package queue

import (
	"path/filepath"
	"testing"
	"time"

	"github.com/stretchr/testify/require"

	"github.com/jfraeys/fetch_ml/internal/queue"
)

func TestSQLiteQueue_PersistenceAcrossRestart(t *testing.T) {
	base := t.TempDir()
	dbPath := filepath.Join(base, "queue.db")

	q1, err := queue.NewSQLiteQueue(dbPath)
	require.NoError(t, err)

	task := &queue.Task{
		ID:        "task-1",
		JobName:   "job-1",
		Status:    "queued",
		Priority:  10,
		CreatedAt: time.Now().UTC(),
	}
	require.NoError(t, q1.AddTask(task))
	require.NoError(t, q1.Close())

	q2, err := queue.NewSQLiteQueue(dbPath)
	require.NoError(t, err)
	t.Cleanup(func() { _ = q2.Close() })

	got, err := q2.PeekNextTask()
	require.NoError(t, err)
	require.NotNil(t, got)
	require.Equal(t, task.ID, got.ID)

	leased, err := q2.GetNextTaskWithLease("worker-1", 30*time.Second)
	require.NoError(t, err)
	require.NotNil(t, leased)
	require.Equal(t, task.ID, leased.ID)
}

func TestSQLiteQueue_LeaseAndRelease(t *testing.T) {
	base := t.TempDir()
	dbPath := filepath.Join(base, "queue.db")

	q, err := queue.NewSQLiteQueue(dbPath)
	require.NoError(t, err)
	t.Cleanup(func() { _ = q.Close() })

	task := &queue.Task{ID: "task-1", JobName: "job-1", Status: "queued", Priority: 1, CreatedAt: time.Now().UTC()}
	require.NoError(t, q.AddTask(task))

	leased, err := q.GetNextTaskWithLease("worker-1", 30*time.Second)
	require.NoError(t, err)
	require.NotNil(t, leased)
	require.Equal(t, "worker-1", leased.LeasedBy)
	require.NotNil(t, leased.LeaseExpiry)

	require.NoError(t, q.ReleaseLease(task.ID, "worker-1"))
	stored, err := q.GetTask(task.ID)
	require.NoError(t, err)
	require.Empty(t, stored.LeasedBy)
	require.Nil(t, stored.LeaseExpiry)
}

func TestSQLiteQueue_GetNextTaskWithLeaseBlocking(t *testing.T) {
	base := t.TempDir()
	dbPath := filepath.Join(base, "queue.db")

	q, err := queue.NewSQLiteQueue(dbPath)
	require.NoError(t, err)
	t.Cleanup(func() { _ = q.Close() })

	start := time.Now()
	go func() {
		time.Sleep(100 * time.Millisecond)
		_ = q.AddTask(&queue.Task{
			ID:        "task-1",
			JobName:   "job-1",
			Status:    "queued",
			Priority:  1,
			CreatedAt: time.Now().UTC(),
		})
	}()

	got, err := q.GetNextTaskWithLeaseBlocking("worker-1", 30*time.Second, 800*time.Millisecond)
	require.NoError(t, err)
	require.NotNil(t, got)
	require.Equal(t, "task-1", got.ID)
	require.GreaterOrEqual(t, time.Since(start), 100*time.Millisecond)
}

func TestSQLiteQueue_RetryTask_SchedulesNextRetryAndNotImmediatelyAvailable(t *testing.T) {
	base := t.TempDir()
	dbPath := filepath.Join(base, "queue.db")

	q, err := queue.NewSQLiteQueue(dbPath)
	require.NoError(t, err)
	t.Cleanup(func() { _ = q.Close() })

	task := &queue.Task{
		ID:         "task-1",
		JobName:    "job-1",
		Status:     "running",
		Priority:   1,
		CreatedAt:  time.Now().UTC(),
		MaxRetries: 3,
		RetryCount: 0,
		Error:      "timeout",
	}
	require.NoError(t, q.AddTask(task))

	require.NoError(t, q.RetryTask(task))

	stored, err := q.GetTask(task.ID)
	require.NoError(t, err)
	require.Equal(t, "queued", stored.Status)
	require.Equal(t, 1, stored.RetryCount)
	require.NotNil(t, stored.NextRetry)
	require.True(t, stored.NextRetry.After(time.Now().UTC().Add(-1*time.Second)))

