package utils

import (
	"errors"
	"github.com/dgrijalva/jwt-go"
	"github.com/gin-gonic/gin"
)

const (
	AdminAccountKey = "AdminAccount"
	AccountTypeKey  = "AccountType"
)

//CreateToken  生成Token算法
func CreateToken(secret string, tokenClaims map[string]interface{}) (tokeness string, err error) {
	if secret == "" {
		return "", errors.New("secret is empty")
	}
	claims := jwt.MapClaims(tokenClaims)
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	tokeness, err = token.SignedString([]byte(secret))
	if err != nil {
		return "", err
	}
	return tokeness, nil
}

func keyFunc(secret string) jwt.Keyfunc {
	return func(token *jwt.Token) (interface{}, error) {
		return []byte(secret), nil
	}
}

//ParseToken 解析Token
func ParseToken(secret string, tokeness string) (map[string]interface{}, error) {
	if secret == "" || tokeness == "" {
		return nil, errors.New("secret or tokeness is empty")
	}
	token, err := jwt.Parse(tokeness, keyFunc(secret))
	if err != nil {
		return nil, err
	}
	//验证token，如果token被修改过则为false
	if !token.Valid {
		return nil, errors.New("token is invalid")
	}
	claimsToken, ok := token.Claims.(jwt.MapClaims)
	if !ok {
		return nil, errors.New("cannot convert claim to MapClaim")
	}
	return claimsToken, nil
}

// GetAdmin  获取管理员账号
// oauth.Auth执行后有效
func GetAdmin(ctx *gin.Context) (account string, err error) {
	val, exists := ctx.Get(AdminAccountKey)
	if !exists {
		err = errors.New("admin account not exist")
		return
	}

	account, ok := val.(string)
	if !ok {
		return "", errors.New("admin account type error")
	}
	return
}

// GetAccountType  获取账号类型
// oauth.Auth执行后有效
func GetAccountType(ctx *gin.Context) (string, error) {
	var err error
	val, exists := ctx.Get(AccountTypeKey)
	if !exists {
		err = errors.New("claims not exist")
		return "", err
	}
	accType, ok := val.(string)
	if !ok {
		return "", errors.New("claims type error")
	}
	return accType, nil
}