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

/**
 * Shared scaffolding for AWS MSK (Kafka) HTTP bindings.
 *
 * NOT exported from `index.ts` — every `{Op}Http.ts` in this service is a
 * thin `Layer.effect(Cap, makeKafkaClusterHttpBinding({ … }))` over the
 * builder below. Everything except the operation and the IAM action list is
 * boilerplate.
 */

/**
 * The cluster ARN is `arn:…:cluster/name/uuid`. Topic resources live under a
 * sibling `topic/` namespace scoped to the same cluster path; both the
 * `kafka:*Topic*` control-plane actions and the `kafka-cluster:*` data-plane
 * actions authorize against these ARNs.
 */
export const topicArnGlob = (clusterArn: string) =>
  `${clusterArn.replace(":cluster/", ":topic/")}/*`;

/** Consumer-group ARNs under the cluster's `group/` namespace. */
export const groupArnGlob = (clusterArn: string) =>
  `${clusterArn.replace(":cluster/", ":group/")}/*`;

/** Transactional-id ARNs under the cluster's `transactional-id/` namespace. */
export const transactionalIdArnGlob = (clusterArn: string) =>
  `${clusterArn.replace(":cluster/", ":transactional-id/")}/*`;

/**
 * Build the impl Effect for a cluster-scoped MSK control-plane operation: the
 * runtime callable injects the bound {@link ServerlessCluster}'s ARN as
 * `ClusterArn` and the deploy-time half grants `actions` on the cluster ARN
 * (plus the cluster's `topic/` ARN namespace when `topicScoped` is set —
 * topic-management actions authorize against topic ARNs).
 */
export const makeKafkaClusterHttpBinding = <
  I extends { ClusterArn: string },
  A,
  E,
  R,
>(options: {
  /** Fully-qualified binding tag, e.g. `AWS.Kafka.ListTopics`. */
  tag: string;
  /** The distilled operation; `ClusterArn` is injected from the cluster. */
  operation: Effect.Effect<(input: I) => Effect.Effect<A, E>, never, R>;
  /** IAM actions granted on the cluster ARN (and topic glob, if scoped). */
  actions: readonly string[];
  /** Also grant `actions` on the cluster's `topic/…/*` ARN namespace. */
  topicScoped?: boolean;
}) =>
  Effect.gen(function* () {
    const op = yield* options.operation;

    return Effect.fn(function* (cluster: ServerlessCluster) {
      const ClusterArn = yield* cluster.clusterArn;
      if (!globalThis.__ALCHEMY_RUNTIME__) {
        const host = yield* Binding.Host;
        if (isBindingHost(host)) {
          yield* host.bind`Allow(${host}, ${options.tag}(${cluster}))`({
            policyStatements: [
              {
                Effect: "Allow",
                Action: [...options.actions],
                Resource: options.topicScoped
                  ? [
                      Output.interpolate`${cluster.clusterArn}`,
                      cluster.clusterArn.pipe(Output.map(topicArnGlob)),
                    ]
                  : [Output.interpolate`${cluster.clusterArn}`],
              },
            ],
          });
        }
      }
      return Effect.fn(`${options.tag}(${cluster.LogicalId})`)(function* (
        request?: Omit<I, "ClusterArn">,
      ) {
        return yield* op({
          ...request,
          ClusterArn: yield* ClusterArn,
        } as I);
      });
    });
  });