[chore][pkg/stanza] Cleanup router operator files (open-telemetry#32069)

pkg/stanza/operator/transformer/router/config.go

@@ -0,0 +1,86 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package router // import "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/operator/transformer/router"
+
+import (
+	"fmt"
+
+	"go.uber.org/zap"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/operator"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/operator/helper"
+)
+
+const operatorType = "router"
+
+func init() {
+	operator.Register(operatorType, func() operator.Builder { return NewConfig() })
+}
+
+// NewConfig config creates a new router operator config with default values
+func NewConfig() *Config {
+	return NewConfigWithID(operatorType)
+}
+
+// NewConfigWithID config creates a new router operator config with default values
+func NewConfigWithID(operatorID string) *Config {
+	return &Config{
+		BasicConfig: helper.NewBasicConfig(operatorID, operatorType),
+	}
+}
+
+// Config is the configuration of a router operator
+type Config struct {
+	helper.BasicConfig `mapstructure:",squash"`
+	Routes             []*RouteConfig `mapstructure:"routes"`
+	Default            []string       `mapstructure:"default"`
+}
+
+// RouteConfig is the configuration of a route on a router operator
+type RouteConfig struct {
+	helper.AttributerConfig `mapstructure:",squash"`
+	Expression              string   `mapstructure:"expr"`
+	OutputIDs               []string `mapstructure:"output"`
+}
+
+// Build will build a router operator from the supplied configuration
+func (c Config) Build(logger *zap.SugaredLogger) (operator.Operator, error) {
+	basicOperator, err := c.BasicConfig.Build(logger)
+	if err != nil {
+		return nil, err
+	}
+
+	if c.Default != nil {
+		defaultRoute := &RouteConfig{
+			Expression: "true",
+			OutputIDs:  c.Default,
+		}
+		c.Routes = append(c.Routes, defaultRoute)
+	}
+
+	routes := make([]*Route, 0, len(c.Routes))
+	for _, routeConfig := range c.Routes {
+		compiled, err := helper.ExprCompileBool(routeConfig.Expression)
+		if err != nil {
+			return nil, fmt.Errorf("failed to compile expression '%s': %w", routeConfig.Expression, err)
+		}
+
+		attributer, err := routeConfig.AttributerConfig.Build()
+		if err != nil {
+			return nil, fmt.Errorf("failed to build attributer for route '%s': %w", routeConfig.Expression, err)
+		}
+
+		route := Route{
+			Attributer: attributer,
+			Expression: compiled,
+			OutputIDs:  routeConfig.OutputIDs,
+		}
+		routes = append(routes, &route)
+	}
+
+	return &Transformer{
+		BasicOperator: basicOperator,
+		routes:        routes,
+	}, nil
+}