// xp_WebBrowser_read_amazon_com_UI.linq - rip book list from the Library page of the Amazon cloud reader
// 2020-09-16
//
// see https://stackoverflow.com/a/63917496/4156577

//<div class="book_container" id="B089DW5DYF">
//    <div class="book_cover">
//        <img title="Il misterioso caso di villa Grada (Le indagini del tenente Roversi Vol. 4) (Italian Edition)" class="book_image book_click_area" src="https://images-na.ssl-images-amazon.com/images/P/B089DW5DYF.01._SX255_SY255_TTXW_SCLZZZZZZZ_.jpg">
//        <div class="alt_title book_click_area"></div>
//    </div>
//    <div class="book_details">
//        <div class="book_title book_click_area">Il misterioso caso di villa Grada (Le indagini del tenente Roversi Vol. 4) (Italian Edition)</div>
//        <div class="book_author book_click_area">Gavino Zucca</div>
//    </div>
//</div>

class KindleBookListProgram
{
	const string FILENAME_TEMPLATE = "x:\\kindle_library_{0:yyyyMMdd}.lst";  // gets DateTime.Now as parameter
	const int TIMER_INTERVAL_MS = 5000;
	const string READ_AMAZON_COM = "https://read.amazon.com/";
	const string USERAGENT = "Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; rv:11.0) like Gecko";
	const int URLMON_OPTION_USERAGENT = 0x10000001;

	static void Main ()
	{
		// setting the user agent in the Navigate() call works only once;
		// this works for the whole session
		UrlMkSetSessionOption(URLMON_OPTION_USERAGENT, USERAGENT, USERAGENT.Length, 0);
	
		using (var form = new BrowserForm())
		{
			form.ShowDialog();
		}
	}

	[DllImport("urlmon.dll", CharSet = CharSet.Ansi)]
	private static extern int UrlMkSetSessionOption (
		int dwOption, string pBuffer, int dwBufferLength, int dwReserved );
	
	class BrowserForm: Form
	{
		WebBrowser m_browser;
		System.Windows.Forms.Timer m_timer;
		string m_text_from_previous_try = null;
	
		public BrowserForm ()
		{	
			Width = 800;
			Height = 600;

			m_timer = new System.Windows.Forms.Timer();
			m_timer.Interval = TIMER_INTERVAL_MS;
			m_timer.Tick += timer_Tick;
			
			Controls.Add(m_browser = new WebBrowser());
			m_browser.DocumentCompleted += browser_DocumentCompleted;
			m_browser.Dock = DockStyle.Fill;
	
			KeyPreview = true;
			KeyDown += this_KeyDown;
	
			m_browser.Navigate(READ_AMAZON_COM);
		}

		string find_book_list_frame_text (WebBrowser browser)
		{
			foreach (HtmlWindow frame in browser.Document.Window.Frames)
			{
				var elt = frame.Document.GetElementById("titles_inner_wrapper");
			
				if (elt != null)
				{
					return elt.InnerHtml;
				}
			}
			
			return null;
		}

		void save_book_list (string text)
		{
			var filename = string.Format(FILENAME_TEMPLATE, DateTime.Now);
#if LINQPAD
			Console.WriteLine("\n##### {0} ######\n\n{1}\n\n", filename, text);
#endif
			File.WriteAllText(filename, text, Encoding.Default);
			this.Text = filename + " saved!";		
		}

		void timer_Tick (Object sender, EventArgs e)
		{
			m_timer.Stop();

#if LINQPAD
			Console.WriteLine("{0} Tick event", DateTime.Now);
#endif
			var text = find_book_list_frame_text(m_browser);

			if (!string.IsNullOrEmpty(text))
			{
				if (!string.IsNullOrEmpty(m_text_from_previous_try) && text == m_text_from_previous_try)
				{
					save_book_list(text);
					return;
				}
			
				m_text_from_previous_try = text;
			}
			
			m_timer.Start();
		}

		void browser_DocumentCompleted (object sender, WebBrowserDocumentCompletedEventArgs e)
		{
#if LINQPAD
			Console.WriteLine("{0} DocumentCompleted event", DateTime.Now);
#endif
			m_timer.Stop();
			m_timer.Start();
		}

		void this_KeyDown (object sender, KeyEventArgs e)
		{
			if (e.Control && e.KeyValue == 17)  // ^S
			{
				e.SuppressKeyPress = true;

				save_book_list(find_book_list_frame_text(m_browser) ?? "");
			}	
		}
	}
}