import { z } from "zod/v4";

/**
 * Surface declarations (plan §7): where an app renders and with which tier.
 *
 * - `tree`  — tier 1: app logic returns a declarative UI tree; the host
 *             renders it with its own components on every platform.
 * - `react` — tier 2: a Coline-built React bundle runs in the sandboxed
 *             client runtime. `entry` is the module path within the app
 *             source.
 * - `web`   — tier 3: an iframe served from the app's external origin.
 *             Requires external hosting; excluded from mobile and preview
 *             composition.
 */

const surfaceEntrySchema = z.string().trim().min(1).max(500);
const surfacePathSchema = z
  .string()
  .trim()
  .min(1)
  .max(2000)
  .startsWith("/", "Web surface paths must be origin-relative (start with /).");

export const treeSurfaceSchema = z.object({
  tier: z.literal("tree"),
});

export const reactSurfaceSchema = z.object({
  tier: z.literal("react"),
  entry: surfaceEntrySchema,
});

export const webSurfaceSchema = z.object({
  tier: z.literal("web"),
  path: surfacePathSchema,
});

export const surfaceVariantSchema = z.discriminatedUnion("tier", [
  treeSurfaceSchema,
  reactSurfaceSchema,
  webSurfaceSchema,
]);
export type SurfaceVariant = z.infer<typeof surfaceVariantSchema>;
export type SurfaceTier = SurfaceVariant["tier"];

/**
 * A surface with an optional mobile override (plan §13): universal by
 * default; specialize only when the interaction genuinely differs.
 */
export const appSurfaceSchema = z.discriminatedUnion("tier", [
  treeSurfaceSchema.extend({ mobile: surfaceVariantSchema.optional() }),
  reactSurfaceSchema.extend({ mobile: surfaceVariantSchema.optional() }),
  webSurfaceSchema.extend({ mobile: surfaceVariantSchema.optional() }),
]);
export type AppSurface = z.infer<typeof appSurfaceSchema>;

export const appSurfacesSchema = z
  .object({
    home: appSurfaceSchema.optional(),
  })
  .default({});
export type AppSurfaces = z.infer<typeof appSurfacesSchema>;