firebase.go

// Copyright 2017 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Package firebase is the entry point to the Firebase Admin SDK. It provides functionality for initializing App
// instances, which serve as the central entities that provide access to various other Firebase services exposed
// from the SDK.
package firebase

import (
	"firebase.google.com/go/auth"
	"firebase.google.com/go/internal"

	"os"

	"golang.org/x/net/context"
	"golang.org/x/oauth2/google"
	"google.golang.org/api/option"
	"google.golang.org/api/transport"
)

var firebaseScopes = []string{
	"https://www.googleapis.com/auth/firebase",
	"https://www.googleapis.com/auth/userinfo.email",
}

// Version of the Firebase Go Admin SDK.
const Version = "1.0.1"

// An App holds configuration and state common to all Firebase services that are exposed from the SDK.
type App struct {
	ctx       context.Context
	creds     *google.DefaultCredentials
	projectID string
	opts      []option.ClientOption
}

// Config represents the configuration used to initialize an App.
type Config struct {
	ProjectID string
}

// Auth returns an instance of auth.Client.
func (a *App) Auth() (*auth.Client, error) {
	conf := &internal.AuthConfig{
		Ctx:       a.ctx,
		Creds:     a.creds,
		ProjectID: a.projectID,
		Opts:      a.opts,
	}
	return auth.NewClient(conf)
}

// NewApp creates a new App from the provided config and client options.
//
// If the client options contain a valid credential (a service account file, a refresh token file or an
// oauth2.TokenSource) the App will be authenticated using that credential. Otherwise, NewApp attempts to
// authenticate the App with Google application default credentials.
func NewApp(ctx context.Context, config *Config, opts ...option.ClientOption) (*App, error) {
	o := []option.ClientOption{option.WithScopes(firebaseScopes...)}
	o = append(o, opts...)

	creds, err := transport.Creds(ctx, o...)
	if err != nil {
		return nil, err
	}

	var pid string
	if config != nil && config.ProjectID != "" {
		pid = config.ProjectID
	} else if creds.ProjectID != "" {
		pid = creds.ProjectID
	} else {
		pid = os.Getenv("GCLOUD_PROJECT")
	}

	return &App{
		ctx:       ctx,
		creds:     creds,
		projectID: pid,
		opts:      o,
	}, nil
}