//
//  StockList.swift
//  HomeStock
//
//  Created by Karl-Peter Zons on 05.01.21.
//

import SwiftUI
import CoreData
import Foundation


struct StockList: View {
    
    @Environment(\.managedObjectContext) private var viewContext
    
    @FetchRequest(
        sortDescriptors: [NSSortDescriptor(keyPath: \Stock.bezeichnung, ascending: true)],
        animation: .default)
    
    private var waren: FetchedResults<Stock>
    
    var body: some View {
        NavigationView {
            List {
                ForEach(waren) { ware in
                    VStack(alignment: .leading) {
                        Text("\(ware.bezeichnung!) in \(ware.mengenEinheit!)")
                        HStack {
                            Text("Datum zu: ")
                            Text(dFormatter.string(from: ware.zugangDatum!))
                            
                            Text("ab:")
                            Text(dFormatter.string(from: ware.verbrauchDatum!))
                        }
                        VStack {
                            Text("Menge ist: \(ware.istMenge) min: \(ware.minMenge)")
                        }
                        
                    }
                    .frame(height: 60)
                    .font(.footnote)
                }
                .onDelete(perform: deleteItems)
            }
            .navigationBarTitle(Text("Gesamt - Bestand"), displayMode: .inline)
            
            
        }
    }
    private func deleteItems(offsets: IndexSet) {
        withAnimation {
            offsets.map { waren[$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 dFormatter: DateFormatter = {
    let dFormatter = DateFormatter()
    dFormatter.locale = Locale(identifier: "fr_FR")
    dFormatter.dateStyle = .short
    dFormatter.timeStyle = .none
    return dFormatter
}()


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