package service

import (
	"errors"
	"fmt"
	"github.com/dgrijalva/jwt-go"
	setting "icloudapp.cn/tools/config"
	"icloudapp.cn/tools/repository/redis"
	"time"
)

// PosterClaims Claims，保存用户id和nickname
type PosterClaims struct {
	Uid      int64  `json:"uid"`
	Username string `json:"username"`
	jwt.StandardClaims
}

// GenToken 生成token
func GenJWTToken(uid int64, username string) (string, error) {
	C := PosterClaims{
		uid,
		username,
		jwt.StandardClaims{
			ExpiresAt: time.Now().Add(JWTExpireDuration()).Unix(), //设置超时时间,输出过期的时间，按照格式
			Issuer:    setting.Conf.JWTConfig.Project,             //签发人
		},
	}
	//使用指定的签名方法创建签名对象
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, C)
	//使用指定的secret签名并获得完整的编码后的字符串token

	signed, err := token.SignedString([]byte(setting.Conf.JWTConfig.Secret))
	if cacheErr := CacheJWTToken(uid, signed); cacheErr != nil {
		return "", errors.New("token缓存失败")
	}
	return signed, err
}

// ParseToken 验证token
func ParseJWTToken(tokenString string) (*PosterClaims, error) {
	token, err := jwt.ParseWithClaims(tokenString, &PosterClaims{}, func(token *jwt.Token) (interface{}, error) {
		return []byte(setting.Conf.JWTConfig.Secret), nil
	})
	if err != nil {
		return nil, err
	}
	if claim, ok := token.Claims.(*PosterClaims); ok && token.Valid { //valid:正确，有效  校验token
		return claim, err //返回JWT中的字段
	}
	return nil, errors.New("Invalid token.")
}

// RemoveJWTToken 移除用户的token
func RemoveJWTToken(uid int64) error {
	return redis.RedisClient.Del(JWTCacheKey(uid)).Err()
}

// GetJWTTokenFromRedis 获取redis中获取的jwt数据
func GetJWTTokenFromRedis(uid int64) string {
	str, err := redis.RedisClient.Get(JWTCacheKey(uid)).Result()
	if err != nil {
		return ""
	}
	return str
}

// CacheJWTToken 缓存jwt token到redis
func CacheJWTToken(uid int64, token string) error {
	return redis.RedisClient.Set(JWTCacheKey(uid), token, JWTExpireDuration()).Err()
}

// JWTCacheKey 获取jwt cache key
func JWTCacheKey(uid int64) string {
	return fmt.Sprintf("%s_%s_%d", setting.Conf.JWTConfig.Prefix, "uid", uid)
}

// JWTExpireDuration jwt过期时间
func JWTExpireDuration() time.Duration {
	duration := time.Duration(setting.Conf.JWTConfig.ExpireAt) * time.Second
	return duration
}