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.Data.SqlClient;
using System.IO;
using System.Text;

public partial class downLoadList : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            string m_name = downMusic();
            string path = new DirectoryInfo(Server.MapPath("")).FullName.ToString() + @"\file\" + m_name;
            string str = path.Replace('\\', '/');
            update_album();
            update_singer();
            System.IO.FileInfo file = new System.IO.FileInfo(str);

            if (file.Exists)
            {
                Response.Clear();
                Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(Encoding.UTF8.GetBytes(m_name)));
                Response.AddHeader("Content-Length", file.Length.ToString());
                Response.ContentType = "application/octet-stream";
                Response.Filter.Close();
                Response.WriteFile(file.FullName);
                Response.End();
            }

            else
            {
                Response.Write("This file does not exist.");
            }
            Response.Redirect("Default.aspx");
        }
    }
    public void update_singer()
    {
        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["LocalSqlServer"].ToString());
        try
        {
            conn.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;
            string s_name = getSinger(cmd);
            cmd.CommandText = "select * from [singer] where singer=@singer";
            cmd.Parameters.Add("@singer", SqlDbType.NChar).Value = s_name.Trim().ToString();
            SqlDataReader dr = cmd.ExecuteReader();
            int count = 0;
            if (dr.Read())
            {
                count = dr.GetInt32(5) + 1;
            }
            dr.Close();
            cmd.CommandText = "update [singer] set count='" + count + "'where singer = @singer";
            cmd.ExecuteNonQuery();
        }
        finally
        {
            conn.Close();
        }
    }
    public string getSinger(SqlCommand cmd)
    {
        cmd.CommandText = "select * from [music] where id=@id";
        cmd.Parameters.Add("@id", SqlDbType.NChar).Value = getId().ToString();
        SqlDataReader dr = cmd.ExecuteReader();
        string m_name = "";
        if (dr.Read())
        {
            m_name = dr.GetString(2).Trim().ToString();
        }
        dr.Close();
        return m_name;
    }
    public void update_album()
    {
        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["LocalSqlServer"].ToString());
        try
        {
            conn.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;
            string a_name = getAlbum(cmd);
            cmd.CommandText = "select * from [album] where album=@album";
            cmd.Parameters.Add("@album", SqlDbType.NChar).Value = a_name.Trim().ToString();
            SqlDataReader dr = cmd.ExecuteReader();
            int count = 0;
            if (dr.Read())
            {
                count = dr.GetInt32(4) + 1;
            }
            dr.Close();
            cmd.CommandText = "update [album] set count='" + count + "'where album = @album";
            cmd.ExecuteNonQuery();
        }
        finally
        {
            conn.Close();
        }
    }
    public string getAlbum(SqlCommand cmd)
    {
        cmd.CommandText = "select * from [music] where id=@id";
        cmd.Parameters.Add("@id", SqlDbType.NChar).Value = getId().ToString();
        SqlDataReader dr = cmd.ExecuteReader();
        string m_name = "";
        if (dr.Read())
        {
            m_name = dr.GetString(3).Trim().ToString();
        }
        dr.Close();
        return m_name;
    }
    public string downMusic()
    {
        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["LocalSqlServer"].ToString());
        try
        {
            conn.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.CommandText = "select * from [music] where id=@id";
            cmd.Connection = conn;
            cmd.Parameters.Add("@id", SqlDbType.NChar).Value = getId().ToString();
            SqlDataReader dr = cmd.ExecuteReader();
            string m_name = "";
            int downLoadCount = 0;
            int count = 0;
            if (dr.Read())
            {
                downLoadCount = dr.GetInt32(6) + 1;
                count = dr.GetInt32(5) + downLoadCount;
                m_name = dr.GetString(1).Trim().ToString();
            }
            dr.Close();
            cmd.CommandText = "update [music] set downLoadCount='" + downLoadCount + "',count='"+count+"'where id = @id";
            cmd.ExecuteNonQuery();
            return m_name;
        }
        finally
        {
            conn.Close();
        }
    }
    public string getId()
    {
        string id = HttpContext.Current.Request.Url.PathAndQuery;
        int n = id.LastIndexOf('=');
        id = id.Substring(n + 1);
        return id;
    }
}