(local { : Gtk : Gdk : WebKit2 : cairo } (require :lgi))

(local Listeners (require :listeners))

(fn scale-surface [source image-width image-height]
  (let [scaled (cairo.ImageSurface.create
                cairo.Format.ARGB32
                image-width image-height)
        ctx (cairo.Context.create scaled)
        source-width (cairo.ImageSurface.get_width source)
        source-height (cairo.ImageSurface.get_height source)
        scale (/ image-width source-width)]
    ;; XXX do we need to destroy this context? the example
    ;; in C called cairo_destroy(cr), but I haven't found a
    ;; gi equivalent
    (doto ctx
      (: :scale scale scale)
      (: :set_source_surface source 0 0)
      (: :paint))
    scaled))

(fn thumbnail-image [widget width height fun]
  ;; underlying call is async, so use callback
  (widget:get_snapshot
   WebKit2.SnapshotRegion.VISIBLE
   WebKit2.SnapshotOptions.NONE
   nil
   (fn [self res]
     (let [surface (widget:get_snapshot_finish res)
           scaled (scale-surface surface width height)
           img (doto (Gtk.Image) (: :set_from_surface scaled))]
       (fun img)))))


{
 :new
 #(let [listeners (Listeners.new)
        props {}
        widget (WebKit2.WebView {
                                 :on_notify
                                 (fn [self pspec]
                                   (when (not (= pspec.name :parent))
                                     (let [val (. self pspec.name)]
                                       (tset props pspec.name val)
                                       (listeners:notify pspec.name val))))
                                 })]
    ;;(load-adblocks webview.user_content_manager content-filter-store)
    {
     :listen #(listeners:add $2 $3)
     :visit (fn [self url]
              (widget:load_uri url))
     :stop-loading #(widget:stop_loading)
     :refresh #(widget:reload)
     :go-back #(and (widget:can_go_back) (widget:go_back))

     :thumbnail-image (fn [self width height fun]
                        (thumbnail-image widget width height fun))

     :properties props
     :widget widget
     })
 }