/**
 * Copy text to clipboard with a fallback for non-secure contexts (HTTP, non-localhost).
 * `navigator.clipboard` is only available in secure contexts; intranet HTTP deployments
 * must fall back to the legacy `document.execCommand('copy')` flow via a hidden textarea.
 */
export async function copyToClipboard(text: string): Promise<boolean> {
  if (typeof navigator !== 'undefined' && navigator.clipboard && window.isSecureContext) {
    try {
      await navigator.clipboard.writeText(text)
      return true
    } catch {
      // fall through to legacy fallback
    }
  }

  if (typeof document === 'undefined') return false

  const textarea = document.createElement('textarea')
  textarea.value = text
  textarea.setAttribute('readonly', '')
  textarea.style.position = 'fixed'
  textarea.style.top = '0'
  textarea.style.left = '0'
  textarea.style.width = '1px'
  textarea.style.height = '1px'
  textarea.style.padding = '0'
  textarea.style.border = 'none'
  textarea.style.outline = 'none'
  textarea.style.boxShadow = 'none'
  textarea.style.background = 'transparent'
  textarea.style.opacity = '0'
  document.body.appendChild(textarea)

  let ok = false
  try {
    textarea.focus()
    textarea.select()
    textarea.setSelectionRange(0, text.length)
    ok = document.execCommand('copy')
  } catch {
    ok = false
  } finally {
    document.body.removeChild(textarea)
  }
  return ok
}