Start reimplementing poor_mans_visualisation.py

This script serves as a simple demonstration of how to use birdvisu.
Over time, it should become shorter, as more of its features are
integrated into birdvisu itself, until at last it becomes only a very
thin wrapper.

The functionality will probably be incorporated into some core /
orchestrator birdvisu module, but there is no such thing yet.

poor_mans_visualisation.py

@@ -3,75 +3,63 @@
 # Get topologies
 
 import sys
-from birdvisu import maps_new
-from birdvisu.maps_new import providers
+from birdvisu.providers import BirdSocketTopologyProvider, OspfFileTopologyProvider
+
 
 ref_topo_file = 'reference.ospf'
 if len(sys.argv) > 1:
 	ref_topo_file = sys.argv[1]
 
-with open(ref_topo_file) as ref_file:
-	ref_topo = providers.OspfFileTopologyProvider(ref_file).get_topology()
+ref_topo = OspfFileTopologyProvider(ref_topo_file).get_topology()
 
 try:
-	cur_topo = providers.BirdSocketTopologyProvider().get_topology()
-except OSError:
-	# HACK!
-	import traceback as tb
-	tb.print_exc(file=sys.stderr)
-	print(f'Could not get current topology from BIRD,\n'
-		'will load reference one with random omissions\n----', file=sys.stderr)
-	with open(ref_topo_file) as ref_file:
-		cur_topo = providers.OspfFileTopologyProvider(ref_file).get_topology()
-	import random
-	random.seed('birdvisu_demo')
-	# Routers:
-	for _ in range(random.randint(1, 3)):
-		key, router_to_delete = random.choice(list(cur_topo.routers.items()))
-		for l in router_to_delete.links:
-			lk = (l.router.ident, l.network.ident)
-			del cur_topo.links[lk]
-			l.network.links.remove(l)
-		del cur_topo.routers[key]
-	# Networks:
-	for _ in range(random.randint(1, 3)):
-		key, network_to_delete = random.choice(list(cur_topo.networks.items()))
-		for l in network_to_delete.links:
-			lk = (l.router.ident, l.network.ident)
-			del cur_topo.links[lk]
-			l.router.links.remove(l)
-		del cur_topo.networks[key]
-	# Links:
-	for _ in range(random.randint(1, 3)):
-		key, link_to_delete = random.choice(list(cur_topo.links.items()))
-		link_to_delete.router.links.remove(link_to_delete)
-		link_to_delete.network.links.remove(link_to_delete)
-		del cur_topo.links[key]
-
-
-
-# Combine topologies
-
-combiner = maps_new.TopologyCombiner()
-# NOTE: the following string literals convey meaning for annotators, so they
-# should not be changed carelessly.
-combiner.add_topology('reference', ref_topo)
-combiner.add_topology('actual', cur_topo)
-
-final_topo = combiner.get_complete_topology()
+	cur_topo = BirdSocketTopologyProvider(instance='ospfv2', area=1).get_topology()
+except OSError as e:
+	raise NotImplementedError('Cannot create a mock topology atm') from e
+
+# Create combined topology
+
+from birdvisu.topo_v3 import TopologyV3
+
+combined_topology = TopologyV3.combine_topologies(reference=ref_topo, current=cur_topo)
+combined_topology.freeze()
 
 # Annotate it
 
+from birdvisu.topo_v3 import VertexID
+from birdvisu.annotations import AnnotatedTopology, AnnotatorID
+from birdvisu.annotations.analysis import TopologyDifference, ShortestPathTree
+from ipaddress import IPv4Address
+
+annot_topo = AnnotatedTopology(combined_topology)
+annotators = [
+	AnnotatorID(TopologyDifference),
+	AnnotatorID(ShortestPathTree, (VertexID(
+		family=None,
+		is_router=True,
+		address=None,
+		router_id=int(IPv4Address('172.23.100.10')),
+		dr_id=None,
+		discriminator=None
+		), 'current')),
+	]
+for ann_id in annotators:
+	annot_topo.run_annotator(ann_id)
+
+# ---
+
+# Show it
+
 from birdvisu.visualisation import annotators
+from birdvisu import maps_new
 
 # annotators.create_qgritems does not like being run without Qt initialization.
 from PySide6 import QtCore, QtGui, QtWidgets
 app = QtWidgets.QApplication([])
 
-annotated_topology = maps_new.annotate_topology(final_topo,
+annotated_topology = maps_new.annotate_topology(combined_topology,
 			# A semi-canonical set of annotators:
 			[
-				annotators.difference_annotator,
 				annotators.extract_positions,
 				annotators.random_position,
 				annotators.assign_brushes,