wip: jwt

pkg/jwt/jwt.go

@@ -0,0 +1,139 @@
+package jwt
+
+import (
+	"context"
+	"errors"
+	"loveuer/utodo/pkg/logger"
+	"reflect"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+type PayloadFn[T any] func(data T) map[string]any
+
+type Option[T any] func(*option[T])
+
+type option[T any] struct {
+	secret    string
+	payloadFn PayloadFn[T]
+}
+
+func WithSecret[T any](secret string) Option[T] {
+	return func(o *option[T]) {
+		if secret != "" {
+			o.secret = secret
+		}
+	}
+}
+
+func WithPayloadFn[T any](payloadFn PayloadFn[T]) Option[T] {
+	return func(o *option[T]) {
+		if payloadFn != nil {
+			o.payloadFn = payloadFn
+		}
+	}
+}
+
+type app[T any] struct {
+	secret    string
+	payloadFn func(data T) map[string]any
+}
+
+func (a *app[T]) Generate(data T) (string, error) {
+
+	type MyClaims struct {
+		jwt.RegisteredClaims
+		User T
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, MyClaims{User: data})
+
+	return token.SignedString([]byte(a.secret))
+}
+
+func (a *app[T]) Parse(token string) (T, error) {
+	type MyClaims struct {
+		jwt.RegisteredClaims
+		User T
+	}
+
+	var (
+		err    error
+		val    T
+		claims *jwt.Token
+	)
+
+	if claims, err = jwt.ParseWithClaims(token, &MyClaims{}, func(token *jwt.Token) (interface{}, error) {
+		return []byte(a.secret), nil
+	}); err != nil {
+		return val, err
+	}
+
+	if !claims.Valid {
+		return val, ErrTokenInvalid
+	}
+
+	cv, ok := claims.Claims.(*MyClaims)
+	if !ok {
+		return val, ErrTokenInvalid
+	}
+
+	return cv.User, nil
+}
+
+var (
+	ErrTokenInvalid                 = errors.New("token is invalid")
+	defaultPayloadFn PayloadFn[any] = func(data any) map[string]any {
+		ref := reflect.ValueOf(data)
+
+		if ref.Kind() == reflect.Pointer {
+			ref = ref.Elem()
+		}
+
+		if ref.Kind() != reflect.Struct {
+			logger.WarnCtx(context.TODO(), "data is not a struct")
+			return nil
+		}
+
+		typ := ref.Type()
+		num := typ.NumField()
+
+		payload := make(map[string]any, num)
+
+		for i := 0; i < num; i++ {
+			field := typ.Field(i)
+			tag := field.Tag.Get("json")
+			if tag == "-" {
+				continue
+			}
+
+			if tag == "" {
+				tag = field.Name
+			}
+
+			payload[tag] = ref.Field(i).Interface()
+		}
+
+		return payload
+	}
+)
+
+const defaultSecret = "{<Z]h/J>[5-F?s#D;~HGpxuBWi=ezNmb"
+
+func New[T any](opts ...Option[T]) *app[T] {
+	opt := &option[T]{
+		secret: defaultSecret,
+		payloadFn: func(data T) map[string]any {
+			return defaultPayloadFn(data)
+		},
+	}
+
+	for _, o := range opts {
+		o(opt)
+	}
+
+	return &app[T]{
+		secret:    opt.secret,
+		payloadFn: opt.payloadFn,
+	}
+}