import * as dax from "@distilled.cloud/aws/dax";
import * as Effect from "effect/Effect";

/**
 * Convert DAX's `[{ Key, Value }]` tag list into a plain record, dropping any
 * entry missing a key or value.
 */
export const toTagRecord = (
  tags: Array<{ Key?: string; Value?: string }> | undefined,
): Record<string, string> =>
  Object.fromEntries(
    (tags ?? [])
      .filter(
        (tag): tag is { Key: string; Value: string } =>
          typeof tag.Key === "string" && typeof tag.Value === "string",
      )
      .map((tag) => [tag.Key, tag.Value]),
  );

/**
 * Read the observed tags for a DAX cluster by ARN. A cluster that is
 * mid-transition (creating/modifying) transiently rejects `listTags` with
 * InvalidClusterStateFault; treat any failure as "no observed tags" so tag
 * reconciliation still runs on the next pass.
 */
export const readDaxTags = Effect.fn(function* (arn: string) {
  const response = yield* dax
    .listTags({ ResourceName: arn })
    .pipe(Effect.catch(() => Effect.succeed(undefined)));
  return toTagRecord(response?.Tags);
});

/** True when two string sets are equal ignoring order and duplicates. */
export const sameStringSet = (
  a: readonly string[] | undefined,
  b: readonly string[] | undefined,
): boolean => {
  const left = [...new Set(a ?? [])].sort();
  const right = [...new Set(b ?? [])].sort();
  return left.length === right.length && left.every((v, i) => v === right[i]);
};