//go:build linux || freebsd
// +build linux freebsd

package queue

import (
	"os"
	"path/filepath"
	"testing"
)

func TestNewQueue(t *testing.T) {
	q, err := NewQueue(nil)
	if err != nil {
		t.Fatalf("Failed to create queue: %v", err)
	}
	if q == nil {
		t.Fatal("Queue is nil")
	}
	if q.config.MaxParallel != 3 {
		t.Errorf("Expected MaxParallel=3, got %d", q.config.MaxParallel)
	}
}

func TestQueueAdd(t *testing.T) {
	tmpDir := t.TempDir()
	queueFile := filepath.Join(tmpDir, "queue.json")

	q, err := NewQueue(&QueueConfig{QueueFile: queueFile, AutoSave: true})
	if err != nil {
		t.Fatalf("Failed to create queue: %v", err)
	}

	item := q.Add("https://example.com/file.zip", "/tmp/file.zip", 5)
	if item == nil {
		t.Fatal("Added item is nil")
	}
	if item.URL != "https://example.com/file.zip" {
		t.Errorf("Expected URL https://example.com/file.zip, got %s", item.URL)
	}
	if item.Priority != 5 {
		t.Errorf("Expected priority 5, got %d", item.Priority)
	}
	if item.Status != "pending" {
		t.Errorf("Expected status pending, got %s", item.Status)
	}
}

func TestQueueAddPriority(t *testing.T) {
	q, err := NewQueue(nil)
	if err != nil {
		t.Fatalf("Failed to create queue: %v", err)
	}

	// Test priority clamping
	item1 := q.Add("https://example.com/1.zip", "/tmp/1.zip", 0)
	if item1.Priority != 5 {
		t.Errorf("Expected priority 5 (default), got %d", item1.Priority)
	}

	item2 := q.Add("https://example.com/2.zip", "/tmp/2.zip", 15)
	if item2.Priority != 10 {
		t.Errorf("Expected priority 10 (max), got %d", item2.Priority)
	}
}

func TestQueueRemove(t *testing.T) {
	q, _ := NewQueue(nil)

	item := q.Add("https://example.com/file.zip", "/tmp/file.zip", 5)
	initialLen := q.Len()

	if !q.Remove(item.ID) {
		t.Error("Failed to remove item")
	}
	if q.Len() != initialLen-1 {
		t.Errorf("Expected queue length %d, got %d", initialLen-1, q.Len())
	}
}

func TestQueueGetNext(t *testing.T) {
	q, _ := NewQueue(nil)

	// Add items with different priorities
	q.Add("https://example.com/low.zip", "/tmp/low.zip", 3)
	q.Add("https://example.com/high.zip", "/tmp/high.zip", 10)
	q.Add("https://example.com/med.zip", "/tmp/med.zip", 5)

	next := q.GetNext()
	if next == nil {
		t.Fatal("GetNext returned nil")
	}
	// Should return highest priority (10)
	if next.Priority < 8 {
		t.Errorf("Expected high priority item (>=8), got %d", next.Priority)
	}
}

func TestQueueUpdateStatus(t *testing.T) {
	q, err := NewQueue(nil)
	if err != nil {
		t.Fatalf("Failed to create queue: %v", err)
	}

	item := q.Add("https://example.com/file.zip", "/tmp/file.zip", 5)

	if !q.UpdateStatus(item.ID, "downloading") {
		t.Error("Failed to update status")
	}

	// Refresh item from queue
	items := q.GetAll()
	var updated *QueueItem
	for _, it := range items {
		if it.ID == item.ID {
			updated = it
			break
		}
	}

	if updated == nil || updated.Status != "downloading" {
		t.Errorf("Expected status downloading, got %s", updated.Status)
	}
}

func TestQueueGetPending(t *testing.T) {
	q, _ := NewQueue(nil)

	q.Add("https://example.com/1.zip", "/tmp/1.zip", 5)
	q.Add("https://example.com/2.zip", "/tmp/2.zip", 5)

	items := q.GetAll()
	if len(items) >= 2 {
		q.UpdateStatus(items[0].ID, "completed")
	}

	pending := q.GetPending()
	if len(pending) < 1 {
		t.Errorf("Expected at least 1 pending item, got %d", len(pending))
	}
}

func TestQueueGetStats(t *testing.T) {
	q, _ := NewQueue(nil)
	initialLen := q.Len()

	q.Add("https://example.com/1.zip", "/tmp/1.zip", 5)
	q.Add("https://example.com/2.zip", "/tmp/2.zip", 5)
	q.Add("https://example.com/3.zip", "/tmp/3.zip", 5)

	items := q.GetAll()
	completedCount := 0
	for _, item := range items {
		if item.Status == "pending" && completedCount == 0 {
			q.UpdateStatus(item.ID, "completed")
			completedCount++
		}
	}

	stats := q.GetStats()
	if stats.Total < initialLen+3 {
		t.Errorf("Expected at least %d total, got %d", initialLen+3, stats.Total)
	}
	if stats.Completed < 1 {
		t.Errorf("Expected at least 1 completed, got %d", stats.Completed)
	}
}

func TestQueueSaveLoad(t *testing.T) {
	tmpDir := t.TempDir()
	queueFile := filepath.Join(tmpDir, "queue.json")

