package logic

import (
	"errors"
	"framework_v2/consts"
	"framework_v2/internal/providers"
	"framework_v2/internal/providers/jwks"
	"framework_v2/types"
	"github.com/gin-gonic/gin"
	"github.com/mitchellh/mapstructure"
	"go.uber.org/zap"
	"strings"
)

type AuthLogic struct {
}

const AnonymousUser = "anonymous"

var (
	ErrNotValidToken  = errors.New("无效的 JWT 令牌。")
	ErrJWTFormatError = errors.New("JWT 格式错误。")
	ErrNotBearerType  = errors.New("不是 Bearer 类型。")
	ErrEmptyResponse  = errors.New("我们的服务器返回了空请求，可能某些环节出了问题。")
	config            = *providers.MustGet[providers.GlobalConfig]()
	logger            = *providers.MustGet[zap.Logger]()
)

func NewAuthLogic() *AuthLogic {
	return &AuthLogic{}
}

func (a *AuthLogic) GinMiddlewareAuth(c *gin.Context) (*types.User, error) {
	var sub = AnonymousUser
	var jwtIdToken = &types.User{}

	if config.DebugMode.Enable {
		jwtIdToken.Token.Sub = sub
		jwtIdToken.Valid = true
		return jwtIdToken, nil
	} else {
		authorization := c.Request.Header.Get(consts.AuthHeader)

		if authorization == "" {
			return nil, ErrJWTFormatError
		}

		authSplit := strings.Split(authorization, " ")
		if len(authSplit) != 2 {
			return nil, ErrJWTFormatError
		}

		if authSplit[0] != consts.AuthPrefix {
			return nil, ErrNotBearerType
		}

		token, err := jwks.ParseJWT(authSplit[1])
		if err != nil {
			return nil, ErrJWTFormatError
		}
		sub, err = token.Claims.GetSubject()
		if err != nil {
			return nil, ErrNotValidToken
		}

		err = mapstructure.Decode(token.Claims, &jwtIdToken.Token)
		if err != nil {
			logger.Error("Failed to map token claims to JwtIDToken struct.\nError: " + err.Error())
			return nil, nil
		}
	}

	return jwtIdToken, nil
}

func (a *AuthLogic) GinUser(c *gin.Context) *types.User {
	user, _ := c.Get(consts.AuthMiddlewareKey)
	return user.(*types.User)
}