log = debug('editchoice')
RDFS = 'http://www.w3.org/2000/01/rdf-schema#'



window.setupDrop = (senseElem, highlightElem, coordinateOriginElem, onDrop) ->

  highlight = -> highlightElem.classList.add('dragging')
  unhighlight = -> highlightElem.classList.remove('dragging')
  
  senseElem.addEventListener 'drag', (event) =>
    
  senseElem.addEventListener 'dragstart', (event) =>
    
  senseElem.addEventListener 'dragend', (event) =>
    
  senseElem.addEventListener 'dragover', (event) =>
    event.preventDefault()
    event.dataTransfer.dropEffect = 'copy'
    highlight()

  senseElem.addEventListener 'dragenter', (event) =>
    highlight()
    
  senseElem.addEventListener 'dragleave', (event) =>
    unhighlight()
   
  senseElem.addEventListener 'drop', (event) ->
    event.preventDefault()
    uri = event.dataTransfer.getData('text/uri-list')

    pos = if coordinateOriginElem?
        root = coordinateOriginElem.getBoundingClientRect()
        $V([event.pageX - root.left, event.pageY - root.top])
      else
        null

    try
      onDrop(uri, pos)
    catch e
      log(e)
    unhighlight()



coffeeElementSetup(class EditChoice extends Polymer.Element
  @is: "edit-choice",
  @getter_properties:
    graph: {type: Object, notify: true},
    uri: {type: String, notify: true},

  _setUri: (u) ->
    @uri = u
    @dispatchEvent(new CustomEvent('edited'))

  connectedCallback: ->
    super.connectedCallback()
    setupDrop(@$.box, @$.box, null, @_setUri.bind(@))

  unlink: ->
    @_setUri(null)
)