using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using Microsoft.Extensions.Logging;
using Microsoft.IdentityModel.Tokens;

namespace JWTService {

  public interface IJWTService {
    string CreateJwtToken();
    JwtSecurityToken ReadJwtToken(string token);
  }
  public class JWTService : IJWTService {

    private readonly ILogger<JWTService> _logger;

    private readonly JwtSecurityTokenHandler _tokenHandler;
    private readonly IJwtConfig _serviceConfig;

    /// <summary>
    /// 
    /// </summary>
    /// <param name="serviceConfig"></param>
    public JWTService(
      ILogger<JWTService> logger,
      IJwtConfig serviceConfig
      
    ) {
      _logger = logger;
      _serviceConfig = serviceConfig;
      _tokenHandler = new JwtSecurityTokenHandler();
    }

    public string? CreateJwtToken() {
      if (_serviceConfig.Secret == null)
        return null;

      if (_serviceConfig.Expires == null)
        return null;


      var key = Convert.FromBase64String(_serviceConfig.Secret);

      // add roles to claims identity from database
      var claims = new List<Claim>() {};


      var token = _tokenHandler.CreateToken(new SecurityTokenDescriptor {
        IssuedAt = DateTime.UtcNow,
        Subject = new ClaimsIdentity(claims),
        Expires = DateTime.UtcNow.AddDays(_serviceConfig.Expires.Value),
        SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha512Signature),
      });

      return _tokenHandler.WriteToken(token);
    }

    
    //public string CreateJwtToken(IEnumerable<string> issuer, DateTime expires, string userId, string userEmail, string userName, IEnumerable<string> userRoles) {
    //  var key = Convert.FromBase64String(_serviceConfig.Secret);

    //  // add roles to claims identity from database
    //  var claims = new List<Claim>() {
    //    new Claim(ClaimTypes.Actor, userId),
    //    new Claim(ClaimTypes.Email, userEmail),
    //    new Claim(ClaimTypes.NameIdentifier, userName),
    //    // new Claim(ClaimTypes.Webpage, issuer)
    //  };

    //  foreach (var role in userRoles)
    //    claims.Add(new Claim(ClaimTypes.Role, role));

    //  foreach (var iss in issuer)
    //    claims.Add(new Claim(ClaimTypes.Webpage, iss));

    //  var token = _tokenHandler.CreateToken(new SecurityTokenDescriptor {
    //    IssuedAt = DateTime.UtcNow,
    //    Subject = new ClaimsIdentity(claims),
    //    Expires = expires,
    //    SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha512Signature),
    //  });

    //  return _tokenHandler.WriteToken(token);
    //}

    public JwtSecurityToken ReadJwtToken(string token) => _tokenHandler.ReadJwtToken(token);
  }
}