From 7e96d4c089d97ee402466fabf5d2de97cf32de8c Mon Sep 17 00:00:00 2001
From: Tim Graham <timograham@gmail.com>
Date: Fri, 27 Dec 2024 20:24:34 -0500
Subject: [PATCH] fix expressions in array lookups

---
 django_mongodb/expressions.py  |  3 +++
 django_mongodb/features.py     |  5 +----
 django_mongodb/fields/array.py | 34 +++++++++++++++-------------------
 3 files changed, 19 insertions(+), 23 deletions(-)

diff --git a/django_mongodb/expressions.py b/django_mongodb/expressions.py
index bf4bf23b..b6268a1c 100644
--- a/django_mongodb/expressions.py
+++ b/django_mongodb/expressions.py
@@ -204,6 +204,9 @@ def when(self, compiler, connection):
 
 def value(self, compiler, connection):  # noqa: ARG001
     value = self.value
+    # TODO: check this, not sure $literal is needed for all cases.
+    if isinstance(value, datetime.datetime):
+        return value
     if isinstance(value, Decimal):
         value = Decimal128(value)
     elif isinstance(value, datetime.date):
diff --git a/django_mongodb/features.py b/django_mongodb/features.py
index 0e29b200..c077fe69 100644
--- a/django_mongodb/features.py
+++ b/django_mongodb/features.py
@@ -82,13 +82,10 @@ class DatabaseFeatures(BaseDatabaseFeatures):
         "auth_tests.test_views.LoginTest.test_login_session_without_hash_session_key",
         # GenericRelation.value_to_string() assumes integer pk.
         "contenttypes_tests.test_fields.GenericRelationTests.test_value_to_string",
-        # contains with expressions/subqueries doesn't work.
-        "model_fields_.test_arrayfield.TestQuerying.test_contains_including_expression",
+        # contains with subqueries doesn't work.
         "model_fields_.test_arrayfield.TestQuerying.test_contains_subquery",
         # Unsupported conversion from array to string in $convert
         "model_fields_.test_arrayfield.TestQuerying.test_icontains",
-        # Field 'field' expected a number but got Value(1).
-        "model_fields_.test_arrayfield.TestQuerying.test_exact_with_expression",
         # $lt treats null values as zero.
         "model_fields_.test_arrayfield.TestQuerying.test_lt",
         "model_fields_.test_arrayfield.TestQuerying.test_len",
diff --git a/django_mongodb/fields/array.py b/django_mongodb/fields/array.py
index 938dadfe..a2c29afc 100644
--- a/django_mongodb/fields/array.py
+++ b/django_mongodb/fields/array.py
@@ -4,7 +4,7 @@
 from django.core import checks, exceptions
 from django.db.models import DecimalField, Field, Func, IntegerField, Transform, Value
 from django.db.models.fields.mixins import CheckFieldDefaultMixin
-from django.db.models.lookups import FieldGetDbPrepValueMixin, In, Lookup
+from django.db.models.lookups import Exact, FieldGetDbPrepValueMixin, In, Lookup
 from django.utils.translation import gettext_lazy as _
 
 from django_mongodb.forms import SimpleArrayField
@@ -235,6 +235,11 @@ def formfield(self, **kwargs):
         )
 
 
+class Array(Func):
+    def as_mql(self, compiler, connection):
+        return [expr.as_mql(compiler, connection) for expr in self.get_source_expressions()]
+
+
 class ArrayRHSMixin:
     def __init__(self, lhs, rhs):
         # Don't wrap arrays that contains only None values, psycopg doesn't
@@ -246,18 +251,9 @@ def __init__(self, lhs, rhs):
                     field = lhs.output_field
                     value = Value(field.base_field.get_prep_value(value))
                 expressions.append(value)
-            rhs = Func(
-                *expressions,
-                function="ARRAY",
-                template="%(function)s[%(expressions)s]",
-            )
+            rhs = Array(*expressions)
         super().__init__(lhs, rhs)
 
-    def process_rhs(self, compiler, connection):
-        rhs, rhs_params = super().process_rhs(compiler, connection)
-        cast_type = self.lhs.output_field.cast_db_type(connection)
-        return f"{rhs}::{cast_type}", rhs_params
-
     def _rhs_not_none_values(self, rhs):
         for x in rhs:
             if isinstance(x, list | tuple):
@@ -267,29 +263,29 @@ def _rhs_not_none_values(self, rhs):
 
 
 @ArrayField.register_lookup
-class ArrayContains(FieldGetDbPrepValueMixin, Lookup):
+class ArrayContains(ArrayRHSMixin, FieldGetDbPrepValueMixin, Lookup):
     lookup_name = "contains"
 
     def as_mql(self, compiler, connection):
         lhs_mql = process_lhs(self, compiler, connection)
         value = process_rhs(self, compiler, connection)
         return {
-            "$gt": [
+            "$eq": [
                 {
                     "$cond": {
                         "if": {"$eq": [lhs_mql, None]},
-                        "then": None,
-                        "else": {"$size": {"$setIntersection": [lhs_mql, value]}},
+                        "then": False,
+                        "else": {"$setIsSubset": [value, lhs_mql]},
                     }
                 },
-                0,
+                True,
             ]
         }
 
 
-# @ArrayField.register_lookup
-# class ArrayExact(ArrayRHSMixin, Exact):
-#     pass
+@ArrayField.register_lookup
+class ArrayExact(ArrayRHSMixin, Exact):
+    pass
 
 
 @ArrayField.register_lookup