	// Create and save queue
	q1, err := NewQueue(&QueueConfig{QueueFile: queueFile, AutoSave: false})
	if err != nil {
		t.Fatalf("Failed to create queue: %v", err)
	}

	q1.Add("https://example.com/file.zip", "/tmp/file.zip", 7)
	q1.Add("https://example.com/other.zip", "/tmp/other.zip", 3)

	if err := q1.Save(); err != nil {
		t.Fatalf("Failed to save queue: %v", err)
	}

	// Load queue
	q2, err := NewQueue(&QueueConfig{QueueFile: queueFile})
	if err != nil {
		t.Fatalf("Failed to load queue: %v", err)
	}

	if q2.Len() != 2 {
		t.Errorf("Expected 2 items after load, got %d", q2.Len())
	}
}

func TestQueueClearCompleted(t *testing.T) {
	q, _ := NewQueue(nil)
	initialLen := q.Len()

	q.Add("https://example.com/1.zip", "/tmp/1.zip", 5)
	q.Add("https://example.com/2.zip", "/tmp/2.zip", 5)
	q.Add("https://example.com/3.zip", "/tmp/3.zip", 5)

	items := q.GetAll()
	completedCount := 0
	for _, item := range items {
		if item.Status == "pending" && completedCount == 0 {
			q.UpdateStatus(item.ID, "completed")
			completedCount++
		}
	}

	count := q.ClearCompleted()
	if count < 1 {
		t.Errorf("Expected to clear at least 1 item, cleared %d", count)
	}
	if q.Len() >= initialLen+3 {
		t.Errorf("Expected less than %d items remaining, got %d", initialLen+3, q.Len())
	}
}

func TestQueueRetry(t *testing.T) {
	q, err := NewQueue(nil)
	if err != nil {
		t.Fatalf("Failed to create queue: %v", err)
	}

	item := q.Add("https://example.com/file.zip", "/tmp/file.zip", 5)
	q.UpdateStatus(item.ID, "failed")

	// Should be able to retry
	if !q.Retry(item.ID) {
		t.Error("Failed to retry item")
	}

	// Check status is back to pending
	items := q.GetAll()
	for _, it := range items {
		if it.ID == item.ID {
			if it.Status != "pending" {
				t.Errorf("Expected status pending after retry, got %s", it.Status)
			}
			break
		}
	}
}

func TestQueueRetryMaxRetries(t *testing.T) {
	q, err := NewQueue(&QueueConfig{DefaultMaxRetries: 2})
	if err != nil {
		t.Fatalf("Failed to create queue: %v", err)
	}

	item := q.Add("https://example.com/file.zip", "/tmp/file.zip", 5)
	q.UpdateStatus(item.ID, "failed")

	// First retry should work
	if !q.Retry(item.ID) {
		t.Error("First retry should succeed")
	}
	q.UpdateStatus(item.ID, "failed")

	// Second retry should work
	if !q.Retry(item.ID) {
		t.Error("Second retry should succeed")
	}
	q.UpdateStatus(item.ID, "failed")

	// Third retry should fail (max retries reached)
	if q.Retry(item.ID) {
		t.Error("Third retry should fail (max retries exceeded)")
	}
}

func TestGenerateID(t *testing.T) {
	id1 := generateID()
	id2 := generateID()

	if id1 == id2 {
		t.Error("Generated IDs should be unique")
	}

	// Check ID format
	if len(id1) < 3 {
		t.Errorf("ID too short: %s", id1)
	}
}

func TestDefaultQueueFile(t *testing.T) {
	path := getDefaultQueueFile()
	if path == "" {
		t.Error("Default queue file path should not be empty")
	}
}

func TestQueueConcurrentAccess(t *testing.T) {
	q, _ := NewQueue(nil)
	initialLen := q.Len()

	done := make(chan bool, 10)

	// Concurrent adds
	for i := 0; i < 10; i++ {
		go func(n int) {
			q.Add("https://example.com/"+string(rune('a'+n))+".zip", "/tmp/"+string(rune('a'+n))+".zip", 5)
			done <- true
		}(i)
	}

	for i := 0; i < 10; i++ {
		<-done
	}

	if q.Len() < initialLen+10 {
		t.Errorf("Expected at least %d items after concurrent adds, got %d", initialLen+10, q.Len())
	}
}

func TestQueueAutoSave(t *testing.T) {
	tmpDir := t.TempDir()
	queueFile := filepath.Join(tmpDir, "queue.json")

	q, err := NewQueue(&QueueConfig{QueueFile: queueFile, AutoSave: true})
	if err != nil {
		t.Fatalf("Failed to create queue: %v", err)
	}

	q.Add("https://example.com/file.zip", "/tmp/file.zip", 5)

	// Check file exists
	if _, err := os.Stat(queueFile); os.IsNotExist(err) {
		t.Error("Queue file should exist with AutoSave enabled")
	}
}

func TestQueueProgressUpdate(t *testing.T) {
	q, err := NewQueue(nil)
	if err != nil {
		t.Fatalf("Failed to create queue: %v", err)
	}

	item := q.Add("https://example.com/file.zip", "/tmp/file.zip", 5)

	q.UpdateProgress(item.ID, 500, 1000)

	items := q.GetAll()
	for _, it := range items {
		if it.ID == item.ID {
			if it.Downloaded != 500 {
				t.Errorf("Expected downloaded 500, got %d", it.Downloaded)
			}
			if it.Size != 1000 {
				t.Errorf("Expected size 1000, got %d", it.Size)
			}
			break
		}
	}
}