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

/**
 * Shared scaffolding for the FSx runtime bindings.
 *
 * NOT exported from `index.ts` — every `{Op}Http.ts` in this service is a
 * thin `Layer.effect(Cap, makeFSx…HttpBinding({ … }))` over one of the two
 * builders below. Everything except the operation, the IAM action list, and
 * (for file-system-scoped operations) the injected file system id is
 * boilerplate.
 */

/**
 * Build the impl Effect for a file-system-scoped FSx operation: the runtime
 * callable injects the bound {@link FileSystem}'s id (as `FileSystemId`, or
 * as `FileSystemIds: [id]` for the describe operation) and the deploy-time
 * half grants `actions` on the file system's ARN.
 */
export const makeFSxFileSystemHttpBinding = <
  I extends { FileSystemId?: string; FileSystemIds?: string[] },
  A,
  E,
  R,
>(options: {
  /** Fully-qualified binding tag, e.g. `AWS.FSx.CreateBackup`. */
  tag: string;
  /** The distilled operation; the file system id is injected. */
  operation: Effect.Effect<(input: I) => Effect.Effect<A, E>, never, R>;
  /** IAM actions granted on the file system ARN (+ `extraResourceArns`). */
  actions: readonly string[];
  /**
   * How the bound file system's id is injected into the request:
   * `FileSystemId` (default) or `FileSystemIds` (`DescribeFileSystems`
   * takes a plural array).
   * @default "FileSystemId"
   */
  requestKey?: "FileSystemId" | "FileSystemIds";
  /**
   * Additional ARN patterns granted alongside the file system ARN. Used for
   * operations that also authorize on a resource created by the call itself
   * (e.g. `CreateBackup` authorizes on the new backup's ARN, unknowable at
   * deploy time — grant `arn:aws:fsx:*:*:backup/*`).
   */
  extraResourceArns?: readonly string[];
}) =>
  Effect.gen(function* () {
    const op = yield* options.operation;

    return Effect.fn(function* (fileSystem: FileSystem) {
      const FileSystemId = yield* fileSystem.fileSystemId;
      if (!globalThis.__ALCHEMY_RUNTIME__) {
        const host = yield* Binding.Host;
        if (isBindingHost(host)) {
          yield* host.bind`Allow(${host}, ${options.tag}(${fileSystem}))`({
            policyStatements: [
              {
                Effect: "Allow",
                Action: [...options.actions],
                Resource: [
                  Output.interpolate`${fileSystem.fileSystemArn}`,
                  ...(options.extraResourceArns ?? []),
                ],
              },
            ],
          });
        }
      }
      return Effect.fn(`${options.tag}(${fileSystem.LogicalId})`)(function* (
        request?: Omit<I, "FileSystemId" | "FileSystemIds">,
      ) {
        const id = yield* FileSystemId;
        return yield* op({
          ...request,
          ...(options.requestKey === "FileSystemIds"
            ? { FileSystemIds: [id] }
            : { FileSystemId: id }),
        } as I);
      });
    });
  });

/**
 * Build the impl Effect for an account-level FSx operation (no file-system
 * argument): the deploy-time half grants `actions` on `*`. Used for
 * operations that authorize against ARNs unknowable at deploy time (e.g.
 * backups, snapshots, and data repository tasks created at runtime) and for
 * account-wide describes.
 */
export const makeFSxAccountHttpBinding = <I, A, E, R>(options: {
  /** Fully-qualified binding tag, e.g. `AWS.FSx.DescribeBackups`. */
  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);
      });
    });
  });