/**
 * Where a plugin route opens when the conversation is the page.
 *
 * On HQ the copilot is the page: the thread, the composer and the setup strip
 * all live there, and a route change unmounts every one of them. So a link the
 * agent writes, a chip it attaches and a directive it emits mid-stream all
 * resolve through here first, and a route with a canvas opens *beside* the
 * conversation rather than instead of it.
 */

import type { CanvasView } from './use-home-canvas';

/** Where a path resolves to on HQ. */
export type InPageTarget =
  | { kind: 'canvas'; view: CanvasView }
  | { kind: 'none' };

/** Routes that have a canvas of their own, longest prefix first so
 *  ``/ai-visibility/contents`` never matches ``/ai-visibility``. */
const CANVAS_ROUTES: ReadonlyArray<readonly [string, CanvasView]> = [
  ['/ai-visibility/page-templates', 'templates'],
  ['/ai-visibility/contents', 'content'],
  ['/ai-visibility', 'week'],
  ['/catalog-quality', 'catalog'],
];

/**
 * What HQ should open for a path.
 *
 * An unknown path answers ``none`` rather than guessing: the caller then
 * decides what to do with it, and a route added elsewhere in the plugin never
 * silently lands in the wrong canvas.
 *
 * @param path - The plugin route, with or without a query string.
 * @return What to open beside the conversation.
 */
export function resolveInPageTarget(path: string): InPageTarget {
  if (!path.startsWith('/')) return { kind: 'none' };

  // The pathname alone decides; a query string is the page's own business and
  // the canvas has no way to honour it.
  const pathname: string = path.split(/[?#]/)[0].replace(/\/+$/, '') || '/';
  for (const [prefix, view] of CANVAS_ROUTES) {
    if (pathname === prefix || pathname.startsWith(`${prefix}/`)) {
      return { kind: 'canvas', view };
    }
  }

  return { kind: 'none' };
}