// @class PolyLine
import * as L from 'leaflet'

const DashFlow = () => {
  L.Path.mergeOptions({
    // @option dashSpeed: Number
    // The speed of the dash array, in pixels per second
    dashSpeed: 0
  })

  var _originalBeforeAdd = L.Path.prototype.beforeAdd

  L.Path.include({

    beforeAdd: function (map) {
      _originalBeforeAdd.bind(this)(map)

      if (this.options.dashSpeed) {
        this._lastDashFrame = performance.now()
        this._dashFrame = L.Util.requestAnimFrame(this._onDashFrame.bind(this))
      }
    },

    _onDashFrame: function () {
      if (!this._renderer) {
        return
      }

      var now = performance.now()
      var dashOffsetDelta = (now - this._lastDashFrame) * this.options.dashSpeed / 1000

      this.options.dashOffset = Number(this.options.dashOffset || 0) + dashOffsetDelta
      this._renderer._updateStyle(this)

      this._lastDashFrame = performance.now()

      this._dashFrame = L.Util.requestAnimFrame(this._onDashFrame.bind(this))
    }

  })
}

export default { DashFlow }