// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package artifacts

import (
	"context"
	"fmt"
	"path"

	"cloud.google.com/go/storage"

	"go.chromium.org/luci/auth"

	"google.golang.org/api/option"
)

// Client provides access to the artifacts produced by Fuchsia CI tasks.
type Client struct {
	client *storage.Client
}

// NewClient creates a new Client.
func NewClient(ctx context.Context, opts auth.Options) (*Client, error) {
	opts.Scopes = append(opts.Scopes, storage.ScopeReadWrite)
	authenticator := auth.NewAuthenticator(ctx, auth.SilentLogin, opts)
	source, err := authenticator.TokenSource()
	if err != nil {
		return nil, fmt.Errorf("failed to create token source: %v", err)
	}
	client, err := storage.NewClient(ctx, option.WithTokenSource(source))
	if err != nil {
		return nil, fmt.Errorf("failed to create Cloud Storage client: %v", err)
	}
	return &Client{client: client}, nil
}

// GetBuildDir returns the BuildDirectory for the given build. bucket is the GCS bucket.
// build is the BuildBucket build ID.
func (c *Client) GetBuildDir(bucket, build string) Directory {
	bkt := c.client.Bucket(bucket)
	root := ""
	if build != "" {
		root = path.Join("builds", build)
	}
	return &BuildDirectory{&directory{
		bucket: bkt,
		root:   root,
	}}
}