/// Author: Francis A. Shanahan
/// http://www.FrancisShanahan.com

using System;
using System.Data;
using System.Configuration;
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 com.amazon.webservices;
using System.Xml;
using System.IO;

/// <summary>

/// Summary description for AmazonUtility
/// </summary>
public static class AmazonUtility
{
    static AmazonUtility()
    {
        //
        // TODO: Add constructor logic here
        //
    }

    public static ItemSearchResponse SearchAmazon(string strKeywords, string strSearchIndex)
    {
        // Create a new instance of the proxy class
        AWSECommerceService myProxy = new AWSECommerceService();

        // Create a new instance of the ItemSearch class
        ItemSearch mySearch = new ItemSearch();

        // ItemSearchRequest stores the actual request parameters
        ItemSearchRequest mySearchRequest = new ItemSearchRequest();

        // Set some parameters, Keyword and Search Index
        mySearchRequest.Keywords = strKeywords;
        mySearchRequest.SearchIndex = strSearchIndex;

        // Just need Small results, not the full enchilada
        mySearchRequest.ResponseGroup = new string[] { "Medium", "Request" };

        // Set the subscription and associate tags here
        mySearch.AWSAccessKeyId = ConfigurationManager.AppSettings["AWSAccessKeyId"];
        mySearch.AssociateTag = ConfigurationManager.AppSettings["AssociateTag"];

        // Setup request
        mySearch.Request = new ItemSearchRequest[] { mySearchRequest };

        // Execute the request and get the response
        ItemSearchResponse myResponse = myProxy.ItemSearch(mySearch);

        return myResponse;
    }

    public static string GetResultsFromResponse(ItemSearchResponse myResponse, bool doRss)
    {
        // Parse the response and return the results 
        string strResults = "";
        foreach (Items myItems in myResponse.Items)
        {
            if (doRss)
            {  // Get the results in RSS
                strResults += FormatAsRSS(myItems);
            }
            else
            {
                if (myItems.Item != null)
                {
                    foreach (Item myItem in myItems.Item)
                    {
                        // Get the results in HTML
                        strResults += FormatAsHTML(myItem);
                    }
                }
            }
        }
        return strResults;
    }

    /// <summary>
    /// Returns RSS XML for a specific Amazon Item
    /// </summary>
    /// <param name="myItems">The Items instance</param>
    /// <returns>a string of XML</returns>
    public static string FormatAsRSS(Items myItems)
    {
        XmlDocument myDoc = new XmlDocument();

        // Create the root RSS node
        XmlNode myRSS = myDoc.CreateNode(XmlNodeType.Element, "rss", "");

        // Add the version attribute
        XmlAttribute rssVersion = myDoc.CreateAttribute("version");
        rssVersion.Value = "2.0";
        myRSS.Attributes.Append(rssVersion);

        // Create a new element node named "channel"
        XmlNode channel = myDoc.CreateNode(XmlNodeType.Element, "channel", "");

        // Create a new element node named "title"
        XmlNode title = myDoc.CreateNode(XmlNodeType.Element, "title", "");
        title.InnerText = "First Amazon Remix";

        // Create a new element node named "link"        
        XmlNode link = myDoc.CreateNode(XmlNodeType.Element, "link", "");
        link.InnerText = "http://www.FrancisShanahan.com/";

        // Create a new element node named "description"        
        XmlNode description = myDoc.CreateNode(XmlNodeType.Element, "description", "");
        description.InnerText = "Amazon results through RSS 2.0";

        // Append the channel specific elements
        channel.AppendChild(title);
        channel.AppendChild(link);
        channel.AppendChild(description);

        // Iterate through the products
        foreach (Item myItem in myItems.Item)
        {
            // Create a new item node for each one
            XmlNode myNode = CreateRSSItem(myDoc, myItem);
            // Append the resulting item to the channel
            channel.AppendChild(myNode);
        }

