using PowerCSharp.Compatibility.Extensions;

// URL query parameter manipulation
string baseUrl = "https://example.com/search";
var parameters = new Dictionary<string, string>
{
    ["q"] = "csharp tutorial",
    ["page"] = "1",
    ["lang"] = "en"
};

string fullUrl = baseUrl.AppendQueryParameters(parameters);
// Result: "https://example.com/search?q=csharp%20tutorial&page=1&lang=en"

using PowerCSharp.Compatibility.Helpers;

// In MVC filters or other synchronous contexts
public class MyMvcFilter : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        // Safely call async methods from sync context
        var result = AsyncHelper.RunSync(() => GetUserDataAsync(filterContext.HttpContext.User));
        
        filterContext.ActionParameters["userData"] = result;
        base.OnActionExecuting(filterContext);
    }
    
    private async Task<UserData> GetUserDataAsync(IPrincipal user)
    {
        // Your async operation here
        return await userService.GetUserAsync(user.Identity.Name);
    }
}

using PowerCSharp.Compatibility.Utilities;
using PowerCSharp.Compatibility.Utilities.Attributes;

// Method parameter validation
public void ProcessData([ValidatedNotNull] string input, int count)
{
    if (string.IsNullOrEmpty(input))
        throw new ArgumentException("Input cannot be null or empty");
    
    // Additional validation logic
}

// Validation helper usage
bool isValid = ValidationHelper.IsValidEmail("user@example.com");
bool isNumeric = ValidationHelper.IsNumeric("12345");

// Phase 1: .NET Framework with PowerCSharp.Compatibility
using PowerCSharp.Compatibility.Extensions;
string url = oldUrl.AppendQueryParameters(params);

// Phase 3: Modern .NET with PowerCSharp.Extensions  
using PowerCSharp.Extensions;
Uri uri = new Uri(oldUrl).AddParameter("key", "value");

// .NET Framework application
using PowerCSharp.Compatibility.Extensions;      // For System.Web utilities
using PowerCSharp.Compatibility.Helpers;         // For async bridging
using PowerCSharp.Core;                          // Shared interfaces

using PowerCSharp.Compatibility.Extensions;
using PowerCSharp.Compatibility.Helpers;

public partial class SearchPage : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            // Build search URL with parameters
            var searchParams = new Dictionary<string, string>
            {
                ["q"] = Request.QueryString["q"] ?? "",
                ["category"] = ddlCategories.SelectedValue,
                ["page"] = "1"
            };
            
            string searchUrl = "~/Search.aspx".AppendQueryParameters(searchParams);
            Response.Redirect(searchUrl);
        }
    }
    
    protected async void btnSearch_Click(object sender, EventArgs e)
    {
        // In Web Forms, you might need to call async from sync
        var results = AsyncHelper.RunSync(() => SearchService.SearchAsync(txtSearch.Text));
        gvResults.DataSource = results;
        gvResults.DataBind();
    }
}

using PowerCSharp.Compatibility.Helpers;
using System.Web.Mvc;

public class UserAuthorizationFilter : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        var user = filterContext.HttpContext.User;
        
        // Safely call async authorization service
        var isAuthorized = AsyncHelper.RunSync(() => 
            AuthorizationService.IsUserAuthorizedAsync(user.Identity.Name));
        
        if (!isAuthorized)
        {
            filterContext.Result = new HttpNotFoundResult();
            return;
        }
        
        base.OnActionExecuting(filterContext);
    }
}

using PowerCSharp.Compatibility.Extensions;
using PowerCSharp.Compatibility.Utilities;

public class LegacyApiService
{
    public string BuildApiUrl(string baseUrl, object parameters)
    {
        var dict = new Dictionary<string, string>();
        
        // Convert object to dictionary
        foreach (var prop in parameters.GetType().GetProperties())
        {
            var value = prop.GetValue(parameters)?.ToString() ?? "";
            if (!string.IsNullOrEmpty(value))
            {
                dict[prop.Name] = value;
            }
        }
        
        return baseUrl.AppendQueryParameters(dict);
    }
    
    public bool ValidateRequest(string request)
    {
        return !string.IsNullOrEmpty(request) && 
               ValidationHelper.IsNumeric(request.Substring(0, 4));
    }
}