fix: allow use of a list of values for field filtering, and format

src/main/kotlin/com/ctrlhub/core/router/request/FilterExpression.kt

@@ -4,8 +4,22 @@ sealed interface FilterOption {
     fun format(): String
 }
 
-class FieldFilterExpression(val field: String, val value: String) : FilterOption {
-    override fun format(): String = "${field}('$value')"
+class FieldFilterExpression<T>(val field: String, val value: T) : FilterOption {
+    private fun quoteIfNeeded(v: Any?): String = when (v) {
+        is String -> "'${v.replace("'", "\\'")}'"
+        null -> "''"
+        else -> v.toString()
+    }
+
+    override fun format(): String {
+        return when (value) {
+            is List<*> -> {
+                val inner = value.joinToString(",") { quoteIfNeeded(it) }
+                "$field($inner)"
+            }
+            else -> "$field(${quoteIfNeeded(value)})"
+        }
+    }
 }
 
 class ValueFilterExpression(val value: String) : FilterOption {
@@ -16,6 +30,7 @@ class AndExpression(val parts: List<FilterOption>) : FilterOption {
     override fun format(): String = "and(${parts.joinToString(",") { it.format() }})"
 }
 
+@Suppress("unused")
 class OrExpression(val parts: List<FilterOption>) : FilterOption {
     override fun format(): String = "or(${parts.joinToString(",") { it.format() }})"
 }

src/test/kotlin/com/ctrlhub/core/router/request/RequestParametersFiltersTest.kt

@@ -49,5 +49,45 @@ class RequestParametersFiltersTest {
 
         assertEquals("and(status('active'),is_latest())", map["filter"])
     }
-}
 
+    @Test
+    fun `field list formats correctly`() {
+        val ids = listOf(
+            "06e55d1c-f816-48b2-b11b-debdb3115b2f",
+            "5f43b904-8d5b-4b81-9258-b14aafe858d4",
+            "9b31bdd1-2785-4419-b1b3-36ccd35d22c6"
+        )
+
+        val expr = FieldFilterExpression("payload_operations", ids)
+        val params = RequestParameters(filters = listOf(expr))
+        val map = params.toMap()
+
+        assertEquals(
+            "payload_operations('06e55d1c-f816-48b2-b11b-debdb3115b2f','5f43b904-8d5b-4b81-9258-b14aafe858d4','9b31bdd1-2785-4419-b1b3-36ccd35d22c6')",
+            map["filter"]
+        )
+    }
+
+    @Test
+    fun `or of field list and single field formats correctly`() {
+        val ids = listOf(
+            "06e55d1c-f816-48b2-b11b-debdb3115b2f",
+            "5f43b904-8d5b-4b81-9258-b14aafe858d4"
+        )
+
+        val expr = OrExpression(
+            listOf(
+                FieldFilterExpression("payload_operations", ids),
+                FieldFilterExpression("category", "updates")
+            )
+        )
+
+        val params = RequestParameters(filters = listOf(expr))
+        val map = params.toMap()
+
+        assertEquals(
+            "or(payload_operations('06e55d1c-f816-48b2-b11b-debdb3115b2f','5f43b904-8d5b-4b81-9258-b14aafe858d4'),category('updates'))",
+            map["filter"]
+        )
+    }
+}