package scopes_test

import (
	"os"
	"testing"
	"time"

	"gorm.io/driver/postgres"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"

	"github.com/treytartt/casera-api/internal/models"
	"github.com/treytartt/casera-api/internal/task/predicates"
	"github.com/treytartt/casera-api/internal/task/scopes"
)

// testDB holds the database connection for integration tests
var testDB *gorm.DB

// TestMain sets up the database connection for all tests in this package
func TestMain(m *testing.M) {
	// Get database URL from environment or use default
	dsn := os.Getenv("TEST_DATABASE_URL")
	if dsn == "" {
		dsn = "host=localhost user=postgres password=postgres dbname=mycrib_test port=5432 sslmode=disable"
	}

	var err error
	testDB, err = gorm.Open(postgres.Open(dsn), &gorm.Config{
		Logger: logger.Default.LogMode(logger.Silent),
	})
	if err != nil {
		// Print message and skip tests if database is not available
		println("Skipping scope integration tests: database not available")
		println("Set TEST_DATABASE_URL to run these tests")
		println("Error:", err.Error())
		os.Exit(0)
	}

	// Verify connection works
	sqlDB, err := testDB.DB()
	if err != nil {
		println("Failed to get underlying DB:", err.Error())
		os.Exit(0)
	}
	if err := sqlDB.Ping(); err != nil {
		println("Failed to ping database:", err.Error())
		os.Exit(0)
	}

	println("Database connected successfully, running integration tests...")

	// Run migrations for test tables
	err = testDB.AutoMigrate(
		&models.Task{},
		&models.TaskCompletion{},
		&models.Residence{},
	)
	if err != nil {
		os.Exit(1)
	}

	// Run tests
	code := m.Run()

	// Cleanup
	cleanupTestData()

	os.Exit(code)
}

// cleanupTestData removes all test data
func cleanupTestData() {
	if testDB == nil {
		return
	}
	testDB.Exec("DELETE FROM task_taskcompletion WHERE task_id IN (SELECT id FROM task_task WHERE title LIKE 'test_%')")
	testDB.Exec("DELETE FROM task_task WHERE title LIKE 'test_%'")
	testDB.Exec("DELETE FROM residence_residence WHERE name LIKE 'test_%'")
}

// Helper to create a time pointer
func timePtr(t time.Time) *time.Time {
	return &t
}

// testUserID is a user ID that exists in the database for foreign key constraints
var testUserID uint = 1

// createTestResidence creates a test residence and returns its ID
func createTestResidence(t *testing.T) uint {
	residence := &models.Residence{
		Name:     "test_residence_" + time.Now().Format("20060102150405"),
		OwnerID:  testUserID,
		IsActive: true,
	}
	if err := testDB.Create(residence).Error; err != nil {
		t.Fatalf("Failed to create test residence: %v", err)
	}
	return residence.ID
}


// createTestTask creates a task with the given properties
func createTestTask(t *testing.T, residenceID uint, task *models.Task) *models.Task {
	task.ResidenceID = residenceID
	task.Title = "test_" + task.Title
	task.CreatedByID = testUserID // Required foreign key
	if err := testDB.Create(task).Error; err != nil {
		t.Fatalf("Failed to create test task: %v", err)
	}
	return task
}

// createTestCompletion creates a completion for a task
func createTestCompletion(t *testing.T, taskID uint) *models.TaskCompletion {
	completion := &models.TaskCompletion{
		TaskID:        taskID,
		CompletedByID: testUserID, // Required foreign key
		CompletedAt:   time.Now().UTC(),
	}
	if err := testDB.Create(completion).Error; err != nil {
		t.Fatalf("Failed to create test completion: %v", err)
	}
	return completion
}

// TestScopeActiveMatchesPredicate verifies ScopeActive produces same results as IsActive
func TestScopeActiveMatchesPredicate(t *testing.T) {
	if testDB == nil {
		t.Skip("Database not available")
	}

	residenceID := createTestResidence(t)
	defer cleanupTestData()

