using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Net;
using System.IO;
using System.Threading;

namespace WebCrawler
{
	/// <summary>
	/// Summary description for WinForm.
	/// </summary>
	public class WinForm : System.Windows.Forms.Form
	{
		/// <summary>
		/// Required designer variable.
		/// </summary>
		private System.ComponentModel.IContainer components;
		private System.Windows.Forms.Timer timer;
		private System.Windows.Forms.Panel panel2;
		private System.Windows.Forms.Button PauseButton;
		private System.Windows.Forms.Button CrawlButton;
		private System.Windows.Forms.Label label1;
		private System.Windows.Forms.Panel panel1;
		private System.Windows.Forms.ListBox URLListBox;
		private System.Windows.Forms.Splitter splitter1;
		private System.Windows.Forms.CheckBox diffDomainCheckBox;
		private System.Windows.Forms.TrackBar updateSpeedTrackBar;
		private System.Windows.Forms.Label label2;
		private System.Windows.Forms.ContextMenu contextMenu1;
		private System.Windows.Forms.MenuItem menuItem1;
		private System.Windows.Forms.TextBox urlEdit;
        private Label countLabel;
        private ListBox imageListBox;
        private Label imageCountLabel;
        private WebBrowser WebBrowser;
        private Thread crawlerThread; 

		public WinForm()
		{
			//
			// Required for Windows Form Designer support
			//
			InitializeComponent();

            Application.EnableVisualStyles();
            Application.DoEvents();
            Application.Idle += new EventHandler(Application_Idle);

            urlEdit.Text = Properties.Settings.Default.StartURL;
            updateSpeedTrackBar.Value = Properties.Settings.Default.UpdateSpeed;
            diffDomainCheckBox.Checked = Properties.Settings.Default.PreferDifferentDomains;
		}

