//
//  AddURLForm.swift
//  OTP
//
//  Created by Shadowfacts on 8/22/21.
//

import SwiftUI
import OTPKit

struct AddURLForm: View {
    let dismiss: (DismissAction) -> Void
    @State private var inputURL = ""
    @State private var extractedKey = EditedKey()
    @FocusState private var urlFocused: Bool
    
    private var isValid: Bool {
        extractedKey.toTOTPKey() != nil
    }
    
    var body: some View {
        Form {
            HStack {
                TextField("URL", text: $inputURL)
                    .focused($urlFocused)
                
                Button {
                    self.inputURL = UIPasteboard.general.string ?? ""
                } label: {
                    Label("Paste", systemImage: "doc.on.clipboard")
                        .labelStyle(.iconOnly)
                        .foregroundColor(.accentColor)
                }
                .buttonStyle(.plain)
                .disabled(!UIPasteboard.general.hasStrings)
            }
            
            Section {
                TextField("Issuer", text: $extractedKey.issuer)
                TextField("Label", text: $extractedKey.label)
                TextField("Secret", text: $extractedKey.secret)
            } header: {
                Text("Extracted Key")
            }
            .disabled(true)
        }
        .onSubmit {
            if isValid {
                dismiss(.save(extractedKey.toTOTPKey()!))
            }
        }
        .onAppear {
            // doesn't work, see FB9551099
            urlFocused = true
        }
        .navigationTitle("Add from URL")
        .toolbar {
            ToolbarItem(placement: .navigationBarLeading) {
                Button("Cancel") {
                    dismiss(.cancel)
                }
            }
            ToolbarItem(placement: .navigationBarTrailing) {
                Button("Save") {
                    dismiss(.save(extractedKey.toTOTPKey()!))
                }
                .disabled(!isValid)
            }
        }
        .onChange(of: inputURL, perform: self.updateExtractedKey(inputURL:))
    }
    
    private func updateExtractedKey(inputURL: String) {
        let text = inputURL.trimmingCharacters(in: .whitespacesAndNewlines)
        if !text.isEmpty,
           let components = URLComponents(string: inputURL),
           let totpKey = TOTPKey(urlComponents: components),
           let edited = EditedKey(totpKey: totpKey) {
            extractedKey = edited
        } else {
            extractedKey = EditedKey()
        }
    }
}

struct AddURLForm_Previews: PreviewProvider {
    static var previews: some View {
        AddURLForm() { (_) in }
    }
}