using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

using System.Net;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;
using System.Xml;

public partial class fs : System.Web.UI.Page
{

    private WebRequest _amazonRequest;
    private WebRequest _yahooRequest;
    private WebRequest _ebayRequest;

    private XmlDocument _amazonDoc;
    private XmlDocument _yahooDoc;
    private XmlDocument _ebayDoc;

    private bool _insufficientArguments = false;

    protected void Page_Load(object sender, EventArgs e)
    {
        string strKeywords = Request.QueryString["Keywords"]; // Keywords

        if ((strKeywords != "") & (strKeywords != null))
        {
            PageAsyncTask amazonTask = new PageAsyncTask(
                new BeginEventHandler(BeginAmazonAsyncOperation),
                new EndEventHandler(EndAmazonAsyncOperation),
                new EndEventHandler(TimeoutAmazonAsyncOperation),
                null);
            RegisterAsyncTask(amazonTask);
            
            PageAsyncTask ebayTask = new PageAsyncTask(
                new BeginEventHandler(BeginEbayAsyncOperation),
                new EndEventHandler(EndEbayAsyncOperation),
                new EndEventHandler(TimeoutEbayAsyncOperation),
                null);
            RegisterAsyncTask(ebayTask);

            PageAsyncTask yahooTask = new PageAsyncTask(
                new BeginEventHandler(BeginYahooAsyncOperation),
                new EndEventHandler(EndYahooAsyncOperation),
                new EndEventHandler(TimeoutYahooAsyncOperation),
                null);
            RegisterAsyncTask(yahooTask);

            
        }
        else
        {
            _insufficientArguments = true;
        }
    }

    protected void Page_PreRenderComplete(object sender, EventArgs e)
    {
        try
        {
            // This is the last thing to happen
            /////////////////////////////
            if (_insufficientArguments)
            {
                // do nothing
            }
            else
            {                
                // Merge the results of all 3 calls
                XmlDocument resultsDoc = new XmlDocument();
                XmlNode cont = resultsDoc.CreateElement("BaeBo");
                resultsDoc.AppendChild(cont);

                // first document to merge
                XmlNode imported;
                if (_amazonDoc != null)
                {
                    imported = resultsDoc.ImportNode(_amazonDoc.DocumentElement, true);
                    resultsDoc.DocumentElement.AppendChild(imported);
                }

                // second document to merge
                if (_yahooDoc != null)
                {
                    imported = resultsDoc.ImportNode(_yahooDoc.DocumentElement, true);
                    resultsDoc.DocumentElement.AppendChild(imported);
                }

                // third document to merge
                if (_ebayDoc != null)
                {
                    imported = resultsDoc.ImportNode(_ebayDoc.DocumentElement, true);
                    resultsDoc.DocumentElement.AppendChild(imported);
                }

                // print merged documents
                if (resultsDoc != null)
                {
                    Response.Clear();
                    Response.ContentType = "text/xml";
                    if (Request.QueryString["format"] == "rss")
                    {
                        Response.Write(webUtility.TransformDoc(resultsDoc, "ayerss"));
                    }
                    else
                    {
                        Response.Write(webUtility.ConvertXmlToString(resultsDoc));
                    }
                    
                    //Response.Write(webUtility.TransformDoc(resultsDoc, "ayerss"));
                }
            }
        }
        catch (Exception ex)
        {
            Response.Write("There was an error whilst merging your results. ");
            Response.Write(ex.Message);
        }        
        
    }

    protected override void  Render(HtmlTextWriter writer)
    {
        if (_insufficientArguments)
        {
            base.Render(writer);
        }
        else
        {
            // override and do nothing as in this case we're outputing XML
        }
    }
    
    IAsyncResult BeginAmazonAsyncOperation(object sender, EventArgs e, AsyncCallback cb, object state)
    {
        string strKeywords = webUtility.nvl(Request.QueryString, "Keywords");
        string strSearchIndex = webUtility.nvl(Request.QueryString, "SearchIndex");
        _amazonRequest = WebRequest.Create("http://webservices.amazon.com/onca/xml?Service=AWSECommerceService&AWSAccessKeyId=16KBB0XN5XP4WSNNVKG2&Operation=ItemSearch&ResponseGroup=Medium&AssociateTag=francshanacom&" + strKeywords + strSearchIndex);
        return _amazonRequest.BeginGetResponse(cb, state);
    }

    IAsyncResult BeginYahooAsyncOperation(object sender, EventArgs e, AsyncCallback cb, object state)
    {
        string strKeywords = Request.QueryString.Get("keywords");
        _yahooRequest = WebRequest.Create("http://api.shopping.yahoo.com/ShoppingService/V1/productSearch?appid=francisshanahan&results=10&query=" + strKeywords);
        return _yahooRequest.BeginGetResponse(cb, state);
    
    }

    IAsyncResult BeginEbayAsyncOperation(object sender, EventArgs e, AsyncCallback cb, object state)
    {
        string strKeywords = Request.QueryString.Get("keywords");

        _ebayRequest = WebRequest.Create("http://rest.api.ebay.com/restapi?CompatibilityLevel=445&CallName=GetSearchResults&RequestToken=UburRjOvd0Q%3D**25lhKIc3hPhgPpZ8ojZzv1TLm1I%3D&RequestUserId=francisshanahan&Schema=1&Currency=1&TrackingProvider=1&TrackingId=1889305&SearchInDescription=1&MaxResults=10&Query=" + strKeywords);
        return _ebayRequest.BeginGetResponse(cb, state);    
    }

    void EndAmazonAsyncOperation(IAsyncResult ar)
    {
        GetXml(_amazonRequest, ar, ref _amazonDoc);
    }
    void EndYahooAsyncOperation(IAsyncResult ar)
    {
        GetXml(_yahooRequest, ar, ref _yahooDoc);
    }
    void EndEbayAsyncOperation(IAsyncResult ar)
    {
        GetXml(_ebayRequest, ar, ref _ebayDoc);
    }

    void GetXml(WebRequest myReq, IAsyncResult myResult, ref XmlDocument myDoc)
    {
        using (WebResponse response = myReq.EndGetResponse(myResult))
        {
            using (StreamReader receiveStream = new StreamReader(response.GetResponseStream()))
            {
                myDoc = new XmlDocument();
                myDoc.Load(receiveStream);
            }
        } 
    }

    void TimeoutAmazonAsyncOperation(IAsyncResult ar) { Response.Write("Amazon Data temporarily unavailable"); }
    void TimeoutYahooAsyncOperation(IAsyncResult ar) { Response.Write("Yahoo Data temporarily unavailable"); }
    void TimeoutEbayAsyncOperation(IAsyncResult ar) { Response.Write("eBay Data temporarily unavailable"); }   
}