// Copyright Google Inc.
//
// 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 datastore

import (
	"io/ioutil"

	"cloud.google.com/go/storage"
	"golang.org/x/net/context"
	"google.golang.org/appengine/file"
)

func ReadFile(ctx context.Context, filename string) ([]byte, error) {
	bucketName, err := file.DefaultBucketName(ctx)
	if err != nil {
		return nil, err
	}

	client, err := storage.NewClient(ctx)
	if err != nil {
		return nil, err
	}
	defer client.Close()

	bucket := client.Bucket(bucketName)

	rc, err := bucket.Object(filename).NewReader(ctx)
	if err != nil {
		return nil, err
	}
	defer rc.Close()

	data, err := ioutil.ReadAll(rc)
	if err != nil {
		return nil, err
	}

	return data, nil
}
