type Backend interface {
    ListObjects(prefix string) ([]Object, error)
    GetObject(path string) (Object, error)
    PutObject(path string, content []byte) error
    DeleteObject(path string) error
}

type Object struct {
    Path         string
    Content      []byte
    LastModified time.Time
}

type ObjectSliceDiff struct {
    Change  bool
    Removed []Object
    Added   []Object
    Updated []Object
}

func GetObjectSliceDiff(prev []Object, curr []Object, timestampTolerance time.Duration) ObjectSliceDiff

// Usage: go run example.go <cloud> <bucket> <file>

package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"

	"github.com/chartmuseum/storage"
)

type (
	Uploader struct {
		Backend storage.Backend
	}
)

func NewUploader(cloud string, bucket string) *Uploader {
	var backend storage.Backend
	switch cloud {
	case "azure":
		backend = storage.NewMicrosoftBlobBackend(bucket, "")
	case "google":
		backend = storage.NewGoogleCSBackend(bucket, "")
	default:
		panic("cloud provider " + cloud + " not supported")
	}
	uploader := Uploader{Backend: backend}
	fmt.Printf("uploader created (cloud: %s, bucket: %s)\n", cloud, bucket)
	return &uploader
}

func (uploader *Uploader) Upload(filename string) {
	basename := filepath.Base(filename)
	content, err := ioutil.ReadFile(filename)
	if err != nil {
		panic(err)
	}
	err = uploader.Backend.PutObject(basename, content)
	if err != nil {
		panic(err)
	}
	fmt.Printf("%s successfully uploaded\n", basename)
}

func main() {
	args := os.Args[1:]
	uploader := NewUploader(args[0], args[1])
	uploader.Upload(args[2])
}