using System.Security.Claims;
using System.Text;
using Microsoft.IdentityModel.Tokens;
using System.IdentityModel.Tokens.Jwt;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.EntityFrameworkCore.Metadata.Internal;

namespace CompetitionAPI
{
    public class TokenService
    {
        private readonly string _secretKey;
        private readonly string _issuer;

        public TokenService(string secretKey, string issuer)
        {
            _secretKey = secretKey;
            _issuer = issuer;
        }

        public string GenerateToken(string userId)
        {
            var tokenHandler = new JwtSecurityTokenHandler();
            var key = Encoding.ASCII.GetBytes(_secretKey);
            var tokenDescriptor = new SecurityTokenDescriptor
            {
                Subject = new ClaimsIdentity(new[] { new Claim("userId", userId) }),
                Expires = DateTime.UtcNow.AddHours(3), // Token 过期时间
                Issuer = _issuer,
                SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha256Signature)
            };
            //注意：使用高版本下面这行代码会报错
            var token = tokenHandler.CreateToken(tokenDescriptor);
            var tokenString = tokenHandler.WriteToken(token);
            return tokenString;
        }
    }
}