init push

internal/shared/pkg/sortkey/sortkey.go

@@ -0,0 +1,32 @@
+package sortkey
+
+import "fmt"
+
+// ActivePositiveSortClauses builds ORDER BY clauses where non-negative sort keys
+// are treated as prioritized values. NULL/negative are grouped as empty values.
+func ActivePositiveSortClauses(tableAlias, activeColumn, sortKeyColumn, fallbackColumn string, descending bool) []string {
+	active := qualify(tableAlias, activeColumn)
+	sortKey := qualify(tableAlias, sortKeyColumn)
+	fallback := qualify(tableAlias, fallbackColumn)
+
+	valid := fmt.Sprintf("%s = 1 AND %s IS NOT NULL AND %s >= 0", active, sortKey, sortKey)
+
+	direction := "ASC"
+	if descending {
+		direction = "DESC"
+	}
+
+	return []string{
+		fmt.Sprintf("%s DESC", active),
+		fmt.Sprintf("CASE WHEN %s THEN 0 ELSE 1 END ASC", valid),
+		fmt.Sprintf("CASE WHEN %s THEN %s END %s", valid, sortKey, direction),
+		fmt.Sprintf("%s ASC", fallback),
+	}
+}
+
+func qualify(tableAlias, column string) string {
+	if tableAlias == "" {
+		return column
+	}
+	return tableAlias + "." + column
+}

internal/shared/pkg/sortkey/sortkey_test.go

@@ -0,0 +1,34 @@
+package sortkey
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestActivePositiveSortClauses(t *testing.T) {
+	t.Run("ascending without alias", func(t *testing.T) {
+		got := ActivePositiveSortClauses("", "is_active", "sortkey", "designation", false)
+		want := []string{
+			"is_active DESC",
+			"CASE WHEN is_active = 1 AND sortkey IS NOT NULL AND sortkey >= 0 THEN 0 ELSE 1 END ASC",
+			"CASE WHEN is_active = 1 AND sortkey IS NOT NULL AND sortkey >= 0 THEN sortkey END ASC",
+			"designation ASC",
+		}
+		if !reflect.DeepEqual(got, want) {
+			t.Fatalf("unexpected clauses: got=%v want=%v", got, want)
+		}
+	})
+
+	t.Run("descending with alias", func(t *testing.T) {
+		got := ActivePositiveSortClauses("helicopters", "is_active", "sortkey", "designation", true)
+		want := []string{
+			"helicopters.is_active DESC",
+			"CASE WHEN helicopters.is_active = 1 AND helicopters.sortkey IS NOT NULL AND helicopters.sortkey >= 0 THEN 0 ELSE 1 END ASC",
+			"CASE WHEN helicopters.is_active = 1 AND helicopters.sortkey IS NOT NULL AND helicopters.sortkey >= 0 THEN helicopters.sortkey END DESC",
+			"helicopters.designation ASC",
+		}
+		if !reflect.DeepEqual(got, want) {
+			t.Fatalf("unexpected clauses: got=%v want=%v", got, want)
+		}
+	})
+}