code.js

import { $, $$, setVar, calcTextWidth } from './util.js';

const snippetNode = $('#snippet');

const setupLines = (node, config) => {
  $$(':scope > br', node).forEach((row) => (row.outerHTML = '<div>&nbsp;</div>'));

  const rows = $$(':scope > div', node);
  setVar('line-number-width', calcTextWidth(rows.length + config.startLine));

  rows.forEach((row, idx) => {
    const newRow = document.createElement('div');
    newRow.classList.add('line');
    row.replaceWith(newRow);

    if (config.showLineNumbers) {
      const lineNum = document.createElement('div');
      lineNum.classList.add('line-number');
      lineNum.textContent = idx + 1 + config.startLine;
      newRow.appendChild(lineNum);
    }

    const span = document.createElement('span');
    span.textContent = ' ';
    row.appendChild(span);

    const lineCodeDiv = document.createElement('div');
    lineCodeDiv.classList.add('line-code');
    const lineCode = document.createElement('span');
    lineCode.innerHTML = row.innerHTML;
    lineCodeDiv.appendChild(lineCode);

    newRow.appendChild(lineCodeDiv);
  });
};

const stripInitialIndent = (node) => {
  const regIndent = /^\s+/u;
  const initialSpans = $$(':scope > div > span:first-child', node);
  if (initialSpans.some((span) => !regIndent.test(span.textContent))) return;
  const minIndent = Math.min(
    ...initialSpans.map((span) => span.textContent.match(regIndent)[0].length)
  );
  initialSpans.forEach((span) => (span.textContent = span.textContent.slice(minIndent)));
};

const isEmptyLine = (node) => node.innerText.match(/^\s*$/);

const trimEmptyLines = (node, config) => {
  while(isEmptyLine(node.firstChild)) {
    node.removeChild(node.firstChild);
    if(config.realLineNumbers) config.startLine++;
  }
  while(isEmptyLine(node.lastChild)) node.removeChild(node.lastChild);
}

const getClipboardHtml = (clip) => {
  const html = clip.getData('text/html');
  if (html) return html;
  const text = clip
    .getData('text/plain')
    .split('\n')
    .map((line) => `<div>${line}</div>`)
    .join('');
  return `<div>${text}</div>`;
};

export const pasteCode = (config, clipboard) => {
  snippetNode.innerHTML = getClipboardHtml(clipboard);
  const code = $('div', snippetNode);
  snippetNode.style.fontSize = code.style.fontSize;
  snippetNode.style.lineHeight = code.style.lineHeight;
  snippetNode.innerHTML = code.innerHTML;
  stripInitialIndent(snippetNode);
  if(config.trimEmptyLines) trimEmptyLines(snippetNode, config);
  setupLines(snippetNode, config);
};