feat(llc): Add location-based filtering support (#22)

Author: xsahil03x

packages/stream_core/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ### ✨ Features
 
+- Added location-based filtering support with `LocationCoordinate`, `Distance`, `CircularRegion`,
+  and `BoundingBox`
 - Added `insertAt` parameter to `upsert` for controlling insertion position of new elements
 
 ## 0.3.1

packages/stream_core/lib/src/query.dart

@@ -1,3 +1,7 @@
-export 'query/filter.dart';
-export 'query/filter_operator.dart';
+export 'query/filter/filter.dart';
+export 'query/filter/filter_operator.dart';
+export 'query/filter/location/bounding_box.dart';
+export 'query/filter/location/circular_region.dart';
+export 'query/filter/location/distance.dart';
+export 'query/filter/location/location_coordinate.dart';
 export 'query/sort.dart';

…es/stream_core/lib/src/query/filter.dart …am_core/lib/src/query/filter/filter.dartpackages/stream_core/lib/src/query/filter.dart renamed to packages/stream_core/lib/src/query/filter/filter.dart packages/stream_core/lib/src/query/filter.dart renamed to packages/stream_core/lib/src/query/filter/filter.dart

@@ -1,6 +1,9 @@
-import '../utils.dart';
+import '../../utils.dart';
 import 'filter_operation_utils.dart';
 import 'filter_operator.dart';
+import 'location/bounding_box.dart';
+import 'location/circular_region.dart';
+import 'location/location_coordinate.dart';
 
 /// Function that extracts a field value from a model instance.
 ///
@@ -217,7 +220,13 @@ sealed class ComparisonOperator<T extends Object> extends Filter<T> {
   @override
   Map<String, Object?> toJson() {
     return {
-      field.remote: {operator: value},
+      field.remote: {
+        operator: switch (value) {
+          final BoundingBox bbox => bbox.toJson(),
+          final CircularRegion region => region.toJson(),
+          _ => value,
+        },
+      },
     };
   }
 }
@@ -243,6 +252,15 @@ final class EqualOperator<T extends Object> extends ComparisonOperator<T> {
     // NULL values can't be compared.
     if (fieldValue == null || comparisonValue == null) return false;
 
+    // Special case for location coordinates
+    if (fieldValue is LocationCoordinate) {
+      final isNear = fieldValue.isNear(comparisonValue);
+      final isWithinBounds = fieldValue.isWithinBounds(comparisonValue);
+
+      // Match if either near or within bounds
+      return isNear || isWithinBounds;
+    }
+
     // Deep equality: order-sensitive for arrays, order-insensitive for objects.
     return fieldValue.deepEquals(comparisonValue);
   }

…ib/src/query/filter_operation_utils.dart …query/filter/filter_operation_utils.dartpackages/stream_core/lib/src/query/filter_operation_utils.dart renamed to packages/stream_core/lib/src/query/filter/filter_operation_utils.dart packages/stream_core/lib/src/query/filter_operation_utils.dart renamed to packages/stream_core/lib/src/query/filter/filter_operation_utils.dart

@@ -1,5 +1,10 @@
 import 'package:collection/collection.dart';
 
+import 'location/bounding_box.dart';
+import 'location/circular_region.dart';
+import 'location/distance.dart';
+import 'location/location_coordinate.dart';
+
 // Deep equality checker.
 //
 // Maps are always compared with key-order-insensitivity (MapEquality).
@@ -86,3 +91,69 @@ extension JSONContainmentExtension<K, V> on Map<K, V> {
     });
   }
 }
+
+/// Extension methods for location-based filtering.
+extension LocationEqualityExtension on LocationCoordinate {
+  /// Returns `true` if this coordinate is within a [CircularRegion].
+  ///
+  /// Supports both [CircularRegion] objects and Map representations with
+  /// keys: 'lat', 'lng', 'distance' (in kilometers).
+  bool isNear(Object? other) {
+    // Check for CircularRegion instance.
+    if (other is CircularRegion) return other.contains(this);
+
+    // Check for Map representation.
+    if (other is Map) {
+      final lat = (other['lat'] as num?)?.toDouble();
+      if (lat == null) return false;
+
+      final lng = (other['lng'] as num?)?.toDouble();
+      if (lng == null) return false;
+
+      final distance = (other['distance'] as num?)?.toDouble();
+      if (distance == null) return false;
+
+      final region = CircularRegion(
+        radius: distance.kilometers,
+        center: LocationCoordinate(latitude: lat, longitude: lng),
+      );
+
+      return region.contains(this);
+    }
+
+    return false;
+  }
+
+  /// Returns `true` if this coordinate is within a [BoundingBox].
+  ///
+  /// Supports both [BoundingBox] objects and Map representations with
+  /// keys: 'ne_lat', 'ne_lng', 'sw_lat', 'sw_lng'.
+  bool isWithinBounds(Object? other) {
+    // Check for BoundingBox instance.
+    if (other is BoundingBox) return other.contains(this);
+
+    // Check for Map representation.
+    if (other is Map) {
+      final neLat = (other['ne_lat'] as num?)?.toDouble();
+      if (neLat == null) return false;
+
+      final neLng = (other['ne_lng'] as num?)?.toDouble();
+      if (neLng == null) return false;
+
+      final swLat = (other['sw_lat'] as num?)?.toDouble();
+      if (swLat == null) return false;
+
+      final swLng = (other['sw_lng'] as num?)?.toDouble();
+      if (swLng == null) return false;
+
+      final box = BoundingBox(
+        northEast: LocationCoordinate(latitude: neLat, longitude: neLng),
+        southWest: LocationCoordinate(latitude: swLat, longitude: swLng),
+      );
+
+      return box.contains(this);
+    }
+
+    return false;
+  }
+}

