import { createSignal, Accessor } from "solid-js";

export function useDragReorder(
  pinnedPaths: Accessor<string[]>,
  persistPins: (paths: string[]) => void,
  isSearchActive: Accessor<boolean>
) {
  const [dragIndex, setDragIndex] = createSignal<number | null>(null);
  const [dragOverIndex, setDragOverIndex] = createSignal<number | null>(null);

  const canDrag = () => !isSearchActive();

  const handleDragStart = (e: DragEvent, index: number) => {
    if (!canDrag()) return;
    setDragIndex(index);
    if (e.dataTransfer) {
      e.dataTransfer.effectAllowed = "move";
      e.dataTransfer.setData("text/plain", String(index));
    }
  };

  const handleDragOver = (e: DragEvent, index: number) => {
    if (!canDrag()) return;
    e.preventDefault();
    if (e.dataTransfer) {
      e.dataTransfer.dropEffect = "move";
    }
    setDragOverIndex(index);
  };

  const handleDrop = (e: DragEvent, dropIndex: number) => {
    if (!canDrag()) return;
    e.preventDefault();

    let from = dragIndex();
    if (from === null && e.dataTransfer) {
      const data = e.dataTransfer.getData("text/plain");
      if (data !== "") {
        const parsed = Number(data);
        if (!Number.isNaN(parsed)) from = parsed;
      }
    }

    setDragIndex(null);
    setDragOverIndex(null);

    if (from === null || from === dropIndex) return;

    const list = [...pinnedPaths()];
    if (
      from < 0 ||
      from >= list.length ||
      dropIndex < 0 ||
      dropIndex >= list.length
    ) {
      return;
    }

    const [moved] = list.splice(from, 1);
    list.splice(dropIndex, 0, moved);
    persistPins(list);
  };

  const handleDragEnd = () => {
    setDragIndex(null);
    setDragOverIndex(null);
  };

  return {
    dragIndex,
    dragOverIndex,
    canDrag,
    handleDragStart,
    handleDragOver,
    handleDrop,
    handleDragEnd,
  };
}