		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose (bool disposing)
		{
			if (disposing)
			{
				if (components != null)
				{
					components.Dispose();
				}
			}
			base.Dispose(disposing);
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
            this.components = new System.ComponentModel.Container();
            this.timer = new System.Windows.Forms.Timer(this.components);
            this.panel2 = new System.Windows.Forms.Panel();
            this.imageCountLabel = new System.Windows.Forms.Label();
            this.countLabel = new System.Windows.Forms.Label();
            this.label2 = new System.Windows.Forms.Label();
            this.updateSpeedTrackBar = new System.Windows.Forms.TrackBar();
            this.diffDomainCheckBox = new System.Windows.Forms.CheckBox();
            this.PauseButton = new System.Windows.Forms.Button();
            this.CrawlButton = new System.Windows.Forms.Button();
            this.label1 = new System.Windows.Forms.Label();
            this.urlEdit = new System.Windows.Forms.TextBox();
            this.panel1 = new System.Windows.Forms.Panel();
            this.imageListBox = new System.Windows.Forms.ListBox();
            this.URLListBox = new System.Windows.Forms.ListBox();
            this.contextMenu1 = new System.Windows.Forms.ContextMenu();
            this.menuItem1 = new System.Windows.Forms.MenuItem();
            this.splitter1 = new System.Windows.Forms.Splitter();
            this.WebBrowser = new System.Windows.Forms.WebBrowser();
            this.panel2.SuspendLayout();
            ((System.ComponentModel.ISupportInitialize)(this.updateSpeedTrackBar)).BeginInit();
            this.panel1.SuspendLayout();
            this.SuspendLayout();
            // 
            // timer
            // 
            this.timer.Interval = 10000;
            this.timer.Tick += new System.EventHandler(this.timer_Tick);
            // 
            // panel2
            // 
            this.panel2.Controls.Add(this.imageCountLabel);
            this.panel2.Controls.Add(this.countLabel);
            this.panel2.Controls.Add(this.label2);
            this.panel2.Controls.Add(this.updateSpeedTrackBar);
            this.panel2.Controls.Add(this.diffDomainCheckBox);
            this.panel2.Controls.Add(this.PauseButton);
            this.panel2.Controls.Add(this.CrawlButton);
            this.panel2.Controls.Add(this.label1);
            this.panel2.Controls.Add(this.urlEdit);
            this.panel2.Dock = System.Windows.Forms.DockStyle.Top;
            this.panel2.Location = new System.Drawing.Point(0, 0);
            this.panel2.Name = "panel2";
            this.panel2.Size = new System.Drawing.Size(878, 64);
            this.panel2.TabIndex = 9;
            // 
            // imageCountLabel
            // 
            this.imageCountLabel.AutoSize = true;
            this.imageCountLabel.Location = new System.Drawing.Point(689, 9);
            this.imageCountLabel.Name = "imageCountLabel";
            this.imageCountLabel.Size = new System.Drawing.Size(49, 13);
            this.imageCountLabel.TabIndex = 14;
            this.imageCountLabel.Text = "0 images";
            // 
            // countLabel
            // 
            this.countLabel.AutoSize = true;
            this.countLabel.Location = new System.Drawing.Point(423, 37);
            this.countLabel.Name = "countLabel";
            this.countLabel.Size = new System.Drawing.Size(67, 13);
            this.countLabel.TabIndex = 13;
            this.countLabel.Text = "Pages found";
            // 
            // label2
            // 
            this.label2.Location = new System.Drawing.Point(183, 37);
            this.label2.Name = "label2";
            this.label2.Size = new System.Drawing.Size(136, 16);
            this.label2.TabIndex = 12;
            this.label2.Text = "Update speed (1-10 secs)";
            // 
            // updateSpeedTrackBar
            // 
            this.updateSpeedTrackBar.Location = new System.Drawing.Point(313, 32);
            this.updateSpeedTrackBar.Minimum = 1;
            this.updateSpeedTrackBar.Name = "updateSpeedTrackBar";
            this.updateSpeedTrackBar.Size = new System.Drawing.Size(104, 45);
            this.updateSpeedTrackBar.TabIndex = 11;
            this.updateSpeedTrackBar.Value = 10;
            this.updateSpeedTrackBar.ValueChanged += new System.EventHandler(this.trackBar1_ValueChanged);
            // 
            // diffDomainCheckBox
            // 
            this.diffDomainCheckBox.Checked = true;
            this.diffDomainCheckBox.CheckState = System.Windows.Forms.CheckState.Checked;
            this.diffDomainCheckBox.Location = new System.Drawing.Point(8, 32);
            this.diffDomainCheckBox.Name = "diffDomainCheckBox";
            this.diffDomainCheckBox.Size = new System.Drawing.Size(144, 24);
            this.diffDomainCheckBox.TabIndex = 10;
            this.diffDomainCheckBox.Text = "Prefer different domains";
            // 
            // PauseButton
            // 
            this.PauseButton.Location = new System.Drawing.Point(495, 5);
            this.PauseButton.Name = "PauseButton";
            this.PauseButton.Size = new System.Drawing.Size(75, 24);
            this.PauseButton.TabIndex = 9;
            this.PauseButton.Text = "Pause";
            this.PauseButton.Click += new System.EventHandler(this.PauseButton_Click);
            // 
            // CrawlButton
            // 
            this.CrawlButton.Location = new System.Drawing.Point(414, 5);
            this.CrawlButton.Name = "CrawlButton";
            this.CrawlButton.Size = new System.Drawing.Size(75, 24);
            this.CrawlButton.TabIndex = 8;
            this.CrawlButton.Text = "Crawl!";
            this.CrawlButton.Click += new System.EventHandler(this.CrawlButton_Click);
            // 
            // label1
            // 
            this.label1.Location = new System.Drawing.Point(10, 11);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(56, 17);
            this.label1.TabIndex = 6;
            this.label1.Text = "Start URL";
            // 
            // urlEdit
            // 
            this.urlEdit.AutoCompleteMode = System.Windows.Forms.AutoCompleteMode.Suggest;
            this.urlEdit.AutoCompleteSource = System.Windows.Forms.AutoCompleteSource.AllUrl;
            this.urlEdit.Location = new System.Drawing.Point(72, 8);
            this.urlEdit.Name = "urlEdit";
            this.urlEdit.Size = new System.Drawing.Size(336, 20);
            this.urlEdit.TabIndex = 7;
            this.urlEdit.Text = "http://www.doogal.co.uk/links.php";
            // 
            // panel1
            // 
            this.panel1.Controls.Add(this.imageListBox);
            this.panel1.Controls.Add(this.URLListBox);
            this.panel1.Dock = System.Windows.Forms.DockStyle.Top;
            this.panel1.Location = new System.Drawing.Point(0, 64);
            this.panel1.Name = "panel1";
            this.panel1.Size = new System.Drawing.Size(878, 69);
            this.panel1.TabIndex = 10;
            // 
            // imageListBox
            // 
            this.imageListBox.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left)
                        | System.Windows.Forms.AnchorStyles.Right)));
            this.imageListBox.FormattingEnabled = true;
            this.imageListBox.Location = new System.Drawing.Point(416, 0);
            this.imageListBox.Name = "imageListBox";
            this.imageListBox.Size = new System.Drawing.Size(462, 69);
            this.imageListBox.TabIndex = 1;
            // 
            // URLListBox
            // 
            this.URLListBox.ContextMenu = this.contextMenu1;
            this.URLListBox.Location = new System.Drawing.Point(0, 0);
            this.URLListBox.Name = "URLListBox";
            this.URLListBox.Size = new System.Drawing.Size(400, 69);
            this.URLListBox.TabIndex = 0;
            // 
            // contextMenu1
            // 
            this.contextMenu1.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
            this.menuItem1});
            // 
            // menuItem1
            // 
            this.menuItem1.Index = 0;
            this.menuItem1.Text = "Copy";
            this.menuItem1.Click += new System.EventHandler(this.menuItem1_Click);
            // 
            // splitter1
            // 
            this.splitter1.Dock = System.Windows.Forms.DockStyle.Top;
            this.splitter1.Location = new System.Drawing.Point(0, 133);
            this.splitter1.Name = "splitter1";
            this.splitter1.Size = new System.Drawing.Size(878, 10);
            this.splitter1.TabIndex = 11;
            this.splitter1.TabStop = false;
            // 
            // WebBrowser
            // 
            this.WebBrowser.Dock = System.Windows.Forms.DockStyle.Fill;
            this.WebBrowser.Location = new System.Drawing.Point(0, 143);
            this.WebBrowser.Name = "WebBrowser";
            this.WebBrowser.ScriptErrorsSuppressed = true;
            this.WebBrowser.Size = new System.Drawing.Size(878, 364);
            this.WebBrowser.TabIndex = 12;
            this.WebBrowser.NewWindow += new System.ComponentModel.CancelEventHandler(this.WebBrowser_NewWindow);
            this.WebBrowser.DocumentCompleted += new System.Windows.Forms.WebBrowserDocumentCompletedEventHandler(this.WebBrowser_DocumentCompleted);
            // 
            // WinForm
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.ClientSize = new System.Drawing.Size(878, 507);
            this.Controls.Add(this.WebBrowser);
            this.Controls.Add(this.splitter1);
            this.Controls.Add(this.panel1);
            this.Controls.Add(this.panel2);
            this.Name = "WinForm";
            this.Text = "Web Crawler";
            this.FormClosing += new System.Windows.Forms.FormClosingEventHandler(this.WinForm_FormClosing);
            this.panel2.ResumeLayout(false);
            this.panel2.PerformLayout();
            ((System.ComponentModel.ISupportInitialize)(this.updateSpeedTrackBar)).EndInit();
            this.panel1.ResumeLayout(false);
            this.ResumeLayout(false);

