package auth

import (
	"context"
	"fmt"

	"google.golang.org/grpc/metadata"

	"google.golang.org/grpc"
	auth "src.dualinventive.com/go/authentication-service/grpc"
)

//Service contains authentication related operations
type Service interface {
	VerifyToken(token string) (bool, error)
}

//ServiceGrpc contains authentication related operations over GRPC
type ServiceGrpc struct {
	client auth.AuthenticationServiceClient
}

//NewAuthService returns a new GRPC based AuthService
func NewAuthService(host, port string) (Service, error) {
	conn, err := grpc.Dial(fmt.Sprintf("%s:%s", host, port), grpc.WithInsecure())
	if err != nil {
		return nil, err
	}

	client := auth.NewAuthenticationServiceClient(conn)
	return &ServiceGrpc{client}, nil
}

//VerifyToken verifies the given token to see if its valid
func (as *ServiceGrpc) VerifyToken(token string) (bool, error) {
	// Login
	md := metadata.Pairs(
		"token", token,
	)
	ctx := metadata.NewOutgoingContext(context.Background(), md)
	in := &auth.Empty{}

	resp, err := as.client.VerifyToken(ctx, in)
	if err != nil {
		return false, err
	}

	return resp.Valid, nil
}