import { SchemaBase } from './dsl.js';
import { FrontAppSchema } from './project.js';
import type { PageDef } from './page-def.js';
import type { RouteDataSchema } from './route.js';

// Page definitions: standalone page schemas and the page node type used by
// page-driven flows. Kept separate from page-flow.ts (the flow graph itself).

// Module-level registry: every definePage/defineTabPage call registers its
// result so definePageFlow can check that no page is left out.
const _pageRegistry = new Set<PageSchema>();

export function getRegisteredPages(): ReadonlySet<PageSchema> {
  return _pageRegistry;
}

export function clearRegisteredPages(): void {
  _pageRegistry.clear();
}

/** Standalone page definition. A page is a shared value object: it belongs to
 *  exactly one frontend app. Actions live in the page skeleton (PageDef.actions),
 *  not on the page itself — the page only carries what the flow/topology needs. */
export interface PageSchema extends SchemaBase {
  /** Short display name for topology diagrams. */
  label: string;
  /** The frontend app this page belongs to (shared instance from project.config). */
  app: FrontAppSchema;
  /** Full page skeleton definition (optional). */
  pageDef?: PageDef;
  /** Route params this page expects (e.g. detail page expects productId). */
  params?: RouteDataSchema;
}

export function definePage(schema: {
  name: string;
  label: string;
  description?: string;
  app: FrontAppSchema;
  pageDef?: PageDef;
  params?: RouteDataSchema;
}): PageSchema {
  const p: PageSchema = { ...schema };
  _pageRegistry.add(p);
  return p;
}

/** Page with bottom tab navigation. tabs collects the child pages reachable via tab switch. */
export interface TabPageSchema extends PageSchema {
  tabs: PageSchema[];
}

export function defineTabPage(schema: {
  name: string;
  label: string;
  description?: string;
  app: FrontAppSchema;
  tabs: PageSchema[];
  pageDef?: PageDef;
  params?: RouteDataSchema;
}): TabPageSchema {
  const p: TabPageSchema = { ...schema };
  _pageRegistry.add(p);
  return p;
}

/** A page node in a page-driven flow: every node is a page, and a page belongs to an app. */
export interface Page extends SchemaBase {
  /** Short display name for topology diagrams. */
  label?: string;
  /** The frontend app this page belongs to (shared instance from project.config). */
  app: FrontAppSchema;
}

export function page(app: FrontAppSchema, name: string, description?: string, label?: string): Page {
  return { name, label, app, description };
}