"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, Search, Tag, X } from "lucide-react";
import { useMemo, useState } from "react";

import { Badge } from "@/components/ui/badge";
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 {
  Popover,
  PopoverContent,
  PopoverTrigger,
} from "@/components/ui/popover";
import { cn } from "@/lib/utils";

interface TagOption {
  id: string;
  label: string;
}

interface Todo {
  id: string;
  title: string;
  completed: boolean;
  tags: string[];
}

interface Todo9Props {
  heading?: string;
  description?: string;
  searchPlaceholder?: string;
  filterByTagsLabel?: string;
  clearFiltersLabel?: string;
  emptySearchMessage?: string;
  emptyListMessage?: string;
  addTagLabel?: string;
  tagCatalog?: TagOption[];
  initialTodos?: Todo[];
  className?: string;
}

const defaultTagCatalog: TagOption[] = [
  { id: "work", label: "کاری" },
  { id: "personal", label: "شخصی" },
  { id: "urgent", label: "فوری" },
  { id: "shopping", label: "خرید" },
  { id: "health", label: "سلامت" },
  { id: "fitness", label: "ورزش" },
  { id: "learning", label: "یادگیری" },
  { id: "documentation", label: "مستندات" },
  { id: "code-review", label: "بازبینی کد" },
];

const defaultTodos: Todo[] = [
  {
    id: "1",
    title: "تکمیل مستندات فنی پروژه",
    completed: false,
    tags: ["work", "urgent", "documentation"],
  },
  {
    id: "2",
    title: "بررسی و تأیید طراحی رابط کاربری",
    completed: false,
    tags: ["work", "code-review"],
  },
  {
    id: "3",
    title: "آماده‌سازی گزارش هفتگی",
    completed: false,
    tags: ["personal", "shopping"],
  },
  {
    id: "4",
    title: "هماهنگی جلسات تیم",
    completed: true,
    tags: ["health", "fitness"],
  },
  {
    id: "5",
    title: "بررسی مستندات فنی",
    completed: false,
    tags: ["learning", "work"],
  },
];

interface SortableTodoItemProps {
  todo: Todo;
  onToggle: (id: string) => void;
  onRemoveTag: (id: string, tag: string) => void;
  onAddTag: (id: string, tag: string) => void;
  tagCatalog: TagOption[];
  getTagLabel: (tagId: string) => string;
  addTagLabel: string;
}

const SortableTodoItem = ({
  todo,
  onToggle,
  onRemoveTag,
  onAddTag,
  tagCatalog,
  getTagLabel,
  addTagLabel,
}: 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,
  };

  const availableToAdd = tagCatalog.filter((tag) => !todo.tags.includes(tag.id));

  return (
    <div ref={setNodeRef} style={style}>
      <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>
          <div className="flex flex-col gap-2">
            <div className="flex items-center gap-2">
              <ItemTitle
                className={
                  todo.completed ? "text-muted-foreground line-through" : ""
                }
              >
                {todo.title}
              </ItemTitle>
            </div>
            <div className="flex flex-wrap items-center gap-1">
              {todo.tags.map((tag) => (
                <Badge
                  key={tag}
                  variant="secondary"
                  className="cursor-pointer text-xs"
                  onClick={(e) => {
                    e.stopPropagation();
                    onRemoveTag(todo.id, tag);
                  }}
                  aria-label={`حذف برچسب ${getTagLabel(tag)}`}
                >
                  {getTagLabel(tag)}
                  <X className="ms-1 size-3" aria-hidden />
                </Badge>
              ))}
              <Popover>
                <PopoverTrigger asChild>
                  <Button
                    variant="ghost"
                    size="sm"
                    className="h-6 px-2"
                    onClick={(e) => e.stopPropagation()}
                    aria-label={addTagLabel}
                  >
                    <Plus className="size-3" aria-hidden />
                    <Tag className="size-3" aria-hidden />
                  </Button>
                </PopoverTrigger>
                <PopoverContent
                  dir="rtl"
                  lang="fa"
                  className="w-48 p-2"
                  align="start"
                >
                  <div className="space-y-1">
                    {availableToAdd.map((tag) => (
                      <Button
                        key={tag.id}
                        variant="ghost"
                        className="w-full justify-start"
                        onClick={() => onAddTag(todo.id, tag.id)}
                      >
                        <Tag className="me-2 size-3" aria-hidden />
                        {tag.label}
                      </Button>
                    ))}
                  </div>
                </PopoverContent>
              </Popover>
            </div>
          </div>
        </ItemContent>
      </Item>
    </div>
  );
};

const Todo9 = ({
  heading = "مدیریت وظایف با جستجو و برچسب",
  description =
    "جستجوی لحظه‌ای، چند برچسب برای هر وظیفه، فیلتر بر اساس برچسب و مرتب‌سازی با کشیدن. برچسب‌ها را به هر وظیفه اضافه یا حذف کنید.",
  searchPlaceholder = "جستجوی وظایف...",
  filterByTagsLabel = "فیلتر بر اساس برچسب:",
  clearFiltersLabel = "پاک کردن فیلترها",
  emptySearchMessage = "هیچ وظیفه‌ای با جستجوی شما مطابقت ندارد.",
  emptyListMessage = "وظیفه‌ای وجود ندارد.",
  addTagLabel = "افزودن برچسب",
  tagCatalog = defaultTagCatalog,
  initialTodos = defaultTodos,
  className,
}: Todo9Props) => {
  const [todos, setTodos] = useState(initialTodos);
  const [searchQuery, setSearchQuery] = useState("");
  const [selectedTags, setSelectedTags] = useState<string[]>([]);
  const [activeTodo, setActiveTodo] = useState<Todo | null>(null);

  const getTagLabel = (tagId: string) =>
    tagCatalog.find((tag) => tag.id === tagId)?.label ?? tagId;

