import { useEffect, useRef } from 'react';
import { type Editor } from '@tiptap/react';
import { getMarkRange, getMarksBetween } from '@tiptap/core';
import type { OnLinkDetected } from '../types';
import { tiptapPosToNativePos } from './positionMapping';

export const useOnLinkDetected = (
  editor: Editor | null,
  onLinkDetected?: (e: OnLinkDetected) => void
) => {
  const lastEmittedRef = useRef<OnLinkDetected | null>(null);
  const wasInLinkRef = useRef(false);

  useEffect(() => {
    if (!editor || !onLinkDetected) return;

    const handleUpdate = () => {
      const { state } = editor;
      const linkType = state.schema.marks.link;
      if (!linkType) return;

      const $pos = state.selection.$from;
      const range = getMarkRange($pos, linkType);

      if (!range) {
        if (wasInLinkRef.current) {
          wasInLinkRef.current = false;
          onLinkDetected({
            text: '',
            url: '',
            start: 0,
            end: 0,
          });
        }
        lastEmittedRef.current = null;
        return;
      }

      const linkMark = getMarksBetween(range.from, range.to, state.doc).find(
        (entry) => entry.mark.type === linkType
      )?.mark;

      if (!linkMark) {
        wasInLinkRef.current = false;
        lastEmittedRef.current = null;
        return;
      }

      wasInLinkRef.current = true;

      const { from, to } = range;
      const url = (linkMark.attrs.href as string | undefined) ?? '';
      const text = state.doc.textBetween(from, to, '\n');
      const start = tiptapPosToNativePos(state.doc, from);
      const end = tiptapPosToNativePos(state.doc, to);

      const next: OnLinkDetected = { text, url, start, end };
      const prev = lastEmittedRef.current;

      if (
        prev !== null &&
        prev.text === next.text &&
        prev.url === next.url &&
        prev.start === next.start &&
        prev.end === next.end
      ) {
        return;
      }

      lastEmittedRef.current = next;
      onLinkDetected(next);
    };

    handleUpdate();
    editor.on('transaction', handleUpdate);

    return () => {
      wasInLinkRef.current = false;
      editor.off('transaction', handleUpdate);
    };
  }, [editor, onLinkDetected]);
};