Start region work

api/s32_virtual_district.py

@@ -0,0 +1,65 @@
+from .database import *
+
+
+def generate_virtual_district(name: str, centers: list[str]):
+    i = 0
+    node_index: dict[str, int] = {}
+    rows = read_all(name, 'select id from _node')
+    for row in rows:
+        i += 1
+        node_index[str(row['id'])] = i
+
+    write(name, 'drop table if exists vd_graph')
+    write(name, 'create table vd_graph (id serial, source integer, target integer, cost numeric)')
+
+    pipes = read_all(name, 'select node1, node2, length from pipes')
+    for pipe in pipes:
+        source = node_index[str(pipe['node1'])]
+        target = node_index[str(pipe['node2'])]
+        cost = float(pipe['length'])
+        write(name, f"insert into vd_graph (source, target, cost) values ({source}, {target}, {cost})")
+    pumps = read_all(name, 'select node1, node2 from pumps')
+    for pump in pumps:
+        source = node_index[str(pump['node1'])]
+        target = node_index[str(pump['node2'])]
+        write(name, f"insert into vd_graph (source, target, cost) values ({source}, {target}, 0.0)")
+    valves = read_all(name, 'select node1, node2 from valves')
+    for valve in valves:
+        source = node_index[str(valve['node1'])]
+        target = node_index[str(valve['node2'])]
+        write(name, f"insert into vd_graph (source, target, cost) values ({source}, {target}, 0.0)")
+
+    node_distance: dict[str, dict[str, Any]] = {}
+    for center in centers:
+        for node, index in node_index.items():
+            if node == center:
+                continue
+            # TODO: check none
+            distance = float(read(name, f"select max(agg_cost) as distance from pgr_dijkstraCost('select id, source, target, cost from vd_graph', {index}, {node_index[center]}, false)")['distance'])
+            if node not in node_distance:
+                node_distance[node] = { 'center': center, 'distance' : distance }
+            elif distance < node_distance[node]['distance']:
+                node_distance[node] = { 'center': center, 'distance' : distance }
+
+    write(name, 'drop table vd_graph')
+
+    center_node: dict[str, list[str]] = {}
+    for node, value in node_distance.items():
+        if value['center'] not in center_node:
+            center_node[value['center']] = []
+        center_node[value['center']].append(node)
+
+    write(name, 'delete from virtual_district')
+
+    for center, value in center_node.items():
+        write(name, f'drop table if exists vd_{center}')
+        write(name, f'create table vd_{center} (node varchar(32) primary key references _node(id))')
+
+        for node in value:
+            write(name, f"insert into vd_{center} values ('{node}')")
+
+        # TODO: check none
+        boundary = read(name, f'select st_astext(st_convexhull(st_collect(array(select coord from coordinates where node in (select * from vd_{center}))))) as boundary' )['boundary']
+        write(name, f"insert into virtual_district (id, center, boundary) values ('vd_{center}', '{center}', st_geomfromtext('{boundary}'))")
+
+        write(name, f'drop table vd_{center}')