package loadgen

import (
	"math"
	"strings"
	"testing"
	"time"
)

func TestEvaluateAcceptancePassesWithinConfiguredThresholds(t *testing.T) {
	report := Report{
		Completed: 100,
		Failed:    1,
		Latency:   LatencyReport{Samples: 100, P99UpperBound: 80 * time.Millisecond},
	}

	result, err := EvaluateAcceptance(report, AcceptanceCriteria{
		EnforceFailureRate: true,
		MaxFailureRate:     0.02,
		EnforceP99Latency:  true,
		MaxP99Latency:      100 * time.Millisecond,
	})
	if err != nil || !result.Passed || result.FailureRate != 0.01 || len(result.Violations) != 0 {
		t.Fatalf("EvaluateAcceptance() = (%+v, %v)", result, err)
	}
}

func TestEvaluateAcceptanceReportsEveryBreachedThreshold(t *testing.T) {
	report := Report{
		Completed: 10,
		Failed:    2,
		Latency:   LatencyReport{Samples: 10, P99UpperBound: 250 * time.Millisecond},
	}

	result, err := EvaluateAcceptance(report, AcceptanceCriteria{
		EnforceFailureRate: true,
		MaxFailureRate:     0.1,
		EnforceP99Latency:  true,
		MaxP99Latency:      100 * time.Millisecond,
	})
	if err != nil || result.Passed || result.FailureRate != 0.2 || len(result.Violations) != 2 ||
		!strings.Contains(result.Violations[0], "failure rate") || !strings.Contains(result.Violations[1], "p99 latency") {
		t.Fatalf("EvaluateAcceptance() = (%+v, %v)", result, err)
	}
}

func TestEvaluateAcceptanceRejectsInvalidCriteriaAndEmptyMeasurements(t *testing.T) {
	if _, err := EvaluateAcceptance(Report{}, AcceptanceCriteria{EnforceFailureRate: true, MaxFailureRate: 1.1}); err == nil {
		t.Fatal("EvaluateAcceptance() accepted failure rate above one")
	}
	if _, err := EvaluateAcceptance(Report{}, AcceptanceCriteria{EnforceP99Latency: true, MaxP99Latency: 0}); err == nil {
		t.Fatal("EvaluateAcceptance() accepted zero p99 limit")
	}
	for _, value := range []float64{math.NaN(), math.Inf(1)} {
		if _, err := EvaluateAcceptance(Report{}, AcceptanceCriteria{EnforceFailureRate: true, MaxFailureRate: value}); err == nil {
			t.Fatalf("EvaluateAcceptance() accepted non-finite failure rate %v", value)
		}
	}

	result, err := EvaluateAcceptance(Report{}, AcceptanceCriteria{EnforceFailureRate: true, MaxFailureRate: 0})
	if err != nil || result.Passed || len(result.Violations) != 1 || !strings.Contains(result.Violations[0], "no completed requests") {
		t.Fatalf("EvaluateAcceptance(empty) = (%+v, %v)", result, err)
	}
}