Refactor schema type handling and enhance utility functions in utils and database modules

This commit introduces several utility functions to improve schema type handling, including `getEmbeddedSchemaType` and `getObjectIdSchemaTypeFromPath`. The `getFilterFieldKind` function is updated to utilize these new utilities for better clarity and functionality. Additionally, the `getArrayParentPaths` function is renamed to `getArrayUnwindPaths` for improved readability, and the logic for fetching unique IDs is enhanced with a new `flattenRefIds` function. These changes streamline the code and enhance the overall management of schema references and array paths.

src/database/database.js

@@ -657,21 +657,26 @@ export const listPropertyValues = async ({ model, property, filter = {}, search
   return await model.aggregate(aggregateCommand);
 };
 
+function getEmbeddedSchemaType(path) {
+  if (!path) return null;
+  return path.embeddedSchemaType ?? path.$embeddedSchemaType ?? path.caster ?? null;
+}
+
 function getObjectRefPathInfo(model, property) {
   if (!model?.schema || !property) return null;
 
   const path = model.schema.path(property);
   if (!path) return null;
 
-  const schemaType = path.instance === 'Array' ? path.caster : path;
+  const schemaType = path.instance === 'Array' ? getEmbeddedSchemaType(path) : path;
   if (!schemaType) return null;
 
   const instance = schemaType.instance;
   if (instance !== 'ObjectID' && instance !== 'ObjectId') return null;
 
   return {
-    ref: schemaType.options?.ref,
-    refPath: schemaType.options?.refPath,
+    ref: schemaType.options?.ref ?? path.options?.ref,
+    refPath: schemaType.options?.refPath ?? path.options?.refPath,
   };
 }
 
@@ -690,28 +695,52 @@ function inferTypeFieldFromRefFunction(refFn) {
   return matches.find((name) => name.endsWith('Type') || name === 'type') || matches[0] || null;
 }
 
-function getArrayParentPaths(model, property) {
-  if (!model?.schema || !property?.includes('.')) return [];
+function getArrayUnwindPaths(model, property) {
+  if (!model?.schema || !property) return [];
 
-  const parents = [];
+  const paths = [];
   const parts = property.split('.');
   for (let i = 1; i < parts.length; i++) {
     const parentPath = parts.slice(0, i).join('.');
     const parentSchemaPath = model.schema.path(parentPath);
     if (parentSchemaPath?.instance === 'Array') {
-      parents.push(parentPath);
+      paths.push(parentPath);
     }
   }
-  return parents;
+
+  const path = model.schema.path(property);
+  if (path?.instance === 'Array') {
+    paths.push(property);
+  }
+  return paths;
+}
+
+function flattenRefIds(ids) {
+  const flattened = [];
+  const visit = (value) => {
+    if (value == null) return;
+    if (Array.isArray(value)) {
+      value.forEach(visit);
+      return;
+    }
+    if (
+      typeof value === 'object' &&
+      !(value instanceof mongoose.Types.ObjectId) &&
+      !(value instanceof Date) &&
+      value._id != null
+    ) {
+      visit(value._id);
+      return;
+    }
+    flattened.push(value);
+  };
+  visit(ids);
+  return flattened;
 }
 
 async function fetchBasicObjectsByIds(refName, ids) {
   const uniqueIds = [
-    ...new Map(
-      (ids || [])
-        .filter((id) => id != null)
-        .map((id) => [id.toString(), id])
-    ).values(),
+    ...new Map(flattenRefIds(ids).map((id) => [id.toString(), id])).values(),
   ];
   if (uniqueIds.length === 0) return [];
 
@@ -762,10 +791,10 @@ export const getPropertyValues = async ({ model, property, filter = {} }) => {
         pipeline.push({ $match: convertedFilter });
       }
 
-      for (const parentPath of getArrayParentPaths(model, property)) {
+      for (const unwindPath of getArrayUnwindPaths(model, property)) {
         pipeline.push({
           $unwind: {
-            path: `$${parentPath}`,
+            path: `$${unwindPath}`,
             preserveNullAndEmptyArrays: false,
           },
         });
@@ -803,6 +832,28 @@ export const getPropertyValues = async ({ model, property, filter = {} }) => {
   }
 
   if (hasFixedRef) {
+    const unwindPaths = getArrayUnwindPaths(model, property);
+    if (unwindPaths.length > 0) {
+      const pipeline = [];
+      if (Object.keys(convertedFilter).length > 0) {
+        pipeline.push({ $match: convertedFilter });
+      }
+      for (const unwindPath of unwindPaths) {
+        pipeline.push({
+          $unwind: {
+            path: `$${unwindPath}`,
+            preserveNullAndEmptyArrays: false,
+          },
+        });
+      }
+      pipeline.push(
+        { $match: { [property]: { $ne: null } } },
+        { $group: { _id: `$${property}` } }
+      );
+      const ids = (await model.aggregate(pipeline)).map((row) => row._id);
+      return fetchBasicObjectsByIds(pathInfo.ref, ids);
+    }
+
     const ids = await model.distinct(property, convertedFilter);
     return fetchBasicObjectsByIds(pathInfo.ref, ids);
   }

src/utils.js

@@ -93,8 +93,19 @@ function getBaseProperty(property) {
   return property;
 }
 
-function isObjectIdSchemaType(path) {
-  return path?.instance === 'ObjectId' || path?.instance === 'ObjectID';
+function getEmbeddedSchemaType(path) {
+  if (!path) return null;
+  return path.embeddedSchemaType ?? path.$embeddedSchemaType ?? path.caster ?? null;
+}
+
+function getObjectIdSchemaTypeFromPath(path) {
+  if (!path) return null;
+  const schemaType = path.instance === 'Array' ? getEmbeddedSchemaType(path) : path;
+  if (!schemaType) return null;
+  if (schemaType.instance === 'ObjectId' || schemaType.instance === 'ObjectID') {
+    return schemaType;
+  }
+  return null;
 }
 
 function getSchemaPathFromModels(property, model = null) {
@@ -112,12 +123,14 @@ function getFilterFieldKind(property, model = null) {
   const inspectPath = (path) => {
     if (!path) return null;
 
-    if (isObjectIdPath(property) || isObjectIdSchemaType(path)) {
-      if (property.endsWith('._id') && property !== '_id' && path.options?.ref) {
+    const objectIdType = getObjectIdSchemaTypeFromPath(path);
+    if (isObjectIdPath(property) || objectIdType) {
+      const ref = objectIdType?.options?.ref ?? path.options?.ref;
+      if (property.endsWith('._id') && property !== '_id' && ref) {
         return { kind: 'objectId', property: baseProperty };
       }
-      if (path.options?.ref) {
-        return { kind: 'objectRef', property: baseProperty, ref: path.options.ref };
+      if (ref) {
+        return { kind: 'objectRef', property: baseProperty, ref };
       }
       return { kind: 'objectId', property: baseProperty };
     }
@@ -162,7 +175,8 @@ function buildRegexOp(pattern, useOptions = true) {
 function getSchemaRefName(property, model = null) {
   const baseProperty = getBaseProperty(property);
   const path = model?.schema?.path(baseProperty) ?? getSchemaPathFromModels(baseProperty);
-  return path?.options?.ref ?? path?.caster?.options?.ref ?? null;
+  const embeddedType = getEmbeddedSchemaType(path);
+  return path?.options?.ref ?? embeddedType?.options?.ref ?? null;
 }
 
 function getRefModelEntryFromSchemaRef(refName) {