Move db querying logic to separate files

src/db/getDriverNames.ts

@@ -0,0 +1,16 @@
+import { db } from '.';
+
+export async function getDriverNames() {
+  const { records } = await db.executeQuery(
+    `MATCH (d:Driver)
+    RETURN
+      (d.forename + " " + d.surname) AS fullname
+    ORDER BY
+      toUpper(d.surname),
+      toUpper(d.forename)`
+  );
+
+  const driverNames = records.map((rec) => rec.get('fullname') as string);
+
+  return driverNames;
+}

src/db/getShortestPaths.ts

@@ -0,0 +1,64 @@
+import type { Path } from 'neo4j-driver';
+import type { Edge, Node } from 'vis-network';
+import type { Driver } from '@/models/driver';
+
+import { db } from '.';
+
+export async function getShortestPaths(source: string, dest: string) {
+  let nodes: Node[] = [];
+  let edges: Edge[] = [];
+  let numPaths = 0;
+  let degsOfSeparation = 0;
+
+  const { records } = await db.executeQuery(
+    `MATCH (n:Driver)
+    WHERE
+      (n.forename + " " + n.surname) = $source
+      OR (n.forename + " " + n.surname) = $dest
+    WITH collect(n) AS nodes
+    UNWIND nodes AS s
+    UNWIND nodes AS d
+    WITH *
+    WHERE
+      (s.forename + " " + s.surname) = $source
+      AND (d.forename + " " + d.surname) = $dest
+    MATCH path = allShortestPaths((s)-[*..20]-(d))
+    RETURN path`,
+    { source, dest }
+  );
+
+  numPaths = records.length;
+  degsOfSeparation =
+    records.length > 0 ? (records[0].get('path') as Path).length : 0;
+
+  const pairsOfRelatedDrivers = records.flatMap((rec) =>
+    (rec.get('path') as Path).segments.map(
+      ({ start, end }) => [start.properties, end.properties] as Driver[]
+    )
+  );
+
+  nodes = [
+    ...new Map(
+      pairsOfRelatedDrivers.flatMap((pair) =>
+        pair.map(({ driverId, forename, surname }) => [
+          driverId.toNumber(),
+          forename + ' ' + surname
+        ])
+      )
+    ).entries()
+  ].map(([id, label]) => ({ id, label }));
+
+  edges = [
+    ...new Set(
+      pairsOfRelatedDrivers.map(
+        ([from, to]) => from.driverId.toString() + '-' + to.driverId.toString()
+      )
+    ).values()
+  ].map((pair) => {
+    const [from, to] = pair.split('-').map(Number);
+
+    return { from, to };
+  });
+
+  return { nodes, edges, numPaths, degsOfSeparation };
+}