using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using System.Security.Cryptography;
using System.Text;
using Microsoft.IdentityModel.Tokens;
using GestorFacturas.API.Models;
using GestorFacturas.API.Data;
using BCrypt.Net;

namespace GestorFacturas.API.Services;

public class AuthService
{
  private readonly IConfiguration _config;
  private readonly ApplicationDbContext _context;

  public AuthService(IConfiguration config, ApplicationDbContext context)
  {
    _config = config;
    _context = context;
  }

  public bool VerificarPassword(string password, string hash)
  {
    try { return BCrypt.Net.BCrypt.Verify(password, hash); } catch { return false; }
  }

  public string GenerarHash(string password)
  {
    return BCrypt.Net.BCrypt.HashPassword(password);
  }

  // Generar JWT (Access Token) - Vida corta (ej. 15 min)
  public string GenerarAccessToken(Usuario usuario)
  {
    var keyStr = _config["Jwt:Key"] ?? throw new InvalidOperationException("Jwt:Key no configurada");
    var securityKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(keyStr));
    var credentials = new SigningCredentials(securityKey, SecurityAlgorithms.HmacSha256);

    var claims = new[]
    {
            new Claim(ClaimTypes.NameIdentifier, usuario.Id.ToString()),
            new Claim(ClaimTypes.Name, usuario.Username)
        };

    var token = new JwtSecurityToken(
        _config["Jwt:Issuer"],
        _config["Jwt:Audience"],
        claims,
        expires: DateTime.UtcNow.AddMinutes(15),
        signingCredentials: credentials);

    return new JwtSecurityTokenHandler().WriteToken(token);
  }

  // Generar Refresh Token - Vida larga (ej. 7 días)
  public RefreshToken GenerarRefreshToken(int usuarioId, bool isPersistent)
  {
    // Si es persistente: 30 días.
    // Si NO es persistente: 12 horas.
    var duracion = isPersistent ? TimeSpan.FromDays(30) : TimeSpan.FromHours(12);

    var refreshToken = new RefreshToken
    {
      Token = Convert.ToBase64String(RandomNumberGenerator.GetBytes(64)),
      Expires = DateTime.UtcNow.Add(duracion),
      Created = DateTime.UtcNow,
      UsuarioId = usuarioId,
      IsPersistent = isPersistent
    };

    return refreshToken;
  }
}