import os
import enum
import cairo

from hexagram.svg import render_to_image

class Icon():
    __slots__ = 'name', 'width', 'height', 'style', 'variants', \
                '_path', '_surfaces',

    __dirs__ = ('./icons',
                '/usr/local/share/hexagram/icons'
                '/usr/share/hexagram/icons')

    @staticmethod
    def _locate(name: str):
        for dir in Icon.__dirs__:
            path = "%s/%s.svg" % (dir, name)

            if os.path.exists(path):
                return path

        raise FileNotFoundError(name + '.svg')

    STYLE = 'rect,path,circle{stroke:%(s)s;}'

    def __init__(self, name: str, width: float, height: float, variants: dict, style: str=STYLE):
        self.name      = name
        self.width     = width
        self.height    = height
        self.style     = style
        self.variants  = variants
        self._path     = Icon._locate(name)
        self._surfaces: dict[enum.Enum, cairo.ImageSurface] = dict()

    def __del__(self):
        for key in self._surfaces:
            self._surfaces[key].finish()

    def _surface(self, status) -> cairo.ImageSurface:
        surface = self._surfaces.get(status)

        if surface is not None:
            return surface

        color   = self.variants[status]
        surface = render_to_image(self._path,
                                  self.width,
                                  self.height,
                                  self.style % {'s': color})

        self._surfaces[status] = surface

        return surface

    def drawable(self, status: enum.Enum):
        return status in self.variants

    def draw(self, cr: cairo.Context, x: float, y: float, status):
        surface = self._surface(status)

        cr.set_source_surface(surface, x, y)
        cr.rectangle(x, y, self.width, self.height)
        cr.fill()