using System;
using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using System.Text;
using InternshipSystem.Api.Options;
using Microsoft.Extensions.Options;
using Microsoft.IdentityModel.Tokens;

namespace InternshipSystem.Api.Security
{
    public class JwtTokenService
    {
        private SecurityOptions _securityOptions;

        public JwtTokenService(IOptions<SecurityOptions> securityOptions)
        {
            _securityOptions = securityOptions.Value;
        }

        public string generateToken(ClaimsIdentity identity)
        {
            var handler = new JwtSecurityTokenHandler();
            var key = Encoding.ASCII.GetBytes(_securityOptions.Secret);

            var descriptor = new SecurityTokenDescriptor
            {
                Subject = identity,
                Expires = DateTime.UtcNow.AddMinutes(_securityOptions.Expiration),
                SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha256Signature)
            };

            var jwtToken = handler.CreateJwtSecurityToken(descriptor);
            
            return handler.WriteToken(jwtToken);
        }
    }
}