package starlog

import (
	"sync/atomic"
	"testing"
	"time"
)

type metricsSink struct {
	writes uint64
}

func (sink *metricsSink) Write(data []byte) error {
	_ = data
	atomic.AddUint64(&sink.writes, 1)
	return nil
}

func (sink *metricsSink) Close() error {
	return nil
}

func TestMetricsSnapshotIncludesPendingAndMultiSink(t *testing.T) {
	logger := NewStarlog(nil)
	logger.SetShowStd(false)
	logger.SetShowColor(false)
	logger.SetPendingWriteLimit(8)
	logger.SetPendingDropPolicy(PendingDropOldest)
	logger.SetSamplingConfig(SamplingConfig{
		Enable: true,
		Levels: []int{LvInfo},
		Rate:   0.5,
		Scope:  SamplingScopeGlobal,
	})
	logger.SetDedupConfig(DedupConfig{
		Enable: true,
		Levels: []int{LvInfo},
		Window: time.Second,
		Scope:  DedupScopeByKey,
	})

	multi := NewMultiSink(&metricsSink{})
	logger.SetSink(multi)
	logger.SetSwitching(true)
	logger.Infoln("pending")

	snapshot := logger.GetMetricsSnapshot()
	if !snapshot.HasSink {
		t.Fatalf("snapshot should report sink")
	}
	if !snapshot.HasMultiSink {
		t.Fatalf("snapshot should report multi sink")
	}
	if len(snapshot.MultiSink.Sinks) != 1 {
		t.Fatalf("snapshot multi sink stats should include one sink")
	}
	if snapshot.Pending.Length == 0 {
		t.Fatalf("snapshot should include pending queue length")
	}
	if snapshot.Pending.Policy != PendingDropOldest {
		t.Fatalf("snapshot should include pending policy")
	}
	if snapshot.Errors.WriteErrors != GetWriteErrorCount() {
		t.Fatalf("snapshot write error count should match global counter")
	}
	if !snapshot.Sampling.Enabled || snapshot.Sampling.Rate != 0.5 {
		t.Fatalf("snapshot should include sampling stats, got %+v", snapshot.Sampling)
	}
	if !snapshot.Dedup.Enabled || snapshot.Dedup.Window != time.Second {
		t.Fatalf("snapshot should include dedup stats, got %+v", snapshot.Dedup)
	}

	logger.SetSwitching(false)
}

func TestGetAsyncMetrics(t *testing.T) {
	StopStacks()
	StartStacks()
	metrics := GetAsyncMetrics()
	if !metrics.Started {
		t.Fatalf("async metrics should show started state")
	}
	if metrics.QueueCapacity == 0 {
		t.Fatalf("async metrics should expose queue capacity")
	}
	StopStacks()
	metrics = GetAsyncMetrics()
	if metrics.Started {
		t.Fatalf("async metrics should show stopped state after StopStacks")
	}
}

func TestMetricsSnapshotNilLogger(t *testing.T) {
	var logger *StarLogger
	snapshot := logger.GetMetricsSnapshot()
	if snapshot.Time.IsZero() {
		t.Fatalf("snapshot should contain timestamp")
	}
}