using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.IdentityModel.Tokens;
using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using System.Text;
using phronCare.API.Models;
using Services.Models;
using Services.Interfaces;
using phronCare.API.Models.Authentication.Login;
using phronCare.API.Models.Authentication.SingUp;
using Google.Authenticator;
using QRCoder;
using System.ComponentModel.DataAnnotations;

namespace phronCare.API.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class AuthenticationController(UserManager<IdentityUser> userManager, RoleManager<IdentityRole> roleManager, IEmailService emailService, IConfiguration configuration, SignInManager<IdentityUser> signInManager, TwoFactorAuthenticator twoFactorAuthenticator) : ControllerBase
    {
        private const int JWT_TOKEN_VALIDITY_HOURS = 48;

        #region Declaration Section
        private readonly UserManager<IdentityUser> userManager = userManager;
        private readonly RoleManager<IdentityRole> roleManager = roleManager;
        private readonly SignInManager<IdentityUser> signInManager = signInManager;
        private readonly TwoFactorAuthenticator authenticator = twoFactorAuthenticator;
        private readonly IEmailService emailService = emailService;
        private readonly IConfiguration configuration = configuration;

        #endregion

        [HttpPost]
        [Route("generate-qr-code")]
        public async Task<IActionResult> GenerateQRCodeAsync()
        {
            try
            {
                var user = await signInManager.GetTwoFactorAuthenticationUserAsync(); // Obtén el nombre de usuario actual

                if (user == null)
                {
                    return BadRequest(new Response { Status = "Error", Message = "Usuario no autenticado." });
                }
                var setupInfo = authenticator.GenerateSetupCode("MiApp", user.Email, user.Id, false, 10);

                // Genera el código QR como una imagen
                var qrCodeGenerator = new QRCodeGenerator();
                var qrCodeData = qrCodeGenerator.CreateQrCode(setupInfo.ManualEntryKey, QRCodeGenerator.ECCLevel.Q);
                var qrCode = new PngByteQRCode(qrCodeData);

                // Convierte la imagen del código QR en bytes
                var qrCodeImage = qrCode.GetGraphic(10); // Ajusta el tamaño según tus necesidades
                var qrCodeImageData = Convert.ToBase64String(qrCodeImage);

                // Devuelve el userId (clave secreta) y la imagen del código QR en la respuesta
                return Ok(new AuthResponse
                {
                    Status = "Success",
                    Message = "Código QR generado satisfactoriamente.",
                    ManualSetupKey = setupInfo.ManualEntryKey, // Proporciona esto al usuario para configuración manual en Google Authenticator
                    QRCodeImage = qrCodeImageData // Devuelve la imagen del código QR
                });
            }
            catch (Exception)
            {
                return StatusCode(StatusCodes.Status500InternalServerError, new AuthResponse { Status = "Error", Message = "Error al generar el código QR." });
            }
        }

        [HttpPost]
        [Route("register")]
        public async Task<IActionResult> Register([FromBody] RegisterUser registerUser)
        {
            //Chequeo Correo existente
            var userExist = await userManager.FindByEmailAsync(registerUser.EmailAddress);
            if (userExist != null)
            {
                return StatusCode(StatusCodes.Status409Conflict, "El correo ingresado ya esta en uso.");
            }
            userExist = await userManager.FindByNameAsync(registerUser.UserName);
            if (userExist != null)
            {
                return StatusCode(StatusCodes.Status409Conflict, "El usuario ingresado ya existe.");
            }

            IdentityUser user = new()
            {
                Email = registerUser.EmailAddress,
                SecurityStamp = Guid.NewGuid().ToString(),
                UserName = registerUser.UserName
            };

            if (await roleManager.RoleExistsAsync(registerUser.Role))
            {
                var result = await userManager.CreateAsync(user, registerUser.Password);
                if (!result.Succeeded)
                {
                    return StatusCode(StatusCodes.Status500InternalServerError, $"Creacion de usuario fallida: {result}");
                }
                await userManager.AddToRoleAsync(user, registerUser.Role);

                //Add Token to Verify the email
                var token = await userManager.GenerateEmailConfirmationTokenAsync(user);
                var confirmationLink = Url.Action(nameof(ConfirmEmail), "Authentication", new { token, email = user.Email }, Request.Scheme);
                var message = new Message([user.Email!], "phronCare - Link de verificacion", confirmationLink!);
                emailService.SendEmail(message);

                return StatusCode(StatusCodes.Status201Created, $"Usuario creado satisfactoriamente. Debe autenticar la cuenta generada desde la direccion de correo registrada: {user.Email}");
            }
            else
            {
                return StatusCode(StatusCodes.Status500InternalServerError, "El rol no existe. Intentalo nuevamente!");
            }
        }

