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

/**
 * Shared scaffolding for AWS Elemental MediaConnect HTTP bindings.
 *
 * NOT exported from `index.ts` — every thin `{Op}Http.ts` in this service
 * is a `Layer.effect(Cap, make…HttpBinding({ … }))` over one of the two
 * builders below. Everything except the operation and the IAM action list
 * is boilerplate: flow-scoped bindings inject the bound flow's ARN as the
 * request's `FlowArn` and grant `actions` on that ARN; account-scoped
 * bindings pass the request through and grant `actions` on `*`.
 */

/**
 * Build the impl Effect for a MediaConnect operation scoped to a
 * {@link Flow}: the deploy-time half grants `actions` on the bound flow's
 * ARN (plus any `extraResources` — e.g. the entitlement wildcard for
 * Grant/RevokeFlowEntitlement, whose IAM resource types are both the flow
 * AND the entitlement, a sibling ARN not derived from the flow ARN), and
 * the runtime half injects the flow's ARN into every request as `FlowArn`.
 */
export const makeMediaConnectFlowHttpBinding = <
  I extends { FlowArn: string },
  A,
  E,
  R,
>(options: {
  /** Fully-qualified binding tag, e.g. `AWS.MediaConnect.StartFlow`. */
  tag: string;
  /** The distilled operation; `FlowArn` is injected from the flow. */
  operation: Effect.Effect<(input: I) => Effect.Effect<A, E>, never, R>;
  /** IAM actions granted on the flow ARN + `extraResources`. */
  actions: readonly string[];
  /**
   * Additional IAM resource ARNs granted alongside the flow ARN — for
   * operations whose IAM resource types include more than the flow (e.g.
   * entitlement ops act on `…:entitlement:*` ARNs too).
   */
  extraResources?: readonly string[];
}) =>
  Effect.gen(function* () {
    const op = yield* options.operation;

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

/**
 * Build the impl Effect for an account-level MediaConnect operation (e.g.
 * enumerating the account's flows or granted entitlements). The
 * deploy-time half grants `actions` on `*` — these list operations are
 * not scoped to a single flow resource.
 */
export const makeMediaConnectAccountHttpBinding = <I, A, E, R>(options: {
  /** Fully-qualified binding tag, e.g. `AWS.MediaConnect.ListFlows`. */
  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);
      });
    });
  });