//-----------------------------------------------------------------------
// <copyright file="OpenIdHelper.cs" company="Outercurve Foundation">
//     Copyright (c) Outercurve Foundation. All rights reserved.
// </copyright>
//-----------------------------------------------------------------------

namespace DotNetOpenAuth.Mvc {
	using System;
	using System.Collections.Generic;
	using System.Diagnostics.CodeAnalysis;
	using System.Globalization;
	using System.IO;
	using System.Linq;
	using System.Text;
	using System.Web;
	using System.Web.Mvc;
	using System.Web.Routing;
	using System.Web.UI;
	using DotNetOpenAuth.Configuration;
	using DotNetOpenAuth.Messaging;
	using DotNetOpenAuth.OpenId;
	using DotNetOpenAuth.OpenId.RelyingParty;
	using Validation;

	/// <summary>
	/// Methods that generate HTML or Javascript for hosting AJAX OpenID "controls" on
	/// ASP.NET MVC web sites.
	/// </summary>
	public static class OpenIdHelper {
		/// <summary>
		/// Emits a series of stylesheet import tags to support the AJAX OpenID Selector.
		/// </summary>
		/// <param name="html">The <see cref="HtmlHelper"/> on the view.</param>
		/// <returns>HTML that should be sent directly to the browser.</returns>
		[SuppressMessage("Microsoft.Reliability", "CA2000:Dispose objects before losing scope", Justification = "False positive.")]
		public static string OpenIdSelectorStyles(this HtmlHelper html) {
			Requires.NotNull(html, "html");

			using (var result = new StringWriter(CultureInfo.CurrentCulture)) {
				result.WriteStylesheetLink(OpenId.RelyingParty.OpenIdSelector.EmbeddedStylesheetResourceName);
				result.WriteStylesheetLink(OpenId.RelyingParty.OpenIdAjaxTextBox.EmbeddedStylesheetResourceName);
				return result.ToString();
			}
		}

		/// <summary>
		/// Emits a series of script import tags and some inline script to support the AJAX OpenID Selector.
		/// </summary>
		/// <param name="html">The <see cref="HtmlHelper"/> on the view.</param>
		/// <returns>HTML that should be sent directly to the browser.</returns>
		public static string OpenIdSelectorScripts(this HtmlHelper html) {
			return OpenIdSelectorScripts(html, null, null);
		}

		/// <summary>
		/// Emits a series of script import tags and some inline script to support the AJAX OpenID Selector.
		/// </summary>
		/// <param name="html">The <see cref="HtmlHelper"/> on the view.</param>
		/// <param name="selectorOptions">An optional instance of an <see cref="OpenIdSelector"/> control, whose properties have been customized to express how this MVC control should be rendered.</param>
		/// <param name="additionalOptions">An optional set of additional script customizations.</param>
		/// <returns>
		/// HTML that should be sent directly to the browser.
		/// </returns>
		[SuppressMessage("Microsoft.Reliability", "CA2000:Dispose objects before losing scope", Justification = "False positive")]
		public static string OpenIdSelectorScripts(this HtmlHelper html, OpenIdSelector selectorOptions, OpenIdAjaxOptions additionalOptions) {
			Requires.NotNull(html, "html");

			bool selectorOptionsOwned = false;
			if (selectorOptions == null) {
				selectorOptionsOwned = true;
				selectorOptions = new OpenId.RelyingParty.OpenIdSelector();
			}
			try {
				if (additionalOptions == null) {
					additionalOptions = new OpenIdAjaxOptions();
				}

				using (StringWriter result = new StringWriter(CultureInfo.CurrentCulture)) {
					if (additionalOptions.ShowDiagnosticIFrame || additionalOptions.ShowDiagnosticTrace) {
						string scriptFormat = @"window.openid_visible_iframe = {0}; // causes the hidden iframe to show up
window.openid_trace = {1}; // causes lots of messages";
						result.WriteScriptBlock(string.Format(
							CultureInfo.InvariantCulture,
							scriptFormat,
							additionalOptions.ShowDiagnosticIFrame ? "true" : "false",
							additionalOptions.ShowDiagnosticTrace ? "true" : "false"));
					}
					var scriptResources = new[] {
					OpenIdRelyingPartyControlBase.EmbeddedJavascriptResource,
					OpenIdRelyingPartyAjaxControlBase.EmbeddedAjaxJavascriptResource,
					OpenId.RelyingParty.OpenIdAjaxTextBox.EmbeddedScriptResourceName,
				};
					result.WriteScriptTags(scriptResources);

