//
//  MainView.swift
//  AutoCat2SUI
//
//  Created by Selim Mustafaev on 24.07.2022.
//

import SwiftUI
import AutoCatCore

struct SidebarSection: Identifiable {
    
    let name: String
    let filters: [Filter]
    let id = UUID()
    
    func contains(filter id: UUID) -> Bool {
        filters.contains { $0.id == id }
    }
}

struct MainView: View {
    
    @FetchRequest(entity: CDVehicle.entity(), sortDescriptors: []) var vehicles: FetchedResults<CDVehicle>
    
    @State private var selectedFilterId: UUID?
    @State var selectedVehicle: CDVehicle?
    @State private var checkSheetPresented = false
    @State private var searchText = ""
    
    @State var columnVisibility = NavigationSplitViewVisibility.all
    
    private let sections: [SidebarSection] = [
        SidebarSection(name: "History", filters: [
            .allLocal,
            .unrecognized,
            .outdated
        ]),
        SidebarSection(name: "Remote", filters: [
            .allRemote
        ])
    ]
    
    var selectedFilter: Filter? {
        guard let filterId = selectedFilterId else {
            return nil
        }
        
        return sections.first(where: { $0.contains(filter: filterId) })?
            .filters.first(where: { $0.id == filterId })
    }
    
    var body: some View {
        NavigationSplitView(columnVisibility: $columnVisibility) {
            List(selection: $selectedFilterId) {
                ForEach(sections) { section in
                    Section(section.name) {
                        ForEach(section.filters) { filter in
                            Label(filter.name, systemImage: filter.iconName)
                                .badge(vehicles.filter(filter.match).count)
                        }
                    }
                }
            }
            .navigationSplitViewColumnWidth(180)
            .toolbar {
                ToolbarItemGroup(placement: .primaryAction) {
                    Spacer()
                    Button {
                        checkSheetPresented = true
                    } label: {
                        Image(systemName: "plus")
                    }
                    .sheet(isPresented: $checkSheetPresented) {
                        CheckNumber()
                    }

                }
            }
        } content: {
            if let filter = selectedFilter {
                let filtered = vehicles.filter(filter.match)
                if filtered.isEmpty {
                    VStack {
                        Image(systemName: filter.iconName)
                            .resizable()
                            .aspectRatio(contentMode: .fit)
                            .frame(width: 64)
                            .foregroundColor(.secondary)
                        
                        Text("Nothing here")
                            .font(.system(size: 18))
                            .foregroundColor(.secondary)
                    }
                } else {
                    VehiclesListView(vehicles: filtered, selection: $selectedVehicle)
                        .toolbar {
                            ToolbarItem {
                                Button(action: {}) {
                                    Image(systemName: "line.3.horizontal.decrease.circle")
                                }
                            }
                        }
                        .navigationTitle(filter.name)
                        .navigationSubtitle("\(filtered.count) vehicles")
                }
            } else {
                EmptyView()
            }
        } detail: {
            if let vehicle = selectedVehicle {
                VehicleDetailView(vehicle: vehicle)
                    .toolbar {
                        ToolbarItem(placement: .automatic) {
                            Button(action: {}) {
                                Image(systemName: "square.and.arrow.up")
                            }
                        }
                    }
                    .navigationTitle(vehicle.brand?.name?.original ?? "")
                    .navigationSubtitle("\(vehicle.year)")
                    .searchable(text: $searchText, placement: .toolbar)
            } else {
                EmptyView()
            }
        }
        .navigationSplitViewStyle(.balanced)

    }
}

struct MainView_Previews: PreviewProvider {
    static var previews: some View {
        MainView()
    }
}