	// Create tasks with different active states
	tasks := []*models.Task{
		{Title: "active_task", IsCancelled: false, IsArchived: false},
		{Title: "cancelled_task", IsCancelled: true, IsArchived: false},
		{Title: "archived_task", IsCancelled: false, IsArchived: true},
		{Title: "both_task", IsCancelled: true, IsArchived: true},
	}

	for _, task := range tasks {
		createTestTask(t, residenceID, task)
	}

	// Query using scope
	var scopeResults []models.Task
	err := testDB.Model(&models.Task{}).
		Scopes(scopes.ScopeForResidence(residenceID), scopes.ScopeActive).
		Find(&scopeResults).Error
	if err != nil {
		t.Fatalf("Scope query failed: %v", err)
	}

	// Query all tasks and filter with predicate
	var allTasks []models.Task
	testDB.Where("residence_id = ?", residenceID).Find(&allTasks)

	var predicateResults []models.Task
	for _, task := range allTasks {
		if predicates.IsActive(&task) {
			predicateResults = append(predicateResults, task)
		}
	}

	// Compare results
	if len(scopeResults) != len(predicateResults) {
		t.Errorf("ScopeActive returned %d tasks, IsActive predicate returned %d tasks",
			len(scopeResults), len(predicateResults))
	}

	// Should only have the active task
	if len(scopeResults) != 1 {
		t.Errorf("Expected 1 active task, got %d", len(scopeResults))
	}
}

// TestScopeCompletedMatchesPredicate verifies ScopeCompleted produces same results as IsCompleted
func TestScopeCompletedMatchesPredicate(t *testing.T) {
	if testDB == nil {
		t.Skip("Database not available")
	}

	residenceID := createTestResidence(t)
	defer cleanupTestData()

	now := time.Now().UTC()
	nextWeek := now.AddDate(0, 0, 7)

	// Create tasks with different completion states
	// Completed: NextDueDate nil AND has completions
	completedTask := createTestTask(t, residenceID, &models.Task{
		Title:       "completed_task",
		NextDueDate: nil,
		IsCancelled: false,
		IsArchived:  false,
	})
	createTestCompletion(t, completedTask.ID)

	// Not completed: has completions but NextDueDate set (recurring)
	recurringTask := createTestTask(t, residenceID, &models.Task{
		Title:       "recurring_with_completion",
		NextDueDate: timePtr(nextWeek),
		IsCancelled: false,
		IsArchived:  false,
	})
	createTestCompletion(t, recurringTask.ID)

	// Not completed: NextDueDate nil but no completions
	createTestTask(t, residenceID, &models.Task{
		Title:       "no_completions",
		NextDueDate: nil,
		IsCancelled: false,
		IsArchived:  false,
	})

	// Not completed: has NextDueDate, no completions
	createTestTask(t, residenceID, &models.Task{
		Title:       "pending_task",
		NextDueDate: timePtr(nextWeek),
		IsCancelled: false,
		IsArchived:  false,
	})

	// Query using scope
	var scopeResults []models.Task
	err := testDB.Model(&models.Task{}).
		Scopes(scopes.ScopeForResidence(residenceID), scopes.ScopeCompleted).
		Find(&scopeResults).Error
	if err != nil {
		t.Fatalf("Scope query failed: %v", err)
	}

	// Query all tasks with completions preloaded and filter with predicate
	var allTasks []models.Task
	testDB.Preload("Completions").Where("residence_id = ?", residenceID).Find(&allTasks)

	var predicateResults []models.Task
	for _, task := range allTasks {
		if predicates.IsCompleted(&task) {
			predicateResults = append(predicateResults, task)
		}
	}

	// Compare results
	if len(scopeResults) != len(predicateResults) {
		t.Errorf("ScopeCompleted returned %d tasks, IsCompleted predicate returned %d tasks",
			len(scopeResults), len(predicateResults))
	}

	// Should only have the completed task (nil NextDueDate + has completion)
	if len(scopeResults) != 1 {
		t.Errorf("Expected 1 completed task, got %d", len(scopeResults))
	}
}

// TestScopeOverdueMatchesPredicate verifies ScopeOverdue produces same results as IsOverdue
func TestScopeOverdueMatchesPredicate(t *testing.T) {
	if testDB == nil {
		t.Skip("Database not available")
	}

	residenceID := createTestResidence(t)
	defer cleanupTestData()

	now := time.Now().UTC()
	yesterday := now.AddDate(0, 0, -1)
	tomorrow := now.AddDate(0, 0, 1)

	// Overdue: NextDueDate in past, active, not completed
	createTestTask(t, residenceID, &models.Task{
		Title:       "overdue_task",
		NextDueDate: timePtr(yesterday),
		IsCancelled: false,
		IsArchived:  false,
	})

