"""Web endpoint showing graph of running :pypi:`mode` services."""
import io

from faust import web

__all__ = ["Graph", "blueprint"]

blueprint = web.Blueprint("graph")


@blueprint.route("/", name="detail")
class Graph(web.View):
    """Render image from graph of running services."""

    async def get(self, request: web.Request) -> web.Response:
        """Draw image of the services running in this worker."""
        try:
            import pydot
        except ImportError:
            return self.text("Please install pydot: pip install pydot", status=500)
        o = io.StringIO()
        beacon = self.app.beacon.root or self.app.beacon
        beacon.as_graph().to_dot(o)
        (graph,) = pydot.graph_from_dot_data(o.getvalue())
        return self.bytes(graph.create_png(), content_type="image/png")