  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 removeTag = (id: string, tag: string) => {
    setTodos((prevTodos) =>
      prevTodos.map((todo) =>
        todo.id === id
          ? { ...todo, tags: todo.tags.filter((t) => t !== tag) }
          : todo,
      ),
    );
  };

  const addTag = (id: string, tag: string) => {
    setTodos((prevTodos) =>
      prevTodos.map((todo) =>
        todo.id === id && !todo.tags.includes(tag)
          ? { ...todo, tags: [...todo.tags, tag] }
          : todo,
      ),
    );
  };

  const toggleTagFilter = (tag: string) => {
    setSelectedTags((prev) =>
      prev.includes(tag) ? prev.filter((t) => t !== tag) : [...prev, tag],
    );
  };

  const filteredTodos = useMemo(() => {
    const query = searchQuery.trim();
    return todos.filter((todo) => {
      if (query && !todo.title.includes(query)) {
        return false;
      }

      if (selectedTags.length > 0) {
        const hasSelectedTag = selectedTags.some((tag) =>
          todo.tags.includes(tag),
        );
        if (!hasSelectedTag) return false;
      }

      return true;
    });
  }, [todos, searchQuery, selectedTags]);

  const allTags = useMemo(() => {
    const tagSet = new Set<string>();
    todos.forEach((todo) => {
      todo.tags.forEach((tag) => tagSet.add(tag));
    });
    return Array.from(tagSet).sort((a, b) =>
      getTagLabel(a).localeCompare(getTagLabel(b), "fa"),
    );
  }, [todos, tagCatalog]);

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

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

    if (over && active.id !== over.id) {
      const oldIndex = filteredTodos.findIndex((item) => item.id === active.id);
      const newIndex = filteredTodos.findIndex((item) => item.id === over.id);

      if (oldIndex !== -1 && newIndex !== -1) {
        const reorderedFiltered = arrayMove(filteredTodos, oldIndex, newIndex);
        const reorderedIds = reorderedFiltered.map((t) => t.id);
        setTodos((items) => {
          const sortedItems = [...items].sort((a, b) => {
            const aIndex = reorderedIds.indexOf(a.id);
            const bIndex = reorderedIds.indexOf(b.id);
            if (aIndex === -1) return 1;
            if (bIndex === -1) return -1;
            return aIndex - bIndex;
          });
          return sortedItems;
        });
      }
    }

    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">
              <div className="flex flex-col gap-4">
                <div className="relative">
                  <Search
                    className="absolute top-1/2 inset-s-3 size-4 -translate-y-1/2 text-muted-foreground"
                    aria-hidden
                  />
                  <Input
                    placeholder={searchPlaceholder}
                    value={searchQuery}
                    onChange={(e) => setSearchQuery(e.target.value)}
                    className="ps-9"
                    aria-label={searchPlaceholder}
                  />
                </div>
                <div className="flex flex-wrap items-center gap-2">
                  <span className="text-sm text-muted-foreground">
                    {filterByTagsLabel}
                  </span>
                  {allTags.map((tag) => (
                    <Badge
                      key={tag}
                      variant={
                        selectedTags.includes(tag) ? "default" : "outline"
                      }
                      className="cursor-pointer"
                      onClick={() => toggleTagFilter(tag)}
                    >
                      <Tag className="me-1 size-3" aria-hidden />
                      {getTagLabel(tag)}
                    </Badge>
                  ))}
                  {selectedTags.length > 0 && (
                    <Button
                      variant="ghost"
                      size="sm"
                      onClick={() => setSelectedTags([])}
                    >
                      <X className="me-1 size-3" aria-hidden />
                      {clearFiltersLabel}
                    </Button>
                  )}
                </div>
              </div>

              <SortableContext
                items={filteredTodos.map((t) => t.id)}
                strategy={verticalListSortingStrategy}
              >
                <ItemGroup>
                  {filteredTodos.length === 0 ? (
                    <div className="py-8 text-center text-sm text-muted-foreground">
                      {searchQuery || selectedTags.length > 0
                        ? emptySearchMessage
                        : emptyListMessage}
                    </div>
                  ) : (
                    filteredTodos.map((todo) => (
                      <SortableTodoItem
                        key={todo.id}
                        todo={todo}
                        onToggle={toggleTodo}
                        onRemoveTag={removeTag}
                        onAddTag={addTag}
                        tagCatalog={tagCatalog}
                        getTagLabel={getTagLabel}
                        addTagLabel={addTagLabel}
                      />
                    ))
                  )}
                </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 { Todo9 };