import * as Madlad from 'madlad'
import { Command } from './command'

const optionMetadataKey = Symbol('Option')

/**
 * Creates CLI Option based on the passed `options` and assigns its value to the property
 *
 * @param options IOption object, which defines the option of the command
 */
export function Option(options: Madlad.Argument): PropertyDecorator {
  return Reflect.metadata(optionMetadataKey, options)
}

/**
 * Get the yargs option key from ExternalOption metadata on the given property
 *
 * @param target Command instance
 * @param propertyKey Property of the command instance
 */
export function getOption<T extends Command, K extends Extract<keyof T, string>>(
  target: T,
  propertyKey: K,
): Madlad.Argument {
  return Reflect.getMetadata(optionMetadataKey, target, propertyKey)
}

const externalOptionMetadataKey = Symbol('ExternalOption')

/**
 * Init the parameter with value of the desired option, which is defined outside of the class
 *
 * @param key CLI option reference of the required option value (without dashes)
 */
export function ExternalOption(key: string): PropertyDecorator {
  return Reflect.metadata(externalOptionMetadataKey, key)
}

/**
 * Get the yargs option key from ExternalOption metadata on the given property
 *
 * @param target Command instance
 * @param propertyKey Property of the command instance
 */
export function getExternalOption<T extends Command, K extends Extract<keyof T, string>>(
  target: T,
  propertyKey: K,
): string {
  return Reflect.getMetadata(externalOptionMetadataKey, target, propertyKey)
}