using System;
using System.Web;
using System.Net;
using System.Data;
using System.Data.SqlClient;
using System.Collections;
using System.IO;
using System.Text;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Xml;

/// <summary>
/// YahooStockQuotes retrieves last traded price, last traded date, last traded time, and change for a comma-separated list of stock symbols
/// </summary>
[WebService(Namespace = "http://xxxxx.stei.com/")] //namespace has been altered to conceal implementation details
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class YahooStockQuotes : System.Web.Services.WebService
{
    
    private String queryURL;
    private String stockSymbols;
    private String queryString;
    Char[] delims = { ',' };

    public YahooStockQuotes()
    {
        DataSet stockQuoteConfigDataSet = null;
        FileStream stockQuoteConfigXML = null;        
        
        try
        {
            //create a DataSet object to hold configuration settings
            stockQuoteConfigDataSet = new DataSet();

            //set path to config file
            string stockQuoteConfigFilePath = "x:\\Sites\\YahooQuotes\\YahooStockQuoteConfig.xml";  //path has been altered to conceal implementation details

            //open file for reading
            stockQuoteConfigXML = new FileStream(stockQuoteConfigFilePath, FileMode.Open);

            //read XML schema and data into DataSet object
            stockQuoteConfigDataSet.ReadXml(stockQuoteConfigXML);

            //load retrieved data into their global variables 
            queryURL = stockQuoteConfigDataSet.Tables[0].Rows[0]["queryurl"].ToString();
            stockSymbols = stockQuoteConfigDataSet.Tables[0].Rows[0]["symbollist"].ToString();
            queryString = stockQuoteConfigDataSet.Tables[0].Rows[0]["querystring"].ToString();
        }
        catch (Exception xmlExc)
        {
            queryURL = null;
            stockSymbols = null;
            queryString = null;
        }
        finally
        {
            //close file
            stockQuoteConfigXML.Close();
        }
    }

    [WebMethod]
    public DataSet GetStockQuotes()
    {
        //initialize a DataSet to contain stock quotes
        DataSet stockQuoteDataSet = new DataSet();

        //create a table within the DataSet
        stockQuoteDataSet.Tables.Add("StockQuotes");

        //create table columns
        stockQuoteDataSet.Tables["StockQuotes"].Columns.Add("Symbol");
        stockQuoteDataSet.Tables["StockQuotes"].Columns.Add("Last_Traded_Price");
        stockQuoteDataSet.Tables["StockQuotes"].Columns.Add("Last_Traded_Date");
        stockQuoteDataSet.Tables["StockQuotes"].Columns.Add("Last_Traded_Time");
        stockQuoteDataSet.Tables["StockQuotes"].Columns.Add("Change");

        //parse symbol list into an array
        String[] stockSymbolList = stockSymbols.Split(delims);

        //iterate through stock symbol array and get data for each symbol; if an exception occurs, return an empty DataSet
        try
        {
            foreach (string stockSymbol in stockSymbolList)
            {
                //read response stream into a string (comma-delimited)
                String quote = getStockQuote(stockSymbol);

                //split string into an array
                String[] quoteDataItems = quote.Split(delims);

                //create and populate a DataRow object
                DataRow stockDataRow = stockQuoteDataSet.Tables["StockQuotes"].NewRow();
                Char[] quoteMarks = { '"' };
                stockDataRow["Symbol"] = quoteDataItems[0].ToString().Trim(quoteMarks);
                stockDataRow["Last_Traded_Price"] = "$ " + quoteDataItems[1].ToString().Trim(quoteMarks);
                stockDataRow["Last_Traded_Date"] = quoteDataItems[2].ToString().Trim(quoteMarks);
                stockDataRow["Last_Traded_Time"] = quoteDataItems[3].ToString().Trim(quoteMarks);
                stockDataRow["Change"] = quoteDataItems[4].ToString().Trim(quoteMarks);

                //add DataRow to the StockQuotes table in the DataSet object
                stockQuoteDataSet.Tables["StockQuotes"].Rows.Add(stockDataRow);
            }
        }
        catch (Exception sqExc)
        {
            stockQuoteDataSet.Tables["StockQuotes"].EndLoadData();
        }

        return stockQuoteDataSet;
    }

    private string getStockQuote(string stockSymbol)
    {
        String requestURL = queryURL.ToString() + "?s=" + stockSymbol.ToString() + "&f=" + queryString.ToString();
        WebClient yahooStockDataReq = new WebClient();
        Byte[] yahooStockDataResp = yahooStockDataReq.DownloadData(requestURL);
        UTF8Encoding yahooStockDataConv = new UTF8Encoding();
        String yahooStockData = yahooStockDataConv.GetString(yahooStockDataResp);

        return yahooStockData;
    }
}