	// Overdue: DueDate in past (NextDueDate nil, no completions)
	createTestTask(t, residenceID, &models.Task{
		Title:       "overdue_duedate",
		NextDueDate: nil,
		DueDate:     timePtr(yesterday),
		IsCancelled: false,
		IsArchived:  false,
	})

	// Not overdue: future date
	createTestTask(t, residenceID, &models.Task{
		Title:       "future_task",
		NextDueDate: timePtr(tomorrow),
		IsCancelled: false,
		IsArchived:  false,
	})

	// Not overdue: cancelled
	createTestTask(t, residenceID, &models.Task{
		Title:       "cancelled_overdue",
		NextDueDate: timePtr(yesterday),
		IsCancelled: true,
		IsArchived:  false,
	})

	// Not overdue: completed (NextDueDate nil with completion)
	completedTask := createTestTask(t, residenceID, &models.Task{
		Title:       "completed_past_due",
		NextDueDate: nil,
		DueDate:     timePtr(yesterday),
		IsCancelled: false,
		IsArchived:  false,
	})
	createTestCompletion(t, completedTask.ID)

	// Not overdue: no due date
	createTestTask(t, residenceID, &models.Task{
		Title:       "no_due_date",
		NextDueDate: nil,
		DueDate:     nil,
		IsCancelled: false,
		IsArchived:  false,
	})

	// Query using scope
	var scopeResults []models.Task
	err := testDB.Model(&models.Task{}).
		Scopes(scopes.ScopeForResidence(residenceID), scopes.ScopeOverdue(now)).
		Find(&scopeResults).Error
	if err != nil {
		t.Fatalf("Scope query failed: %v", err)
	}

	// Query all tasks with completions preloaded and filter with predicate
	var allTasks []models.Task
	testDB.Preload("Completions").Where("residence_id = ?", residenceID).Find(&allTasks)

	var predicateResults []models.Task
	for _, task := range allTasks {
		if predicates.IsOverdue(&task, now) {
			predicateResults = append(predicateResults, task)
		}
	}

	// Compare results
	if len(scopeResults) != len(predicateResults) {
		t.Errorf("ScopeOverdue returned %d tasks, IsOverdue predicate returned %d tasks",
			len(scopeResults), len(predicateResults))
		t.Logf("Scope results: %v", getTaskTitles(scopeResults))
		t.Logf("Predicate results: %v", getTaskTitles(predicateResults))
	}

	// Should have 2 overdue tasks
	if len(scopeResults) != 2 {
		t.Errorf("Expected 2 overdue tasks, got %d", len(scopeResults))
	}
}

// TestScopeOverdueWithSameDayTask tests day-based overdue comparison.
// With day-based logic, a task due TODAY is NOT overdue during that same day.
// It only becomes overdue the NEXT day. Both scope and predicate should agree.
func TestScopeOverdueWithSameDayTask(t *testing.T) {
	if testDB == nil {
		t.Skip("Database not available")
	}

	residenceID := createTestResidence(t)
	defer cleanupTestData()

	// Create a task due at midnight today (simulating a DATE column)
	now := time.Now().UTC()
	todayMidnight := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.UTC)

	createTestTask(t, residenceID, &models.Task{
		Title:       "due_today_midnight",
		NextDueDate: timePtr(todayMidnight),
		IsCancelled: false,
		IsArchived:  false,
	})

	// Query using scope with current time (after midnight)
	var scopeResults []models.Task
	err := testDB.Model(&models.Task{}).
		Scopes(scopes.ScopeForResidence(residenceID), scopes.ScopeOverdue(now)).
		Find(&scopeResults).Error
	if err != nil {
		t.Fatalf("Scope query failed: %v", err)
	}

	// Query with predicate
	var allTasks []models.Task
	testDB.Preload("Completions").Where("residence_id = ?", residenceID).Find(&allTasks)

	var predicateResults []models.Task
	for _, task := range allTasks {
		if predicates.IsOverdue(&task, now) {
			predicateResults = append(predicateResults, task)
		}
	}

	// Both should agree: with day-based comparison, task due today is NOT overdue
	if len(scopeResults) != len(predicateResults) {
		t.Errorf("Scope/predicate mismatch! Scope returned %d, predicate returned %d",
			len(scopeResults), len(predicateResults))
	}

