;
using MotoresArgentinosV2.Core.DTOs;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.RateLimiting;

namespace MotoresArgentinosV2.API.Controllers;

[ApiController]
[Route("api/[controller]")]
[EnableRateLimiting("AuthPolicy")]
public class AuthController : ControllerBase
{
    private readonly IIdentityService _identityService;
    private readonly ITokenService _tokenService;
    private readonly INotificationService _notificationService;
    private readonly MotoresV2DbContext _context;

    public AuthController(IIdentityService identityService, ITokenService tokenService, INotificationService notificationService, MotoresV2DbContext context)
    {
        _identityService = identityService;
        _tokenService = tokenService;
        _notificationService = notificationService;
        _context = context;
    }

    // Helper privado para cookies
    private void SetTokenCookie(string token, string cookieName)
    {
        var cookieOptions = new CookieOptions
        {
            HttpOnly = true, // Seguridad: JS no puede leer esto
            Expires = DateTime.UtcNow.AddMinutes(15),
            Secure = true, // Solo HTTPS (localhost con https cuenta)
            SameSite = SameSiteMode.Strict,
            IsEssential = true
        };
        Response.Cookies.Append(cookieName, token, cookieOptions);
    }

    [HttpPost("login")]
    [EnableRateLimiting("AuthPolicy")] // PROTEGIDO (5 intentos/min)
    public async Task<IActionResult> Login([FromBody] LoginRequest request)
    {
        var (user, message) = await _identityService.AuthenticateAsync(request.Username, request.Password);

        if (user == null)
        {
            if (message == "EMAIL_NOT_VERIFIED")
                return Unauthorized(new { message = "Debes verificar tu email antes de ingresar." });

            if (message == "USER_BLOCKED")
                return Unauthorized(new { message = "Tu usuario ha sido bloqueado por un administrador." });

            return Unauthorized(new { message = "Credenciales inválidas" });
        }

        if (message == "FORCE_PASSWORD_CHANGE")
        {
            return Ok(new { status = "MIGRATION_REQUIRED", username = user.UserName });
        }

        // Lógica MFA (Si aplica)
        if (user.IsMFAEnabled)
        {
            return Ok(new { status = "TOTP_REQUIRED", username = user.UserName });
        }
        if (user.UserType == 3 && string.IsNullOrEmpty(user.MFASecret)) // Admin forzar setup
        {
            var secret = _tokenService.GenerateBase32Secret();
            user.MFASecret = secret;
            await _context.SaveChangesAsync();
            var qrUri = _tokenService.GetQrCodeUri(user.Email, secret);
            return Ok(new { status = "MFA_SETUP_REQUIRED", username = user.UserName, qrUri, secret });
        }

        // --- LOGIN EXITOSO ---

        // 1. Generar Tokens
        var jwtToken = _tokenService.GenerateJwtToken(user);
        var refreshToken = _tokenService.GenerateRefreshToken(HttpContext.Connection.RemoteIpAddress?.ToString() ?? "0.0.0.0");

        // 2. Guardar RefreshToken en DB
        // Asegúrate de que la propiedad RefreshTokens exista en User (Paso 2 abajo)
        user.RefreshTokens.Add(refreshToken);
        await _context.SaveChangesAsync();

        // 3. Setear Cookies
        SetTokenCookie(jwtToken, "accessToken");
        SetTokenCookie(refreshToken.Token, "refreshToken");

        // 4. Audit Log
        _context.AuditLogs.Add(new AuditLog
        {
            Action = "LOGIN_SUCCESS",
            Entity = "User",
            EntityID = user.UserID,
            UserID = user.UserID,
            Details = "Login con Cookies exitoso"
        });
        await _context.SaveChangesAsync();

        // 5. Retornar User (Sin el token, porque va en cookie)
        return Ok(new
        {
            status = "SUCCESS",
            recommendMfa = !user.IsMFAEnabled,
            user = new
            {
                id = user.UserID,
                username = user.UserName,
                email = user.Email,
                firstName = user.FirstName,
                lastName = user.LastName,
                userType = user.UserType,
                isMFAEnabled = user.IsMFAEnabled
            }
        });
    }

