// Copyright (c) 2025 Alibaba Group Holding Ltd.
//
// 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 experimental

import (
	"log"
	"os"

	"go.opentelemetry.io/otel/metric"
)

type sentinelEnabler struct{}

func (n sentinelEnabler) Enable() bool {
	return os.Getenv("OTEL_INSTRUMENTATION_SENTINEL_EXPERIMENTAL_ENABLE") == "true"
}

var SentinelEnabler sentinelEnabler

var (
	SentinelBlockQPS metric.Float64ObservableGauge
	SentinelPassQPS  metric.Float64ObservableGauge
	SentinelMeter    metric.Meter
)

func InitSentinelExperimentalMetrics(m metric.Meter) {
	SentinelMeter = m
	if SentinelMeter == nil {
		log.Printf("meter is nil, skip init SentinelExperimentalMetrics")
		return
	}
	var err error
	SentinelBlockQPS, err = SentinelMeter.Float64ObservableGauge("sentinel.blocked.qps",
		metric.WithDescription("The QPS of Sentinel Block"))
	if err != nil {
		log.Printf("failed to init SentinelBlockQPS metrics")
	}
	SentinelPassQPS, err = SentinelMeter.Float64ObservableGauge("sentinel.passed.qps",
		metric.WithDescription("The QPS of Sentinel Pass"))
	if err != nil {
		log.Printf("failed to init SentinelPassQPS metrics")
	}
}
