package middleware

import (
	"errors"
	"fmt"
	"speechAnalysis/conf"
	"strings"
	"time"

	jwt "github.com/dgrijalva/jwt-go"
	"github.com/gin-gonic/gin"
	"speechAnalysis/extend/util"
)

func validateToken(tokenString string) (util.JSON, error) {
	secretKey := []byte(conf.WebConf.JWTSecret)

	token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
		// Don't forget to validate the alg is what you expect:
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, fmt.Errorf("Unexpected signing method: %v", token.Header["alg"])
		}

		return secretKey, nil
	})

	if err != nil {
		return util.JSON{}, err
	}

	if !token.Valid {
		return util.JSON{}, errors.New("invalid token")
	}

	return token.Claims.(jwt.MapClaims), nil
}

// JWTMiddleware parses JWT token from cookie and stores data and expires date to the context
// JWT Token can be passed as cookie, or Authorization header
func JWTMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {
		tokenString, err := c.Cookie("token")
		// failed to read cookie
		if err != nil {
			// try reading HTTP Header
			authorization := c.Request.Header.Get("Authorization")
			if authorization == "" {
				c.Next()
				return
			}
			sp := strings.Split(authorization, "Bearer ")
			// invalid token
			if len(sp) < 1 {
				c.Next()
				return
			}
			tokenString = sp[1]
		}

		tokenData, err := validateToken(tokenString)
		if err != nil {
			fmt.Println(err.Error())
			c.Next()
			return
		}

		userParentId := tokenData["parentId"].(string)
		if userParentId == conf.WebConf.NodeId {
			c.Set("parentId", userParentId)
		} else {
			c.Next()
			return
		}

		c.Set("token_expire", tokenData["exp"])
		c.Next()
	}
}

func GenerateToken(data interface{}) (string, error) {
	//  token is valid for 1 hour
	date := time.Now().Add(time.Hour * 12)

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.MapClaims{
		"user": data,
		"exp":  date.Unix(),
	})

	secretKey := []byte(conf.WebConf.JWTSecret)

	tokenString, err := token.SignedString(secretKey)

	return tokenString, err
}