"use client";

import type { DragEndEvent, DragStartEvent } from "@dnd-kit/core";
import {
  closestCenter,
  DndContext,
  DragOverlay,
  KeyboardSensor,
  PointerSensor,
  useSensor,
  useSensors,
} from "@dnd-kit/core";
import {
  arrayMove,
  SortableContext,
  sortableKeyboardCoordinates,
  useSortable,
  verticalListSortingStrategy,
} from "@dnd-kit/sortable";
import { CSS } from "@dnd-kit/utilities";
import { GripVertical, Plus, X } from "lucide-react";
import { useState } from "react";

import { Button } from "@/components/ui/button";
import { Checkbox } from "@/components/ui/checkbox";
import { Input } from "@/components/ui/input";
import {
  Item,
  ItemContent,
  ItemGroup,
  ItemMedia,
  ItemTitle,
} from "@/components/ui/item";
import { cn } from "@/lib/utils";

interface Todo {
  id: string;
  title: string;
  completed: boolean;
}

interface Todo4Props {
  heading?: string;
  description?: string;
  addTaskLabel?: string;
  taskPlaceholder?: string;
  cancelLabel?: string;
  submitLabel?: string;
  initialTodos?: Todo[];
  className?: string;
}

const defaultTodos: Todo[] = [
  {
    id: "1",
    title: "تکمیل مستندات فنی پروژه",
    completed: false,
  },
  {
    id: "2",
    title: "بررسی و تأیید طراحی رابط کاربری",
    completed: false,
  },
  {
    id: "3",
    title: "آماده‌سازی گزارش هفتگی",
    completed: false,
  },
];

interface SortableTodoItemProps {
  todo: Todo;
  onToggle: (id: string) => void;
  isNew?: boolean;
}

const SortableTodoItem = ({
  todo,
  onToggle,
  isNew = false,
}: SortableTodoItemProps) => {
  const {
    attributes,
    listeners,
    setNodeRef,
    transform,
    transition,
    isDragging,
  } = useSortable({ id: todo.id });

  const style = {
    transform: CSS.Translate.toString(transform),
    transition,
    opacity: isDragging ? 0.5 : 1,
  };

  return (
    <div
      ref={setNodeRef}
      style={style}
      className={isNew ? "animate-in duration-500 fade-in" : ""}
    >
      <Item
        variant={todo.completed ? "muted" : "default"}
        className={cn(
          "cursor-pointer items-center border-b transition-opacity",
          todo.completed && "opacity-60",
        )}
        onClick={() => onToggle(todo.id)}
      >
        <ItemMedia>
          <div className="flex items-center gap-2">
            <Button
              variant="ghost"
              size="icon-sm"
              {...attributes}
              {...listeners}
              className="cursor-grab active:cursor-grabbing"
              onClick={(e) => e.stopPropagation()}
              aria-label={`جابه‌جایی «${todo.title}»`}
            >
              <GripVertical className="size-4 text-muted-foreground" />
            </Button>
            <Checkbox
              checked={todo.completed}
              onCheckedChange={() => onToggle(todo.id)}
              onClick={(e) => e.stopPropagation()}
              aria-label={
                todo.completed
                  ? `علامت‌گذاری «${todo.title}» به‌عنوان انجام‌نشده`
                  : `علامت‌گذاری «${todo.title}» به‌عنوان انجام‌شده`
              }
            />
          </div>
        </ItemMedia>
        <ItemContent>
          <ItemTitle
            className={
              todo.completed ? "text-muted-foreground line-through" : ""
            }
          >
            {todo.title}
          </ItemTitle>
        </ItemContent>
      </Item>
    </div>
  );
};

const Todo4 = ({
  heading = "مدیریت وظایف با افزودن وظیفه جدید",
  description =
    "وظیفه جدید اضافه کنید، ترتیب را با کشیدن تغییر دهید و وضعیت تکمیل را علامت بزنید.",
  addTaskLabel = "افزودن وظیفه جدید",
  taskPlaceholder = "عنوان وظیفه",
  cancelLabel = "انصراف",
  submitLabel = "افزودن",
  initialTodos = defaultTodos,
  className,
}: Todo4Props) => {
  const [todos, setTodos] = useState(initialTodos);
  const [isFormExpanded, setIsFormExpanded] = useState(false);
  const [newTaskTitle, setNewTaskTitle] = useState("");
  const [activeTodo, setActiveTodo] = useState<Todo | null>(null);
  const [newTodoIds, setNewTodoIds] = useState<Set<string>>(new Set());

  const sensors = useSensors(
    useSensor(PointerSensor),
    useSensor(KeyboardSensor, {
      coordinateGetter: sortableKeyboardCoordinates,
    }),
  );

  const toggleTodo = (id: string) => {
    setTodos((prevTodos) =>
      prevTodos.map((todo) =>
        todo.id === id ? { ...todo, completed: !todo.completed } : todo,
      ),
    );
  };