	// With day-based comparison, task due today should NOT be overdue (it's due soon)
	if len(scopeResults) != 0 {
		t.Errorf("Task due today should NOT be overdue, got %d results (expected 0)", len(scopeResults))
	}
}

// TestScopeDueSoonMatchesPredicate verifies ScopeDueSoon produces same results as IsDueSoon
func TestScopeDueSoonMatchesPredicate(t *testing.T) {
	if testDB == nil {
		t.Skip("Database not available")
	}

	residenceID := createTestResidence(t)
	defer cleanupTestData()

	now := time.Now().UTC()
	yesterday := now.AddDate(0, 0, -1)
	in5Days := now.AddDate(0, 0, 5)
	in60Days := now.AddDate(0, 0, 60)
	daysThreshold := 30

	// Due soon: within threshold
	createTestTask(t, residenceID, &models.Task{
		Title:       "due_soon",
		NextDueDate: timePtr(in5Days),
		IsCancelled: false,
		IsArchived:  false,
	})

	// Not due soon: beyond threshold
	createTestTask(t, residenceID, &models.Task{
		Title:       "far_future",
		NextDueDate: timePtr(in60Days),
		IsCancelled: false,
		IsArchived:  false,
	})

	// Not due soon: overdue (in past)
	createTestTask(t, residenceID, &models.Task{
		Title:       "overdue",
		NextDueDate: timePtr(yesterday),
		IsCancelled: false,
		IsArchived:  false,
	})

	// Not due soon: cancelled
	createTestTask(t, residenceID, &models.Task{
		Title:       "cancelled",
		NextDueDate: timePtr(in5Days),
		IsCancelled: true,
		IsArchived:  false,
	})

	// Query using scope
	var scopeResults []models.Task
	err := testDB.Model(&models.Task{}).
		Scopes(scopes.ScopeForResidence(residenceID), scopes.ScopeDueSoon(now, daysThreshold)).
		Find(&scopeResults).Error
	if err != nil {
		t.Fatalf("Scope query failed: %v", err)
	}

	// Query all tasks and filter with predicate
	var allTasks []models.Task
	testDB.Preload("Completions").Where("residence_id = ?", residenceID).Find(&allTasks)

	var predicateResults []models.Task
	for _, task := range allTasks {
		if predicates.IsDueSoon(&task, now, daysThreshold) {
			predicateResults = append(predicateResults, task)
		}
	}

	// Compare results
	if len(scopeResults) != len(predicateResults) {
		t.Errorf("ScopeDueSoon returned %d tasks, IsDueSoon predicate returned %d tasks",
			len(scopeResults), len(predicateResults))
	}

	// Should have 1 due soon task
	if len(scopeResults) != 1 {
		t.Errorf("Expected 1 due soon task, got %d", len(scopeResults))
	}
}

// TestScopeUpcomingMatchesPredicate verifies ScopeUpcoming produces same results as IsUpcoming
func TestScopeUpcomingMatchesPredicate(t *testing.T) {
	if testDB == nil {
		t.Skip("Database not available")
	}

	residenceID := createTestResidence(t)
	defer cleanupTestData()

	now := time.Now().UTC()
	in5Days := now.AddDate(0, 0, 5)
	in60Days := now.AddDate(0, 0, 60)
	daysThreshold := 30

	// Upcoming: beyond threshold
	createTestTask(t, residenceID, &models.Task{
		Title:       "far_future",
		NextDueDate: timePtr(in60Days),
		IsCancelled: false,
		IsArchived:  false,
	})

	// Upcoming: no due date
	createTestTask(t, residenceID, &models.Task{
		Title:       "no_due_date",
		NextDueDate: nil,
		DueDate:     nil,
		IsCancelled: false,
		IsArchived:  false,
	})

	// Not upcoming: within due soon threshold
	createTestTask(t, residenceID, &models.Task{
		Title:       "due_soon",
		NextDueDate: timePtr(in5Days),
		IsCancelled: false,
		IsArchived:  false,
	})

	// Not upcoming: cancelled
	createTestTask(t, residenceID, &models.Task{
		Title:       "cancelled",
		NextDueDate: timePtr(in60Days),
		IsCancelled: true,
		IsArchived:  false,
	})

