From a854a0dc0aa79a31695db833184c5ca3698632a9 Mon Sep 17 00:00:00 2001
From: Sam Atkins <atkinssj@gmail.com>
Date: Wed, 24 Apr 2024 12:27:26 +0100
Subject: [PATCH] feat: Implement 'Like' predicate in entity storage

This acts like the SQL 'LIKE' keyword, allowing partial string matches.
---
 packages/backend/src/om/entitystorage/SQLES.js | 18 +++++++++++++++++-
 packages/backend/src/om/query/query.js         | 10 ++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/packages/backend/src/om/entitystorage/SQLES.js b/packages/backend/src/om/entitystorage/SQLES.js
index 61b6eecb..ede60eb6 100644
--- a/packages/backend/src/om/entitystorage/SQLES.js
+++ b/packages/backend/src/om/entitystorage/SQLES.js
@@ -22,7 +22,7 @@ const { BaseES } = require("./BaseES");
 const APIError = require("../../api/APIError");
 const { Entity } = require("./Entity");
 const { WeakConstructorTrait } = require("../../traits/WeakConstructorTrait");
-const { And, Or, Eq, Predicate, Null, PredicateUtil } = require("../query/query");
+const { And, Or, Eq, Like, Null, Predicate, PredicateUtil } = require("../query/query");
 const { DB_WRITE } = require("../../services/database/consts");
 
 class RawCondition extends AdvancedBase {
@@ -355,6 +355,22 @@ class SQLES extends BaseES {
 
                 return new RawCondition({ sql, values });
             }
+
+            if ( om_query instanceof Like ) {
+                const key = om_query.key;
+                let value = om_query.value;
+                const prop = this.om.properties[key];
+
+                value = await prop.sql_reference(value);
+
+                const options = prop.descriptor.sql ?? {};
+                const col_name = options.column_name ?? prop.name;
+
+                const sql = `${col_name} LIKE ?`;
+                const values = [value];
+
+                return new RawCondition({ sql, values });
+            }
         }
     }
 }
diff --git a/packages/backend/src/om/query/query.js b/packages/backend/src/om/query/query.js
index 8817afde..4533076b 100644
--- a/packages/backend/src/om/query/query.js
+++ b/packages/backend/src/om/query/query.js
@@ -50,6 +50,15 @@ class Eq extends Predicate {
     }
 }
 
+class Like extends Predicate {
+    async check (entity) {
+        // Convert SQL LIKE pattern to RegExp
+        // TODO: Support escaping the pattern characters
+        const regex = new RegExp(this.value.replaceAll('%', '.*').replaceAll('_', '.'), 'i');
+        return regex.test(await entity.get(this.key));
+    }
+}
+
 Predicate.prototype.and = function (other) {
     return new And({ children: [this, other] });
 }
@@ -105,4 +114,5 @@ module.exports = {
     And,
     Or,
     Eq,
+    Like,
 };