    [HttpPost("refresh-token")]
    // NO PROTEGIDO ESTRICTAMENTE (Usa límite global)
    public async Task<IActionResult> RefreshToken()
    {
        var refreshToken = Request.Cookies["refreshToken"];
        if (string.IsNullOrEmpty(refreshToken))
            return Unauthorized(new { message = "Token no proporcionado" });

        var user = await _context.Users
            .Include(u => u.RefreshTokens)
            .FirstOrDefaultAsync(u => u.RefreshTokens.Any(t => t.Token == refreshToken));

        if (user == null) return Unauthorized(new { message = "Usuario no encontrado" });

        var storedToken = user.RefreshTokens.SingleOrDefault(x => x.Token == refreshToken);

        if (storedToken == null || !storedToken.IsActive)
            return Unauthorized(new { message = "Token inválido o expirado" });

        // Rotar Refresh Token
        var newRefreshToken = _tokenService.GenerateRefreshToken(HttpContext.Connection.RemoteIpAddress?.ToString() ?? "0.0.0.0");

        storedToken.Revoked = DateTime.UtcNow;
        storedToken.RevokedByIp = HttpContext.Connection.RemoteIpAddress?.ToString();
        storedToken.ReplacedByToken = newRefreshToken.Token;

        user.RefreshTokens.Add(newRefreshToken);
        await _context.SaveChangesAsync();

        // Nuevo JWT
        var newJwtToken = _tokenService.GenerateJwtToken(user);

        // Actualizar Cookies
        SetTokenCookie(newJwtToken, "accessToken");
        SetTokenCookie(newRefreshToken.Token, "refreshToken");

        return Ok(new { message = "Token renovado" });
    }

    [HttpPost("logout")]
    // NO PROTEGIDO ESTRICTAMENTE
    public IActionResult Logout()
    {
        Response.Cookies.Delete("accessToken");
        Response.Cookies.Delete("refreshToken");
        return Ok(new { message = "Sesión cerrada" });
    }

    [HttpGet("me")]
    // 1. Sin [Authorize] para controlar nosotros la respuesta
    public async Task<IActionResult> GetMe()
    {
        // 2. Verificamos si existe la cookie de acceso
        var hasToken = Request.Cookies.ContainsKey("accessToken");

        // 3. Si NO tiene cookie, es un visitante anónimo. 
        // Devolvemos 200 OK con null para no ensuciar la consola con 401.
        if (!hasToken)
        {
            return Ok(null);
        }

        // 4. Si TIENE cookie, verificamos si el Middleware pudo leer el usuario.
        var userIdStr = User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value;

        // Si tiene cookie pero userIdStr es null, significa que el token expiró o es inválido.
        // Aquí SI devolvemos 401 para disparar el "Auto Refresh" del frontend.
        if (string.IsNullOrEmpty(userIdStr))
        {
            return Unauthorized();
        }

        // 5. Todo válido, buscamos datos
        var userId = int.Parse(userIdStr);
        var user = await _context.Users.FindAsync(userId);

        if (user == null) return Unauthorized(); // Usuario borrado de DB

        return Ok(new
        {
            id = user.UserID,
            username = user.UserName,
            email = user.Email,
            firstName = user.FirstName,
            lastName = user.LastName,
            userType = user.UserType,
            phoneNumber = user.PhoneNumber,
            isMFAEnabled = user.IsMFAEnabled
        });
    }

    // Permite a un usuario logueado iniciar el proceso de MFA voluntariamente
    [Authorize]
    [HttpPost("init-mfa")]
    public async Task<IActionResult> InitMFA()
    {
        var userIdStr = User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value;
        if (string.IsNullOrEmpty(userIdStr)) return Unauthorized();

        var user = await _context.Users.FindAsync(int.Parse(userIdStr));
        if (user == null) return NotFound();

        // Generar secreto si no tiene
        if (string.IsNullOrEmpty(user.MFASecret))
        {
            user.MFASecret = _tokenService.GenerateBase32Secret();
            await _context.SaveChangesAsync();
        }

