interface SourceCodeLinkProps {
  /** URL to the Corresponding Source of the running version (AGPL § 13). */
  sourceCodeUrl: string;
  /** Running version string, e.g. "1.0.0". Omitted from the label when unknown. */
  version?: string;
  /** Short git commit/tag of the running build; appended to pin the exact version. */
  commit?: string | null;
  /** Extra classes for layout composition (alignment, spacing) at the call site. */
  className?: string;
}

/**
 * AGPL-3.0 § 13 "network-use source offer".
 *
 * Renders an accessible external link to the Corresponding Source of the version
 * the instance is actually running. The URL is operator-configurable server-side
 * (BACKSPACE_SOURCE_URL) and surfaced via GET /api/instance/info, so a modified
 * self-hosted fork points humans at its own source.
 *
 * Rendered on every network-facing surface (settings sidebars, pre-auth pages)
 * so any network user — authenticated or anonymous — can reach the source.
 */
export function SourceCodeLink({ sourceCodeUrl, version, commit, className }: SourceCodeLinkProps) {
  const build = version ? `v${version}${commit ? ` (${commit})` : ''}` : '';
  const label = build ? `Source code (AGPL) · ${build}` : 'Source code (AGPL)';

  return (
    <a
      href={sourceCodeUrl}
      target="_blank"
      rel="noreferrer noopener"
      className={`inline-flex items-center gap-1.5 text-xs text-txt-tertiary hover:text-txt-secondary transition-colors${
        className ? ` ${className}` : ''
      }`}
      title="View the source code of the version this instance is running (AGPL-3.0)"
    >
      <svg
        width="12"
        height="12"
        viewBox="0 0 24 24"
        fill="none"
        stroke="currentColor"
        strokeWidth="2"
        strokeLinecap="round"
        strokeLinejoin="round"
        aria-hidden="true"
        className="flex-shrink-0"
      >
        <polyline points="16 18 22 12 16 6" />
        <polyline points="8 6 2 12 8 18" />
      </svg>
      <span>{label}</span>
    </a>
  );
}