using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Xml;
using System.Net;
using System.IO;

namespace RSSViewer
{
    public partial class frmAddFeed : Form
    {
        enum templateId {
            tWordpress = 0,
            tBlogspot = 1,
            tLivejournal = 2,
            tFeedburner = 3,
            tOther = 4
        };

        string[] arrTemplateName = {
            "Wordpress",
            "Blogspot",
            "Livejournal",
            "Feedburner",
            "Other"
        };

        enum xmlTypeId
        {
            xtAtom = 0,
            xtRSS = 1
        };

        string[] arrXmlTypeName = {
            "Atom",
            "RSS"
        };


        private templateId iCurrentTemplate;

        public frmAddFeed() {
            InitializeComponent();

            for ( int i = 0; i < arrTemplateName.Length; i++ ) {
                cmbTemplate.Items.Add( arrTemplateName[i] );
            }

            for ( int i = 0; i < arrXmlTypeName.Length; i++ ) {
                cmbFeedType.Items.Add( arrXmlTypeName[i] );
            }

            iCurrentTemplate = templateId.tWordpress;
            cmbTemplate.SelectedIndex = (int)iCurrentTemplate;

            updateVisuals();
        }

        public string getShortName() {
            return Guid.NewGuid().ToString();
        }

        public string getLongName() {
            return edtTitle.Text;
        }

        public string getUrl() {
            return edtUrl.Text;
        }

        public int getXmlType() {
            return cmbFeedType.SelectedIndex;
        }

        private void updateUrl() {
            xmlTypeId feedtype = (xmlTypeId)cmbFeedType.SelectedIndex;
            switch ( iCurrentTemplate ) {
                case templateId.tWordpress:
                    edtUrl.Text = "http://" + edtUsername.Text + ".wordpress.com/feed";
                    break;
                case templateId.tBlogspot:
                    edtUrl.Text = "http://" + edtUsername.Text + ".blogspot.com/feeds/posts/default";
                    break;
                case templateId.tLivejournal:
                    if ( feedtype == xmlTypeId.xtAtom ) {
                        edtUrl.Text = "http://" + edtUsername.Text + ".livejournal.com/data/atom";
                    } else if ( feedtype == xmlTypeId.xtRSS ) {
                        edtUrl.Text = "http://" + edtUsername.Text + ".livejournal.com/data/rss";
                    }
                    break;
                case templateId.tFeedburner:
                    edtUrl.Text = "http://feeds.feedburner.com/" + edtUsername.Text;
                    break;
                case templateId.tOther:
                    break;
            }
        }

        private void updateVisuals() {
            switch ( iCurrentTemplate ) {
                case templateId.tWordpress:
                    cmbFeedType.SelectedIndex = (int)xmlTypeId.xtRSS;
                    cmbFeedType.Enabled = false;
                    edtUrl.Enabled = false;
                    edtUsername.Visible = true;
                    lblUsername.Visible = true;
                    break;
                case templateId.tBlogspot:
                    cmbFeedType.SelectedIndex = (int)xmlTypeId.xtAtom;
                    cmbFeedType.Enabled = false;
                    edtUrl.Enabled = false;
                    edtUsername.Visible = true;
                    lblUsername.Visible = true;
                    break;
                case templateId.tLivejournal:
                    //cmbFeedType.SelectedIndex = (int)xmlTypeId.xtRSS;
                    cmbFeedType.Enabled = true;
                    edtUrl.Enabled = false;
                    edtUsername.Visible = true;
                    lblUsername.Visible = true;
                    break;
                case templateId.tFeedburner:
                    cmbFeedType.SelectedIndex = (int)xmlTypeId.xtRSS;
                    cmbFeedType.Enabled = false;
                    edtUrl.Enabled = false;
                    edtUsername.Visible = true;
                    lblUsername.Visible = true;
                    break;
                case templateId.tOther:
                    cmbFeedType.Enabled = true;
                    edtUrl.Enabled = true;
                    edtUsername.Visible = false;
                    lblUsername.Visible = false;
                    break;
            }

            updateUrl();
        }

        private void cmbTemplate_SelectedIndexChanged( object sender, EventArgs e ) {
            iCurrentTemplate = (templateId)cmbTemplate.SelectedIndex;

            updateVisuals();
        }

        private void menuItem2_Click( object sender, EventArgs e ) {
            this.DialogResult = DialogResult.Cancel;
        }

        private XmlNode digAndFindNodeByName( XmlNode parent, string name ) {
            int c = parent.ChildNodes.Count;
            for ( int i = 0; i < c; i++ ) {
                XmlNode node = parent.ChildNodes[i];
                if ( node.Name.Equals( name ) ) {
                    return node;
                } else {
                    node = digAndFindNodeByName( node, name );
                    if ( node != null ) {
                        return node;
                    }
                }
            }

            return null;
        }

        private bool saveAndTest() {
            bool bIsOk = false;

            Cursor.Current = Cursors.WaitCursor;
            try {
                string content = downloadFile( edtUrl.Text );
                if ( edtTitle.Text.Length == 0 ) {
                    XmlDocument doc = new XmlDocument();
                    doc.LoadXml( content );

                    XmlNode node = digAndFindNodeByName( doc, "title" );
                    if ( node != null ) {
                        edtTitle.Text = node.InnerText;
                    }
                }

                bIsOk = true;
            } catch ( Exception ) {
            }
            Cursor.Current = Cursors.Default;

            return bIsOk;
        }

        private void menuItem1_Click( object sender, EventArgs e ) {
            DialogResult = DialogResult.OK;
        }

        private void edtUsername_TextChanged( object sender, EventArgs e ) {
            updateUrl();
        }

        private void cmbFeedType_SelectedIndexChanged( object sender, EventArgs e ) {
            updateUrl();
        }

        private string downloadFile( string url ) {
            HttpWebRequest loHttp = (HttpWebRequest)WebRequest.Create( url );

            loHttp.Timeout = 10000;     // 10 secs
            loHttp.UserAgent = "RSSViewer";

            HttpWebResponse loWebResponse = (HttpWebResponse)loHttp.GetResponse();
            Encoding enc = Encoding.GetEncoding( 65001 );  // UTF8?
            StreamReader loResponseStream = new StreamReader( loWebResponse.GetResponseStream(), enc );
            string lcHtml = loResponseStream.ReadToEnd();
            loWebResponse.Close();
            loResponseStream.Close();

            return lcHtml;
        }

        private void frmAddFeed_Closing( object sender, CancelEventArgs e ) {
            if ( DialogResult != DialogResult.Cancel ) {
                if ( saveAndTest() ) {
                    e.Cancel = false;
                } else {
                    MessageBox.Show( "Connection failed" );
                    e.Cancel = true;
                }
            }
        }
    }
}