  const handleAddTask = () => {
    if (newTaskTitle.trim()) {
      const newTodo: Todo = {
        id: Date.now().toString(),
        title: newTaskTitle.trim(),
        completed: false,
      };
      setTodos((prevTodos) => [...prevTodos, newTodo]);
      setNewTodoIds((prev) => new Set(prev).add(newTodo.id));
      setNewTaskTitle("");
      setIsFormExpanded(false);

      setTimeout(() => {
        setNewTodoIds((prev) => {
          const updated = new Set(prev);
          updated.delete(newTodo.id);
          return updated;
        });
      }, 500);
    }
  };

  const handleCancel = () => {
    setNewTaskTitle("");
    setIsFormExpanded(false);
  };

  const handleDragStart = (event: DragStartEvent) => {
    const { active } = event;
    const todo = todos.find((t) => t.id === active.id);
    setActiveTodo(todo || null);
  };

  const handleDragEnd = (event: DragEndEvent) => {
    const { active, over } = event;

    if (over && active.id !== over.id) {
      setTodos((items) => {
        const oldIndex = items.findIndex((item) => item.id === active.id);
        const newIndex = items.findIndex((item) => item.id === over.id);
        return arrayMove(items, oldIndex, newIndex);
      });
    }

    setActiveTodo(null);
  };

  return (
    <section dir="rtl" lang="fa" className={cn("py-32", className)}>
      <div className="container">
        <div className="mx-auto flex max-w-2xl flex-col gap-8">
          <div className="flex flex-col gap-2">
            <h2 className="text-3xl font-semibold md:text-xl">{heading}</h2>
            <p className="text-muted-foreground">{description}</p>
          </div>
          <DndContext
            sensors={sensors}
            collisionDetection={closestCenter}
            onDragStart={handleDragStart}
            onDragEnd={handleDragEnd}
          >
            <div className="flex max-w-2xl flex-col gap-4">
              {!isFormExpanded ? (
                <Button
                  variant="ghost"
                  size="lg"
                  className="w-full justify-start gap-2"
                  onClick={() => setIsFormExpanded(true)}
                >
                  <Plus className="h-4 w-4" aria-hidden />
                  {addTaskLabel}
                </Button>
              ) : (
                <div className="flex flex-col gap-2 rounded-lg border p-4">
                  <Input
                    autoFocus
                    placeholder={taskPlaceholder}
                    value={newTaskTitle}
                    onChange={(e) => setNewTaskTitle(e.target.value)}
                    onKeyDown={(e) => {
                      if (e.key === "Enter" && newTaskTitle.trim()) {
                        handleAddTask();
                      }
                      if (e.key === "Escape") {
                        handleCancel();
                      }
                    }}
                    className="text-base font-medium"
                    aria-label={taskPlaceholder}
                  />
                  <div className="flex items-center justify-end gap-2">
                    <Button
                      variant="secondary"
                      size="sm"
                      onClick={handleCancel}
                    >
                      <X className="h-4 w-4" aria-hidden />
                      {cancelLabel}
                    </Button>
                    <Button
                      size="sm"
                      onClick={handleAddTask}
                      disabled={!newTaskTitle.trim()}
                    >
                      <Plus className="h-4 w-4" aria-hidden />
                      {submitLabel}
                    </Button>
                  </div>
                </div>
              )}

              <SortableContext
                items={todos.map((t) => t.id)}
                strategy={verticalListSortingStrategy}
              >
                <ItemGroup>
                  {todos.map((todo) => (
                    <SortableTodoItem
                      key={todo.id}
                      todo={todo}
                      onToggle={toggleTodo}
                      isNew={newTodoIds.has(todo.id)}
                    />
                  ))}
                </ItemGroup>
              </SortableContext>
            </div>
            <DragOverlay>
              {activeTodo ? (
                <Item
                  variant={activeTodo.completed ? "muted" : "default"}
                  className="cursor-grabbing items-center border-b opacity-90 shadow-lg"
                >
                  <ItemMedia>
                    <div className="flex items-center gap-2">
                      <Button
                        variant="ghost"
                        size="icon-sm"
                        className="cursor-grabbing"
                        aria-hidden
                        tabIndex={-1}
                      >
                        <GripVertical className="size-4 text-muted-foreground" />
                      </Button>
                      <Checkbox
                        checked={activeTodo.completed}
                        aria-hidden
                        tabIndex={-1}
                      />
                    </div>
                  </ItemMedia>
                  <ItemContent>
                    <ItemTitle
                      className={
                        activeTodo.completed
                          ? "text-muted-foreground line-through"
                          : ""
                      }
                    >
                      {activeTodo.title}
                    </ItemTitle>
                  </ItemContent>
                </Item>
              ) : null}
            </DragOverlay>
          </DndContext>
        </div>
      </div>
    </section>
  );
};

export { Todo4 };