exoRift/cyclone-engine

const Argument = require('../argument/')

/**
 * A class used to register keywords in a message that are replaced with live data
 */
class Replacer {
  /**
   * Create a replacer
   * @class
   * @param {Object}                data                   The data to make a replacer with
   * @prop  {String}                data.key               The key that invokes the replacer
   * @prop  {String}                data.desc              The description of the replacer
   * @prop  {Object}                [data.options={}]      The options for the replacer
   * @prop  {Array<ArgData|String>} [data.options.args=[]] The arguments for the replacer (Can be an argument data object or just the name of the argument)
   * @prop  {ReplacerAction}        data.action            A function returning the string to replace with
   */
  constructor ({ key, desc, options = {}, action }) {
    const {
      args = []
    } = options

    /**
     * The data to make a replacer with
     * @type {String}
     */
    this.key = key

    /**
     * The description of the replacer
     * @type {String}
     */
    this.desc = desc

    /**
     * The options for the replacer
     * @type {Object}
     * @prop {Argument[]} args The arguments for the replacer
     */
    this.options = {
      args: args.map((arg) => new Argument(arg))
    }

    /**
     * Function returning the string to replace with
     * @type {ReplacerAction}
     */
    this.action = action
  }

  /**
   * Get the info of this replacer as a string
   * @type    {String}
   * @example          '**name** **<mandatory arg> (optional arg) (#number arg)** - *description*'
   */
  get info () {
    const args = this.options.args.reduce((accum, arg, index) => {
      const lastArg = index === this.options.args.length - 1

      const content = (index ? accum : '') + (arg.mand ? '<' : '(') + `${arg.type === 'number' ? '#' : ''}${arg.name}` + (arg.mand ? '>' : ')') + (lastArg ? '' : arg.delim)
      return content
    }, '')

    return `**${this.key}**${args ? ` **${args}**` : ''} - *${this.desc}*`
  }
}

module.exports = Replacer

/**
 * The replacer action
 * @callback                                              ReplacerAction
 * @param   {Object}                                      data           The data passed to the replacer
 * @prop    {String}                                      data.content   The content of the message
 * @prop    {String}                                      data.capture   What was captured in the replacer braces
 * @prop    {Array<String|Number|Eris.User|Eris.Channel>} data.args      The arguments provided for the replacer
 * @returns {String}                                                     The content to inject
 */