TodosApp/Todos/View/ContentView.swift

//
//  ContentView.swift
//  Todos
//
//  Created by Sam Jaffe on 2/28/26.
//

import SwiftUI
import SwiftData

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

  @Query(sort: \Project.sortOrder) private var items: [Project]
  @State private var selection: Project?
  @Binding var hasAutosave: Bool

  var body: some View {
    NavigationSplitView {
      List(selection: $selection) {
        ForEach(items, id: \.id) { item in
          NavigationLink(value: item) {
            Text(item.name)
          }.swipeActions(content: {
            Button("Delete", systemImage: "trash", role: .destructive) {
              deleteItem(item: item)
            }
          })
        }
        .onMove(perform: reOrder)
      }
      .navigationSplitViewColumnWidth(min: 180, ideal: 200)
      .toolbar {
        ToolbarItem {
          Button(action: addItem) {
            Label("New Project", systemImage: "plus")
          }
        }
      }
    } detail: {
      if let selection = selection {
        ProjectPanelView(item: selection)
      } else {
        let header = items.isEmpty ? "Create a New Project" : "Select a project from the sidebar"
        ContentUnavailableView(header, systemImage: "doc.text.image.fill")
      }
    }
    .alert("Autosave", isPresented: $hasAutosave) {
      Button("OK") {
        hasAutosave = false
      }
    } message: {
      Text("All completed tasks/subtasks have been deleted")
    }
  }

  private func addItem() {
    withAnimation {
      let newItem = Project(sortOrder: items.count)
      modelContext.insert(newItem)
    }
  }

  @MainActor
  private func reOrder(fromOffsets: IndexSet, toOffset: Int) {
    var tmp = items.sorted(by: Project.less)
    tmp.move(fromOffsets: fromOffsets, toOffset: toOffset)
    for (index, item) in tmp.enumerated() {
      item.sortOrder = index
    }
    try? self.modelContext.save()
  }

  private func deleteItem(item: Project) {
    if let selection = selection, selection == item {
      self.selection = nil
    }
    withAnimation {
      modelContext.delete(item)
    }
  }
}

#Preview {
  @Previewable @State var hasAutosave = false
  ContentView(hasAutosave: $hasAutosave)
    .modelContainer(for: Project.self, inMemory: true)
}