const debug = require('debug')('treelab:common');

interface IExhaustiveSwitchArgs {
  switchValue: never;
  returnValue?: any;
}

export const exhaustiveSwitch = (({
  switchValue,
  returnValue,
}: IExhaustiveSwitchArgs) => {
  debug(
    `Received invalid switch value: \`${switchValue}\`.${
      typeof returnValue === 'undefined'
        ? ''
        : ` Substituting \`${returnValue}\` as a fallback.`
    }`
  );
  return returnValue;
}) as (args: IExhaustiveSwitchArgs) => never;

export const exhaustiveSwitchThrow = (({
  switchValue,
}: Pick<IExhaustiveSwitchArgs, 'switchValue'>) => {
  throw new Error(`Received invalid switch value: \`${switchValue}\`.`);
}) as (args: Pick<IExhaustiveSwitchArgs, 'switchValue'>) => never;