//
//  BudgetsListView.swift
//  ydnab
//
//  Created by Andrea Franceschini on 23/09/2020.
//

import SwiftUI

class BudgetsListViewModel: ObservableObject {

    @Published var items: BudgetsList

    init() {
        let applicationSupportURL = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask)[0]
        guard !applicationSupportURL.path.isEmpty else {
            print("Couldn't find Application Support path.")
            items = []
            return
        }
        let budgetsListURL = URL(fileURLWithPath: "Budgets.json", relativeTo: applicationSupportURL)
        guard FileManager.default.fileExists(atPath: budgetsListURL.path) else {
            print("Couldn't find the budgets list in Application Support.")
            print(budgetsListURL.path)
            items = []
            return
        }
        do {
            items = try JSONDecoder().decode(BudgetsList.self, from: Data.init(contentsOf: budgetsListURL))
        } catch {
            print("Couldn't open the budgets list.")
            print("Error: \(error)")
            items = []
            return
        }
    }
}

struct BudgetsListView: View {
    @State var currentBudgetId: UUID?
    @ObservedObject var budgetsList = BudgetsListViewModel()

    init(currentBudgetId: UUID?, budgetsList: BudgetsListViewModel = BudgetsListViewModel()) {
        self.currentBudgetId = currentBudgetId
        self.budgetsList = budgetsList
    }

    func createBudget() {
        print("Creating new budget...")

        print("... done creating new budget.")
    }

    var body: some View {
        VStack {
            List {
                ForEach(budgetsList.items) { budget in
                    NavigationLink(destination: BudgetView(budget: budget, currentBudgetId: $currentBudgetId),
                                   tag: budget.id,
                                   selection: $currentBudgetId) {
                        Text(budget.name)
                    }
                }
                .onDelete(perform: { indexSet in
                    print(indexSet)
                })
                .onMove(perform: { indices, newOffset in
                    print("\(indices) :: \(newOffset)")
                })
            }

            Text(currentBudgetId?.uuidString ?? "--")
        }
        .listStyle(PlainListStyle())
        .navigationTitle("Budgets")
        .toolbar {
            #if os(iOS)
            ToolbarItem(placement: .primaryAction) {
                EditButton()
            }
            #endif

            ToolbarItem(placement: .navigationBarLeading) {
                Button("Add") {
                    print(self)
                }
            }
        }
    }
}

struct BudgetsListView_Previews: PreviewProvider {
    static var previews: some View {
        NavigationView {
            BudgetsListView(currentBudgetId: UUID())
        }
    }
}