using Microsoft.IdentityModel.Tokens;
using SqlSugar.Extensions;
using System;
using System.Collections.Generic;
using System.IdentityModel.Tokens.Jwt;
using System.Linq;
using System.Security.Claims;
using System.Text;

namespace VideoAnalysisCore.Common
{
    public class JwtHelper
    {

        public static string GetToken(AuthKeyConfig jwt, params Claim[] claims)
        {
            return GetToken(jwt.Issuer, jwt.Audience, jwt.Secret, jwt.Expires, claims);
        }

        /// <summary>
        /// 生成Token
        /// </summary>
        /// <param name="issuer">签发人</param>
        /// <param name="audience">受众</param>
        /// <param name="secreKey">密钥</param>
        /// <param name="expires">过期时间(单位：小时)</param>
        public static string GetToken(string issuer, string audience, string secreKey, int expires, params Claim[] claims)
        {
            var now = DateTime.Now;
            //添加用户的信息，转成一组声明，还可以写入更多用户信息声明
            var claimss = new List<Claim>
            { 
                //JWT ID 唯一标识符
                new Claim(JwtRegisteredClaimNames.Jti,Guid.NewGuid().ToString() ),
                //发布时间戳 issued timestamp
                new Claim(JwtRegisteredClaimNames.Iat, DateTimeOffset.UtcNow.ToUnixTimeSeconds().ToString(), ClaimValueTypes.Integer64),
            };
            if (claims != null && claims.Length > 0)
            {
                claimss.AddRange(claims);
            }

            //下面使用 Microsoft.IdentityModel.Tokens帮助库下的类来创建JwtToken 
            //安全秘钥
            var signingKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(secreKey));

            var jwt = new JwtSecurityToken(
                //jwt签发人
                issuer: issuer,
                //jwt受众
                audience: audience,
                //jwt一组声明
                claims: claimss,
                notBefore: now,
                //jwt令牌过期时间
                expires: now.AddHours(value: expires),
                //签名凭证: 安全密钥、签名算法
                signingCredentials: new SigningCredentials(signingKey, SecurityAlgorithms.HmacSha256)
            );

            //生成jwt令牌(json web token)
            var encodedJwt = new JwtSecurityTokenHandler().WriteToken(jwt);
            return encodedJwt;
        }
    }
}