\chapter{Design}\label{ch:design}

We now explain the design of Birdvisu in depth. First, we explain some
important decisions and present the overall structure of the project, then we
look into individual parts of the program.

Birdvisu is implemented in Python, using PySide6, the official bindings for
Qt6, for drawing on screen. We decided to use Qt, because it provides a lot of
pre-made widgets and tools and since it is widely used, it is easy to find help
for it on the Internet. The decision to use Python was not hard either. Not
only Qt has official bindings for it, but we use the language very often and
thus are comfortable writing in it. We do not expect the potential slowness of
Python to be an issue, because for handling graphics we are using Qt, which is
written in C++. Also, as we have analysed in section~\ref{s:areas}, we expect
the topologies to be quite small.

The project comprises of three main parts: data collection, annotation and
presentation part. The data collection part is tasked with finding out the
current topology and creating a usable representation of such topologies and
their combinations. In the annotation part, we add additional information to
the topologies like the difference from the expectation or graph properties of
the topology. Finally, when we have all the needed information, we draw the
topology on the screen, highlighting the relevant information.

\section{Recurring and general patterns}

\XXX{dictionaries everywhere, hashable recipes. ospffile with comments as a reusable format. Format of VertexID}

\section{Data collection: providers and parsing}

\XXX{sub-parts, why a topology is not a graph, stacking topologies with
multiedges, fake-freezing, why is everything static. Graph representation, selection of BIRD's
instance}

\section{Annotations}

\XXX{scoping, annotator creation, advantages of storing data in annotations and
not vertices. Annotator protocol and posibility of export. Various uses of annotators: enhancing, analysis, visualisation}

\section{Visualisation}

\XXX{Layouting (nonexistent), why not graphviz, why not consensual metrics, how we are re-using annotations internally. Saving layouts}