#!/usr/bin/env python3

import inkex

class HoneyCombExtension(inkex.EffectExtension):
    def add_arguments(self, pars):
        pars.add_argument("--spacing", type=float, default=0.0)
        pars.add_argument("--count_x", type=int, default=0)
        pars.add_argument("--count_y", type=int, default=0)

    def effect(self):

        if len(self.svg.selection) != 2:
            inkex.errormsg("Must select a bounding box and a circle to honeycomb")
            return

        target = self.svg.selection.popitem()[1]
        bounding_box = self.svg.selection.popitem()[1]

        # Validate bounding box
        if bounding_box is None:
            inkex.errormsg("Must have a bounding box selected")
            return
        bounding_box_h = float(bounding_box.get("height"))
        bounding_box_w = float(bounding_box.get("width"))
        bounding_box_x = float(bounding_box.get("x"))
        bounding_box_y = float(bounding_box.get("y"))
        bounding_box_style = bounding_box.get("style")

        if (bounding_box_h and bounding_box_w and bounding_box_x and bounding_box_y) \
           is None:
            inkex.errormsg("Bounding Box must be the first selection")
            return

        # Validate honeycomb target
        if target is None:
            inkex.errormsg("Must make a selection of an object to honycomb")

        if target.get("r"):
            # Selection is a circle
            target_rad = float(target.get("r"))
            target_dia = 2 * float(target_rad)
            target_style = target.get("style")

            difference = bounding_box_w - (target_dia * self.options.count_x)
            target_spacing = difference/(self.options.count_x)

            shift_row = True
            for y_cnt in range(0, self.options.count_y):
                y_coord =  (bounding_box_y + target_rad)
                y_coord += y_cnt * target_dia
                if y_cnt % 2 != 0:
                    shift_row = True
                    num_x = self.options.count_x + 1
                else:
                    shift_row = False
                    num_x = self.options.count_x
                for x_cnt in range(0, num_x):
                    x_coord = bounding_box_x + target_rad
                    x_coord += x_cnt * (target_spacing + target_dia)
                    if shift_row:
                        x_coord -= target_rad
                    else:
                        x_coord += target_spacing / 2
                    circ = inkex.Circle(attrib={"cx": f"{x_coord}",
                                                "cy": f"{y_coord}",
                                                "r": f"{target_rad}",
                                                "style": target_style})
                    layer = self.svg.get_current_layer()
                    layer.append(circ)

        elif target.get("rx"):
            # Selection is an elipse
            inkex.errormsg("Elipses are not supported\n"
                           "Selection must have 'r' attribute")

        else:
            inkex.errormsg("Other shapes not supported\n"
                           "Selection must have 'r' attribute")

        return


if __name__ == '__main__':
    HoneyCombExtension().run()