implement api to fetch node neighbours

src/index.js

@@ -204,6 +204,62 @@ app.get('/api/v1/nodes/:nodeId/mqtt-metrics', async (req, res) => {
     }
 });
 
+app.get('/api/v1/nodes/:nodeId/neighbours', async (req, res) => {
+    try {
+
+        const nodeId = parseInt(req.params.nodeId);
+
+        // find node
+        const node = await prisma.node.findFirst({
+            where: {
+                node_id: nodeId,
+            },
+        });
+
+        // make sure node exists
+        if(!node){
+            res.status(404).json({
+                message: "Not Found",
+            });
+            return;
+        }
+
+        // get nodes from db that have this node as a neighbour
+        const nodesThatHeardUs = await prisma.node.findMany({
+            where: {
+                neighbours: {
+                    array_contains: {
+                        node_id: Number(nodeId),
+                    },
+                },
+            },
+        });
+
+        res.json({
+            nodes_that_we_heard: node.neighbours.map((neighbour) => {
+                return {
+                    ...neighbour,
+                    updated_at: node.neighbours_updated_at,
+                };
+            }),
+            nodes_that_heard_us: nodesThatHeardUs.map((nodeThatHeardUs) => {
+                const neighbourInfo = nodeThatHeardUs.neighbours.find((neighbour) => neighbour.node_id.toString() === node.node_id.toString());
+                return {
+                    node_id: Number(nodeThatHeardUs.node_id),
+                    snr: neighbourInfo.snr,
+                    updated_at: nodeThatHeardUs.neighbours_updated_at,
+                };
+            }),
+        });
+
+    } catch(err) {
+        console.error(err);
+        res.status(500).json({
+            message: "Something went wrong, try again later.",
+        });
+    }
+});
+
 app.get('/api/v1/nodes/:nodeId/traceroutes', async (req, res) => {
     try {