package jwt_adapter

import (
	"context"
	"fmt"
	"github.com/dgrijalva/jwt-go"
	"github.com/rs/xid"
	"github.com/skeris/identity/cookie"
	"os"
	"time"
)

var _ cookie.Cookie = new(JwtAdapter)

func init() {
	aS := os.Getenv("JWT_SECRET")
	if len(aS) != 0 {
		accessSecret = aS
	}
}

type JwtAdapter struct {
	ID      string
	Session string
	User    string

	Tariff uint8

	Created  int64
	LastSeen int64
	jwt.StandardClaims
}

func (c *JwtAdapter) Init() {
	if c.ID == "" {
		c.ID = xid.New().String()
	}

	c.Session = xid.New().String()
	c.User = ""
	c.Tariff = uint8(0)

	t := Timestamp()
	c.Created = t
	c.LastSeen = t
}


func Get(ctx context.Context) *JwtAdapter {
	if adapter, ok := ctx.Value(DefaultHeaderKey).(*JwtAdapter); ok {
		return adapter
	}

	return nil
}

func (c *JwtAdapter) SetUserID(id string) {
	c.User = id
}

func (c *JwtAdapter) GetUserID() string {
	return c.User
}

func (c *JwtAdapter) GetTariff() uint8 {
	return c.Tariff
}

func (c *JwtAdapter) SetTariff(status uint8) {
	c.Tariff = status
}

func (c *JwtAdapter) GetSessionID() string {
	return c.Session
}

func (c *JwtAdapter) SetSessionID(id string) {
	c.Session = id
	c.User = ""
}

const (
	DefaultAccessSecret = "awesomeAC"
	DefaultHeaderKey    = "Authorization"
)

var accessSecret = DefaultAccessSecret

func (c *JwtAdapter) Encode() (string, error) {
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, c)
	ss, err := token.SignedString([]byte(accessSecret))

	return ss, err
}

func Decode(tokenString string) (*JwtAdapter, error) {
	claims := JwtAdapter{}

	token, err := jwt.ParseWithClaims(tokenString, &claims, func(token *jwt.Token) (interface{}, error) {
		//Make sure that the token method conform to "SigningMethodHMAC"
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
		}
		return []byte(accessSecret), nil
	})

	if err != nil {
		return nil, err
	}

	if _, ok := token.Claims.(jwt.Claims); !ok && !token.Valid {
		return nil, fmt.Errorf("ErrorNoValidClaims")
	}

	return &claims, nil
}

func Timestamp() int64 {
	return time.Now().UnixNano() / int64(time.Millisecond)
}