					if (selectorOptions.DownloadYahooUILibrary) {
						result.WriteScriptTagsUrls(new[] { "https://ajax.googleapis.com/ajax/libs/yui/2.8.0r4/build/yuiloader/yuiloader-min.js" });
					}

					using (var blockBuilder = new StringWriter(CultureInfo.CurrentCulture)) {
						if (selectorOptions.DownloadYahooUILibrary) {
							blockBuilder.WriteLine(@"	try {
		if (YAHOO) {
			var loader = new YAHOO.util.YUILoader({
				require: ['button', 'menu'],
				loadOptional: false,
				combine: true
			});

			loader.insert();
		}
	} catch (e) { }");
						}

						blockBuilder.WriteLine("window.aspnetapppath = '{0}';", VirtualPathUtility.AppendTrailingSlash(HttpContext.Current.Request.ApplicationPath));

						// Positive assertions can last no longer than this library is willing to consider them valid,
						// and when they come with OP private associations they last no longer than the OP is willing
						// to consider them valid.  We assume the OP will hold them valid for at least five minutes.
						double assertionLifetimeInMilliseconds = Math.Min(TimeSpan.FromMinutes(5).TotalMilliseconds, Math.Min(OpenIdElement.Configuration.MaxAuthenticationTime.TotalMilliseconds, DotNetOpenAuthSection.Messaging.MaximumMessageLifetime.TotalMilliseconds));
						blockBuilder.WriteLine(
							"{0} = {1};",
							OpenIdRelyingPartyAjaxControlBase.MaxPositiveAssertionLifetimeJsName,
							assertionLifetimeInMilliseconds.ToString(CultureInfo.InvariantCulture));

						if (additionalOptions.PreloadedDiscoveryResults != null) {
							blockBuilder.WriteLine(additionalOptions.PreloadedDiscoveryResults);
						}

						string discoverUrl = VirtualPathUtility.AppendTrailingSlash(HttpContext.Current.Request.ApplicationPath) + html.RouteCollection["OpenIdDiscover"].GetVirtualPath(html.ViewContext.RequestContext, new RouteValueDictionary(new { identifier = "xxx" })).VirtualPath;
						string blockFormat = @"	{0} = function (argument, resultFunction, errorCallback) {{
		jQuery.ajax({{
			async: true,
			dataType: 'text',
			error: function (request, status, error) {{ errorCallback(status, argument); }},
			success: function (result) {{ resultFunction(result, argument); }},
			url: '{1}'.replace('xxx', encodeURIComponent(argument))
		}});
	}};";
						blockBuilder.WriteLine(blockFormat, OpenIdRelyingPartyAjaxControlBase.CallbackJSFunctionAsync, discoverUrl);

						blockFormat = @"	window.postLoginAssertion = function (positiveAssertion) {{
		$('#{0}')[0].setAttribute('value', positiveAssertion);
		if ($('#{1}')[0] && !$('#{1}')[0].value) {{ // popups have no ReturnUrl predefined, but full page LogOn does.
			$('#{1}')[0].setAttribute('value', window.parent.location.href);
		}}
		document.forms[{2}].submit();
	}};";
						blockBuilder.WriteLine(
							blockFormat,
							additionalOptions.AssertionHiddenFieldId,
							additionalOptions.ReturnUrlHiddenFieldId,
							additionalOptions.FormKey);

