yasshi2525/RushHour

package auth

import (
    "context"
    "fmt"

    "google.golang.org/api/option"

    "golang.org/x/oauth2"
    "golang.org/x/oauth2/google"
    v2 "google.golang.org/api/oauth2/v2"

    "github.com/yasshi2525/RushHour/config"
)

func (a *Auther) initGoogle(conf config.CnfOAuth) {
    a.googleConf = &oauth2.Config{
        ClientID:     conf.Client,
        ClientSecret: conf.Secret,
        RedirectURL:  fmt.Sprintf("%s/google/callback", a.baseURL),
        Endpoint:     google.Endpoint,
        Scopes:       []string{"openid", "email", "profile"},
    }
}

// GetGoogleAuthURL returns auth url
func (a *Auther) GetGoogleAuthURL() string {
    return a.googleConf.AuthCodeURL(a.state)
}

// GetGoogleOAuthInfo returns user info
func (a *Auther) GetGoogleOAuthInfo(resState string, code string) (*OAuthInfo, error) {
    if resState != a.state {
        return nil, fmt.Errorf("invalid state")
    }
    ctx := context.Background()
    if token, err := a.googleConf.Exchange(ctx, code); err != nil {
        return nil, err
    } else if !token.Valid() {
        return nil, fmt.Errorf("invalid token")
    } else {
        service, err := v2.NewService(ctx, option.WithTokenSource(a.googleConf.TokenSource(ctx, token)))
        if err != nil {
            return nil, err
        }
        info, err := service.Tokeninfo().Do()
        if err != nil {
            return nil, err
        }
        person, err := service.Userinfo.V2.Me.Get().Do()
        if err != nil {
            return nil, err
        }
        return &OAuthInfo{
            Handler:     a,
            OAuthToken:  token.AccessToken,
            LoginID:     info.UserId,
            DisplayName: person.Name,
            Image:       person.Picture,
        }, nil
    }
}