using System.Linq;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
namespace MCPForUnity.Editor.Helpers
{
/// <summary>
/// Unified parameter validation and extraction wrapper for MCP tools.
/// Eliminates repetitive IsNullOrEmpty checks and provides consistent error messages.
/// </summary>
public class ToolParams
{
private readonly JObject _params;
public ToolParams(JObject @params)
{
_params = @params ?? throw new ArgumentNullException(nameof(@params));
}
/// <summary>
/// Get required string parameter. Returns ErrorResponse if missing or empty.
/// </summary>
public Result<string> GetRequired(string key, string errorMessage = null)
{
var value = GetString(key);
if (string.IsNullOrEmpty(value))
{
return Result<string>.Error(
errorMessage ?? $"'{key}' parameter is required."
);
}
return Result<string>.Success(value);
}
/// <summary>
/// Get optional string parameter with default value.
/// Supports both snake_case and camelCase automatically.
/// </summary>
public string Get(string key, string defaultValue = null)
{
return GetString(key) ?? defaultValue;
}
/// <summary>
/// Get optional int parameter.
/// </summary>
public int? GetInt(string key, int? defaultValue = null)
{
var str = GetString(key);
if (string.IsNullOrEmpty(str)) return defaultValue;
return int.TryParse(str, out var result) ? result : defaultValue;
}
/// <summary>
/// Get optional bool parameter.
/// Supports both snake_case and camelCase automatically.
/// </summary>
public bool GetBool(string key, bool defaultValue = false)
{
return ParamCoercion.CoerceBool(GetToken(key), defaultValue);
}
/// <summary>
/// Get optional float parameter.
/// </summary>
public float? GetFloat(string key, float? defaultValue = null)
{
var str = GetString(key);
if (string.IsNullOrEmpty(str)) return defaultValue;
return float.TryParse(str, out var result) ? result : defaultValue;
}
/// <summary>
/// Check if parameter exists (even if null).
/// Supports both snake_case and camelCase automatically.
/// </summary>
public bool Has(string key)
{
return GetToken(key) != null;
}
/// <summary>
/// Get raw JToken for complex types.
/// Supports both snake_case and camelCase automatically.
/// </summary>
public JToken GetRaw(string key)
{
return GetToken(key);
}
/// <summary>
/// Get optional string array parameter, handling various MCP serialization formats:
/// plain strings, JSON arrays, stringified JSON arrays, and double-serialized arrays.
/// Supports both snake_case and camelCase automatically.
/// </summary>
public string[] GetStringArray(string key)
{
return CoerceStringArray(GetToken(key));
}
/// <summary>
/// Coerces a JToken to a string array, handling various MCP serialization formats:
/// plain strings, JSON arrays, stringified JSON arrays, and double-serialized arrays.
/// </summary>
internal static string[] CoerceStringArray(JToken token)
{
if (token == null || token.Type == JTokenType.Null) return null;
if (token.Type == JTokenType.String)
{
var value = token.ToString();
if (string.IsNullOrWhiteSpace(value)) return null;
// Handle stringified JSON arrays (e.g. "[\"name1\", \"name2\"]")
var trimmed = value.Trim();
if (trimmed.StartsWith("[") && trimmed.EndsWith("]"))
{
try
{
var parsed = JArray.Parse(trimmed);
var values = parsed.Values<string>()
.Where(s => !string.IsNullOrWhiteSpace(s))
.ToArray();
return values.Length > 0 ? values : null;
}
catch (JsonException) { /* not a valid JSON array, treat as plain string */ }
}
return new[] { value };
}
if (token.Type == JTokenType.Array)
{
var array = token as JArray;
if (array == null || array.Count == 0) return null;
// Handle double-serialized arrays: MCP bridge may send ["[\"name1\"]"]
// where the inner string is a stringified JSON array
if (array.Count == 1 && array[0].Type == JTokenType.String)
{
var inner = array[0].ToString().Trim();
if (inner.StartsWith("[") && inner.EndsWith("]"))
{
try
{
array = JArray.Parse(inner);
}
catch (JsonException) { /* use original array */ }
}
}
// Handle single-level nested arrays: [[name1, name2]]
// Multi-element outer arrays (e.g. [["a"], ["b"]]) are not unwrapped
// as that format is not produced by known MCP clients.
else if (array.Count == 1 && array[0].Type == JTokenType.Array)
{
array = array[0] as JArray ?? array;
}
var values = array
.Values<string>()
.Where(s => !string.IsNullOrWhiteSpace(s))
.ToArray();
return values.Length > 0 ? values : null;
}
return null;
}
/// <summary>
/// Get raw JToken with snake_case/camelCase fallback.
/// </summary>
private JToken GetToken(string key)
{
// Try exact match first
var token = _params[key];
if (token != null) return token;
// Try snake_case if camelCase was provided
var snakeKey = ToSnakeCase(key);
if (snakeKey != key)
{
token = _params[snakeKey];
if (token != null) return token;
}
// Try camelCase if snake_case was provided
var camelKey = ToCamelCase(key);
if (camelKey != key)
{
token = _params[camelKey];
}
return token;
}
private string GetString(string key)
{
// Try exact match first
var value = _params[key]?.ToString();
if (value != null) return value;
// Try snake_case if camelCase was provided
var snakeKey = ToSnakeCase(key);
if (snakeKey != key)
{
value = _params[snakeKey]?.ToString();
if (value != null) return value;
}
// Try camelCase if snake_case was provided
var camelKey = ToCamelCase(key);
if (camelKey != key)
{
value = _params[camelKey]?.ToString();
}
return value;
}
private static string ToSnakeCase(string str) => StringCaseUtility.ToSnakeCase(str);
private static string ToCamelCase(string str) => StringCaseUtility.ToCamelCase(str);
}
/// <summary>
/// Result type for operations that can fail with an error message.
/// </summary>
public class Result<T>
{
public bool IsSuccess { get; }
public T Value { get; }
public string ErrorMessage { get; }
private Result(bool isSuccess, T value, string errorMessage)
{
IsSuccess = isSuccess;
Value = value;
ErrorMessage = errorMessage;
}
public static Result<T> Success(T value) => new Result<T>(true, value, null);
public static Result<T> Error(string errorMessage) => new Result<T>(false, default, errorMessage);
/// <summary>
/// Get value or return ErrorResponse.
/// </summary>
public object GetOrError(out T value)
{
if (IsSuccess)
{
value = Value;
return null;
}
value = default;
return new ErrorResponse(ErrorMessage);
}
}
}