						blockFormat = @"	$(function () {{
		var box = document.getElementsByName('openid_identifier')[0];
		initAjaxOpenId(box, {0}, {1}, {2}, {3}, {4}, {5},
			null, // js function to invoke on receiving a positive assertion
			{6}, {7}, {8}, {9}, {10}, {11}, {12}, {13}, {14}, {15}, {16}, {17},
			false, // auto postback
			null); // PostBackEventReference (unused in MVC)
	}});";
						blockBuilder.WriteLine(
							blockFormat,
							MessagingUtilities.GetSafeJavascriptValue(Util.GetWebResourceUrl(typeof(OpenIdRelyingPartyControlBase), OpenIdTextBox.EmbeddedLogoResourceName)),
							MessagingUtilities.GetSafeJavascriptValue(Util.GetWebResourceUrl(typeof(OpenIdRelyingPartyControlBase), OpenId.RelyingParty.OpenIdAjaxTextBox.EmbeddedSpinnerResourceName)),
							MessagingUtilities.GetSafeJavascriptValue(Util.GetWebResourceUrl(typeof(OpenIdRelyingPartyControlBase), OpenId.RelyingParty.OpenIdAjaxTextBox.EmbeddedLoginSuccessResourceName)),
							MessagingUtilities.GetSafeJavascriptValue(Util.GetWebResourceUrl(typeof(OpenIdRelyingPartyControlBase), OpenId.RelyingParty.OpenIdAjaxTextBox.EmbeddedLoginFailureResourceName)),
							selectorOptions.Throttle,
							selectorOptions.Timeout.TotalMilliseconds,
							MessagingUtilities.GetSafeJavascriptValue(selectorOptions.TextBox.LogOnText),
							MessagingUtilities.GetSafeJavascriptValue(selectorOptions.TextBox.LogOnToolTip),
							selectorOptions.TextBox.ShowLogOnPostBackButton ? "true" : "false",
							MessagingUtilities.GetSafeJavascriptValue(selectorOptions.TextBox.LogOnPostBackToolTip),
							MessagingUtilities.GetSafeJavascriptValue(selectorOptions.TextBox.RetryText),
							MessagingUtilities.GetSafeJavascriptValue(selectorOptions.TextBox.RetryToolTip),
							MessagingUtilities.GetSafeJavascriptValue(selectorOptions.TextBox.BusyToolTip),
							MessagingUtilities.GetSafeJavascriptValue(selectorOptions.TextBox.IdentifierRequiredMessage),
							MessagingUtilities.GetSafeJavascriptValue(selectorOptions.TextBox.LogOnInProgressMessage),
							MessagingUtilities.GetSafeJavascriptValue(selectorOptions.TextBox.AuthenticationSucceededToolTip),
							MessagingUtilities.GetSafeJavascriptValue(selectorOptions.TextBox.AuthenticatedAsToolTip),
							MessagingUtilities.GetSafeJavascriptValue(selectorOptions.TextBox.AuthenticationFailedToolTip));

						result.WriteScriptBlock(blockBuilder.ToString());
						result.WriteScriptTags(OpenId.RelyingParty.OpenIdSelector.EmbeddedScriptResourceName);

						Reporting.RecordFeatureUse("MVC " + typeof(OpenIdSelector).Name);
						return result.ToString();
					}
				}
			} catch {
				if (selectorOptionsOwned) {
					selectorOptions.Dispose();
				}

				throw;
			}
		}

		/// <summary>
		/// Emits the HTML to render an OpenID Provider button as a part of the overall OpenID Selector UI.
		/// </summary>
		/// <param name="html">The <see cref="HtmlHelper"/> on the view.</param>
		/// <param name="providerIdentifier">The OP Identifier.</param>
		/// <param name="imageUrl">The URL of the image to display on the button.</param>
		/// <returns>
		/// HTML that should be sent directly to the browser.
		/// </returns>
		public static string OpenIdSelectorOPButton(this HtmlHelper html, Identifier providerIdentifier, string imageUrl) {
			Requires.NotNull(html, "html");
			Requires.NotNull(providerIdentifier, "providerIdentifier");
			Requires.NotNullOrEmpty(imageUrl, "imageUrl");

			return OpenIdSelectorButton(html, providerIdentifier, "OPButton", imageUrl);
		}

		/// <summary>
		/// Emits the HTML to render a generic OpenID button as a part of the overall OpenID Selector UI,
		/// allowing the user to enter their own OpenID.
		/// </summary>
		/// <param name="html">The <see cref="HtmlHelper"/> on the view.</param>
		/// <param name="imageUrl">The URL of the image to display on the button.</param>
		/// <returns>
		/// HTML that should be sent directly to the browser.
		/// </returns>
		public static string OpenIdSelectorOpenIdButton(this HtmlHelper html, string imageUrl) {
			Requires.NotNull(html, "html");
			Requires.NotNullOrEmpty(imageUrl, "imageUrl");

			return OpenIdSelectorButton(html, "OpenIDButton", "OpenIDButton", imageUrl);
		}

		/// <summary>
		/// Emits the HTML to render the entire OpenID Selector UI.
		/// </summary>
		/// <param name="html">The <see cref="HtmlHelper"/> on the view.</param>
		/// <param name="buttons">The buttons to include on the selector.</param>
		/// <returns>
		/// HTML that should be sent directly to the browser.
		/// </returns>
		[SuppressMessage("Microsoft.Reliability", "CA2000:Dispose objects before losing scope", Justification = "False positive.")]
		[SuppressMessage("Microsoft.Usage", "CA2202:Do not dispose objects multiple times", Justification = "Not a problem for this type.")]
		public static string OpenIdSelector(this HtmlHelper html, params SelectorButton[] buttons) {
			Requires.NotNull(html, "html");
			Requires.NotNull(buttons, "buttons");

