//
// Copyright 2023 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
//

import Foundation
public import LibSignalClient

public protocol MessageBackupManager {

    // MARK: - Interact with remotes

    /// Download the encrypted backup for the current user to a local file.
    func downloadEncryptedBackup(localIdentifiers: LocalIdentifiers, auth: ChatServiceAuth) async throws -> URL

    /// Upload the local encrypted backup identified by the given metadata for
    /// the current user.
    func uploadEncryptedBackup(
        metadata: Upload.EncryptedBackupUploadMetadata,
        localIdentifiers: LocalIdentifiers,
        auth: ChatServiceAuth
    ) async throws -> Upload.Result<Upload.EncryptedBackupUploadMetadata>

    // MARK: - Export

    /// Export an encrypted backup binary to a local file.
    /// - SeeAlso ``uploadEncryptedBackup(metadata:localIdentifiers:auth:)``
    func exportEncryptedBackup(
        localIdentifiers: LocalIdentifiers,
        backupKey: BackupKey,
        backupPurpose: MessageBackupPurpose,
        progress: OWSProgressSink?
    ) async throws -> Upload.EncryptedBackupUploadMetadata

#if TESTABLE_BUILD
    /// Export a plaintext backup binary at the returned file URL, for use in
    /// integration tests.
    func exportPlaintextBackupForTests(
        localIdentifiers: LocalIdentifiers,
        progress: OWSProgressSink?
    ) async throws -> URL
#endif

    // MARK: - Import

    /// Returns true if this device has ever successfully restored from a backup
    /// and committed the contents to the database.
    func hasRestoredFromBackup(tx: DBReadTransaction) -> Bool

    /// Import a backup from the encrypted binary file at the given local URL.
    /// - SeeAlso ``downloadEncryptedBackup(localIdentifiers:auth:)``
    func importEncryptedBackup(
        fileUrl: URL,
        localIdentifiers: LocalIdentifiers,
        backupKey: BackupKey,
        progress: OWSProgressSink?
    ) async throws

    /// Import a backup from the plaintext binary file at the given local URL.
    func importPlaintextBackup(
        fileUrl: URL,
        localIdentifiers: LocalIdentifiers,
        progress: OWSProgressSink?
    ) async throws

    // MARK: -

    /// Validate the encrypted backup file located at the given local URL.
    func validateEncryptedBackup(
        fileUrl: URL,
        localIdentifiers: LocalIdentifiers,
        backupKey: BackupKey,
        backupPurpose: MessageBackupPurpose
    ) async throws
}