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

import SwiftUI

struct PreferencesView: View {
    let dismiss: () -> Void
    
    @ObservedObject private var preferences: Preferences = .shared
    // todo: this should really be a @StateObject on ToolbarPrefView
    @State private var toolbarViewModel = CustomizeToolbarViewModel()
    
    var body: some View {
        NavigationView {
            List {
                untitledSection
                
                appearanceSection
                
                safariSection
                
                behaviorSection
            }
            .navigationBarTitle("Preferences")
            .insetOrGroupedListStyle()
            .navigationBarItems(trailing: doneButton)
        }
        .navigationViewStyle(.stack)
        .onDisappear {
            Preferences.save()
        }
    }
    
    private var doneButton: some View {
        Button(action: {
            dismiss()
        }, label: {
            Text("Done")
        })
        .hoverEffect(.highlight)
    }
    
    private var untitledSection: some View {
        Section {
            NavigationLink(destination: HomepagePrefView()) {
                Text("Homepage")
            }

        }
    }
    
    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)
            }
            
            Toggle("Show Link Icons", isOn: $preferences.showLinkIcons)
        }
    }
    
    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)
        }
    }
    
    private var behaviorSection: some View {
        Section(header: Text("Behavior")) {
            Toggle("Pull to Refresh", isOn: $preferences.pullToRefreshEnabled)
            Toggle("Hide Toolbars When Scrolling", isOn: $preferences.hideToolbarsWhenScrolling)
            NavigationLink {
                ToolbarPrefView(model: toolbarViewModel)
            } label: {
                Text("Customize Toolbar")
            }
        }
    }
}

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

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