//
//  ContentView.swift
//  Map
//
//  Created by Ruben Beltran del Rio on 2/1/21.
//

import SwiftUI
import CoreData

struct ContentView: View {
    @Environment(\.managedObjectContext) private var viewContext

    @FetchRequest(
        sortDescriptors: [NSSortDescriptor(keyPath: \Map.createdAt, ascending: true)],
        animation: .default)
    private var maps: FetchedResults<Map>

    var body: some View {
        NavigationView {
        List {
            ForEach(maps) { map in
                NavigationLink(destination: MapDetailView(map: map)) {
                HStack {
                    Text(map.title ?? "Untitled Map")
                    Text(map.createdAt!.format())
                        .font(.footnote)
                        .foregroundColor(Color.accentColor)
                }
                }
            }
            .onDelete(perform: deleteMaps)
        }
        .toolbar {
            HStack {
                Button(action: toggleSidebar) {
                    Label("Toggle Sidebar", systemImage: "sidebar.left")
                }
                Button(action: addMap) {
                    Label("Add Map", systemImage: "plus")
                }
            }
        }
        }
    }
    
    private func toggleSidebar() {
            NSApp.keyWindow?.firstResponder?.tryToPerform(#selector(NSSplitViewController.toggleSidebar(_:)), with: nil)
    }

    private func addMap() {
        withAnimation {
            let newMap = Map(context: viewContext)
            newMap.uuid = UUID()
            newMap.createdAt = Date()
            newMap.title = "Map \(newMap.createdAt!.format())"
            newMap.content = ""

            do {
                try viewContext.save()
            } catch {
                // Replace this implementation with code to handle the error appropriately.
                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
                let nsError = error as NSError
                fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
            }
        }
    }

    private func deleteMaps(offsets: IndexSet) {
        withAnimation {
            offsets.map { maps[$0] }.forEach(viewContext.delete)

            do {
                try viewContext.save()
            } catch {
                // Replace this implementation with code to handle the error appropriately.
                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
                let nsError = error as NSError
                fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
            }
        }
    }
}

private let mapFormatter: DateFormatter = {
    let formatter = DateFormatter()
    formatter.dateStyle = .short
    formatter.timeStyle = .medium
    return formatter
}()

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView().environment(\.managedObjectContext, PersistenceController.preview.container.viewContext)
    }
}