Seven Boom

import Cocoa

class FileWriter {
    // Variables
    // For creating string filename location
    var documentPath, fileName, fullPath : String!
    // For getting the ios file manager
    var fileManager = FileManager.default

    init(fileName : String) {
        self.fileName = fileName
        fileSettings()

    }

    func fileSettings() {
        // For getting document path, we need to use our file manager...
        self.documentPath = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true)[0]
        self.fullPath = "\(documentPath!)/\(fileName!)"
    }

    func test() {
        print(self.fullPath!)
    }

    func writeToFile(_ txt: String) {
        var myData = readFromFile()
        do {
            myData += txt
            try myData.write(toFile: self.fullPath, atomically: true, encoding: String.Encoding.utf8)
            print("Wrote to file")
        }
        catch {
            print("Error writing to file")
        }
    }

    func readFromFile() -> String {
        var temp = ""
        if fileManager.fileExists(atPath: fullPath) {
            do {
                try temp = String(contentsOfFile: fullPath)
            } catch {
                print("Cannot read from file \(self.fileName ?? "")") /// In string we can add ?? "with default content"
            }
        } else {
            print("No such file in the system")
        }
        return temp
    }

    func deleteFile() {
        do {
            try fileManager.removeItem(atPath: fullPath)
            print("File \(fileName!) deleted successfully")
        } catch {
            print("Failed to delete file \(fileName ?? "Bad file name")")
        }
    }
}

class SevenBoom {

    let fName = "SevenBoom.txt"
    let fileWriter = FileWriter(fileName: "SevenBoom.txt")
    var res : String = ""

    func runProc() {
        for num in 1...100 {
            if num % 7 == 0 || num % 10 == 7 || num / 10 == 7 {
                res.append("Boom\n")
            } else {
                res.append("\(num)\n")

            }
        }
    }
    func createResultFile() {
        runProc()
        fileWriter.writeToFile(res)
    }

    func readResultFile() {
        print(fileWriter.readFromFile())
    }
}

let SBoom = SevenBoom()
SBoom.readResultFile()
SBoom.createResultFile()
SBoom.readResultFile()