        // 📝 AUDITORÍA
        _context.AuditLogs.Add(new AuditLog
        {
            Action = "MFA_INITIATED",
            Entity = "User",
            EntityID = user.UserID,
            UserID = user.UserID,
            Details = "Proceso de configuración de MFA (TOTP) iniciado."
        });
        await _context.SaveChangesAsync();

        var qrUri = _tokenService.GetQrCodeUri(user.Email, user.MFASecret);

        return Ok(new
        {
            qrUri = qrUri,
            secret = user.MFASecret
        });
    }

    [HttpPost("verify-mfa")]
    [EnableRateLimiting("AuthPolicy")]
    public async Task<IActionResult> VerifyMFA([FromBody] MFARequest request)
    {
        var user = await _context.Users.FirstOrDefaultAsync(u => u.UserName == request.Username);
        if (user == null || string.IsNullOrEmpty(user.MFASecret))
        {
            return Unauthorized(new { message = "Sesión de autenticación inválida" });
        }

        bool isValid = _tokenService.ValidateTOTP(user.MFASecret, request.Code);
        if (!isValid)
        {
            return Unauthorized(new { message = "Código de verificación inválido" });
        }

        if (!user.IsMFAEnabled)
        {
            user.IsMFAEnabled = true;
            await _context.SaveChangesAsync();
        }

        var token = _tokenService.GenerateJwtToken(user);
        var refreshToken = _tokenService.GenerateRefreshToken(HttpContext.Connection.RemoteIpAddress?.ToString() ?? "0.0.0.0");

        // Cargar colección explícitamente para evitar errores de EF
        await _context.Entry(user).Collection(u => u.RefreshTokens).LoadAsync();

        user.RefreshTokens.Add(refreshToken);
        await _context.SaveChangesAsync();

        // Setear Cookies Seguras
        SetTokenCookie(token, "accessToken");
        SetTokenCookie(refreshToken.Token, "refreshToken");

        _context.AuditLogs.Add(new AuditLog
        {
            Action = "LOGIN_TOTP_SUCCESS",
            Entity = "User",
            EntityID = user.UserID,
            UserID = user.UserID,
            Details = "Login con TOTP (Authenticator) exitoso"
        });
        await _context.SaveChangesAsync();

        return Ok(new
        {
            status = "SUCCESS",
            // user: retornamos datos para el frontend, pero NO el token
            user = new
            {
                id = user.UserID,
                username = user.UserName,
                email = user.Email,
                firstName = user.FirstName,
                lastName = user.LastName,
                userType = user.UserType,
                isMFAEnabled = user.IsMFAEnabled
            }
        });
    }

    [Authorize]
    [HttpPost("disable-mfa")]
    public async Task<IActionResult> DisableMFA()
    {
        var userIdStr = User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value;
        if (string.IsNullOrEmpty(userIdStr)) return Unauthorized();

        var user = await _context.Users.FindAsync(int.Parse(userIdStr));
        if (user == null) return NotFound();

        // Desactivamos MFA y limpiamos el secreto por seguridad
        user.IsMFAEnabled = false;
        user.MFASecret = null;

        // 📝 AUDITORÍA
        _context.AuditLogs.Add(new AuditLog
        {
            Action = "MFA_DISABLED",
            Entity = "User",
            EntityID = user.UserID,
            UserID = user.UserID,
            Details = "Autenticación de dos factores desactivada por el usuario."
        });

        await _context.SaveChangesAsync();

        return Ok(new { message = "MFA Desactivado correctamente." });
    }

    [HttpPost("migrate-password")]
    [EnableRateLimiting("AuthPolicy")]
    public async Task<IActionResult> MigratePassword([FromBody] MigrateRequest request)
    {
        var success = await _identityService.MigratePasswordAsync(request.Username, request.NewPassword);

        if (!success)
        {
            return BadRequest(new { message = "No se pudo actualizar la contraseña" });
        }

        return Ok(new { message = "Contraseña actualizada con éxito. Ya puede iniciar sesión." });
    }

    [HttpPost("register")]
    [EnableRateLimiting("AuthPolicy")] // PROTEGIDO
    public async Task<IActionResult> Register([FromBody] RegisterRequest request)
    {
        var (success, message) = await _identityService.RegisterUserAsync(request);
        if (!success) return BadRequest(new { message });

