import * as Effect from "effect/Effect";
import * as Binding from "../../Binding.ts";
import { isBindingHost } from "../Lambda/Function.ts";

/**
 * Shared scaffolding for AWS Shield HTTP bindings.
 *
 * NOT exported from `index.ts` — every thin `{Op}Http.ts` in this service is
 * a `Layer.effect(Cap, makeShieldHttpBinding({ … }))` over the builder below.
 * Everything except the operation and the IAM action list is boilerplate.
 *
 * Shield is an account-level, us-east-1-pinned service: its IAM actions do
 * not support resource-level permissions for the visibility operations bound
 * here (attacks, subscription state, DRT access), and the group-membership
 * read targets groups whose ids are only known at runtime — so the
 * deploy-time half grants `actions` on `*` and the caller's request passes
 * through as-is.
 */
export const makeShieldHttpBinding = <I, A, E, R>(options: {
  /** Fully-qualified binding tag, e.g. `AWS.Shield.ListAttacks`. */
  tag: string;
  /** The distilled operation, invoked with the caller's request as-is. */
  operation: Effect.Effect<(input: I) => Effect.Effect<A, E>, never, R>;
  /** IAM actions granted on `*`. */
  actions: readonly string[];
}) =>
  Effect.gen(function* () {
    const op = yield* options.operation;

    return Effect.fn(function* () {
      if (!globalThis.__ALCHEMY_RUNTIME__) {
        const host = yield* Binding.Host;
        if (isBindingHost(host)) {
          yield* host.bind`Allow(${host}, ${options.tag}())`({
            policyStatements: [
              {
                Effect: "Allow",
                Action: [...options.actions],
                Resource: ["*"],
              },
            ],
          });
        }
      }
      return Effect.fn(options.tag)(function* (request?: I) {
        return yield* op((request ?? {}) as I);
      });
    });
  });