moving insert to another model and done so in database internal

internal/database/revenue.go

@@ -82,3 +82,52 @@ func GetRevenueByCategory(db *sql.DB, companyID int, categoryID int) ([]model.Re
 
 	return revenues, nil
 }
+
+func InsertRevenue(db *sql.DB, rev model.RevenueInsert) error {
+	_, err := GetCompanyByID(db, rev.CompanyID)
+	if err != nil {
+		return err
+	}
+
+	_, err = GetCurrencyByID(db, rev.CurrencyID)
+	if err != nil {
+		return err
+	}
+
+	// checking if period is in db, in case not will insert
+	_, err = GetPeriodByID(db, rev.Period.ID)
+	if err != nil {
+		err = rev.Period.Insert(db)
+		if err != nil {
+			return err
+		}
+	}
+	// Getting Category, if error, trying to insert the category with the company.
+	category, err := GetCategoryByName(db, rev.CompanyID, rev.CategoryName)
+	if err != nil {
+		err := InsertCategory(db, model.RevenueCategory{
+			CompanyID: rev.CompanyID,
+			ParentID:  &rev.ParentID,
+			Name:      rev.CategoryName,
+		})
+		if err != nil {
+			return err
+		}
+
+	}
+	category, err = GetCategoryByName(db, rev.CompanyID, rev.CategoryName)
+	if err != nil {
+		return err
+	}
+
+	_, err = db.Exec(
+		`INSERT INTO revenue_entries (company_id, currency_id, category_id, period_id, value)
+         VALUES (?, ?, ?, ?, ?)`,
+		rev.CompanyID, rev.CurrencyID, category.ID, rev.Period.ID, rev.Value,
+	)
+	if err != nil {
+		return fmt.Errorf("insert revenue_entries: %w", err)
+	}
+
+	return nil
+}