        // 📝 AUDITORÍA
        _context.AuditLogs.Add(new AuditLog
        {
            Action = "USER_REGISTERED",
            Entity = "User",
            EntityID = 0,
            UserID = 0,
            Details = $"Nuevo registro de usuario: {request.Email}"
        });
        await _context.SaveChangesAsync();

        return Ok(new { message });
    }

    [HttpPost("verify-email")]
    [EnableRateLimiting("AuthPolicy")] // PROTEGIDO
    public async Task<IActionResult> VerifyEmail([FromBody] VerifyEmailRequest request)
    {
        var (success, message) = await _identityService.VerifyEmailAsync(request.Token);
        if (!success) return BadRequest(new { message });

        // 📝 AUDITORÍA
        _context.AuditLogs.Add(new AuditLog
        {
            Action = "EMAIL_VERIFIED",
            Entity = "User",
            EntityID = 0,
            UserID = 0,
            Details = "Correo electrónico verificado con éxito vía token."
        });
        await _context.SaveChangesAsync();

        return Ok(new { message });
    }

    [HttpPost("resend-verification")]
    [EnableRateLimiting("AuthPolicy")] // PROTEGIDO
    public async Task<IActionResult> ResendVerification([FromBody] ResendVerificationRequest request)
    {
        var (success, message) = await _identityService.ResendVerificationEmailAsync(request.Email);
        if (!success) return BadRequest(new { message });
        return Ok(new { message });
    }

    [HttpPost("forgot-password")]
    [EnableRateLimiting("AuthPolicy")] // PROTEGIDO
    public async Task<IActionResult> ForgotPassword([FromBody] ForgotPasswordRequest request)
    {
        var (success, message) = await _identityService.ForgotPasswordAsync(request.Email);

        if (!success)
        {
            // Si falló por Rate Limit, devolvemos BadRequest o 429 Too Many Requests
            return BadRequest(new { message });
        }

        return Ok(new { message });
    }

    [HttpPost("reset-password")]
    [EnableRateLimiting("AuthPolicy")] // PROTEGIDO
    public async Task<IActionResult> ResetPassword([FromBody] ResetPasswordRequest request)
    {
        var (success, message) = await _identityService.ResetPasswordAsync(request.Token, request.NewPassword);
        if (!success) return BadRequest(new { message });

        // 📝 AUDITORÍA
        _context.AuditLogs.Add(new AuditLog
        {
            Action = "PASSWORD_RESET_SUCCESS",
            Entity = "User",
            EntityID = 0, // No tenemos el ID directo aquí sin buscarlo
            UserID = 0,
            Details = "Contraseña restablecida vía token de recuperación."
        });
        await _context.SaveChangesAsync();

        return Ok(new { message });
    }

    [Authorize]
    [HttpPost("change-password")]
    [EnableRateLimiting("AuthPolicy")] // PROTEGIDO
    public async Task<IActionResult> ChangePassword([FromBody] ChangePasswordRequest request)
    {
        var userId = int.Parse(User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value ?? "0");
        var (success, message) = await _identityService.ChangePasswordAsync(userId, request.CurrentPassword, request.NewPassword);

        if (!success) return BadRequest(new { message });

        // Enviar notificación por mail
        try
        {
            var user = await _context.Users.FindAsync(userId);
            if (user != null)
            {
                await _notificationService.SendSecurityAlertEmailAsync(user.Email, "Cambio de contraseña");
            }
        }
        catch (Exception) { /* No bloqueamos el éxito si falla el mail */ }

        // 📝 AUDITORÍA
        _context.AuditLogs.Add(new AuditLog
        {
            Action = "PASSWORD_CHANGED",
            Entity = "User",
            EntityID = userId,
            UserID = userId,
            Details = "Contraseña cambiada por el usuario desde la configuración."
        });
        await _context.SaveChangesAsync();

        return Ok(new { message });
    }
}

public class ChangePasswordRequest
{
    public string CurrentPassword { get; set; } = string.Empty;
    public string NewPassword { get; set; } = string.Empty;
}