import SwiftUI
import SwiftData

struct EntityListView<T: EditableEntity>: View {
    @Environment(\.modelContext) private var modelContext

    @Query var items: [T]
    
    @State private var showingAddSheet = false
    @State private var itemToEdit: T? = nil
    @State private var itemToDelete: T? = nil
    
    private var sortDescriptors: [SortDescriptor<T>]
    
    init(sort: [SortDescriptor<T>] = [], searchString: String = "") {
        self.sortDescriptors = sort
        _items = Query(filter: #Predicate { item in
            if searchString.isEmpty {
                return true
            } else {
                return item.name.localizedStandardContains(searchString)
            }
        }, sort: sort)
    }
    
    @State private var isInsideNavigationStack: Bool = false

    var body: some View {
        let content = Form {
            List {
                ForEach(items) { item in
                    ListItem(title: item.name, count: item.count)
                        .swipeActions(edge: .trailing, allowsFullSwipe: false) {
                            Button(role: .destructive) {
                                itemToDelete = item
                            } label: {
                                Label("Delete", systemImage: "trash")
                            }
                            Button {
                                itemToEdit = item
                            } label: {
                                Label("Edit", systemImage: "pencil")
                            }
                            .tint(.indigo)
                        }
                }
            }
        }
        .navigationTitle(T.navigationTitle)
        .toolbar {
            ToolbarItem(placement: .navigationBarTrailing) {
                Button(action: { showingAddSheet.toggle() }) {
                    Image(systemName: "plus")
                }
            }
        }
        .sheet(isPresented: $showingAddSheet) {
            T.formView(for: T.createNew())
        }
        .sheet(item: $itemToEdit) { item in
            T.formView(for: item)
        }
        .confirmationDialog(
            "Delete?",
            isPresented: Binding<Bool>(
                get: { itemToDelete != nil },
                set: { if !$0 { itemToDelete = nil } }
            ),
            titleVisibility: .visible
        ) {
            Button("Delete", role: .destructive) {
                if let item = itemToDelete {
                    modelContext.delete(item)
                    try? modelContext.save()
                    itemToDelete = nil
                }
            }
            Button("Cancel", role: .cancel) {
                itemToDelete = nil
            }
        } message: {
            Text("Are you sure you want to delete \(itemToDelete?.name ?? "this item")?")
        }
        .background(
            NavigationStackChecker(isInside: $isInsideNavigationStack)
        )

        if isInsideNavigationStack {
            content
        } else {
            NavigationStack {
                content
            }
        }
    }
}