Hi, everyone! I'm trying to do challanges that are part of Project 9. I'm using DispatchQueue.main inside DispatchQueue.global(qos: .background) I'm still not sure if these are the right approach, any thoughts? Thanks in advance!

func loadLevel() {
        var clueString = ""
        var solutionString = ""
        var letterBits = [String]()

        DispatchQueue.global(qos: .background).async {
            if let levelFileURL = Bundle.main.url(forResource: "level\(self.level)", withExtension: "txt"){
                if let levelContents = try? String(contentsOf: levelFileURL) {
                    var lines = levelContents.components(separatedBy: "\n")
                    lines.shuffle()

                    for (index, line) in lines.enumerated() {
                        let parts = line.components(separatedBy: ":")
                        let answer = parts[0]
                        let clue = parts[1]

                        clueString += "\(index + 1). \(clue)\n"

                        let solutionWord = answer.replacingOccurrences(of: "|", with: "")
                        solutionString += "\(solutionWord.count) letters\n"
                        self.solutions.append(solutionWord)

                        let bits = answer.components(separatedBy: "|")
                        letterBits += bits
                    }
                }
            }

            DispatchQueue.main.async {
                //Configure the buttons and labels
                self.cluesLabel.text = clueString.trimmingCharacters(in: .whitespacesAndNewlines)
                self.answerLabel.text = solutionString.trimmingCharacters(in: .whitespacesAndNewlines)

                letterBits.shuffle()

                if letterBits.count == self.letterButtons.count {
                    for i in 0 ..< self.letterButtons.count {
                        self.letterButtons[i].setTitle(letterBits[i], for: .normal)
                    }
                }
            }
        }
    }