using Microsoft.IdentityModel.Tokens;
using System.IdentityModel.Tokens.Jwt;
using System.Text;
using System.Security.Claims;

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

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

        public bool ValidateToken(string token)
        {
            var tokenHandler = new JwtSecurityTokenHandler();
            var key = Encoding.ASCII.GetBytes(_secretKey);

            try
            {
                tokenHandler.ValidateToken(token, new TokenValidationParameters
                {
                    ValidateIssuer = true,
                    ValidIssuer = _issuer,
                    ValidateIssuerSigningKey = true,
                    IssuerSigningKey = new SymmetricSecurityKey(key),
                    ValidateAudience = false, // 可选：是否验证 Audience
                    ValidateLifetime = true, // 是否验证 Token 是否过期
                    ClockSkew = TimeSpan.Zero // 设置时间偏差
                }, out var validatedToken);

                return validatedToken != null;
            }
            catch (Exception)
            {
                // Token 验证失败
                return false;
            }
        }
    }
}