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 { Cluster } from "./Cluster.ts";

/**
 * Shared scaffolding for provisioned Amazon Redshift HTTP bindings.
 *
 * NOT exported from `index.ts` — every `{Op}Http.ts` in this service (except
 * the bespoke `ConnectHttp`) is a thin `Layer.effect(Cap, make…HttpBinding({
 * … }))` over one of the builders below. Everything except the operation,
 * the identifier resolver, and the IAM action list is boilerplate.
 */

/**
 * Build the impl Effect for an account-level operation (cluster discovery,
 * event history, snapshot administration). The deploy-time half grants
 * `actions` on `*` — these operations span every cluster in the account and
 * the identifiers they filter on are runtime data.
 */
export const makeRedshiftAccountHttpBinding = <I, A, E, R>(options: {
  /** Fully-qualified binding tag, e.g. `AWS.Redshift.DescribeEvents`. */
  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);
      });
    });
  });

/**
 * Build the impl Effect for a cluster-scoped operation: the runtime callable
 * injects the bound {@link Cluster}'s identifier as `ClusterIdentifier` and
 * the deploy-time half grants `actions` on the cluster ARN (plus any
 * `extraResources`, e.g. the `snapshot:{cluster}/*` ARN pattern for snapshot
 * creation).
 */
export const makeRedshiftClusterHttpBinding = <
  I extends { ClusterIdentifier?: string },
  A,
  E,
  R,
>(options: {
  /** Fully-qualified binding tag, e.g. `AWS.Redshift.PauseCluster`. */
  tag: string;
  /** The distilled operation; `ClusterIdentifier` is injected. */
  operation: Effect.Effect<(input: I) => Effect.Effect<A, E>, never, R>;
  /** IAM actions granted on the cluster ARN. */
  actions: readonly string[];
  /** Additional IAM resource ARNs derived from the cluster ARN. */
  extraResources?: (clusterArn: string) => string[];
}) =>
  Effect.gen(function* () {
    const op = yield* options.operation;

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

/**
 * The `snapshot:{cluster}/*` ARN derived from a cluster ARN — the extra IAM
 * resource snapshot-writing operations are scoped to.
 */
export const clusterSnapshotArnPattern = (clusterArn: string): string =>
  `${clusterArn.replace(":cluster:", ":snapshot:")}/*`;