		}
		#endregion

		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main() 
		{
			Application.Run(new WinForm());
		}

		private int Index, imageCount;

		private void ParseDocument()
		{
            HtmlDocument htmlDoc = WebBrowser.Document;

            if (htmlDoc != null)
			{
                HtmlElementCollection LElements = htmlDoc.All;

                for (int Loop = 0; Loop < LElements.Count; Loop++)
				{
                    HtmlElement LField = LElements[Loop];

                    try
                    {
                        if (LField.TagName.ToUpper() == "A")
                        {
                            string URL = LField.GetAttribute("href");
                            String URLtoUpper = URL.ToUpper();
                            if (URL != null)
                            {
                                AddLink(URL);

                                if ((URLtoUpper.EndsWith(".JPG")) || (URLtoUpper.EndsWith(".GIF")) || (URLtoUpper.EndsWith(".PNG")))
                                {
                                    if (imageListBox.Items.IndexOf(URL) == -1)
                                    {
                                        Stream ImageStream = new WebClient().OpenRead(URL);
                                        Image img = Image.FromStream(ImageStream);
                                        int width = img.Width;
                                        int height = img.Height;
                                        imageListBox.Items.Add(URL + ": " + width + " x " + height);
                                        imageCount++;
                                        imageCountLabel.Text = imageCount + " images";
                                    }
                                }
                            }
                        }

