//
//  PreferencesView.swift
//  OTP
//
//  Created by Shadowfacts on 8/23/21.
//

import SwiftUI

struct PreferencesView: View {
    @ObservedObject private var store = KeyStore.shared
    @Environment(\.dismiss) private var dismiss
    @State private var clearBeforeImport = false
    @State private var isPresentingExport = false
    @State private var isPresentingImportMode = false
    @State private var isPresentingImport = false
    @State private var isPresentingImportFailedAlert = false
    @State private var importFailedError: Error? = nil
    
    var body: some View {
        List {
            Section("Backup") {
                Button("Export to File...") {
                    isPresentingExport = true
                }
                Menu("Import from File...") {
                    Button("Keep Existing Keys") {
                        clearBeforeImport = false
                        isPresentingImport = true
                    }
                    Button("Replace Existing Keys", role: .destructive) {
                        clearBeforeImport = true
                        isPresentingImport = true
                    }
                }
            }
        }
        .navigationTitle("Preferences")
        .toolbar {
            ToolbarItem(placement: .navigationBarTrailing) {
                Button("Done") {
                    dismiss()
                }
            }
        }
        .fileExporter(isPresented: $isPresentingExport, document: BackupDocument(data: store.data), contentType: .propertyList, defaultFilename: "OTPBackup") { (_) in
        }
        .fileImporter(isPresented: $isPresentingImport, allowedContentTypes: [.propertyList], allowsMultipleSelection: false) { (result) in
            switch result {
            case let .failure(error):
                self.importFailedError = error
                self.isPresentingImportFailedAlert = true
            case let .success(urls):
                do {
                    let backup = try BackupDocument(url: urls.first!)
                    store.updateFromStore(backup.data, replaceExisting: clearBeforeImport)
                    dismiss()
                } catch {
                    self.importFailedError = error
                    self.isPresentingImportFailedAlert = true
                }
            }
        }
        .alert("Import Failed", isPresented: $isPresentingImportFailedAlert) {
            Button("OK", role: .cancel) {}
        } message: {
            if let error = importFailedError {
                Text(error.localizedDescription)
            }
        }
    }
    
}

struct PreferencesView_Previews: PreviewProvider {
    static var previews: some View {
        PreferencesView()
    }
}