			using (var writer = new StringWriter(CultureInfo.CurrentCulture)) {
				using (var h = new HtmlTextWriter(writer)) {
					h.AddAttribute(HtmlTextWriterAttribute.Class, "OpenIdProviders");
					h.RenderBeginTag(HtmlTextWriterTag.Ul);

					foreach (SelectorButton button in buttons) {
						var op = button as SelectorProviderButton;
						if (op != null) {
							h.Write(OpenIdSelectorOPButton(html, op.OPIdentifier, op.Image));
							continue;
						}

						var openid = button as SelectorOpenIdButton;
						if (openid != null) {
							h.Write(OpenIdSelectorOpenIdButton(html, openid.Image));
							continue;
						}

						ErrorUtilities.VerifySupported(false, "The {0} button is not yet supported for MVC.", button.GetType().Name);
					}

					h.RenderEndTag(); // ul

					if (buttons.OfType<SelectorOpenIdButton>().Any()) {
						h.Write(OpenIdAjaxTextBox(html));
					}
				}

				return writer.ToString();
			}
		}

		/// <summary>
		/// Emits the HTML to render the <see cref="OpenIdAjaxTextBox"/> control as a part of the overall
		/// OpenID Selector UI.
		/// </summary>
		/// <param name="html">The <see cref="HtmlHelper"/> on the view.</param>
		/// <returns>
		/// HTML that should be sent directly to the browser.
		/// </returns>
		[SuppressMessage("Microsoft.Usage", "CA1801:ReviewUnusedParameters", MessageId = "html", Justification = "Breaking change, and it's an extension method so it's useful.")]
		public static string OpenIdAjaxTextBox(this HtmlHelper html) {
			return @"<div style='display: none' id='OpenIDForm'>
		<span class='OpenIdAjaxTextBox' style='display: inline-block; position: relative; font-size: 16px'>
			<input name='openid_identifier' id='openid_identifier' size='40' style='padding-left: 18px; border-style: solid; border-width: 1px; border-color: lightgray' />
		</span>
	</div>";
		}

		/// <summary>
		/// Emits the HTML to render a button as a part of the overall OpenID Selector UI.
		/// </summary>
		/// <param name="html">The <see cref="HtmlHelper"/> on the view.</param>
		/// <param name="id">The value to assign to the HTML id attribute.</param>
		/// <param name="cssClass">The value to assign to the HTML class attribute.</param>
		/// <param name="imageUrl">The URL of the image to draw on the button.</param>
		/// <returns>
		/// HTML that should be sent directly to the browser.
		/// </returns>
		[SuppressMessage("Microsoft.Usage", "CA2202:Do not dispose objects multiple times", Justification = "Not a problem for this type.")]
		[SuppressMessage("Microsoft.Reliability", "CA2000:Dispose objects before losing scope", Justification = "False positive.")]
		private static string OpenIdSelectorButton(this HtmlHelper html, string id, string cssClass, string imageUrl) {
			Requires.NotNull(html, "html");
			Requires.NotNull(id, "id");
			Requires.NotNullOrEmpty(imageUrl, "imageUrl");

			using (var writer = new StringWriter(CultureInfo.CurrentCulture)) {
				using (var h = new HtmlTextWriter(writer)) {
					h.AddAttribute(HtmlTextWriterAttribute.Id, id);
					if (!string.IsNullOrEmpty(cssClass)) {
						h.AddAttribute(HtmlTextWriterAttribute.Class, cssClass);
					}
					h.RenderBeginTag(HtmlTextWriterTag.Li);

					h.AddAttribute(HtmlTextWriterAttribute.Href, "#");
					h.RenderBeginTag(HtmlTextWriterTag.A);

					h.RenderBeginTag(HtmlTextWriterTag.Div);
					h.RenderBeginTag(HtmlTextWriterTag.Div);

					h.AddAttribute(HtmlTextWriterAttribute.Src, imageUrl);
					h.RenderBeginTag(HtmlTextWriterTag.Img);
					h.RenderEndTag();

