/**
 * Cloudflare Workers entry - the app, cached in Workers KV so cached pages and on-demand purges hold
 * ACROSS instances. `ctx.waitUntil` keeps the worker alive while a stale page regenerates behind the
 * response. `bun run build` then `bunx wrangler dev` (a local KV is provided automatically).
 */
import { inProcessClient } from "@nifrajs/client"
import {
  createWebApp,
  KVCacheStore,
  type KVNamespaceLike,
  revalidateEndpoint,
  withISR,
} from "@nifrajs/web"
import { reactAdapter } from "@nifrajs/web-react"
import { backend } from "./backend"
// Generated by build.ts (buildServer): the static-import route manifest + the baked client entry URL.
import { clientEntry, manifest } from "./server-manifest"

const app = createWebApp({
  adapter: reactAdapter,
  manifest,
  clientEntry,
  api: inProcessClient(backend),
  title: "nifra + ISR",
})

/** Workers bindings (wrangler.toml → [[kv_namespaces]] + [vars]). */
interface Env {
  readonly ISR_CACHE: KVNamespaceLike
  readonly REVALIDATE_SECRET?: string
}

/** Minimal shape of the Workers execution context - just `waitUntil`. */
interface ExecutionContext {
  waitUntil(promise: Promise<unknown>): void
}

export default {
  async fetch(req: Request, env: Env, ctx: ExecutionContext): Promise<Response> {
    const store = new KVCacheStore(env.ISR_CACHE, { expirationTtl: 86_400 }) // 1-day GC backstop

    // On-demand purge: POST /__nifra/revalidate?path=/ with the secret in x-nifra-revalidate-token.
    if (new URL(req.url).pathname === "/__nifra/revalidate") {
      return revalidateEndpoint({ store, secret: env.REVALIDATE_SECRET ?? "" })(req)
    }

    // Cache GET documents stale-while-revalidate. Default 60s; a route's `export const revalidate`
    // overrides it per-page.
    const isr = withISR(app, { store, revalidate: 60, now: () => Date.now() })
    return isr(req, { env, waitUntil: (p) => ctx.waitUntil(p) })
  },
}