…_core/lib/src/query/filter_operator.dart …ib/src/query/filter/filter_operator.dartpackages/stream_core/lib/src/query/filter_operator.dart renamed to packages/stream_core/lib/src/query/filter/filter_operator.dart packages/stream_core/lib/src/query/filter_operator.dart renamed to packages/stream_core/lib/src/query/filter/filter_operator.dart

@@ -0,0 +1,64 @@
+import 'package:json_annotation/json_annotation.dart';
+
+import 'location_coordinate.dart';
+
+part 'bounding_box.g.dart';
+
+/// A rectangular geographic region for area-based location filtering.
+///
+/// Defined by northeast and southwest corners. Used for rectangular
+/// area queries such as map viewports or city boundaries.
+///
+/// ```dart
+/// final bbox = BoundingBox(
+///   northEast: LocationCoordinate(latitude: 37.8324, longitude: -122.3482),
+///   southWest: LocationCoordinate(latitude: 37.7079, longitude: -122.5161),
+/// );
+///
+/// final isInside = bbox.contains(point);
+/// ```
+@JsonSerializable(createFactory: false)
+class BoundingBox {
+  const BoundingBox({
+    required this.northEast,
+    required this.southWest,
+  });
+
+  /// The northeast corner of this bounding box.
+  @JsonKey(includeToJson: false)
+  final LocationCoordinate northEast;
+
+  /// The southwest corner of this bounding box.
+  @JsonKey(includeToJson: false)
+  final LocationCoordinate southWest;
+
+  /// The latitude of the northeast corner.
+  @JsonKey(name: 'ne_lat')
+  double get neLat => northEast.latitude;
+
+  /// The longitude of the northeast corner.
+  @JsonKey(name: 'ne_lng')
+  double get neLng => northEast.longitude;
+
+  /// The latitude of the southwest corner.
+  @JsonKey(name: 'sw_lat')
+  double get swLat => southWest.latitude;
+
+  /// The longitude of the southwest corner.
+  @JsonKey(name: 'sw_lng')
+  double get swLng => southWest.longitude;
+
+  /// Whether [point] is within this bounding box.
+  bool contains(LocationCoordinate point) {
+    var withinLatitude = point.latitude <= northEast.latitude;
+    withinLatitude &= point.latitude >= southWest.latitude;
+
+    var withinLongitude = point.longitude <= northEast.longitude;
+    withinLongitude &= point.longitude >= southWest.longitude;
+
+    return withinLatitude && withinLongitude;
+  }
+
+  /// Converts this bounding box to JSON.
+  Map<String, dynamic> toJson() => _$BoundingBoxToJson(this);
+}

packages/stream_core/lib/src/query/filter/location/bounding_box.dart

@@ -0,0 +1,56 @@
+import 'package:json_annotation/json_annotation.dart';
+
+import 'distance.dart';
+import 'location_coordinate.dart';
+
+part 'circular_region.g.dart';
+
+/// A circular geographic region for proximity-based location filtering.
+///
+/// Defined by a center point and radius. Used for geofencing and
+/// "near" location queries.
+///
+/// ```dart
+/// final region = CircularRegion(
+///   radius: 5.kilometers,
+///   center: LocationCoordinate(latitude: 37.7749, longitude: -122.4194),
+/// );
+///
+/// final isInside = region.contains(point);
+/// ```
+@JsonSerializable(createFactory: false)
+class CircularRegion {
+  const CircularRegion({
+    required this.radius,
+    required this.center,
+  });
+
+  /// The radius of this circular region.
+  @JsonKey(includeToJson: false)
+  final Distance radius;
+
+  /// The center coordinate of this circular region.
+  @JsonKey(includeToJson: false)
+  final LocationCoordinate center;
+
+  /// The latitude of the center point.
+  @JsonKey(name: 'lat')
+  double get lat => center.latitude;
+
+  /// The longitude of the center point.
+  @JsonKey(name: 'lng')
+  double get lng => center.longitude;
+
+  /// The radius in kilometers.
+  @JsonKey(name: 'distance')
+  double get distance => radius.inKilometers;
+
+  /// Whether [point] is within this circular region.
+  bool contains(LocationCoordinate point) {
+    final distance = center.distanceTo(point);
+    return distance <= radius;
+  }
+
+  /// Converts this circular region to JSON.
+  Map<String, dynamic> toJson() => _$CircularRegionToJson(this);
+}

packages/stream_core/lib/src/query/filter/location/bounding_box.g.dart

@@ -0,0 +1,23 @@
+/// A distance value with convenient unit conversions.
+///
+/// ```dart
+/// final distance1 = 1000.meters;  // 1000 meters
+/// final distance2 = 5.kilometers; // 5000 meters
+/// print(distance1.inKilometers);  // 1.0
+/// ```
+extension type const Distance._(double meters) implements double {
+  /// Creates a [Distance] from [meters].
+  const Distance.fromMeters(double meters) : this._(meters);
+
+  /// The distance in kilometers.
+  double get inKilometers => meters / 1000;
+}
+
+/// Extension methods on [num] for creating [Distance] values.
+extension DistanceExtension on num {
+  /// This value as a [Distance] in meters.
+  Distance get meters => Distance.fromMeters(toDouble());
+
+  /// This value as a [Distance] in kilometers.
+  Distance get kilometers => Distance.fromMeters(toDouble() * 1000);
+}