using System;
using System.Data;
using System.Web;
using BlogEngine.Core.Web.Controls;
using BlogEngine.Core.Web.Extensions;

[Extension("SEO Redirection Urls", "1.0", "<a href=\"http://www.spicelogic.com\">SpiceLogic Inc.</a>")]
public class SeoRedirection
{
    static protected ExtensionSettings _settings;

	public SeoRedirection()
	{
        ExtensionSettings settings = new ExtensionSettings("SeoRedirection");
        settings.AddParameter("OldUrl", "Old Url", 255, true, true, ParameterType.String);
        settings.AddParameter("NewUrl", "New Url", 255, true, false, ParameterType.String);

        // describe specific rules for entering parameters
        settings.Help = "Redirects an Old Url to New Url with Http Status Code 301";
        //------------------------------------------------------
        ExtensionManager.ImportSettings(settings);
        _settings = ExtensionManager.GetSettings("SeoRedirection");
	}
}

public class SeoRedirector : IHttpModule
{
    public void Dispose()
    {
    }

    public void Init(HttpApplication context)
    {
        context.BeginRequest += context_BeginRequest;
    }

    private static void context_BeginRequest(object sender, EventArgs e)
    {
        HttpContext context = ((HttpApplication)sender).Context;
        ExtensionSettings seoRedirectorSettings = ExtensionManager.GetSettings("SeoRedirection");
       
        if(seoRedirectorSettings != null)
        {
            DataTable table = seoRedirectorSettings.GetDataTable();
            string newUrl = null;
            foreach(DataRow row in table.Rows)
            {
                if(row["OldUrl"].ToString().Equals(context.Request.Url.AbsoluteUri, StringComparison.OrdinalIgnoreCase))
                {
                    newUrl = row["NewUrl"].ToString();
                    break;
                }
            }

            if(newUrl != null)
            {
                context.Response.StatusCode = 301;
                context.Response.Status = "301 Moved Permanently";
                context.Response.AddHeader("Location", newUrl);
            }
        }
 
    }
}