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

/**
 * Shared HTTP scaffolding for the AWS User Notifications runtime bindings.
 *
 * NOT exported from `index.ts` — every `{Op}Http.ts` in this service is a
 * thin `Layer.effect(Cap, make…HttpBinding({ … }))` over one of the builders
 * below. Everything except the operation, the IAM action, and (for the
 * configuration-scoped builder) the injected ARN is boilerplate.
 *
 * User Notifications is a global service managed from `us-east-1` (other
 * regions reject management calls), so every operation is resolved with the
 * Region pinned via {@link pinNotificationsRegion} — exactly like the
 * resource providers in `internal.ts`.
 *
 * Per the `notifications` service authorization reference, the event/read
 * query actions authorize on event/configuration ARN patterns that are not
 * known until runtime, so the account-level builder grants on
 * `Resource: ["*"]`. `notifications:ListChannels` authorizes on the
 * notification configuration, so the configuration-scoped builder grants on
 * the bound configuration's ARN.
 */

/**
 * Build the impl Effect for an account-level User Notifications operation
 * (the notification-event and managed-notification read APIs — none of
 * which are scoped to a caller-owned resource).
 */
export const makeNotificationsHttpBinding = <
  I extends object,
  A,
  E,
  R,
>(options: {
  /**
   * Short capability name used in the binding sid and runtime span, e.g.
   * `"ListNotificationEvents"`.
   */
  capability: string;
  /** IAM actions granted on `Resource: ["*"]`. */
  iamActions: readonly string[];
  /** The distilled operation implementing the capability. */
  operation: Effect.Effect<(input: I) => Effect.Effect<A, E>, never, R>;
}) =>
  Effect.gen(function* () {
    const op = yield* pinNotificationsRegion(options.operation);

    return Effect.fn(function* () {
      if (!globalThis.__ALCHEMY_RUNTIME__) {
        const host = yield* Binding.Host;
        if (isBindingHost(host)) {
          yield* host.bind`Allow(${host}, AWS.Notifications.${options.capability}())`(
            {
              policyStatements: [
                {
                  Effect: "Allow",
                  Action: [...options.iamActions],
                  Resource: ["*"],
                },
              ],
            },
          );
        }
      }
      return Effect.fn(`AWS.Notifications.${options.capability}`)(function* (
        request?: I,
      ) {
        // The region must also be pinned at the call site: the yield-time
        // snapshot is only a fallback — the calling fiber's ambient Region
        // (the host Function's own region) wins over it.
        return yield* pinNotificationsRegion(op((request ?? {}) as I));
      });
    });
  });

/**
 * Build the impl Effect for an operation scoped to one
 * {@link NotificationConfiguration}. The runtime callable injects the bound
 * configuration's ARN as the request's `notificationConfigurationArn`; the
 * deploy-time half grants `iamActions` on the configuration's ARN.
 */
export const makeNotificationConfigurationHttpBinding = <
  I extends { notificationConfigurationArn?: string },
  A,
  E,
  R,
>(options: {
  /**
   * Short capability name used in the binding sid and runtime span, e.g.
   * `"ListChannels"`.
   */
  capability: string;
  /** IAM actions granted on the configuration ARN. */
  iamActions: readonly string[];
  /** The distilled operation; `notificationConfigurationArn` is injected. */
  operation: Effect.Effect<(input: I) => Effect.Effect<A, E>, never, R>;
}) =>
  Effect.gen(function* () {
    const op = yield* pinNotificationsRegion(options.operation);

    return Effect.fn(function* (configuration: NotificationConfiguration) {
      const configurationArn =
        yield* configuration.notificationConfigurationArn;
      if (!globalThis.__ALCHEMY_RUNTIME__) {
        const host = yield* Binding.Host;
        if (isBindingHost(host)) {
          yield* host.bind`Allow(${host}, AWS.Notifications.${options.capability}(${configuration}))`(
            {
              policyStatements: [
                {
                  Effect: "Allow",
                  Action: [...options.iamActions],
                  Resource: [configuration.notificationConfigurationArn],
                },
              ],
            },
          );
        }
      }
      return Effect.fn(
        `AWS.Notifications.${options.capability}(${configuration.LogicalId})`,
      )(function* (request?: Omit<I, "notificationConfigurationArn">) {
        // Call-site region pin — see makeNotificationsHttpBinding above.
        return yield* pinNotificationsRegion(
          op({
            ...request,
            notificationConfigurationArn: yield* configurationArn,
          } as I),
        );
      });
    });
  });