        [HttpGet("confirmemail")]
        public async Task<IActionResult> ConfirmEmail(string token, string email)
        {
            var user = await userManager.FindByEmailAsync(email);
            if (user != null)
            {
                var result = await userManager.ConfirmEmailAsync(user, token);
                if (result.Succeeded)
                {
                    return StatusCode(StatusCodes.Status200OK,
                      new Response { Status = "Success", Message = "Email verificado satisfactoriamente" });
                }
            }
            return StatusCode(StatusCodes.Status409Conflict,
                       new Response { Status = "Error", Message = "Este usuario no existe" });
        }

        [HttpPost]
        [Route("login")]
        public async Task<IActionResult> Login([FromBody] LoginModel loginModel)
        {
            await signInManager.SignOutAsync();
            var user = await userManager.FindByNameAsync(loginModel.Username);
            if (user is null)
            {
                return Unauthorized("El nombre de usuario o contraseña son incorrectos");
            };

            var canSignIn = await signInManager.CanSignInAsync(user);
            if (!canSignIn)
            {
                string message = string.Empty;
                if (userManager.Options.SignIn.RequireConfirmedEmail && !(await userManager.IsEmailConfirmedAsync(user)))
                {
                    message = "El usuario {" + user.UserName + "} no puede iniciar sesion sin tener el email confirmado.";
                }
                if (userManager.Options.SignIn.RequireConfirmedPhoneNumber && !(await userManager.IsPhoneNumberConfirmedAsync(user)))
                {
                    message = "El usuario {" + user.UserName + "} no puede iniciar sesion sin tener confirmado el numero de telefono.";
                }
                return StatusCode(StatusCodes.Status401Unauthorized, message);
            }
            if (user != null && await userManager.CheckPasswordAsync(user, loginModel.Password))
            {
                if (!user.TwoFactorEnabled)
                {
                    return await GenerateAccess(user);
                }
                else
                {
                    return StatusCode(StatusCodes.Status202Accepted, new Response { Status = "Success", Message = $"Debe ingresar el codigo desde la app Google Authenticator : {user.UserName}" });
                };
            }
            return Unauthorized("El nombre de usuario o contraseña son incorrectos");
        }

        [HttpPost]
        [Route("login-2FA")]
        public async Task<IActionResult> LoginWithOTP(string code, string username)
        {
            var user = await userManager.FindByNameAsync(username);
            if (user is not null)
            {
                string secretKey = user.Id; // Obtén la clave secreta del usuario desde tu base de datos
                bool isBase32 = false; // Define si la clave secreta está en formato Base32
                bool validate = authenticator.ValidateTwoFactorPIN(secretKey, code, isBase32);
                if (validate)
                {
                    return await GenerateAccess(user);
                }
            }
            return StatusCode(StatusCodes.Status401Unauthorized, new Response { Status = "Error", Message = "Código de verificación incorrecto." });
        }

        [HttpPost]
        [AllowAnonymous]
        [Route("forgot-password")]
        public async Task<IActionResult> ForgotPassword([Required]string email)
        {
            var user = await userManager.FindByEmailAsync(email);
            if (user != null)
            {
                var token = await userManager.GeneratePasswordResetTokenAsync(user);
                var forgotPasswordLink = Url.Action(nameof(ResetPassword), "Authentication", new { token, email = user.Email }, Request.Scheme);

                var message = new Message([user.Email!], "phronCare - Enlace de recuperacion de contraseña.", forgotPasswordLink!);
                emailService.SendEmail(message);
                return StatusCode(StatusCodes.Status200OK, $"La solicitud de cambio de contraseña se envio a: {user.Email} con éxito. Por favor verifique el enlace enviado a la casilla de correo.");
            }
            return StatusCode(StatusCodes.Status400BadRequest, "No se pudo enviar el enlace al correo, por favor intente nuevamente.");
        }

