drive

type Client interface {
	// ListFiles retrieves the sha256sum of all of the File objects known to the
	// client.  The elements of the slice may be passed to GetChunk() to retrieve
	// the corresponding shade.File object.  It will be marshaled JSON,
	// optionally encrypted.
	ListFiles() ([][]byte, error)

	// GetFile retrieves the metadata describing a shade.File.
	//
	// f should be marshalled JSON, and may be encrypted.  It differs only from
	// PutChunk in that ListFiles() will return these chunks.  sha256 is the hash
	// of the unencrypted shade.File object.  Nb: this leaks the a bit of
	// information about the file, but given that it contains the AES key, the
	// mtime of the shade.File, etc it should contain enough arbitrary data that
	// you can't infer anything meaningful from the SHA sum.
	GetFile(sha256 []byte) ([]byte, error)

	// PutFile writes the metadata describing a new file.
	// f should be marshalled JSON, and may be encrypted.  It differs only from
	// PutChunk in that ListFiles() will return these chunks.
	PutFile(sha256, chunk []byte) error

	// GetChunk retrieves a chunk with a given SHA-256 sum.  f is required for
	// files to support encryption.  It is used to store the AES key the chunk
	// and chunksum are encrypted with.
	GetChunk(sha256 []byte, f *shade.File) ([]byte, error)

	// PutChunk writes a chunk and returns its SHA-256 sum.  f is required for
	// files to support encryption.  It is used to store the AES key the chunk
	// and chunksum are encrypted with.
	PutChunk(sha256, chunk []byte, f *shade.File) error

	// GetConfig returns the drive.Config object used to initialize this client.
	// This is mostly helpful for debugging, to identify which Provider it is.
	GetConfig() Config

	// Local identifies the storage destination of the client to the caller.
	// If it returns false, code can expect that the content of this storage will
	// persist after the death of the binary, or the machine on which it is
	// running, or the continent on which it is located suffering a high altitude
	// EMP burst.
	Local() bool

	// Persistent identifies the storage durability of the client to the caller.
	// If it returns false, code can expect that the content of this storage will
	// persist after the death of the binary, but perhaps not the machine on
	// which it is running
	Persistent() bool
}

type Config struct {
	Provider      string
	OAuth         OAuthConfig
	FileParentID  string
	ChunkParentID string
	Write         bool
	MaxFiles      uint64
	MaxChunkBytes uint64
	RsaPublicKey  string
	RsaPrivateKey string
	Children      []Config
}

type OAuthConfig struct {
	ClientID     string
	ClientSecret string
	Scopes       []string
	TokenPath    string
}