using Microsoft.Data.SqlClient;
using ModelContextProtocol;
using SqlAugur.Services;
namespace SqlAugur.Tools;
/// <summary>
/// Helper methods for tool implementations.
/// </summary>
internal static class ToolHelper
{
/// <summary>
/// Executes an async tool operation with rate limiting and standardized exception handling.
/// Acquires a rate limit lease before executing, and releases the concurrency slot on completion.
/// Converts ArgumentException, InvalidOperationException, and SqlException to McpException.
/// </summary>
public static async Task<string> ExecuteAsync(IRateLimitingService rateLimiter, Func<Task<string>> operation,
CancellationToken cancellationToken = default)
{
using var lease = await rateLimiter.AcquireAsync(cancellationToken);
try
{
return await operation();
}
catch (Exception ex) when (ex is ArgumentException or InvalidOperationException or SqlException)
{
throw new McpException(ex.Message);
}
}
/// <summary>
/// Saves content to a file, validating the extension, creating directories as needed,
/// and returning a confirmation message with the line count.
/// </summary>
public static async Task<string> SaveToFileAsync(
string content, string outputPath, string allowedExtension,
string description, CancellationToken cancellationToken)
{
var fullPath = Path.GetFullPath(outputPath);
if (!Path.GetExtension(fullPath).Equals(allowedExtension, StringComparison.OrdinalIgnoreCase))
throw new McpException($"Output path must have a {allowedExtension} file extension.");
var directory = Path.GetDirectoryName(fullPath);
if (directory is not null)
Directory.CreateDirectory(directory);
await File.WriteAllTextAsync(fullPath, content, cancellationToken);
var lineCount = content.AsSpan().Count('\n');
return $"{description} saved to {fullPath} ({lineCount} lines)";
}
/// <summary>
/// Parses a comma-separated string into a deduplicated list.
/// Returns null if the input is null, empty, or contains only whitespace/commas.
/// </summary>
public static IReadOnlyList<string>? ParseCommaSeparatedList(string? input)
{
if (string.IsNullOrWhiteSpace(input))
return null;
var items = input.Split(',')
.Select(s => s.Trim())
.Where(s => s.Length > 0)
.Distinct(StringComparer.OrdinalIgnoreCase)
.ToList();
return items.Count > 0 ? items : null;
}
}
