BackupFile.swift

BackupFile.swift

//
//  BackupFile.swift
//  BackupFile
//
//  Created by Rudolf Farkas on 21.05.22.
//

import Foundation

// a wrapper struct that backs up the wrapped struct in an iOS file
public struct BackupFile<Wrapped: Codable>: Codable {
    public let wrapped: Wrapped
    public init(wrapped: Wrapped) {
        self.wrapped = wrapped
    }
}

public extension FileManager {
    func backupFile<Wrapped: Codable>(at url: URL, with wrapped: Wrapped) throws {
        let backupFile = BackupFile(wrapped: wrapped)
        try backupFile.write(to: url)
    }

    func restoreFile<Wrapped: Codable>(at url: URL) throws -> Wrapped {
        let backupFile = try BackupFile<Wrapped>(from: url)
        return backupFile.wrapped
    }
}

public extension BackupFile {
    init(from url: URL) throws {
        let data = try Data(contentsOf: url)
        let decoder = JSONDecoder()
        self = try decoder.decode(BackupFile.self, from: data)
    }

    func write(to url: URL) throws {
        let encoder = JSONEncoder()
        let data = try encoder.encode(self)
        try data.write(to: url)
    }
}