package benchmarks_test

import (
	"fmt"
	"testing"
	"time"

	"github.com/jfraeys/fetch_ml/internal/scheduler"
	fixtures "github.com/jfraeys/fetch_ml/tests/fixtures"
)

// BenchmarkPriorityQueueAdd measures job enqueue performance
func BenchmarkPriorityQueueAdd(b *testing.B) {
	pq := scheduler.NewPriorityQueue(0.1)

	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		task := &scheduler.Task{
			ID:       fmt.Sprintf("task-%d", i),
			Priority: i % 100,
		}
		pq.Add(task)
	}
}

// BenchmarkPriorityQueueTake measures job dequeue performance
func BenchmarkPriorityQueueTake(b *testing.B) {
	pq := scheduler.NewPriorityQueue(0.1)

	// Pre-populate queue
	for i := 0; i < b.N; i++ {
		task := &scheduler.Task{
			ID:       fmt.Sprintf("task-%d", i),
			Priority: i % 100,
		}
		pq.Add(task)
	}

	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		pq.Take()
	}
}

// BenchmarkPortAllocator measures port allocation performance
func BenchmarkPortAllocator(b *testing.B) {
	pa := scheduler.NewPortAllocator(10000, 20000)

	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		port, _ := pa.Allocate(fmt.Sprintf("service-%d", i))
		_ = port
	}
}

// BenchmarkStateStoreAppend measures state persistence performance
func BenchmarkStateStoreAppend(b *testing.B) {
	dir := b.TempDir()
	store, _ := scheduler.NewStateStore(dir + "/bench.state")

	event := scheduler.StateEvent{
		Type:      scheduler.EventJobEnqueued,
		TaskID:    "bench-task",
		Timestamp: time.Now(),
	}

	b.ReportAllocs()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		event.TaskID = fmt.Sprintf("bench-task-%d", i)
		store.Append(event)
	}
}

// BenchmarkSchedulerSubmitJob measures job submission throughput
func BenchmarkSchedulerSubmitJob(b *testing.B) {
	// Create isolated state directory
	stateDir := b.TempDir()

	// Create scheduler directly for benchmark
	cfg := scheduler.HubConfig{
		BindAddr:                "localhost:0",
		StateDir:                stateDir,
		DefaultBatchSlots:       4,
		StarvationThresholdMins: 5,
		AcceptanceTimeoutSecs:   5,
	}
	hub, err := scheduler.NewHub(cfg, nil)
	if err != nil {
		b.Fatal(err)
	}
	defer hub.Stop()

	if err := hub.Start(); err != nil {
		b.Fatal(err)
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		hub.SubmitJob(scheduler.JobSpec{
			ID:   fmt.Sprintf("bench-job-%d", i),
			Type: scheduler.JobTypeBatch,
		})
	}
}

// BenchmarkWorkerRegistration measures worker registration throughput
func BenchmarkWorkerRegistration(b *testing.B) {
	fixture := fixtures.NewSchedulerTestFixture(b, fixtures.DefaultHubConfig())
	defer fixture.Cleanup()

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		workerID := fmt.Sprintf("bench-worker-%d", i)
		worker := fixtures.NewMockWorker(b, fixture.Hub, workerID)
		worker.Register(scheduler.WorkerCapabilities{GPUCount: 0})
		worker.Close()
	}
}

// BenchmarkHeartbeatProcessing measures heartbeat handling throughput
func BenchmarkHeartbeatProcessing(b *testing.B) {
	fixture := fixtures.NewSchedulerTestFixture(b, fixtures.DefaultHubConfig())
	defer fixture.Cleanup()

	worker := fixture.CreateWorker("bench-hb-worker", scheduler.WorkerCapabilities{GPUCount: 0})

	slots := scheduler.SlotStatus{
		BatchTotal: 4,
		BatchInUse: 0,
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		worker.SendHeartbeat(slots)
	}
}

// BenchmarkJobAssignment measures job scheduling latency
func BenchmarkJobAssignment(b *testing.B) {
	fixture := fixtures.NewSchedulerTestFixture(b, fixtures.DefaultHubConfig())
	defer fixture.Cleanup()

	// Create worker
	worker := fixture.CreateWorker("bench-assign-worker", scheduler.WorkerCapabilities{GPUCount: 0})

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		// Submit job
		jobID := fmt.Sprintf("bench-assign-%d", i)
		fixture.SubmitJob(scheduler.JobSpec{
			ID:   jobID,
			Type: scheduler.JobTypeBatch,
		})

		// Signal ready to trigger assignment
		worker.SignalReady(scheduler.SlotStatus{BatchTotal: 4, BatchInUse: 0}, "polling")

		// Wait for assignment
		worker.RecvTimeout(100 * time.Millisecond)
	}
}

// BenchmarkMultiWorkerScheduling measures scheduling with multiple workers
func BenchmarkMultiWorkerScheduling(b *testing.B) {
	fixture := fixtures.NewSchedulerTestFixture(b, fixtures.DefaultHubConfig())
	defer fixture.Cleanup()

	// Create multiple workers
	workers := make([]*fixtures.MockWorker, 10)
	for i := 0; i < 10; i++ {
		workers[i] = fixture.CreateWorker(
			fmt.Sprintf("bench-multi-worker-%d", i),
			scheduler.WorkerCapabilities{GPUCount: 0},
		)
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		// Submit job
		jobID := fmt.Sprintf("bench-multi-%d", i)
		fixture.SubmitJob(scheduler.JobSpec{
			ID:   jobID,
			Type: scheduler.JobTypeBatch,
		})

		// All workers signal ready
		for _, w := range workers {
			w.SignalReady(scheduler.SlotStatus{BatchTotal: 4, BatchInUse: 0}, "polling")
		}

		// One worker gets the job
		workers[i%10].RecvTimeout(100 * time.Millisecond)
	}
}