init commit

plugin/filter/filter.go

@@ -0,0 +1,48 @@
+package filter
+
+import (
+	"time"
+
+	"github.com/google/cel-go/cel"
+	"github.com/google/cel-go/common/types"
+	"github.com/google/cel-go/common/types/ref"
+	"github.com/pkg/errors"
+	exprv1 "google.golang.org/genproto/googleapis/api/expr/v1alpha1"
+)
+
+// MemoFilterCELAttributes are the CEL attributes for memo.
+var MemoFilterCELAttributes = []cel.EnvOption{
+	cel.Variable("content", cel.StringType),
+	cel.Variable("creator_id", cel.IntType),
+	cel.Variable("created_ts", cel.IntType),
+	cel.Variable("updated_ts", cel.IntType),
+	cel.Variable("pinned", cel.BoolType),
+	cel.Variable("tag", cel.StringType),
+	cel.Variable("tags", cel.ListType(cel.StringType)),
+	cel.Variable("visibility", cel.StringType),
+	cel.Variable("has_task_list", cel.BoolType),
+	// Current timestamp function.
+	cel.Function("now",
+		cel.Overload("now",
+			[]*cel.Type{},
+			cel.IntType,
+			cel.FunctionBinding(func(_ ...ref.Val) ref.Val {
+				return types.Int(time.Now().Unix())
+			}),
+		),
+	),
+}
+
+// Parse parses the filter string and returns the parsed expression.
+// The filter string should be a CEL expression.
+func Parse(filter string, opts ...cel.EnvOption) (expr *exprv1.ParsedExpr, err error) {
+	e, err := cel.NewEnv(opts...)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to create CEL environment")
+	}
+	ast, issues := e.Compile(filter)
+	if issues != nil {
+		return nil, errors.Errorf("failed to compile filter: %v", issues)
+	}
+	return cel.AstToParsedExpr(ast)
+}