import type { z } from "zod";

/**
 * Structural interface that `validatePlan` and `generatePrompt` accept. Renderer
 * adapters (e.g. for json-render, A2UI) implement this by wrapping their native
 * component-declaration format. The default implementation is `defineUIAdapter`
 * below.
 *
 * Binding is not represented in this interface. Props that accept `{ $bind }`
 * references declare so structurally in their Zod schema (see `bindable()`).
 * Adapters just hand back the schemas; detection is structural.
 */
export interface UIAdapter {
  hasComponent(id: string): boolean;
  getComponentIds(): string[];
  getDescription(id: string): string | undefined;
  getProps(componentId: string): z.ZodObject<z.ZodRawShape> | undefined;
}

export interface UIComponentEntry<
  P extends z.ZodObject<z.ZodRawShape> = z.ZodObject<z.ZodRawShape>,
> {
  id: string;
  description?: string;
  props: P;
}

/**
 * Default adapter implementation, useful for tests and for renderers that don't
 * have a native component-declaration format. Most users should reach for a
 * renderer-specific adapter (e.g. `toUIAdapter` from `@usecarte/json-render`) —
 * this is the slow path.
 */
export function defineUIAdapter(entries: ReadonlyArray<UIComponentEntry>): UIAdapter {
  const map = new Map<string, UIComponentEntry>();
  for (const entry of entries) {
    if (map.has(entry.id)) {
      throw new Error(`Duplicate UI component id: ${entry.id}`);
    }
    map.set(entry.id, entry);
  }
  return {
    hasComponent: (id) => map.has(id),
    getComponentIds: () => [...map.keys()],
    getDescription: (id) => map.get(id)?.description,
    getProps: (id) => map.get(id)?.props,
  };
}