        [HttpGet("reset-password")]
        public async Task<IActionResult> ResetPassword(string token, string email)
        {
            //var model =new ResetPassword {Token=token, Email = email};
            var htmlContent = GetResetPasswordHtmlContent(email,token); 
            var bytes = Encoding.UTF8.GetBytes(htmlContent);
            var stream = new MemoryStream(bytes);
            return File(stream, "text/html");
        }
        private static string GetResetPasswordHtmlContent(string username, string token)
        {
            string htmlContent = @"<!DOCTYPE html><html><head><meta name=viewport content=""width=device-width""><meta http-equiv=Content-Type content=""text/html; charset=UTF-8""><title>phronCare - Notificación</title><style>body{background:white;font-family:'Helvetica',sans-serif;color:#fff}.container{background-image:linear-gradient(45deg,rgb(5,39,103) 0%,#3a0647 70%);border-radius:50px;color:#fff;padding:20px;margin:30px auto;width:500px;text-align:center;}h1{font-size:20px}h2{font-size:16px;color:yellow;overflow-wrap:break-word;}p{font-size:16px}.form-control{width: 90%;padding: .375rem .75rem;height: 110px;max-height: 150px;border: 1px solid #ced4da;border-radius: .25rem;font-size: 1rem;}textarea{resize: none;}</style></head><body><table class=container><tr><td><h1>phronCare XL: Notificación</h1><h2>" + username + "</h2><h2>Token</h2><textarea class='form-control' readonly style='max-height: 150px;'>" + token + "</textarea><h3>Tu solicitud de restablecimiento de contraseña ha sido confirmada</h3><p>Para restablecer tu contraseña en phronCare, ingrese las credenciales proporcionadas.</p></td></tr></table></body></html>";
            return htmlContent;
        }

        [HttpPost]
        [AllowAnonymous]
        [Route("reset-password")]
        public async Task<IActionResult> ResetPassword([FromBody] ResetPassword resetPassword)
        {
            var user = await userManager.FindByEmailAsync(resetPassword.Email);
            if (user != null)
            {
                var resetPassResult = await userManager.ResetPasswordAsync(user, resetPassword.Token, resetPassword.Password);
                if (!resetPassResult.Succeeded)
                {
                    return StatusCode(StatusCodes.Status500InternalServerError, resetPassResult.Errors.First().Description);
                }
                return StatusCode(StatusCodes.Status200OK,$"La password ha sido cambiada correctamente.");
            }
            return StatusCode(StatusCodes.Status500InternalServerError,"No se pudo encontrar el usuario, por favor intente nuevamente.");
        }
        
        #region GenerateAccess
        private async Task<IActionResult> GenerateAccess(IdentityUser? user)
        {
            var authClaims = new List<Claim>
            {
                new(ClaimTypes.Name, user.UserName),
                new(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()),
            };
            var userRoles = await userManager.GetRolesAsync(user);
            foreach (var role in userRoles)
            {
                authClaims.Add(new Claim(ClaimTypes.Role, role));
            }
            var jwtToken = GetToken(authClaims);
            /* Returning the User Session object */
            var userSession = new UserSession
            {
                UserName = user.UserName,
                Role = userRoles.First(),
                Token = new JwtSecurityTokenHandler().WriteToken(jwtToken),
                ExpiresIn = (int)jwtToken.ValidTo.Subtract(DateTime.Now).TotalSeconds,
                ExpiryTimeStamp = jwtToken.ValidTo
            };
            return Ok(userSession);
            /* Returning simple jwt object */
            //return Ok(new
            //{
            //    token = new JwtSecurityTokenHandler().WriteToken(jwtToken),
            //    expiration = jwtToken.ValidTo
            //});
        }
        public class UserSession
        {
            public string UserName { get; set; }
            public string Token { get; set; }
            public string Role { get; set; }
            public int ExpiresIn { get; set; }
            public DateTime ExpiryTimeStamp { get; set; }
        }
        #endregion
        #region GenerateToken
        private JwtSecurityToken GetToken(List<Claim> authClaims)
        {
            var authSigningKey = new SymmetricSecurityKey(Encoding.ASCII.GetBytes(configuration["JWT:Secret"]));
            var token = new JwtSecurityToken(
                issuer: configuration["JWT:ValidIssuer"],
                audience: configuration["JWT:ValidAudience"],
                expires: DateTime.Now.AddHours(JWT_TOKEN_VALIDITY_HOURS),
                claims: authClaims,
                signingCredentials: new SigningCredentials(authSigningKey, SecurityAlgorithms.HmacSha256Signature) 
            );
            return token;
        }
        #endregion
    }
}