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

/**
 * Shared scaffolding for the AWS Fault Injection Service (FIS) 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, the IAM action list, and the
 * injected identifier is boilerplate.
 */

/**
 * Build the impl Effect for a FIS operation scoped to a bound
 * {@link ExperimentTemplate}: the deploy-time half grants `actions` on the
 * template's ARN (plus, when `grantExperimentWildcard` is set, the account's
 * `experiment/*` ARNs — `fis:StartExperiment` authorizes against both the
 * template being started and the experiment being created), and the runtime
 * half injects the template's id into every request as `requestKey`.
 *
 * `clientToken` (an idempotency token) is auto-generated by distilled when
 * absent, so it is omitted from the runtime request shape.
 */
export const makeFisTemplateHttpBinding = <I, A, E, R>(options: {
  /** Fully-qualified binding tag, e.g. `AWS.FIS.StartExperiment`. */
  tag: string;
  /** The distilled operation. */
  operation: Effect.Effect<(input: I) => Effect.Effect<A, E>, never, R>;
  /** IAM actions granted on the experiment template ARN. */
  actions: readonly string[];
  /** The request field the bound template's id is injected as. */
  requestKey: "id" | "experimentTemplateId";
  /**
   * Additionally grant `actions` on the account's `experiment/*` ARN —
   * `fis:StartExperiment` is authorized against both the template and the
   * experiment it creates.
   */
  grantExperimentWildcard?: boolean;
  /**
   * Additionally grant `iam:CreateServiceLinkedRole` scoped to FIS — the
   * first `fis:StartExperiment` in an account creates the
   * `AWSServiceRoleForFIS` service-linked role on the caller's behalf and is
   * denied without it.
   */
  grantServiceLinkedRole?: boolean;
}) =>
  Effect.gen(function* () {
    const op = yield* options.operation;

    return Effect.fn(function* (template: ExperimentTemplate) {
      const TemplateId = yield* template.id;
      if (!globalThis.__ALCHEMY_RUNTIME__) {
        const host = yield* Binding.Host;
        if (isBindingHost(host)) {
          yield* host.bind`Allow(${host}, ${options.tag}(${template}))`({
            policyStatements: [
              {
                Effect: "Allow",
                Action: [...options.actions],
                Resource: [
                  Output.interpolate`${template.arn}`,
                  ...(options.grantExperimentWildcard
                    ? [
                        // arn:…:experiment-template/EXT… → arn:…:experiment/*
                        template.arn.pipe(
                          Output.map(
                            (arn) =>
                              `${arn.slice(0, arn.lastIndexOf(":"))}:experiment/*`,
                          ),
                        ),
                      ]
                    : []),
                ],
              },
              ...(options.grantServiceLinkedRole
                ? [
                    {
                      Effect: "Allow" as const,
                      Action: ["iam:CreateServiceLinkedRole"],
                      Resource: [
                        "arn:aws:iam::*:role/aws-service-role/fis.amazonaws.com/AWSServiceRoleForFIS",
                      ],
                      Condition: {
                        StringEquals: {
                          "iam:AWSServiceName": "fis.amazonaws.com",
                        },
                      },
                    },
                  ]
                : []),
            ],
          });
        }
      }
      return Effect.fn(`${options.tag}(${template.LogicalId})`)(function* (
        request?: Omit<I, "id" | "experimentTemplateId" | "clientToken">,
      ) {
        return yield* op({
          ...request,
          [options.requestKey]: yield* TemplateId,
        } as I);
      });
    });
  });

/**
 * Build the impl Effect for an account-level FIS operation (experiment
 * control and reads, the action/target-resource-type catalogs, the safety
 * lever). The deploy-time half grants `actions` on `*` — experiments are
 * created dynamically at runtime and the catalog/list actions are not scoped
 * to a single resource.
 */
export const makeFisAccountHttpBinding = <I, A, E, R>(options: {
  /** Fully-qualified binding tag, e.g. `AWS.FIS.GetExperiment`. */
  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);
      });
    });
  });