text: const { InvalidArgumentError } = require('./error.js');
  
  // @ts-check
  
  class Option {
    /**
     * Initialize a new `Option` with the given `flags` and `description`.
     *
     * @param {string} flags
     * @param {string} [description]
     */
  
    constructor(flags, description) {
      this.flags = flags;
      this.description = description || '';
  
      this.required = flags.includes('<'); // A value must be supplied when the option is specified.
      this.optional = flags.includes('['); // A value is optional when the option is specified.
      // variadic test ignores <value,...> et al which might be used to describe custom splitting of single argument
      this.variadic = /\w\.\.\.[>\]]$/.test(flags); // The option can take multiple values.
      this.mandatory = false; // The option must have a value after parsing, which usually means it must be specified on command line.
      const optionFlags = splitOptionFlags(flags);
      this.short = optionFlags.shortFlag;
      this.long = optionFlags.longFlag;
      this.negate = false;
      if (this.long) {
        this.negate = this.long.startsWith('--no-');
      }
      this.defaultValue = undefined;
      this.defaultValueDescription = undefined;
      this.presetArg = undefined;
      this.envVar = undefined;
      this.parseArg = undefined;
      this.hidden = false;
      this.argChoices = undefined;
      this.conflictsWith = [];
      this.implied = undefined;
    }
  
    /**
     * Set the default value, and optionally supply the description to be displayed in the help.
     *
     * @param {any} value
     * @param {string} [description]
     * @return {Option}
     */
  
    default(value, description) {
      this.defaultValue = value;
      this.defaultValueDescription = description;
      return this;
    }
  
    /**
     * Preset to use when option used without option-argument, especially optional but also boolean and negated.
     * The custom processing (parseArg) is called.
     *
     * @example
     * new Option('--color').default('GREYSCALE').preset('RGB');
     * new Option('--donate [amount]').preset('20').argParser(parseFloat);
     *
     * @param {any} arg
     * @return {Option}
     */
  
    preset(arg) {
      this.presetArg = arg;
      return this;
    }
  
    /**
     * Add option name(s) that conflict with this option.
     * An error will be displayed if conflicting options are found during parsing.
     *
     * @example
     * new Option('--rgb').conflicts('cmyk');
     * new Option('--js').conflicts(['ts', 'jsx']);
     *
     * @param {string | string[]} names
     * @return {Option}
     */
  
    conflicts(names) {
      this.conflictsWith = this.conflictsWith.concat(names);
      return this;
    }
  
    /**
     * Specify implied option values for when this option is set and the implied options are not.
     *
     * The custom processing (parseArg) is not called on the implied values.
     *
     * @example
     * program
     *   .addOption(new Option('--log', 'write logging information to file'))
     *   .addOption(new Option('--trace', 'log extra details').implies({ log: 'trace.txt' }));
     *
     * @param {Object} impliedOptionValues
     * @return {Option}
     */
    implies(impliedOptionValues) {
      this.implied = Object.assign(this.implied || {}, impliedOptionValues);
      return this;
    }
  
    /**
     * Set environment variable to check for option value.
     * Priority order of option values is default < env < cli
     *
     * @param {string} name
     * @return {Option}
     */
  
    env(name) {
      this.envVar = name;
      return this;
    }
  
    /**
     * Set the custom handler for processing CLI option arguments into option values.
     *
     * @param {Function} [fn]
     * @return {Option}
     */
  
    argParser(fn) {
      this.parseArg = fn;
      return this;
    }
  
    /**
     * Whether the option is mandatory and must have a value after parsing.
     *
     * @param {boolean} [mandatory=true]
     * @return {Option}
     */
  
    makeOptionMandatory(mandatory = true) {
      this.mandatory = !!mandatory;
      return this;
    }
  
