/**
 * Shared rendering utilities used by the Rendering node and output views.
 * Pure functions only; no React or node-specific logic.
 */

/** Extract <think>...</think> blocks from HTML/markdown; return main (with blocks removed) and think for collapsible. */
export function parseThinkSections(html: string): { main: string; think: string } {
  const thinkRegex = /<think>([\s\S]*?)<\/think>/gi
  const thinkParts: string[] = []
  let match
  while ((match = thinkRegex.exec(html)) !== null) thinkParts.push(match[1].trim())
  const think = thinkParts.join('\n\n')
  const main = html.replace(thinkRegex, '').replace(/\n{3,}/g, '\n\n').trim()
  return { main, think }
}

/** Process SVG HTML for viewport display (aspect ratio, fill container). */
export function processSvgDisplay(html: string): string {
  let out = html
  out = out.replace(/\bpreserveAspectRatio\s*=\s*["']none["']/gi, 'preserveAspectRatio="xMidYMid meet"')
  out = out.replace(/\bwidth\s*=\s*["'][^"']*["']/i, 'width="100%"')
  out = out.replace(/\bheight\s*=\s*["'][^"']*["']/i, 'height="100%"')
  out = out.replace(/\bstyle\s*=\s*["']([^"']*)["']/i, (_, style) => {
    const overridden = style.replace(/\b(width|height):[^;]+/gi, '$1:100%')
    return `style="${overridden}"`
  })
  return out
}

/** Strip Nunjucks/template syntax for raw view. */
export function stripTemplateSyntax(text: string): string {
  return text
    .replace(/\{%[\s\S]*?%\}/g, '')
    .replace(/\{\{[\s\S]*?\}\}/g, '')
    .replace(/\{#[\s\S]*?#\}/g, '')
    .replace(/(\r?\n)\s*(\r?\n)/g, '$1$2')
    .replace(/^\s*\n|\n\s*$/g, (m) => (m === '\n' ? '\n' : ''))
    .trim()
}