import type { RuleInline } from 'markdown-it/lib/parser_inline';

import { HTML_TAG_RE } from './htmlRe';

// Forked and modified from 'markdown-it/lib/rules_inline/html_inline.js'

const isLetter = (ch: number): boolean => {
  const lc = ch | 0x20; // to lower case
  return lc >= 0x61 /* a */ && lc <= 0x7a; /* z */
};

export const htmlInlineRule: RuleInline = (state, silent) => {
  const pos = state.pos;

  if (!state.md.options.html) {
    return false;
  }

  // Check start.
  const max = state.posMax;
  if (state.src.charCodeAt(pos) !== 0x3c /* < */ || pos + 2 >= max) {
    return false;
  }

  // Quick fail on second char.
  const ch = state.src.charCodeAt(pos + 1);
  if (
    ch !== 0x21 /* ! */ &&
    ch !== 0x3f /* ? */ &&
    ch !== 0x2f /* / */ &&
    !isLetter(ch)
  ) {
    return false;
  }

  // MODIFIED HERE: Tweak the original HTML_TAG_RE.
  const match = state.src.slice(pos).match(HTML_TAG_RE);
  if (!match) {
    return false;
  }

  if (!silent) {
    const token = state.push('html_inline', '', 0);
    token.content = state.src.slice(pos, pos + match[0].length);
  }

  state.pos += match[0].length;
  return true;
};