Day 29, 30, 31 of #100DaysOfSwiftUI

Start 100DaysOfSwiftUI from 2020.Mar.18th.

Day 29, 30, 31: Project 5, part one, two, three
done with 80min

New findings: followings are new findings

List

show some rows with data, looks similar to Form, but Form will ask for the input.

UITextChecker

for spell checking, but it comes from Objective-C world...

RoundedBorderTextFieldStyle

this will show rounded border for TextField

TextField trainig closure

it will be called when user press return key, it is same with onCommit

.autocapitalization

this modifier can stop "auto-capitalization" feature of textfield

OnAppear

looks simlar with viewWillAppear

fatalError

in the case no way to continue, fatalError will be the only way we can take.

struct ContentView: View {
    @State private var usedWords = [String]()
    @State private var rootWord = ""
    @State private var newWord = ""
    @State private var score = 0
    
    @State private var errorTitle = ""
    @State private var errorMessage = ""
    @State private var showingError = false

    
    var body: some View {
        NavigationView {
            VStack {
                TextField("Enter your word",
                          text: $newWord, onCommit: addNewWord)
                .textFieldStyle(RoundedBorderTextFieldStyle())
                .padding()
                .autocapitalization(.none)
                List(usedWords, id:\.self) {
                    Image(systemName: "\($0.count).circle")
                    Text($0)
                }
                Text("Score : \(score)")
                .padding()
            }
            .navigationBarTitle(rootWord)
            .navigationBarItems(leading: Button(action: startGame ) {
                Text("Restart Game")
            })
            .onAppear(perform: startGame)
            .alert(isPresented: $showingError) {
                Alert(title: Text(errorTitle), message: Text(errorMessage), dismissButton: .default(Text("OK")))
            }
        }
    }
    
    func addNewWord() {
        let answer = newWord.lowercased()
            .trimmingCharacters(in: .whitespacesAndNewlines)
        guard answer.count > 0 else {
            return
        }
        
        guard isOriginal(word: answer) else {
            wordError(title: "Word used already", message: "Be more original")
            return
        }
        
        guard isPossible(word: answer) else {
            wordError(title: "Word not recognized", message: "You can't just make them up, you know!")
            return
        }
        
        guard isReal(word: answer) else {
            wordError(title: "Word not possible", message: "That isn't a real word.")
            return
        }
        
        usedWords.insert(answer, at: 0)
        newWord = ""
        score += (answer.count)*(answer.count)
    }
    
    func startGame() {
        usedWords = []
        score = 0
        if let startTxtUrl = Bundle.main.url(forResource: "start", withExtension: "txt") {
            if let startWords = try? String(contentsOf: startTxtUrl) {
                let allWords = startWords.components(separatedBy: "\n")
                rootWord = allWords.randomElement() ?? "silkworm"
                return
            }
        }
        fatalError("Could not load start.txt from bundle.")
    }
    
    func isOriginal(word: String) -> Bool {
        !usedWords.contains(word)
    }
    
    func isPossible(word: String) -> Bool {
        var tempWord = rootWord
        
        for letter in word {
            if let pos = tempWord.firstIndex(of: letter) {
                tempWord.remove(at: pos)
            } else {
                return false
            }
        }
        return true
    }
    
    func isReal(word: String) -> Bool {
        if word.count  3 { return false}
        if word == rootWord { return false }
        
        let checker = UITextChecker()
        let range = NSRange(location: 0, length: word.utf16.count)
        let missspelledRange = checker.rangeOfMisspelledWord(in: word, range: range,
                                                             startingAt: 0, wrap: false, language: "en")
        return missspelledRange.location == NSNotFound
    }
    
    func wordError(title: String, message: String) {
        errorTitle = title
        errorMessage = message
        showingError = true
    }
}