/*
 * Copyright 2024 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package stats

import (
	

	estats 
	
	
)

// MetricsRecorderList forwards Record calls to all of its metricsRecorders.
//
// It eats any record calls where the label values provided do not match the
// number of label keys.
type MetricsRecorderList struct {
	internal.EnforceMetricsRecorderEmbedding
	// metricsRecorders are the metrics recorders this list will forward to.
	metricsRecorders []estats.MetricsRecorder
}

// NewMetricsRecorderList creates a new metric recorder list with all the stats
// handlers provided which implement the MetricsRecorder interface.
// If no stats handlers provided implement the MetricsRecorder interface,
// the MetricsRecorder list returned is a no-op.
func ( []stats.Handler) *MetricsRecorderList {
	var  []estats.MetricsRecorder
	for ,  := range  {
		if ,  := .(estats.MetricsRecorder);  {
			 = append(, )
		}
	}
	return &MetricsRecorderList{
		metricsRecorders: ,
	}
}

func verifyLabels( *estats.MetricDescriptor,  ...string) {
	if ,  := len(), len(.Labels)+len(.OptionalLabels);  !=  {
		panic(fmt.Sprintf("Received %d labels in call to record metric %q, but expected %d.", , .Name, ))
	}
}

// RecordInt64Count records the measurement alongside labels on the int
// count associated with the provided handle.
func ( *MetricsRecorderList) ( *estats.Int64CountHandle,  int64,  ...string) {
	verifyLabels(.Descriptor(), ...)

	for ,  := range .metricsRecorders {
		.RecordInt64Count(, , ...)
	}
}

// RecordInt64UpDownCount records the measurement alongside labels on the int
// count associated with the provided handle.
func ( *MetricsRecorderList) ( *estats.Int64UpDownCountHandle,  int64,  ...string) {
	verifyLabels(.Descriptor(), ...)

	for ,  := range .metricsRecorders {
		.RecordInt64UpDownCount(, , ...)
	}
}

// RecordFloat64Count records the measurement alongside labels on the float
// count associated with the provided handle.
func ( *MetricsRecorderList) ( *estats.Float64CountHandle,  float64,  ...string) {
	verifyLabels(.Descriptor(), ...)

	for ,  := range .metricsRecorders {
		.RecordFloat64Count(, , ...)
	}
}

// RecordInt64Histo records the measurement alongside labels on the int
// histo associated with the provided handle.
func ( *MetricsRecorderList) ( *estats.Int64HistoHandle,  int64,  ...string) {
	verifyLabels(.Descriptor(), ...)

	for ,  := range .metricsRecorders {
		.RecordInt64Histo(, , ...)
	}
}

// RecordFloat64Histo records the measurement alongside labels on the float
// histo associated with the provided handle.
func ( *MetricsRecorderList) ( *estats.Float64HistoHandle,  float64,  ...string) {
	verifyLabels(.Descriptor(), ...)

	for ,  := range .metricsRecorders {
		.RecordFloat64Histo(, , ...)
	}
}

// RecordInt64Gauge records the measurement alongside labels on the int
// gauge associated with the provided handle.
func ( *MetricsRecorderList) ( *estats.Int64GaugeHandle,  int64,  ...string) {
	verifyLabels(.Descriptor(), ...)

	for ,  := range .metricsRecorders {
		.RecordInt64Gauge(, , ...)
	}
}

// RegisterAsyncReporter forwards the registration to all underlying metrics
// recorders.
//
// It returns a cleanup function that, when called, invokes the cleanup function
// returned by each underlying recorder, ensuring the reporter is unregistered
// from all of them.
func ( *MetricsRecorderList) ( estats.AsyncMetricReporter,  ...estats.AsyncMetric) func() {
	 := make(map[*estats.MetricDescriptor]bool, len())
	for ,  := range  {
		[.Descriptor()] = true
	}
	 := make([]func(), 0, len(.metricsRecorders))
	for ,  := range .metricsRecorders {
		// Wrap the AsyncMetricsRecorder to intercept calls to RecordInt64Gauge
		// and validate the labels.
		 := func( estats.AsyncMetricsRecorder) error {
			 := &asyncRecorderWrapper{
				delegate:    ,
				descriptors: ,
			}
			return .Report()
		}
		 = append(, .RegisterAsyncReporter(estats.AsyncMetricReporterFunc(), ...))
	}

	// Wrap the cleanup function using the internal delegate.
	// In production, this returns realCleanup as-is.
	// In tests, the leak checker can swap this to track the registration lifetime.
	return internal.AsyncReporterCleanupDelegate(defaultCleanUp())
}

func defaultCleanUp( []func()) func() {
	return func() {
		for ,  := range  {
			()
		}
	}
}

type asyncRecorderWrapper struct {
	delegate    estats.AsyncMetricsRecorder
	descriptors map[*estats.MetricDescriptor]bool
}

// RecordIntAsync64Gauge records the measurement alongside labels on the int
// gauge associated with the provided handle.
func ( *asyncRecorderWrapper) ( *estats.Int64AsyncGaugeHandle,  int64,  ...string) {
	// Ensure only metrics for descriptors passed during callback registration
	// are emitted.
	 := .Descriptor()
	if ,  := .descriptors[]; ! {
		return
	}
	// Validate labels and delegate.
	verifyLabels(, ...)
	.delegate.RecordInt64AsyncGauge(, , ...)
}