    /**
     * Hide option in help.
     *
     * @param {boolean} [hide=true]
     * @return {Option}
     */
  
    hideHelp(hide = true) {
      this.hidden = !!hide;
      return this;
    }
  
    /**
     * @api private
     */
  
    _concatValue(value, previous) {
      if (previous === this.defaultValue || !Array.isArray(previous)) {
        return [value];
      }
  
      return previous.concat(value);
    }
  
    /**
     * Only allow option value to be one of choices.
     *
     * @param {string[]} values
     * @return {Option}
     */
  
    choices(values) {
      this.argChoices = values.slice();
      this.parseArg = (arg, previous) => {
        if (!this.argChoices.includes(arg)) {
          throw new InvalidArgumentError(`Allowed choices are ${this.argChoices.join(', ')}.`);
        }
        if (this.variadic) {
          return this._concatValue(arg, previous);
        }
        return arg;
      };
      return this;
    }
  
    /**
     * Return option name.
     *
     * @return {string}
     */
  
    name() {
      if (this.long) {
        return this.long.replace(/^--/, '');
      }
      return this.short.replace(/^-/, '');
    }
  
    /**
     * Return option name, in a camelcase format that can be used
     * as a object attribute key.
     *
     * @return {string}
     * @api private
     */
  
    attributeName() {
      return camelcase(this.name().replace(/^no-/, ''));
    }
  
    /**
     * Check if `arg` matches the short or long flag.
     *
     * @param {string} arg
     * @return {boolean}
     * @api private
     */
  
    is(arg) {
      return this.short === arg || this.long === arg;
    }
  
    /**
     * Return whether a boolean option.
     *
     * Options are one of boolean, negated, required argument, or optional argument.
     *
     * @return {boolean}
     * @api private
     */
  
    isBoolean() {
      return !this.required && !this.optional && !this.negate;
    }
  }
  
  /**
   * This class is to make it easier to work with dual options, without changing the existing
   * implementation. We support separate dual options for separate positive and negative options,
   * like `--build` and `--no-build`, which share a single option value. This works nicely for some
   * use cases, but is tricky for others where we want separate behaviours despite
   * the single shared option value.
   */
  class DualOptions {
    /**
     * @param {Option[]} options
     */
    constructor(options) {
      this.positiveOptions = new Map();
      this.negativeOptions = new Map();
      this.dualOptions = new Set();
      options.forEach(option => {
        if (option.negate) {
          this.negativeOptions.set(option.attributeName(), option);
        } else {
          this.positiveOptions.set(option.attributeName(), option);
        }
      });
      this.negativeOptions.forEach((value, key) => {
        if (this.positiveOptions.has(key)) {
          this.dualOptions.add(key);
        }
      });
    }
  
    /**
     * Did the value come from the option, and not from possible matching dual option?
     *
     * @param {any} value
     * @param {Option} option
     * @returns {boolean}
     */
    valueFromOption(value, option) {
      const optionKey = option.attributeName();
      if (!this.dualOptions.has(optionKey)) return true;
  
      // Use the value to deduce if (probably) came from the option.
      const preset = this.negativeOptions.get(optionKey).presetArg;
      const negativeValue = (preset !== undefined) ? preset : false;
      return option.negate === (negativeValue === value);
    }
  }
  
  /**
   * Convert string from kebab-case to camelCase.
   *
   * @param {string} str
   * @return {string}
   * @api private
   */
  
  function camelcase(str) {
    return str.split('-').reduce((str, word) => {
      return str + word[0].toUpperCase() + word.slice(1);
    });
  }
  
  /**
   * Split the short and long flag out of something like '-m,--mixed <value>'
   *
   * @api private
   */
  
  function splitOptionFlags(flags) {
    let shortFlag;
    let longFlag;
    // Use original very loose parsing to maintain backwards compatibility for now,
    // which allowed for example unintended `-sw, --short-word` [sic].
    const flagParts = flags.split(/[ |,]+/);
    if (flagParts.length > 1 && !/^[[<]/.test(flagParts[1])) shortFlag = flagParts.shift();
    longFlag = flagParts.shift();
    // Add support for lone short flag without significantly changing parsing!
    if (!shortFlag && /^-[^-]$/.test(longFlag)) {
      shortFlag = longFlag;
      longFlag = undefined;
    }
    return { shortFlag, longFlag };
  }
  
  exports.Option = Option;
  exports.splitOptionFlags = splitOptionFlags;
  exports.DualOptions = DualOptions;
  