import logging
import hippo
import gtk
 
from sugar import util
from sugar.graphics import style
from view.clipboardicon import ClipboardIcon
from sugar.clipboard import clipboardservice

class _ContextMap:
    """Maps a drag context to the clipboard object involved in the dragging."""
    def __init__(self):
        self._context_map = {}
        
    def add_context(self, context, object_id, data_types):
        """Establishes the mapping. data_types will serve us for reference-
        counting this mapping.
        """
        self._context_map[context] = [object_id, data_types]
    
    def get_object_id(self, context):
        """Retrieves the object_id associated with context.
        Will release the association when this function was called as many times
        as the number of data_types that this clipboard object contains.
        """
        [object_id, data_types_left] = self._context_map[context]
        
        data_types_left = data_types_left - 1
        if data_types_left == 0:
            del self._context_map[context]
        else:
            self._context_map[context] = [object_id, data_types_left]

        return object_id
 
class ClipboardBox(hippo.CanvasBox):
    
    def __init__(self, menu_shell):
        hippo.CanvasBox.__init__(self)
        self._menu_shell = menu_shell
        self._icons = {}
        self._context_map = _ContextMap()

        self._pressed_button = None
        self._press_start_x = None
        self._press_start_y = None
        
        cb_service = clipboardservice.get_instance()
        cb_service.connect('object-added', self._object_added_cb)
        cb_service.connect('object-deleted', self._object_deleted_cb)
        cb_service.connect('object-state-changed', self._object_state_changed_cb)

    def _get_icon_at_coords(self, x, y):
        for object_id, icon in self._icons.iteritems():
            [icon_x, icon_y] = self.get_position(icon)
            [icon_width, icon_height] = icon.get_allocation()

            if (x >= icon_x ) and (x <= icon_x + icon_width) and        \
                    (y >= icon_y ) and (y <= icon_y + icon_height):
                return icon
                
        return None

    def _add_selection(self, object_id, selection):
        if selection.data:
            logging.debug('ClipboardBox: adding type ' + selection.type + '.')
                        
            cb_service = clipboardservice.get_instance()
            cb_service.add_object_format(object_id, 
                                  selection.type,
                                  selection.data,
                                  on_disk = False)
    
    def _object_added_cb(self, cb_service, object_id, name):
        icon = ClipboardIcon(self._menu_shell, object_id, name)
        style.apply_stylesheet(icon, 'frame.BuddyIcon')
        self.append(icon)
        self._icons[object_id] = icon
        
        logging.debug('ClipboardBox: ' + object_id + ' was added.')

    def _object_deleted_cb(self, cb_service, object_id):
        icon = self._icons[object_id]
        self.remove(icon)
        del self._icons[object_id]
        logging.debug('ClipboardBox: ' + object_id + ' was deleted.')

    def _object_state_changed_cb(self, cb_service, object_id, percent):
        icon = self._icons[object_id]
        icon.set_percent(percent)
        logging.debug('ClipboardBox: ' + object_id + ' state was changed.')

    def drag_motion_cb(self, widget, context, x, y, time):
        context.drag_status(gtk.gdk.ACTION_COPY, time)
        return True

    def drag_drop_cb(self, widget, context, x, y, time):
        object_id = util.unique_id()
        self._context_map.add_context(context, object_id, len(context.targets))
        
        cb_service = clipboardservice.get_instance()
        cb_service.add_object(object_id, "name")

        for target in context.targets:
            if str(target) not in ('TIMESTAMP', 'TARGETS', 'MULTIPLE'):
                widget.drag_get_data(context, target, time)

        cb_service.set_object_state(object_id, percent = 100)
        
        return True

    def drag_data_received_cb(self, widget, context, x, y, selection, targetType, time):
        logging.debug('ClipboardBox: got data for target ' + selection.target)
        if selection:
            object_id = self._context_map.get_object_id(context)
            self._add_selection(object_id, selection)
        else:
            logging.warn('ClipboardBox: empty selection for target ' + selection.target)            

    def drag_data_get_cb(self, widget, context, selection, targetType, eventTime):
        logging.debug("drag_data_get_cb: requested target " + selection.target)
        
        object_id = self._last_clicked_icon.get_object_id()
        cb_service = clipboardservice.get_instance()
        data = cb_service.get_object_data(object_id, selection.target)
        
        selection.set(selection.target, 8, data)

    def button_press_event_cb(self, widget, event):
        logging.debug("button_press_event_cb")

        if event.button == 1 and event.type == gtk.gdk.BUTTON_PRESS:
            self._last_clicked_icon = self._get_icon_at_coords(event.x, event.y)
            if self._last_clicked_icon:
                self._pressed_button = event.button
                self._press_start_x = event.x
                self._press_start_y = event.y

        return True;

    def motion_notify_event_cb(self, widget, event):
       
        if not self._pressed_button:
            return True
        
        # if the mouse button is not pressed, no drag should occurr
        if not event.state & gtk.gdk.BUTTON1_MASK:
            self._pressed_button = None
            return True

        logging.debug("motion_notify_event_cb")
                        
        if event.is_hint:
            x, y, state = event.window.get_pointer()
        else:
            x = event.x
            y = event.y
            state = event.state

        if widget.drag_check_threshold(int(self._press_start_x),
                                       int(self._press_start_y),
                                       int(x),
                                       int(y)):
            targets = self._get_targets_for_dnd(
                self._last_clicked_icon.get_object_id())

            context = widget.drag_begin(targets,
                                        gtk.gdk.ACTION_COPY,
                                        1,
                                        event);

        return True

    def drag_end_cb(self, widget, drag_context):
        logging.debug("drag_end_cb")
        self._pressed_button = None

    def _get_targets_for_dnd(self, object_id):
        cb_service = clipboardservice.get_instance()
        format_types = cb_service.get_object_format_types(object_id)
        targets = []
        
        for format_type in format_types:
            targets.append((format_type, 0, 0))

        logging.debug(str(targets))
        
        return targets