feat: Add location search

pkg/citydb/provider.go

@@ -35,7 +35,11 @@ func Open(path string) (Provider, error) {
 }
 
 func (p Provider) Close() error {
-	return p.db.Db.(*sql.DB).Close()
+	if err := p.db.Db.(*sql.DB).Close(); err != nil {
+		return fmt.Errorf("failed to close cities database: %w", err)
+	}
+
+	return nil
 }
 
 type locationRow struct {
@@ -46,6 +50,7 @@ type locationRow struct {
 	CountryCode    string  `db:"country_code"`
 	Latitude       float64 `db:"latitude"`
 	Longitude      float64 `db:"longitude"`
+	DistanceSq     float64 `db:"distance_sq"`
 }
 
 func (p Provider) SearchLocations(ctx context.Context, query string) ([]prayer.Location, error) {
@@ -66,6 +71,7 @@ func (p Provider) SearchLocations(ctx context.Context, query string) ([]prayer.L
 			goqu.I("country_code"),
 			goqu.I("latitude"),
 			goqu.I("longitude"),
+			goqu.V(0).As("distance_sq"),
 		).
 		Where(
 			goqu.Or(
@@ -97,3 +103,49 @@ func (p Provider) SearchLocations(ctx context.Context, query string) ([]prayer.L
 
 	return locations, nil
 }
+
+func (p Provider) SearchLocationsByCoords(ctx context.Context, coords prayer.Coordinates) ([]prayer.Location, error) {
+	q := p.db.
+		From("cities").
+		Select(
+			goqu.I("geoname_id"),
+			goqu.I("name"),
+			goqu.I("ascii_name"),
+			goqu.COALESCE(goqu.I("alternate_names"), "").As("alternate_names"),
+			goqu.I("country_code"),
+			goqu.I("latitude"),
+			goqu.I("longitude"),
+			goqu.L(
+				"((latitude - ?) * (latitude - ?) + (longitude - ?) * (longitude - ?))",
+				coords.Latitude,
+				coords.Latitude,
+				coords.Longitude,
+				coords.Longitude,
+			).As("distance_sq"),
+		).
+		Order(
+			goqu.I("distance_sq").Asc(),
+			goqu.I("population").Desc(),
+		).
+		Limit(50)
+
+	var rows []locationRow
+	if err := q.ScanStructsContext(ctx, &rows); err != nil {
+		return nil, fmt.Errorf("failed to query locations by coordinates from cities database: %w", err)
+	}
+
+	locations := make([]prayer.Location, 0, len(rows))
+	for _, row := range rows {
+		locations = append(locations, prayer.Location{
+			ID:             row.ID,
+			Name:           row.Name,
+			ASCIIName:      row.ASCIIName,
+			AlternateNames: row.AlternateNames,
+			CountryCode:    row.CountryCode,
+			Latitude:       row.Latitude,
+			Longitude:      row.Longitude,
+		})
+	}
+
+	return locations, nil
+}