TodosApp/Todos/View/ProjectPanelView.swift

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

import SwiftUI
import SwiftData

struct ProjectPanelView: View {
  @Environment(\.modelContext) private var modelContext
  @AppStorage(UserDefaultsKeys.Category) var allGroups = CodableArray<Category>()

  @Bindable var item: Project
  @State private var empty = Category()
  @State private var move = false

  var body: some View {
    let style = Date.FormatStyle(date: .numeric, time: .standard)
    HStack {
      TextField("", text: $item.name)
        .font(.title)
        .padding(.leading, 10)
      Spacer()
      Button(action: addItem) {
        Image(systemName: "plus")
      }
      .help("New Task")
      .padding(.trailing, 10)
      Toggle("Move Tasks", isOn: $move)
        .padding(.trailing, 10)
    }
    HStack {
      if let grp = $allGroups.first(where: { $0.name.wrappedValue == item.category }) {
        ColorPicker("", selection: grp.color).disabled(true).scaledToFit()
      }
      Picker("", selection: $item.category) {
        Text(empty.name).tag("")
        ForEach(allGroups) { group in
          Text(group.name)
        }
      }.help("Default category for new Tasks")
      Text("Created on \(item.timestamp, format: style)")
    }
    List {
      ForEach($item.tasks.sorted(by: Task.less)) { task in
        TaskView(task: task)
          .swipeActions {
            Button("Delete", systemImage: "trash", role: .destructive) {
              deleteItem(item: task.wrappedValue, from: item)
            }
          }

        ForEach(task.subtasks.sorted(by: SubTask.less)) { subtask in
          SubTaskView(task: subtask)
            .swipeActions {
              Button("Delete", systemImage: "trash", role: .destructive) {
                deleteItem(item: subtask.wrappedValue, from: task.wrappedValue)
              }
            }
        }
        .onMove(perform: { moveItem(task.wrappedValue, $0, $1) })
        .moveDisabled(!move)
      }
      .onMove(perform: { moveItem(item, $0, $1) })
      .moveDisabled(!move)
    }
  }

  private func addItem() {
    withAnimation {
      let newTask = Task(name: "New Task", parent: item)
      modelContext.insert(newTask)
      item.tasks.append(newTask)
    }
  }

  private func moveItem(_ within: Project, _ fromOffsets: IndexSet, _ toOffset: Int) {
    withAnimation {
      within.tasks.move(fromOffsets: fromOffsets, toOffset: toOffset)
      for (index, item) in within.tasks.enumerated() {
        item.sortOrder = index
      }
    }
  }

  private func moveItem(_ within: Task, _ fromOffsets: IndexSet, _ toOffset: Int) {
    withAnimation {
      within.subtasks.move(fromOffsets: fromOffsets, toOffset: toOffset)
      for (index, item) in within.subtasks.enumerated() {
        item.sortOrder = index
      }
    }
  }

  private func deleteItem(item: Task, from: Project) {
    withAnimation {
      from.tasks.removeAll(where: { $0.id == item.id })
      modelContext.delete(item)
    }
  }

  private func deleteItem(item: SubTask, from: Task) {
    withAnimation {
      from.subtasks.removeAll(where: { $0.id == item.id })
      modelContext.delete(item)
    }
  }
}

#Preview {
  @Previewable @State var item = Project(timestamp: Date())
  ProjectPanelView(item: item)
}