// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: MIT

//go:build !windows

package metric

import (
	"github.com/aws/amazon-cloudwatch-agent-test/test/metric/dimension"
	"github.com/aws/amazon-cloudwatch-agent-test/test/status"
	"github.com/aws/aws-sdk-go-v2/aws"
	"log"
	"strings"
	"time"
)

const (
	// Must match JSON config
	statsdMetricsAggregationInterval = 30 * time.Second
	statsdMetricsCollectionInterval  = 5 * time.Second
)

var (
	// metric name must use "_"" as a separator and include the metric type.
	StatsdMetricNames = []string{
		"statsd_counter_1",
		"statsd_gauge_2",
		"statsd_timing_3",
		"statsd_counter_4",
		"statsd_gauge_5",
		"statsd_timing_6",
	}
	StatsdMetricValues = []float64{1000, 2000, 3000, 4000, 5000, 6000}
)

func ValidateStatsdMetric(dimFactory dimension.Factory, namespace string, dimensionKey string, metricName string, expectedValue float64, runDuration time.Duration, sendInterval time.Duration) status.TestResult {
	testResult := status.TestResult{
		Name:   metricName,
		Status: status.FAILED,
	}
	instructions := []dimension.Instruction{
		{
			Key:   dimensionKey,
			Value: dimension.UnknownDimensionValue(),
		},
		{
			Key:   "key",
			Value: dimension.ExpectedDimensionValue{Value: aws.String("value")},
		},
	}
	split := strings.Split(metricName, "_")
	if len(split) != 3 {
		log.Printf("unexpected metric name format, %s", metricName)
	}
	metricType := split[1]
	instructions = append(instructions, dimension.Instruction{
		// CWA adds this metric_type dimension.
		Key:   "metric_type",
		Value: dimension.ExpectedDimensionValue{Value: aws.String(metricType)},
	})
	dims, failed := dimFactory.GetDimensions(instructions)
	if len(failed) > 0 {
		return testResult
	}
	fetcher := MetricValueFetcher{}
	// Check average.
	values, err := fetcher.Fetch(namespace, metricName, dims, AVERAGE, HighResolutionStatPeriod)
	if err != nil {
		return testResult
	}

	lowerBound := int(runDuration/statsdMetricsAggregationInterval) - 4
	if len(values) < lowerBound {
		log.Printf("fail: lowerBound %v, actual %v", lowerBound, len(values))
		return testResult
	}
	// Counters get summed up over the metrics_collection_interval.
	if metricType == "counter" {
		expectedValue *= float64(statsdMetricsCollectionInterval / sendInterval)
	}
	if !IsAllValuesGreaterThanOrEqualToExpectedValue(metricName, values, float64(expectedValue)) {
		return testResult
	}
	// Check aggregation by checking sample count.
	// Expect samples to be metrics_aggregation_interval / metrics_collection_interval
	expectedSampleCount := statsdMetricsAggregationInterval / statsdMetricsCollectionInterval
	if metricType == "timing" {
		// Every single timing is counted.
		// Sent twice per send_interval.
		expectedSampleCount = 2 * statsdMetricsAggregationInterval / sendInterval
	}
	values, err = fetcher.Fetch(namespace, metricName, dims, SAMPLE_COUNT, HighResolutionStatPeriod)
	if err != nil {
		return testResult
	}
	// Skip check on the last value.
	values = values[:len(values)-1]
	if !IsAllValuesGreaterThanOrEqualToExpectedValue(metricName, values, float64(expectedSampleCount)) {
		return testResult
	}
	testResult.Status = status.SUCCESSFUL
	return testResult
}