import * as ec2 from "@distilled.cloud/aws/ec2";
import * as Effect from "effect/Effect";
import * as Layer from "effect/Layer";
import * as Binding from "../../Binding.ts";
import { isBindingHost } from "../Lambda/Function.ts";
import { DescribeInstance } from "./DescribeInstance.ts";
import { isInstance, type Instance } from "./Instance.ts";

// Bespoke (not the shared scaffold): `describeInstances` nests results under
// Reservations[].Instances[] and the client unwraps the single bound
// instance.
export const DescribeInstanceHttp = Layer.effect(
  DescribeInstance,
  Effect.gen(function* () {
    const describe = yield* ec2.describeInstances;

    return Effect.fn(function* (instance: Instance) {
      const instanceId = yield* instance.instanceId;
      if (!globalThis.__ALCHEMY_RUNTIME__) {
        const host = yield* Binding.Host;
        if (isBindingHost(host) || isInstance(host)) {
          yield* host.bind`Allow(${host}, AWS.EC2.DescribeInstance(${instance}))`(
            {
              policyStatements: [
                {
                  Effect: "Allow",
                  Action: ["ec2:DescribeInstances"],
                  Resource: ["*"],
                },
              ],
            },
          );
        }
      }
      return Effect.fn(`AWS.EC2.DescribeInstance(${instance.LogicalId})`)(
        function* () {
          const result = yield* describe({
            InstanceIds: [yield* instanceId],
          });
          return result.Reservations?.[0]?.Instances?.[0];
        },
      );
    });
  }),
);