using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Configuration;
using System.Text;
using System.IO;

using Cuyahoga.Core.Service;
using Cuyahoga.Core.Util;

namespace Cuyahoga.Web.UI
{
	/// <summary>
	/// The BasePage class is the class that webforms have to inherit to use the templates.
	/// </summary>
	public class GenericBasePage : System.Web.UI.Page
	{
		// Member variables
		private string _templateFilename;
		private string _title;
		private string _css;
		private string _templateDir;

		#region properties
		/// <summary>
		/// Template property (filename of the User Control). This property can be used to change 
		/// page templates run-time.
		/// </summary>
		public string TemplateFilename
		{
			set { this._templateFilename = value; }
		}

		/// <summary>
		/// 
		/// </summary>
		protected string TemplateDir
		{
			set { this._templateDir = value; }
		}

		/// <summary>
		/// The page title as shown in the title bar of the browser.
		/// </summary>
		public string Title
		{
			get { return _title; } 
			set { _title = value; }
		}

		/// <summary>
		/// Path to external stylesheet file, relative from the application root.
		/// </summary>
		public string Css
		{
			get { return _css; }
			set { _css = value;	}
		}

		/// <summary>
		/// Property for the template control. This property can be used for finding other controls.
		/// </summary>
		public UserControl TemplateControl
		{
			get
			{
				if (this.Controls.Count > 0)
				{
					if (this.Controls[0] is UserControl)
					{
						return (UserControl)this.Controls[0];
					}
					else
					{
						return null;
					}
				}
				else
				{
					return null;
				}
			}
		}

		/// <summary>
		/// The messagebox.
		/// </summary>
		public HtmlGenericControl MessageBox
		{
			get
			{
				if (this.TemplateControl != null)
				{
					return this.TemplateControl.FindControl("MessageBox") as HtmlGenericControl;
				}
				else
				{
					return null;
				}
			}
		}

		/// <summary>
		/// The core repository for persisting Cuyahoga objects.
		/// </summary>
		public CoreRepository CoreRepository
		{
			get 
			{ 
				return HttpContext.Current.Items["CoreRepository"] as CoreRepository;
			}
		}

		#endregion

		/// <summary>
		/// Default constructor
		/// </summary>
		public GenericBasePage()
		{
			this._templateFilename = null;
			this._templateDir = null;
			this._css = null;
		}

		/// <summary>
		/// Protected constructor that accepts template parameters. Could be handled more elegantly.
		/// </summary>
		/// <param name="templateFileName"></param>
		/// <param name="templateDir"></param>
		/// <param name="css"></param>
		protected GenericBasePage(string templateFileName, string templateDir, string css)
		{
			this._templateFilename = templateFileName;
			this._templateDir = templateDir;
			this._css = css;
		}

		/// <summary>
		/// Try to find the MessageBox control, insert the errortext and set visibility to true.
		/// </summary>
		/// <param name="errorText"></param>
		protected virtual void ShowError(string errorText)
		{
			if (this.MessageBox != null)
			{
				this.MessageBox.InnerHtml = "An error occured: " + errorText;
				this.MessageBox.Attributes["class"] = "errorbox";
				this.MessageBox.Visible = true;
			}
			else
			{
				// Throw an Exception and hope it will be handled by the global application exception handler.
				throw new Exception(errorText);
			}
		}

		/// <summary>
		/// Try to find the MessageBox control, insert the message and set visibility to true.
		/// </summary>
		/// <param name="message"></param>
		protected virtual void ShowMessage(string message)
		{
			if (this.MessageBox != null)
			{
				this.MessageBox.InnerHtml = message;
				this.MessageBox.Attributes["class"] = "messagebox";
				this.MessageBox.Visible = true;
			}
			// TODO: change the class attribute to make a difference with the error (nice background image?)
		}

		/// <summary>
		/// Show the message of the exception, and the messages of the inner exceptions.
		/// </summary>
		/// <param name="ex"></param>
		protected virtual void ShowException(Exception exception)
		{
			string exceptionMessage = "<p>" + exception.Message + "</p>";
			Exception innerException = exception.InnerException;
			while (innerException != null)
			{
				exceptionMessage +=  "<p>" + innerException.Message + "</p>";
				innerException = innerException.InnerException;
			}
			ShowError(exceptionMessage);
		}

		protected override void OnInit(EventArgs e)
		{
			// Init
			PlaceHolder plc = null;
			ControlCollection col = this.Controls; 

			// Set template directory
			if (this._templateDir == null && ConfigurationSettings.AppSettings["TemplateDir"] != null)
			{
				this._templateDir = ConfigurationSettings.AppSettings["TemplateDir"];
			}

			// Get the template control
			if (this._templateFilename == null)
			{
				this._templateFilename = ConfigurationSettings.AppSettings["DefaultTemplate"];
			}
			BasePageControl pageControl = (BasePageControl)this.LoadControl(this.ResolveUrl(this._templateDir + this._templateFilename));

			// Add the pagecontrol on top of the control collection of the page
			pageControl.ID = "p";
			col.AddAt(0, pageControl);

			// Get the Content placeholder
			plc = pageControl.Content;
			if (plc != null)
			{
				// Iterate through the controls in the page to find the form control.
				foreach (Control control in col)
				{
					if (control is HtmlForm)
					{
						// We've found the form control. Now move all child controls into the placeholder.
						HtmlForm formControl = (HtmlForm)control;
						while (formControl.Controls.Count > 0)
							plc.Controls.Add(formControl.Controls[0]);						
					}
				}
				// throw away all controls in the page, except the page control 
				while (col.Count > 1)
					col.Remove(col[1]);				
			}
			base.OnInit(e);
		}

		/// <summary>
		/// Use the PreRender event to set the page title and stylesheet. These are properties of the page control
		/// which is at position 0 in the controls collection.
		/// </summary>
		/// <param name="e"></param>
		protected override void OnPreRender(System.EventArgs e) 
		{
			BasePageControl pageControl = (BasePageControl)this.Controls[0];

			// Set the stylesheet and title properties
			if (this._css == null)
			{
				this._css = ResolveUrl(ConfigurationSettings.AppSettings["DefaultCss"]);
			}
			if (this._title == null)
			{
				this._title = ConfigurationSettings.AppSettings["DefaultTitle"];
			}
			pageControl.Title = this._title;
			pageControl.Css = this._css;
		}

		/// <summary>
		/// Resolution of the __doPostBack bug (MS .NET 1.1). Forgot where the source came from. 
		/// Perhaps somewhere from the ASP.NET forum.
		/// </summary>
		/// <param name="writer"></param>
		protected override void Render(HtmlTextWriter writer) 
		{
			StringBuilder stringBuilder = new StringBuilder();
			StringWriter stringWriter = new StringWriter(stringBuilder);
			HtmlTextWriter htmlWriter = new HtmlTextWriter(stringWriter);
			base.Render(htmlWriter);
			string html = stringBuilder.ToString();
			int start = html.IndexOf("<form name=\"") + 12;
			int end = html.IndexOf("\"", start);
			string formID = html.Substring(start, end - start);
			string replace = formID.Replace(":", "_");
			html = html.Replace("document." + formID, "document." + replace);
			writer.Write(html);
		}
	}
}