        // Finally append the channel and the RSS node
        myRSS.AppendChild(channel);
        myDoc.AppendChild(myRSS);

        return GetStringFromXml(myDoc);
    }

private static XmlNode CreateRSSItem(XmlDocument myDoc, Item myItem)
{
    // Create a new element node named "item"        
    XmlNode rssItem = myDoc.CreateNode(XmlNodeType.Element, "item", "");

    // Create a new element node named "title"        
    XmlNode title = myDoc.CreateNode(XmlNodeType.Element, "title", "");
    title.InnerText = myItem.ItemAttributes.Title;

    // Create a new element node named "link"        
    XmlNode link = myDoc.CreateNode(XmlNodeType.Element, "link", "");
    link.InnerText = myItem.DetailPageURL;

    // Create a new element node named "description"        
    XmlNode description = myDoc.CreateNode(XmlNodeType.Element, "description", "");

    // Build the description from the underlying item details
    string strDescription = "";
    // Display an image if one is present
    if (myItem.SmallImage != null)
    {
        strDescription += "<img src=" + myItem.SmallImage.URL + " align=right/>";
    }
    // The lowest price (essential)
    strDescription += "Lowest Price:" + myItem.OfferSummary.LowestNewPrice.FormattedPrice + "<br/>";

    // The editor's review if present
    if (myItem.EditorialReviews[0] != null)
    {
        strDescription += myItem.EditorialReviews[0].Content;
    }

    description.InnerText = strDescription;

    // Create a new element node named "pubDate"        
    XmlNode pubDate = myDoc.CreateNode(XmlNodeType.Element, "pubDate", "");
    pubDate.InnerText = DateTime.Today.ToShortDateString().ToString();

    // Append the new elements to this rss Item.
    rssItem.AppendChild(title);
    rssItem.AppendChild(link);
    rssItem.AppendChild(description);
    rssItem.AppendChild(pubDate);

    return rssItem;
}

    /// <summary>
    /// Returns HTML for a specific Amazon Item
    /// </summary>
    /// <param name="myItem">The Item instance</param>
    /// <returns>a string of HTML</returns>
    public static string FormatAsHTML(Item myItem)
    {
        // Will contain the results
        string strHTML = "";

        // Check for null
        if (myItem != null)
        {
            // Begin the item HTML
            strHTML += "<div class=\"item\">";
            // Add the title
            strHTML += "<h2>" + myItem.ItemAttributes.Title + "</h2>";

            // Add the item image if present
            if (myItem.SmallImage != null)
            {
                strHTML += "<img src=" + myItem.SmallImage.URL;
                strHTML += " width=" + myItem.SmallImage.Width.Value;
                strHTML += " height=" + myItem.SmallImage.Height.Value;
                strHTML += " align=\"left\" >";
            }

            // Add the ASIN
            strHTML += "<b>ASIN:</b> " + myItem.ASIN + "<br/>";

            // Add the price if present
            if (myItem.OfferSummary != null)
            {
                if (myItem.OfferSummary.LowestNewPrice != null)
                {
                    strHTML += "<b>Lowest Price:</b> " +
                       myItem.OfferSummary.LowestNewPrice.FormattedPrice
                       + "<br/>";
                }
            }
            // Add a link to the details
            strHTML += "<a href=\"" + myItem.DetailPageURL + "\">View Details</a><br/>";

            // Close the output
            strHTML += "</div>";
        }
        return strHTML;
    }
    /// <summary>
    /// Simple utility function to convert an XML document to a string
    /// </summary>
    /// <param name="myDoc"></param>
    /// <returns></returns>
    public static string GetStringFromXml(XmlDocument myDoc)
    {
        StringWriter myStringWriter = new StringWriter();
        XmlTextWriter myXmlTextWriter = new XmlTextWriter(myStringWriter);

        // Write the Xml document out to a string
        myDoc.WriteTo(myXmlTextWriter);

        string strResults = myStringWriter.ToString();
        return strResults;
    }
}