import {
  Credentials,
  oauthCredentials,
  Retry,
  type CloudflareOpContext,
} from "@distilled.cloud/cloudflare";
import * as Effect from "effect/Effect";
import * as FetchHttpClient from "effect/unstable/http/FetchHttpClient";
import { bodyBytes, withResponse } from "../server/http.ts";

// No process credentials, refresh cache or nested retries. The calling request
// or native Workflow attempt has already resolved its own authorized grant.
export function cloudflare<A, E>(
  operation: Effect.Effect<A, E, CloudflareOpContext>,
  accessToken: string,
  network: typeof fetch,
  timeout = 60_000,
  limit = 2 * 1024 * 1024,
) {
  const boundedFetch: typeof fetch = (input, init) =>
    Effect.runPromise(
      withResponse(
        network,
        input,
        init ?? {},
        timeout,
        new Error("Cloudflare transport unavailable"),
        (response) =>
          Effect.gen(function* () {
            if (response.status >= 300 && response.status < 400)
              return yield* Effect.die(
                new Error("Cloudflare redirect rejected"),
              );
            if (!response.body) return response;
            const bytes = yield* bodyBytes(
              response,
              limit,
              new Error("Cloudflare response unavailable"),
            );
            // The SDK also accepts bare JSON for other services. These control-plane
            // operations require Cloudflare's successful v4 envelope explicitly.
            if (response.ok) {
              yield* Effect.try({
                try: () => {
                  const envelope: unknown = JSON.parse(
                    new TextDecoder().decode(bytes),
                  );
                  if (
                    !envelope ||
                    typeof envelope !== "object" ||
                    !("success" in envelope) ||
                    envelope.success !== true ||
                    !("result" in envelope)
                  )
                    throw new Error("Invalid Cloudflare envelope");
                },
                catch: () => new Error("Cloudflare response unavailable"),
              });
            }
            return new Response(bytes, response);
          }),
      ),
      { signal: init?.signal ?? undefined },
    );
  return operation.pipe(
    Retry.none,
    Effect.provideService(
      Credentials,
      Effect.succeed(oauthCredentials({ accessToken })),
    ),
    Effect.provide(FetchHttpClient.layer),
    Effect.provideService(FetchHttpClient.Fetch, boundedFetch),
    Effect.provideService(FetchHttpClient.RequestInit, { redirect: "manual" }),
  );
}