package jwt

import (
	"fmt"
	"time"

	"github.com/golang-jwt/jwt/v4"
)

func GenerateAccessToken(token Token, data any, sign string, issuer string) (string, error) {
	claim := Claims{
		Data: data,
		RegisteredClaims: jwt.RegisteredClaims{
			ID:        token.ID,
			ExpiresAt: jwt.NewNumericDate(time.Unix(int64(token.ExpiresIn), 0)),
			Issuer:    issuer,
		},
	}

	accessToken, err := jwt.NewWithClaims(jwt.SigningMethodHS256, claim).
		SignedString([]byte(sign))
	if err != nil {
		return "", err
	}

	return accessToken, nil
}

func ParseToken(accessToken string, secret string, validate bool) (jwt.MapClaims, error) {
	// 跳過驗證的解析
	var token *jwt.Token
	var err error

	if validate {
		token, err = jwt.Parse(accessToken, func(token *jwt.Token) (interface{}, error) {
			if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
				return nil, fmt.Errorf("token unexpected signing method: %v", token.Header["alg"])
			}

			return []byte(secret), nil
		})
		if err != nil {
			return jwt.MapClaims{}, err
		}
	} else {
		parser := jwt.NewParser(jwt.WithoutClaimsValidation())
		token, err = parser.Parse(accessToken, func(_ *jwt.Token) (interface{}, error) {
			return []byte(secret), nil
		})
		if err != nil {
			return jwt.MapClaims{}, err
		}
	}

	claims, ok := token.Claims.(jwt.MapClaims)
	if !ok && token.Valid {
		return jwt.MapClaims{}, fmt.Errorf("token valid error")
	}

	return claims, nil
}

func ParseClaims(accessToken string, secret string, validate bool) (DataClaims, error) {
	claimMap, err := ParseToken(accessToken, secret, validate)
	if err != nil {
		return DataClaims{}, err
	}

	claimsData, ok := claimMap["data"].(map[string]any)
	if ok {
		return convertMap(claimsData), nil
	}

	return DataClaims{}, fmt.Errorf("get data from claim map error")
}

func convertMap(input map[string]interface{}) map[string]string {
	output := make(map[string]string)
	for key, value := range input {
		switch v := value.(type) {
		case string:
			output[key] = v
		case fmt.Stringer:
			output[key] = v.String()
		default:
			output[key] = fmt.Sprintf("%v", value)
		}
	}

	return output
}