SideStore/SideStoreApp/Sources/SideStoreAppKit/Operations/RemoveAppBackupOperation.swift

//
//  RemoveAppBackupOperation.swift
//  AltStore
//
//  Created by Riley Testut on 5/13/20.
//  Copyright © 2020 Riley Testut. All rights reserved.
//

import Foundation
import os.log

@objc(RemoveAppBackupOperation)
final class RemoveAppBackupOperation: ResultOperation<Void> {
    let context: InstallAppOperationContext

    private let coordinator = NSFileCoordinator()
    private let coordinatorQueue = OperationQueue()

    init(context: InstallAppOperationContext) {
        self.context = context

        super.init()

        coordinatorQueue.name = "AltStore - RemoveAppBackupOperation Queue"
    }

    override func main() {
        super.main()

        if let error = context.error {
            finish(.failure(error))
            return
        }

        guard let installedApp = context.installedApp else { return finish(.failure(OperationError.invalidParameters)) }
        installedApp.managedObjectContext?.perform {
            guard let backupDirectoryURL = FileManager.default.backupDirectoryURL(for: installedApp) else { return self.finish(.failure(OperationError.missingAppGroup)) }

            let intent = NSFileAccessIntent.writingIntent(with: backupDirectoryURL, options: [.forDeleting])
            self.coordinator.coordinate(with: [intent], queue: self.coordinatorQueue) { error in
                do {
                    if let error = error {
                        throw error
                    }

                    try FileManager.default.removeItem(at: intent.url)

                    self.finish(.success(()))
                } catch let error as CocoaError where error.code == CocoaError.Code.fileNoSuchFile {
                    #if DEBUG

                        // When debugging, it's expected that app groups don't match, so ignore.
                        self.finish(.success(()))

                    #else

                        os_log("Failed to remove app backup directory: %@", type: .error , error.localizedDescription)
                        self.finish(.failure(error))

                    #endif
                } catch {
                    os_log("Failed to remove app backup directory: %@", type: .error , error.localizedDescription)
                    self.finish(.failure(error))
                }
            }
        }
    }
}