using System.Text.RegularExpressions;
namespace Sbroenne.ExcelMcp.Core.Commands.Table;
/// <summary>
/// Excel Table (ListObject) management commands - main partial class with shared state and helper methods
/// </summary>
public partial class TableCommands : ITableCommands
{
#region Constants and Validation
/// <summary>
/// Regex pattern for valid table names
/// </summary>
private static readonly Regex TableNameRegex = new(@"^[a-zA-Z_][a-zA-Z0-9_]*$", RegexOptions.Compiled);
/// <summary>
/// Maximum allowed table name length
/// </summary>
private const int MaxTableNameLength = 255;
/// <summary>
/// Validates a table name to prevent injection attacks and ensure Excel compatibility
/// </summary>
/// <param name="tableName">Table name to validate</param>
/// <exception cref="ArgumentException">Thrown if table name is invalid</exception>
private static void ValidateTableName(string tableName)
{
if (string.IsNullOrWhiteSpace(tableName))
{
throw new ArgumentException("Table name cannot be null or empty", nameof(tableName));
}
if (tableName.Length > MaxTableNameLength)
{
throw new ArgumentException(
$"Table name too long: {tableName.Length} characters (maximum: {MaxTableNameLength})",
nameof(tableName));
}
if (!TableNameRegex.IsMatch(tableName))
{
throw new ArgumentException(
$"Invalid table name '{tableName}'. Table names must start with a letter or underscore, " +
"and can only contain letters, numbers, and underscores (no spaces or special characters).",
nameof(tableName));
}
// Check for reserved names
string upperName = tableName.ToUpperInvariant();
if (upperName == "PRINT_AREA" || upperName == "PRINT_TITLES" ||
upperName == "_XLNM" || upperName.StartsWith("_XLNM.", StringComparison.Ordinal))
{
throw new ArgumentException(
$"Table name '{tableName}' is reserved by Excel",
nameof(tableName));
}
}
#endregion
#region Helper Methods
/// <summary>
/// Finds a table by name in the workbook, throwing if not found.
/// Delegates to CoreLookupHelpers.FindTable for the actual lookup.
/// </summary>
/// <param name="workbook">The workbook to search</param>
/// <param name="tableName">Name of the table to find</param>
/// <returns>The table object (caller must release)</returns>
/// <exception cref="InvalidOperationException">Thrown if table is not found</exception>
private static dynamic FindTable(dynamic workbook, string tableName)
=> CoreLookupHelpers.FindTable(workbook, tableName);
/// <summary>
/// Checks if a table with the given name exists in the workbook
/// </summary>
/// <param name="workbook">The workbook to search</param>
/// <param name="tableName">Name of the table to check</param>
/// <returns>True if table exists, false otherwise</returns>
private static bool TableExists(dynamic workbook, string tableName)
=> CoreLookupHelpers.TableExists(workbook, tableName);
#endregion
}
