Gemini/Gemini-iOS/PreferencesView.swift

//
//  PreferencesView.swift
//  Gemini-iOS
//
//  Created by Shadowfacts on 9/27/20.
//

import SwiftUI

struct PreferencesView: View {
    @ObservedObject var preferences: Preferences = .shared
    
    @Environment(\.presentationMode) @Binding var presentationMode: PresentationMode
    
    var body: some View {
        NavigationView {
            List {
                appearanceSection
                
                safariSection
            }
            .navigationBarTitle("Preferences")
            .insetOrGroupedListStyle()
            .navigationBarItems(trailing: doneButton)
        }
        .navigationViewStyle(StackNavigationViewStyle())
        .onDisappear {
            Preferences.save()
        }
    }
    
    private var doneButton: some View {
        Button(action: {
            presentationMode.dismiss()
        }, label: {
            Text("Done")
        })
        .hoverEffect(.highlight)
    }
    
    private var appearanceSection: some View {
        Section(header: Text("Appearance")) {
            Picker(selection: $preferences.theme, label: Text("Theme")) {
                Text("Use System Theme").tag(UIUserInterfaceStyle.unspecified)
                Text("Always Light").tag(UIUserInterfaceStyle.light)
                Text("Always Dark").tag(UIUserInterfaceStyle.dark)
            }
        }
    }
    
    private var safariSection: some View {
        Section(header: Text("Safari")) {
            Toggle("Use In-App Safari", isOn: $preferences.useInAppSafari)
            
            Toggle("Use Reader Mode", isOn: $preferences.useReaderMode)
                .disabled(!preferences.useInAppSafari)
        }
    }
}

fileprivate extension View {
    @ViewBuilder
    func insetOrGroupedListStyle() -> some View {
        if #available(iOS 14.0, *) {
            self.listStyle(InsetGroupedListStyle())
        } else {
            self.listStyle(GroupedListStyle())
        }
    }
}

struct PreferencesView_Previews: PreviewProvider {
    @State static var presented = true
    
    static var previews: some View {
        PreferencesView()
    }
}