init

internal/repository/budget_repository.go

@@ -0,0 +1,169 @@
+package repository
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"accounting-app/internal/models"
+
+	"gorm.io/gorm"
+)
+
+// Common repository errors
+var (
+	ErrBudgetNotFound = errors.New("budget not found")
+	ErrBudgetInUse    = errors.New("budget is in use and cannot be deleted")
+)
+
+// BudgetRepository handles database operations for budgets
+type BudgetRepository struct {
+	db *gorm.DB
+}
+
+// NewBudgetRepository creates a new BudgetRepository instance
+func NewBudgetRepository(db *gorm.DB) *BudgetRepository {
+	return &BudgetRepository{db: db}
+}
+
+// Create creates a new budget in the database
+func (r *BudgetRepository) Create(budget *models.Budget) error {
+	if err := r.db.Create(budget).Error; err != nil {
+		return fmt.Errorf("failed to create budget: %w", err)
+	}
+	return nil
+}
+
+// GetByID retrieves a budget by its ID
+func (r *BudgetRepository) GetByID(userID uint, id uint) (*models.Budget, error) {
+	var budget models.Budget
+	if err := r.db.Preload("Category").Preload("Account").Where("user_id = ?", userID).First(&budget, id).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, ErrBudgetNotFound
+		}
+		return nil, fmt.Errorf("failed to get budget: %w", err)
+	}
+	return &budget, nil
+}
+
+// GetAll retrieves all budgets for a user
+func (r *BudgetRepository) GetAll(userID uint) ([]models.Budget, error) {
+	var budgets []models.Budget
+	if err := r.db.Preload("Category").Preload("Account").Where("user_id = ?", userID).Order("created_at DESC").Find(&budgets).Error; err != nil {
+		return nil, fmt.Errorf("failed to get budgets: %w", err)
+	}
+	return budgets, nil
+}
+
+// Update updates an existing budget in the database
+func (r *BudgetRepository) Update(budget *models.Budget) error {
+	// First check if the budget exists
+	var existing models.Budget
+	if err := r.db.Where("user_id = ?", budget.UserID).First(&existing, budget.ID).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return ErrBudgetNotFound
+		}
+		return fmt.Errorf("failed to check budget existence: %w", err)
+	}
+
+	// Update the budget
+	if err := r.db.Save(budget).Error; err != nil {
+		return fmt.Errorf("failed to update budget: %w", err)
+	}
+	return nil
+}
+
+// Delete deletes a budget by its ID
+func (r *BudgetRepository) Delete(userID uint, id uint) error {
+	// First check if the budget exists
+	var budget models.Budget
+	if err := r.db.Where("user_id = ?", userID).First(&budget, id).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return ErrBudgetNotFound
+		}
+		return fmt.Errorf("failed to check budget existence: %w", err)
+	}
+
+	// Delete the budget (soft delete due to gorm.DeletedAt field)
+	if err := r.db.Delete(&budget).Error; err != nil {
+		return fmt.Errorf("failed to delete budget: %w", err)
+	}
+	return nil
+}
+
+// GetByCategoryID retrieves all budgets for a specific category and user
+func (r *BudgetRepository) GetByCategoryID(userID, categoryID uint) ([]models.Budget, error) {
+	var budgets []models.Budget
+	if err := r.db.Preload("Category").Preload("Account").Where("user_id = ? AND category_id = ?", userID, categoryID).Order("created_at DESC").Find(&budgets).Error; err != nil {
+		return nil, fmt.Errorf("failed to get budgets by category: %w", err)
+	}
+	return budgets, nil
+}
+
+// GetByAccountID retrieves all budgets for a specific account and user
+func (r *BudgetRepository) GetByAccountID(userID, accountID uint) ([]models.Budget, error) {
+	var budgets []models.Budget
+	if err := r.db.Preload("Category").Preload("Account").Where("user_id = ? AND account_id = ?", userID, accountID).Order("created_at DESC").Find(&budgets).Error; err != nil {
+		return nil, fmt.Errorf("failed to get budgets by account: %w", err)
+	}
+	return budgets, nil
+}
+
+// GetByPeriodType retrieves all budgets of a specific period type for a user
+func (r *BudgetRepository) GetByPeriodType(userID uint, periodType models.PeriodType) ([]models.Budget, error) {
+	var budgets []models.Budget
+	if err := r.db.Preload("Category").Preload("Account").Where("user_id = ? AND period_type = ?", userID, periodType).Order("created_at DESC").Find(&budgets).Error; err != nil {
+		return nil, fmt.Errorf("failed to get budgets by period type: %w", err)
+	}
+	return budgets, nil
+}
+
+// GetActiveBudgets retrieves all budgets that are currently active for a user
+func (r *BudgetRepository) GetActiveBudgets(userID uint, currentDate time.Time) ([]models.Budget, error) {
+	var budgets []models.Budget
+	query := r.db.Preload("Category").Preload("Account").
+		Where("user_id = ?", userID).
+		Where("start_date <= ?", currentDate).
+		Where("end_date IS NULL OR end_date >= ?", currentDate).
+		Order("created_at DESC")
+
+	if err := query.Find(&budgets).Error; err != nil {
+		return nil, fmt.Errorf("failed to get active budgets: %w", err)
+	}
+	return budgets, nil
+}
+
+// GetSpentAmount calculates the total spent amount for a budget within a specific date range
+func (r *BudgetRepository) GetSpentAmount(budget *models.Budget, startDate, endDate time.Time) (float64, error) {
+	var totalSpent float64
+
+	query := r.db.Model(&models.Transaction{}).
+		Where("user_id = ?", budget.UserID).
+		Where("type = ?", models.TransactionTypeExpense).
+		Where("transaction_date >= ? AND transaction_date <= ?", startDate, endDate)
+
+	// Filter by category if specified
+	if budget.CategoryID != nil {
+		query = query.Where("category_id = ?", *budget.CategoryID)
+	}
+
+	// Filter by account if specified
+	if budget.AccountID != nil {
+		query = query.Where("account_id = ?", *budget.AccountID)
+	}
+
+	if err := query.Select("COALESCE(SUM(amount), 0)").Scan(&totalSpent).Error; err != nil {
+		return 0, fmt.Errorf("failed to calculate spent amount: %w", err)
+	}
+
+	return totalSpent, nil
+}
+
+// ExistsByID checks if a budget with the given ID exists for a user
+func (r *BudgetRepository) ExistsByID(userID, id uint) (bool, error) {
+	var count int64
+	if err := r.db.Model(&models.Budget{}).Where("user_id = ? AND id = ?", userID, id).Count(&count).Error; err != nil {
+		return false, fmt.Errorf("failed to check budget existence: %w", err)
+	}
+	return count > 0, nil
+}