From 34cfe8ca9d9d4465e9166db684bee3e258da1322 Mon Sep 17 00:00:00 2001
From: javibookline <98887695+javibookline@users.noreply.github.com>
Date: Wed, 7 Aug 2024 16:02:24 +0200
Subject: [PATCH] Handle cases where gateway query at account level returns
 more than one (#135)

* Handle cases where gateway query at account level returns more than one

* Change constant variable as it needs to be reassigned

* Fix mistake for handling case where sql query returned no match

* grammar

* Fix linting errors

* Avoid checking for duplicates in case there is only one match to avoid stringifying+parsing for nothing
---
 lib/db-utils.js | 48 ++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 40 insertions(+), 8 deletions(-)

diff --git a/lib/db-utils.js b/lib/db-utils.js
index 6999c5a..2b0a81c 100644
--- a/lib/db-utils.js
+++ b/lib/db-utils.js
@@ -173,21 +173,51 @@ module.exports = (srf, logger) => {
         const gw = gwAcc
           .concat(gwSP)
           .sort((a, b) => b.netmask - a.netmask);
-        const selected = gw.find(gatewayMatchesSourceAddress.bind(null, logger, req.source_address));
-        if (selected) {
+        const gateways = gw.filter(gatewayMatchesSourceAddress.bind(null, logger, req.source_address));
+        let voip_carriers = gateways.map((gw) => {
+          return {
+            voip_carrier_sid: gw.voip_carrier_sid,
+            name: gw.name,
+            service_provider_sid: gw.service_provider_sid,
+            account_sid: gw.account_sid,
+            application_sid: gw.application_sid
+          };
+        });
+        /* remove duplicates, winnow down to voip_carriers, not gateways */
+        if (voip_carriers.length > 1) {
+          voip_carriers = [...new Set(voip_carriers.map(JSON.stringify))].map(JSON.parse);
+        }
+        if (voip_carriers.length) {
+          /* we have one or more matches.  Now check for one with a provisioned phone number matching the DID */
+          const vc_sids = voip_carriers.map((m) => `'${m.voip_carrier_sid}'`).join(',');
           const sql =
-            `SELECT application_sid FROM phone_numbers WHERE number = '${did}'
-            AND voip_carrier_sid = '${selected.voip_carrier_sid}'
+            `SELECT * FROM phone_numbers WHERE number = '${did}'
+            AND voip_carrier_sid IN (${vc_sids})
             AND account_sid = '${a[0].account_sid}'`;
-          logger.debug({selected, sql, did}, 'looking up DID');
+          logger.debug({voip_carriers, sql, did}, 'looking up DID');
+
           const [r] = await pp.query(sql);
+          if (r.length > 1) {
+            logger.info({r},
+              'multiple carriers with the same gateway have the same number provisioned for the same account'
+              + ' -- cannot determine which one to use');
+            return {
+              fromCarrier: true,
+              error: 'Multiple carriers with the same gateway are attempting to route the same number for this account'
+            };
+          }
 
+          /**
+           * We have one or no routes for this phone number, carrier and account combination
+           * Either take the matching gateway, or if no route has matched, the first gateway of the ones available.
+          */
+          const gateway = r[0] ? gateways.find((m) => m.voip_carrier_sid === r[0]?.voip_carrier_sid) : gateways[0];
           return {
             fromCarrier: true,
-            gateway: selected,
+            gateway: gateway,
             service_provider_sid: a[0].service_provider_sid,
             account_sid: a[0].account_sid,
-            application_sid: r[0]?.application_sid || selected.application_sid,
+            application_sid: r[0]?.application_sid || gateway.application_sid,
             account: a[0]
           };
         }
@@ -274,7 +304,9 @@ module.exports = (srf, logger) => {
           };
         });
       /* remove duplicates, winnow down to voip_carriers, not gateways */
-      matches = [...new Set(matches.map(JSON.stringify))].map(JSON.parse);
+      if (matches.length > 1) {
+        matches = [...new Set(matches.map(JSON.stringify))].map(JSON.parse);
+      }
       if (matches.length) {
         /* we have one or more matches.  Now check for one with a provisioned phone number matching the DID */
         const vc_sids = matches.map((m) => `'${m.voip_carrier_sid}'`).join(',');