import { createContext, useContext } from 'react';

function getGlobalObject() {
  if (typeof window !== "undefined" && window.Math === Math) {
    return window;
  }
  if (typeof self !== "undefined" && self.Math === Math) {
    return self;
  }
  return Function("return this")();
}
const globalObject = getGlobalObject();
const makeKey = (id) => `__@backstage/${id}__`;
function getOrCreateGlobalSingleton(id, supplier) {
  const key = makeKey(id);
  let value = globalObject[key];
  if (value) {
    return value;
  }
  value = supplier();
  globalObject[key] = value;
  return value;
}

function createVersionedValueMap(versions) {
  Object.freeze(versions);
  const versionedValue = {
    atVersion(version) {
      return versions[version];
    }
  };
  Object.defineProperty(versionedValue, "$map", {
    configurable: true,
    enumerable: true,
    get() {
      return versions;
    }
  });
  return versionedValue;
}

function createVersionedContext(key) {
  return getOrCreateGlobalSingleton(
    key,
    () => createContext(void 0)
  );
}
function useVersionedContext(key) {
  return useContext(createVersionedContext(key));
}
function createVersionedContextForTesting(key) {
  return {
    set(versions) {
      globalThis[`__@backstage/${key}__`] = createContext(
        createVersionedValueMap(versions)
      );
    },
    reset() {
      delete globalThis[`__@backstage/${key}__`];
    }
  };
}

export { createVersionedContext, createVersionedContextForTesting, createVersionedValueMap, getOrCreateGlobalSingleton, useVersionedContext };
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