package server

import (
	"encoding/json"
	"errors"

	"golang.org/x/net/context"
	"google.golang.org/grpc/metadata"
	"gopkg.in/redis.v2"
	"xiaoniaokuaiyan.com/xiaoniao/util"
)

type AuthService interface {
	GetAccessToken(strToken string) (interface{}, error)
}

func AuthGrpc(ctx context.Context) error {
	md, _ := metadata.FromIncomingContext(ctx)
	var clientid []string
	var hasOk bool
	if clientid, hasOk = md["clientid"]; !hasOk {
		return errors.New("clientid required")
	}
	if tokenKey, ok := md["token"]; !ok {
		return errors.New("token is empty")
	} else {
		return ValidateToken(tokenKey[0], clientid[0])
	}
}
func ValidateToken(tokenStr string, clientid string) error {
	token, err := GetTokenFromRedis(clientid)
	if err != nil {
		return err
	}
	if token.expired() {
		go func() {
			var client *redis.Client = util.GetRedis()
			client.Select(REDIS_API_AUTH_DB)
			client.HDel(REDIS_API_AUTH_KEY, clientid)
		}()
		return TokenExipiredError
	}
	if token.AccessToken != tokenStr {
		return errors.New("wrong token")
	}
	if !token.IsValid() {
		return errors.New("invalid token")
	}
	return nil

}

var TokenKeyNotFoundError error = errors.New("token key not found")
var TokenExipiredError error = errors.New("token expired")

func GetTokenFromRedis(tokenKey string) (*AuthToken, error) {
	if tokenKey == "" {
		return nil, errors.New("token key is empty")
	}
	var client *redis.Client = util.GetRedis()
	statusCmd := client.Select(REDIS_API_AUTH_DB)
	if err := statusCmd.Err(); err != nil {
		return nil, err
	}
	strCmd := client.HGet(REDIS_API_AUTH_KEY, tokenKey)
	if tokenStr, err := strCmd.Result(); err != nil {
		return nil, TokenKeyNotFoundError
	} else {
		token := &AuthToken{}
		err = json.Unmarshal([]byte(tokenStr), token)
		return token, nil
	}
}