					h.AddAttribute(HtmlTextWriterAttribute.Src, Util.GetWebResourceUrl(typeof(OpenIdSelector), OpenId.RelyingParty.OpenIdAjaxTextBox.EmbeddedLoginSuccessResourceName));
					h.AddAttribute(HtmlTextWriterAttribute.Class, "loginSuccess");
					h.AddAttribute(HtmlTextWriterAttribute.Title, "Authenticated as {0}");
					h.RenderBeginTag(HtmlTextWriterTag.Img);
					h.RenderEndTag();

					h.RenderEndTag(); // div

					h.AddAttribute(HtmlTextWriterAttribute.Class, "ui-widget-overlay");
					h.RenderBeginTag(HtmlTextWriterTag.Div);
					h.RenderEndTag(); // div

					h.RenderEndTag(); // div
					h.RenderEndTag(); // a
					h.RenderEndTag(); // li
				}

				return writer.ToString();
			}
		}

		/// <summary>
		/// Emits &lt;script&gt; tags that import a given set of scripts given their URLs.
		/// </summary>
		/// <param name="writer">The writer to emit the tags to.</param>
		/// <param name="scriptUrls">The locations of the scripts to import.</param>
		private static void WriteScriptTagsUrls(this TextWriter writer, IEnumerable<string> scriptUrls) {
			Requires.NotNull(writer, "writer");
			Requires.NotNull(scriptUrls, "scriptUrls");

			foreach (string script in scriptUrls) {
				writer.WriteLine("<script type='text/javascript' src='{0}'></script>", script);
			}
		}

		/// <summary>
		/// Writes out script tags that import a script from resources embedded in this assembly.
		/// </summary>
		/// <param name="writer">The writer to emit the tags to.</param>
		/// <param name="resourceName">Name of the resource.</param>
		private static void WriteScriptTags(this TextWriter writer, string resourceName) {
			Requires.NotNull(writer, "writer");
			Requires.NotNullOrEmpty(resourceName, "resourceName");

			WriteScriptTags(writer, new[] { resourceName });
		}

		/// <summary>
		/// Writes out script tags that import scripts from resources embedded in this assembly.
		/// </summary>
		/// <param name="writer">The writer to emit the tags to.</param>
		/// <param name="resourceNames">The resource names.</param>
		private static void WriteScriptTags(this TextWriter writer, IEnumerable<string> resourceNames) {
			Requires.NotNull(writer, "writer");
			Requires.NotNull(resourceNames, "resourceNames");

			writer.WriteScriptTagsUrls(resourceNames.Select(r => Util.GetWebResourceUrl(typeof(OpenIdRelyingPartyControlBase), r)));
		}

		/// <summary>
		/// Writes a given script block, surrounding it with &lt;script&gt; and CDATA tags.
		/// </summary>
		/// <param name="writer">The writer to emit the tags to.</param>
		/// <param name="script">The script to inline on the page.</param>
		private static void WriteScriptBlock(this TextWriter writer, string script) {
			Requires.NotNull(writer, "writer");
			Requires.NotNullOrEmpty(script, "script");

			writer.WriteLine("<script type='text/javascript' language='javascript'><!--");
			writer.WriteLine("//<![CDATA[");
			writer.WriteLine(script);
			writer.WriteLine("//]]>--></script>");
		}

		/// <summary>
		/// Writes a given CSS link.
		/// </summary>
		/// <param name="writer">The writer to emit the tags to.</param>
		/// <param name="resourceName">Name of the resource containing the CSS content.</param>
		private static void WriteStylesheetLink(this TextWriter writer, string resourceName) {
			Requires.NotNull(writer, "writer");
			Requires.NotNullOrEmpty(resourceName, "resourceName");

			WriteStylesheetLinkUrl(writer, Util.GetWebResourceUrl(typeof(OpenIdRelyingPartyAjaxControlBase), resourceName));
		}

		/// <summary>
		/// Writes a given CSS link.
		/// </summary>
		/// <param name="writer">The writer to emit the tags to.</param>
		/// <param name="stylesheet">The stylesheet to link in.</param>
		private static void WriteStylesheetLinkUrl(this TextWriter writer, string stylesheet) {
			Requires.NotNull(writer, "writer");
			Requires.NotNullOrEmpty(stylesheet, "stylesheet");

			writer.WriteLine("<link rel='stylesheet' type='text/css' href='{0}' />", stylesheet);
		}
	}
}