	// Query using scope
	var scopeResults []models.Task
	err := testDB.Model(&models.Task{}).
		Scopes(scopes.ScopeForResidence(residenceID), scopes.ScopeUpcoming(now, daysThreshold)).
		Find(&scopeResults).Error
	if err != nil {
		t.Fatalf("Scope query failed: %v", err)
	}

	// Query all tasks and filter with predicate
	var allTasks []models.Task
	testDB.Preload("Completions").Where("residence_id = ?", residenceID).Find(&allTasks)

	var predicateResults []models.Task
	for _, task := range allTasks {
		if predicates.IsUpcoming(&task, now, daysThreshold) {
			predicateResults = append(predicateResults, task)
		}
	}

	// Compare results
	if len(scopeResults) != len(predicateResults) {
		t.Errorf("ScopeUpcoming returned %d tasks, IsUpcoming predicate returned %d tasks",
			len(scopeResults), len(predicateResults))
	}

	// Should have 2 upcoming tasks
	if len(scopeResults) != 2 {
		t.Errorf("Expected 2 upcoming tasks, got %d", len(scopeResults))
	}
}

// TestScopeInProgressMatchesPredicate verifies ScopeInProgress produces same results as IsInProgress
func TestScopeInProgressMatchesPredicate(t *testing.T) {
	if testDB == nil {
		t.Skip("Database not available")
	}

	residenceID := createTestResidence(t)
	defer cleanupTestData()

	// In progress task
	createTestTask(t, residenceID, &models.Task{
		Title:      "in_progress",
		InProgress: true,
	})

	// Not in progress: InProgress is false
	createTestTask(t, residenceID, &models.Task{
		Title:      "not_in_progress",
		InProgress: false,
	})

	// Query using scope
	var scopeResults []models.Task
	err := testDB.Model(&models.Task{}).
		Scopes(scopes.ScopeForResidence(residenceID), scopes.ScopeInProgress).
		Find(&scopeResults).Error
	if err != nil {
		t.Fatalf("Scope query failed: %v", err)
	}

	// Query all tasks and filter with predicate
	var allTasks []models.Task
	testDB.Where("residence_id = ?", residenceID).Find(&allTasks)

	var predicateResults []models.Task
	for _, task := range allTasks {
		if predicates.IsInProgress(&task) {
			predicateResults = append(predicateResults, task)
		}
	}

	// Compare results
	if len(scopeResults) != len(predicateResults) {
		t.Errorf("ScopeInProgress returned %d tasks, IsInProgress predicate returned %d tasks",
			len(scopeResults), len(predicateResults))
	}

	// Should have 1 in progress task
	if len(scopeResults) != 1 {
		t.Errorf("Expected 1 in progress task, got %d", len(scopeResults))
	}
}

// TestScopeForResidences verifies filtering by multiple residence IDs
func TestScopeForResidences(t *testing.T) {
	if testDB == nil {
		t.Skip("Database not available")
	}

	residenceID1 := createTestResidence(t)
	residenceID2 := createTestResidence(t)
	residenceID3 := createTestResidence(t)
	defer cleanupTestData()

	// Create tasks in different residences
	createTestTask(t, residenceID1, &models.Task{Title: "task_r1"})
	createTestTask(t, residenceID2, &models.Task{Title: "task_r2"})
	createTestTask(t, residenceID3, &models.Task{Title: "task_r3"})

	// Query for residences 1 and 2 only
	var results []models.Task
	err := testDB.Model(&models.Task{}).
		Scopes(scopes.ScopeForResidences([]uint{residenceID1, residenceID2})).
		Find(&results).Error
	if err != nil {
		t.Fatalf("Scope query failed: %v", err)
	}

	if len(results) != 2 {
		t.Errorf("Expected 2 tasks from residences 1 and 2, got %d", len(results))
	}

	// Verify empty slice returns no results
	var emptyResults []models.Task
	testDB.Model(&models.Task{}).
		Scopes(scopes.ScopeForResidences([]uint{})).
		Find(&emptyResults)

	if len(emptyResults) != 0 {
		t.Errorf("Expected 0 tasks for empty residence list, got %d", len(emptyResults))
	}
}

// Helper to get task titles for debugging
func getTaskTitles(tasks []models.Task) []string {
	titles := make([]string, len(tasks))
	for i, task := range tasks {
		titles[i] = task.Title
	}
	return titles
}