import IOption from './interfaces/IOption';
import IState from './interfaces/IState';

export default function parseSpecEntry({ outputArgs, requiredOptions, shortToLongLookup }: IState, [longOption, { short: shortOption, default: defaultValue }]: [string, IOption]) {
  if (longOption === '') {
    throw new Error(`The long option may not be an empty string. This is a bug in the source code of the script that you tried to call.`);
  }
  if (longOption.match(/^[a-z0-9]+(?:-[a-z0-9]+)*$/) === null) {
    throw new Error(`The long option "${longOption}" must only contain alpha-numeric characters, optionally separated by hyphens. This is a bug in the source code of the script that you tried to call.`);
  }

  if (shortOption !== undefined && shortOption !== '') {
    if (shortOption.length > 1) {
      throw new Error(`Short options must only be one character long but the short option "${shortOption}" for "${longOption}" was ${shortOption.length} characters long. This is a bug in the source code of the script that you tried to call.`);
    }
    shortToLongLookup[shortOption] = longOption;
  }

  //If a default value is given, use the default value (it can be overridden later), otherwise mark argument as being required
  if (defaultValue !== undefined) {
    outputArgs[longOption] = defaultValue;
  } else {
    requiredOptions[longOption] = false;
  }
}