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

import SwiftUI
import SwiftData

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

  @State private var hideTags: Bool = false
  @State private var hideNotes: Bool = false
  @State private var empty = Category()

  @Binding var isMoveMode: Bool
  @FocusState private var isFocused: Bool

  var body: some View {
    VStack {
      HStack {
        if let grp = $allGroups.first(where: { $0.name.wrappedValue == task.category }) {
          ColorPicker("", selection: grp.color).disabled(true).scaledToFit()
        }
        Image(systemName: task.status.label)
          .frame(width: 20)
          .padding(.trailing, -10)
        Picker("", selection: $task.status) {
          ForEach(Status.allCases) { unit in
            Text(String(describing: unit))
          }
        }
        .fixedSize(horizontal: true, vertical: false)
        .onChange(of: task.status) {
          if task.status.isStrong {
            task.subtasks
              .filter({ !$0.status.isStrong })
              .forEach({ subtask in subtask.status = task.status })
          }
        }
        
        TextField("Task Name", text: $task.name)
          .focused($isFocused)
        if isMoveMode {
          Button {
            deleteItem(item: task)
          } label: {
            Image(systemName: "trash")
          }.help("Delete Task '\(task.name)'")
        } else {
          Button(action: addItem) {
            Image(systemName: "plus")
              .help("Add a Subtask")
          }
        }
      }
      
      if isFocused || !(hideTags || task.tags.isEmpty) {
        HStack {
          TagBarView(task: $task)
            .font(.footnote)
            .padding(.leading, 30)
          VisibilityTapper(hideToggle: $hideTags)
          if isFocused {
            Picker("", selection: $task.category) {
              Text(empty.name).tag("")
              ForEach(allGroups) { group in
                Text(group.name)
              }
            }
            .fixedSize(horizontal: true, vertical: false)
          }
        }.focused($isFocused)
      }
      
      if isFocused || !(hideNotes || task.notes.isEmpty) {
        HStack {
          TextField("Notes", text: $task.notes, axis: .vertical)
            .font(.footnote)
            .padding(.leading, 30)
          VisibilityTapper(hideToggle: $hideNotes)
        }.focused($isFocused)
      }
      
      VStack {
        ForEach($task.subtasks, id: \.self) { subtask in
          HStack {
            SubTaskView(task: subtask)
              .padding(.leading, 5)
            if isMoveMode {
              Button {
                deleteItem(item: subtask.wrappedValue, fromTask: task)
              } label: {
                Image(systemName: "trash")
              }.help("Delete Subtask '\(subtask.name.wrappedValue)'")
            }
          }
        }
      }
    }
  }

  private func addItem() {
    withAnimation {
      let newSubtask = SubTask(name: "Subtask", parent: task)
      modelContext.insert(newSubtask)
      task.subtasks.append(newSubtask)
    }
  }

  private func deleteItem(item: Task) {
    withAnimation {
      if let fromProject = item.project {
        fromProject.tasks.removeAll(where: { $0.id == item.id })
        modelContext.delete(item)
      }
    }
  }

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

#Preview {
  @Previewable @State var isMoveMode = false
  @Previewable @State var task = Task(name: "New Task")
  TaskView(task: $task, isMoveMode: $isMoveMode)
      .frame(minHeight: 100) // Preview does not resize window properly
}