bemusic/bms-js

// Public: A module that exposes {Keysounds}
/* module */

var _ = require('../util/lodash')

// Public: A Keysounds is a simple mapping between keysounds ID and the file name.
//
// ## Example
//
// If you have a BMS like this:
//
// ```
// #WAVAA cat.wav
// ```
//
// Having parsed it using a {Compiler} into a {BMSChart},
// you can create a {Keysounds} using `fromBMSChart()`:
//
// ```js
// var keysounds = Keysounds.fromBMSChart(bmsChart)
// ```
//
// Then you can retrieve the filename using `.get()`:
//
// ```js
// keysounds.get('aa') // => 'cat.wav'
// ```
//
/* class Keysounds */

// Public: Constructs an empty {Keysounds} object.
function Keysounds (map) {
  this._map = map
}

// Public: Returns the keysound file at the specified ID.
//
// * `id` {String} representing the two-character keysound ID
//
// Returns {String} representing the filename
// Returns undefined if not found
//
Keysounds.prototype.get = function (id) {
  return this._map[id.toLowerCase()]
}

// Public: Returns an array of unique filenames in this Keysounds object.
//
// Returns an {Array} of {String} representing a list of filenames
//
Keysounds.prototype.files = function () {
  return _.uniq(_.values(this._map))
}

// Public: Returns a mapping from keysound ID to keysound filename.
//
// Warning: This method returns the internal data structure used in this Keysounds object.
// Do not mutate!
//
// Returns an {Object} that maps from keysound ID to keysound filename
//
Keysounds.prototype.all = function () {
  return this._map
}

// Public: Constructs a new {Keysounds} object from a {BMSChart}.
//
// * `chart` A {BMSChart} to construct a {Keysounds} from
//
// Returns a {Keysounds} object
//
Keysounds.fromBMSChart = function (chart) {
  var map = {}
  chart.headers.each(function (name, value) {
    var match = name.match(/^wav(\S\S)$/i)
    if (!match) return
    map[match[1].toLowerCase()] = value
  })
  return new Keysounds(map)
}

module.exports = Keysounds