	peek, err := q.PeekNextTask()
	require.NoError(t, err)
	require.Nil(t, peek)
}

func TestSQLiteQueue_RetryTask_MaxRetriesMovesToDLQ(t *testing.T) {
	base := t.TempDir()
	dbPath := filepath.Join(base, "queue.db")

	q, err := queue.NewSQLiteQueue(dbPath)
	require.NoError(t, err)
	t.Cleanup(func() { _ = q.Close() })

	task := &queue.Task{
		ID:         "task-1",
		JobName:    "job-1",
		Status:     "running",
		Priority:   1,
		CreatedAt:  time.Now().UTC(),
		MaxRetries: 2,
		RetryCount: 2,
		LastError:  "boom",
		Error:      "boom",
	}
	require.NoError(t, q.AddTask(task))

	require.NoError(t, q.RetryTask(task))

	stored, err := q.GetTask(task.ID)
	require.NoError(t, err)
	require.Equal(t, "failed", stored.Status)
	require.Contains(t, stored.Error, "DLQ:")

	depth, err := q.QueueDepth()
	require.NoError(t, err)
	require.EqualValues(t, 0, depth)
}

func TestSQLiteQueue_PrewarmState_CRUD(t *testing.T) {
	base := t.TempDir()
	dbPath := filepath.Join(base, "queue.db")

	q, err := queue.NewSQLiteQueue(dbPath)
	require.NoError(t, err)
	t.Cleanup(func() { _ = q.Close() })

	st := queue.PrewarmState{WorkerID: "worker-1", TaskID: "task-1", Phase: "env", DatasetCnt: 0}
	require.NoError(t, q.SetWorkerPrewarmState(st))

	got, err := q.GetWorkerPrewarmState("worker-1")
	require.NoError(t, err)
	require.NotNil(t, got)
	require.Equal(t, "worker-1", got.WorkerID)

	all, err := q.GetAllWorkerPrewarmStates()
	require.NoError(t, err)
	require.NotEmpty(t, all)

	require.NoError(t, q.ClearWorkerPrewarmState("worker-1"))
	got2, err := q.GetWorkerPrewarmState("worker-1")
	require.NoError(t, err)
	require.Nil(t, got2)
}

func TestSQLiteQueue_ReclaimExpiredLeases_QueuesRetry(t *testing.T) {
	base := t.TempDir()
	dbPath := filepath.Join(base, "queue.db")

	q, err := queue.NewSQLiteQueue(dbPath)
	require.NoError(t, err)
	t.Cleanup(func() { _ = q.Close() })

	expired := time.Now().UTC().Add(-1 * time.Second)
	task := &queue.Task{
		ID:          "task-1",
		JobName:     "job-1",
		Status:      "running",
		Priority:    1,
		CreatedAt:   time.Now().UTC(),
		MaxRetries:  3,
		RetryCount:  0,
		LeasedBy:    "worker-1",
		LeaseExpiry: &expired,
	}
	require.NoError(t, q.AddTask(task))

	require.NoError(t, q.ReclaimExpiredLeases())

	stored, err := q.GetTask(task.ID)
	require.NoError(t, err)
	require.Equal(t, "queued", stored.Status)
	require.Equal(t, 1, stored.RetryCount)
	require.Empty(t, stored.LeasedBy)
	require.Nil(t, stored.LeaseExpiry)
	require.NotNil(t, stored.NextRetry)
	require.NotEmpty(t, stored.LastError)
}

func TestSQLiteQueue_PrewarmGCSignal(t *testing.T) {
	base := t.TempDir()
	dbPath := filepath.Join(base, "queue.db")

	q, err := queue.NewSQLiteQueue(dbPath)
	require.NoError(t, err)
	t.Cleanup(func() { _ = q.Close() })

	v0, err := q.PrewarmGCRequestValue()
	require.NoError(t, err)
	require.Equal(t, "", v0)

	require.NoError(t, q.SignalPrewarmGC())
	v1, err := q.PrewarmGCRequestValue()
	require.NoError(t, err)
	require.NotEmpty(t, v1)

	time.Sleep(2 * time.Millisecond)
	require.NoError(t, q.SignalPrewarmGC())
	v2, err := q.PrewarmGCRequestValue()
	require.NoError(t, err)
	require.NotEmpty(t, v2)
	require.NotEqual(t, v1, v2)
}