                        if (LField.TagName.ToUpper() == "IMG")
                        {
                            string src = LField.GetAttribute("src");
                            if (imageListBox.Items.IndexOf(src) == -1)
                            {
                                Stream ImageStream = new WebClient().OpenRead(src);
                                Image img = Image.FromStream(ImageStream);
                                int width = img.Width;
                                int height = img.Height;
                                imageListBox.Items.Add(src + ": " + width + " x " + height);
                                imageCount++;
                                imageCountLabel.Text = imageCount + " images";
                            }
                        }
                    }
                    catch (ArgumentException ex)
                    {
                    }
                    catch (WebException ex)
                    {
                    }
                    catch (Exception ex)
                    {
                    }
				}  
			}
				
			if (Index < URLListBox.Items.Count-1)
			{
				Index++;
	
				WebBrowser.Navigate(URLListBox.Items[Index].ToString());
			}
		}

		private string GetDomainName(string URL)
		{
            Uri uri = new Uri(URL);
            return uri.Host;
		}

		private void AddLink(string URL)
		{
			// don't add it if we already have it
			if (URLListBox.Items.IndexOf(URL) == -1)
			{
				// only add valid http links
                if (URL.StartsWith("http"))
				{
					// we prefer different domain names since these mean we do more crawling
					bool AlreadyGotDomain = false;
					if (diffDomainCheckBox.Checked)
					{
						string URLDomainName = GetDomainName(URL);
						int Loop = 0;
						while (Loop<URLListBox.Items.Count && !AlreadyGotDomain)
						{
							string CurrentDomainName = GetDomainName(URLListBox.Items[Loop].ToString());
							if (CurrentDomainName == URLDomainName)
							{
								AlreadyGotDomain = true;
                                break;
							}
							Loop++;
						}
					}
					else
					{
						// always add at the end if unchecked
						AlreadyGotDomain = true;
					}
						
					if (AlreadyGotDomain)
					{
						// don't bother adding too many items
						if (URLListBox.Items.Count < (Index+1000))
							URLListBox.Items.Add(URL);
					}
					else
						URLListBox.Items.Insert(Index+1, URL);
				}
			}
		}
		
		private void timer_Tick(object sender, System.EventArgs e)
		{
            timer.Enabled = false;
            try
            {
                ParseDocument();
            }
            finally
            {
                timer.Enabled = true;
            }
		}

		private void ShowPauseButtonText()
		{
			if (timer.Enabled)
			{
				PauseButton.Text = "Pause";
			}
			else
			{
				PauseButton.Text = "Resume";
			}
		}

		private void CrawlButton_Click(object sender, System.EventArgs e)
		{
			timer.Enabled = true;
			ShowPauseButtonText();
			Index = 0;
			URLListBox.Items.Clear();
			URLListBox.Items.Add(urlEdit.Text);

            crawlerThread = new Thread(new ThreadStart(webCrawl));
            crawlerThread.Start();
		}

        private void webCrawl()
        {                
            WebBrowser.Navigate(urlEdit.Text);
        }

      /*  private Boolean validateURL(String urlString)
        {
            try
            {
                Uri url = new Uri(urlString);
                HttpWebRequest oReq = (HttpWebRequest)WebRequest.Create(url);
                HttpWebResponse resp = (HttpWebResponse)oReq.GetResponse();
                
                if (resp.StatusDescription.Equals("OK"))
                    return true;
            }
            catch (WebException ex)
            {
            }
            catch (UriFormatException ex)
            {
            }

            return false;
        }  */

		private void PauseButton_Click(object sender, System.EventArgs e)
		{
			timer.Enabled = !timer.Enabled;
			ShowPauseButtonText();
		}

		private void trackBar1_ValueChanged(object sender, System.EventArgs e)
		{
			timer.Interval = updateSpeedTrackBar.Value * 1000;
		}

		private void menuItem1_Click(object sender, System.EventArgs e)
		{
            if (URLListBox.SelectedIndex > -1)
				Clipboard.SetDataObject(URLListBox.Items[URLListBox.SelectedIndex]);
		}

        private void WebBrowser_NewWindow(object sender, CancelEventArgs e)
        {
            e.Cancel = true;
        }

        private void WinForm_FormClosing(object sender, FormClosingEventArgs e)
        {
            Properties.Settings.Default.StartURL = urlEdit.Text;
            Properties.Settings.Default.UpdateSpeed = updateSpeedTrackBar.Value;
            Properties.Settings.Default.PreferDifferentDomains = diffDomainCheckBox.Checked;
            Properties.Settings.Default.Save();

            crawlerThread.Abort();
        }

        private void Application_Idle(object sender, EventArgs e)
        {
            countLabel.Text = "Pages found: " + URLListBox.Items.Count.ToString();
        }

        private void WebBrowser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
        {
            URLListBox.SelectedIndex = Index;
        }
	}
}