/**
 * State Route
 *
 * GET /state - Get full state snapshot.
 * GET /state/:slice - Get a specific state slice.
 */

import { Hono } from "hono";
import type { Runtime, Action } from "@gizmo-ai/runtime";
import type { ErrorResponse } from "../types.ts";

/**
 * Create the state routes
 */
export function createStateRoute<
  S extends Record<string, unknown>,
  A extends Action
>(runtime: Runtime<S, A>, serializer: (value: unknown) => string): Hono {
  const app = new Hono();

  // GET /state - full state snapshot
  app.get("/", (c) => {
    try {
      const state = runtime.getState();
      return c.json(JSON.parse(serializer(state)));
    } catch (error) {
      return c.json<ErrorResponse>(
        { error: `Failed to serialize state: ${error instanceof Error ? error.message : String(error)}` },
        500
      );
    }
  });

  // GET /state/:slice - specific slice
  app.get("/:slice", (c) => {
    try {
      const sliceName = c.req.param("slice");
      const state = runtime.getState();

      if (!(sliceName in state)) {
        return c.json<ErrorResponse>(
          { error: `Slice "${sliceName}" not found` },
          404
        );
      }

      const slice = state[sliceName as keyof S];
      return c.json(JSON.parse(serializer(slice)));
    } catch (error) {
      return c.json<ErrorResponse>(
        { error: `Failed to serialize state: ${error instanceof Error ? error.message : String(error)}` },
        500
      );
    }
  });

  return app;
}