// Copyright (c) 2012, Outercurve Foundation.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
// - Redistributions of source code must  retain  the  above copyright notice, this
//   list of conditions and the following disclaimer.
//
// - Redistributions in binary form  must  reproduce the  above  copyright  notice,
//   this list of conditions  and  the  following  disclaimer in  the documentation
//   and/or other materials provided with the distribution.
//
// - Neither  the  name  of  the  Outercurve Foundation  nor   the   names  of  its
//   contributors may be used to endorse or  promote  products  derived  from  this
//   software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,  BUT  NOT  LIMITED TO, THE IMPLIED
// WARRANTIES  OF  MERCHANTABILITY   AND  FITNESS  FOR  A  PARTICULAR  PURPOSE  ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL,  SPECIAL,  EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO,  PROCUREMENT  OF  SUBSTITUTE  GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)  HOWEVER  CAUSED AND ON
// ANY  THEORY  OF  LIABILITY,  WHETHER  IN  CONTRACT,  STRICT  LIABILITY,  OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE)  ARISING  IN  ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

using Microsoft.Web.Administration;

namespace WebsitePanel.Providers.Web.Iis.WebObjects
{
    using Common;
    using Microsoft.Web.Administration;
    using Microsoft.Web.Management.Server;
    using System;
    using System.Text;
	using System.Collections.Generic;
	using System.Collections;
	using WebsitePanel.Providers.Web.Iis.Utility;
	using System.IO;
	using WebsitePanel.Providers.Utils;

    internal sealed class CustomHttpErrorsModuleService : ConfigurationModuleService
    {
		public const string StatusCodeAttribute = "statusCode";
		public const string SubStatusCodeAttribute = "subStatusCode";
		public const string PathAttribute = "path";
		public const string ResponseModeAttribute = "responseMode";
		public const string PrefixLanguageFilePath = "prefixLanguageFilePath";

		public void GetCustomErrors(ServerManager srvman, WebVirtualDirectory virtualDir)
		{
			var config = srvman.GetWebConfiguration(virtualDir.FullQualifiedPath);
			//
			var httpErrorsSection = config.GetSection(Constants.HttpErrorsSection);
			//
			var errorsCollection = httpErrorsSection.GetCollection();
			//
			var errors = new List<HttpError>();
			//
			foreach (var item in errorsCollection)
			{
				var item2Get = GetHttpError(item, virtualDir);
				//
				if (item2Get == null)
					continue;
				//
				errors.Add(item2Get);
			}
			//
			virtualDir.HttpErrors = errors.ToArray();
		}

		public void SetCustomErrors(WebVirtualDirectory virtualDir)
		{
			#region Revert to parent settings (inherited)
			using (var srvman = GetServerManager())
			{
				var config = srvman.GetWebConfiguration(virtualDir.FullQualifiedPath);
				//
				var section = config.GetSection(Constants.HttpErrorsSection);
				//
				section.RevertToParent();
				//
				srvman.CommitChanges();
			} 
			#endregion

			// Http errors list is either empty or not set so defaults to the parent
			if (virtualDir.HttpErrors == null || virtualDir.HttpErrors.Length == 0)
				return;

			#region Put the change in effect
			using (var srvman = GetServerManager())
			{
				var config = srvman.GetWebConfiguration(virtualDir.FullQualifiedPath);
				//
				var section = config.GetSection(Constants.HttpErrorsSection);

                // enable custom errors
                section.SetAttributeValue("errorMode", "Custom");

				//
				var errorsCollection = section.GetCollection();
				//
				foreach (var item in virtualDir.HttpErrors)
				{
					int indexOf = FindHttpError(errorsCollection, item);
					// Just update the element attributes - IIS 7 API will do the rest
					if (indexOf > -1)
					{
						var item2Renew = errorsCollection[indexOf];
						//
						FillConfigurationElementWithData(item2Renew, item, virtualDir);
						//
						continue;
					}
					//
					var item2Add = CreateHttpError(errorsCollection, item, virtualDir);
					//
					if (item2Add == null)
						continue;
					//
					errorsCollection.Add(item2Add);
				}
				//
				srvman.CommitChanges();
			} 
			#endregion
		}

		private HttpError GetHttpError(ConfigurationElement element, WebVirtualDirectory virtualDir)
		{
			if (element == null || virtualDir == null)
				return null;
			// skip inherited http errors
			if (!element.IsLocallyStored)
				return null;
			//
			var error = new HttpError
			{
				ErrorCode		= Convert.ToString(element.GetAttributeValue(StatusCodeAttribute)),
				ErrorSubcode	= Convert.ToString(element.GetAttributeValue(SubStatusCodeAttribute)),
				ErrorContent	= Convert.ToString(element.GetAttributeValue(PathAttribute)),
				HandlerType		= Enum.GetName(typeof(HttpErrorResponseMode), element.GetAttributeValue(ResponseModeAttribute))
			};

			// Make error path relative to the virtual directory's root folder
			if (error.HandlerType.Equals("File") // 0 is supposed to be File
				&& error.ErrorContent.Length > virtualDir.ContentPath.Length)
			{
				error.ErrorContent = error.ErrorContent.Substring(virtualDir.ContentPath.Length);
			}
			//
			return error;
		}

		private ConfigurationElement CreateHttpError(ConfigurationElementCollection collection, HttpError error, WebVirtualDirectory virtualDir)
		{
			// Skip elements either empty or with empty data
			if (error == null || String.IsNullOrEmpty(error.ErrorContent))
				return null;
			
			// Create new custom error
			ConfigurationElement error2Add = collection.CreateElement("error");
			
			if (!FillConfigurationElementWithData(error2Add, error, virtualDir))
				return null;
			//
			return error2Add;
		}

		private bool FillConfigurationElementWithData(ConfigurationElement item2Fill, HttpError error, WebVirtualDirectory virtualDir)
		{
			// code
			Int64 statusCode = 0;
			if (!Int64.TryParse(error.ErrorCode, out statusCode)
				|| statusCode < 400 || statusCode > 999)
				return false;

			// sub-code
			Int32 subStatusCode = -1;
			if (!Int32.TryParse(error.ErrorSubcode, out subStatusCode))
				return false;
			//
			if (subStatusCode == 0)
				subStatusCode = -1;

            // correct error content
            string errorContent = error.ErrorContent;
            if (error.HandlerType.Equals("File"))
            {
                if(error.ErrorContent.Length > virtualDir.ContentPath.Length)
                    errorContent = errorContent.Substring(virtualDir.ContentPath.Length);

                errorContent = FileUtils.CorrectRelativePath(errorContent);
            }

			item2Fill.SetAttributeValue(StatusCodeAttribute, statusCode);
			item2Fill.SetAttributeValue(SubStatusCodeAttribute, subStatusCode);
			item2Fill.SetAttributeValue(PathAttribute, errorContent);
			// Cleanup prefix language file path attribute.
			item2Fill.SetAttributeValue(PrefixLanguageFilePath, String.Empty);

			//
			item2Fill.SetAttributeValue(ResponseModeAttribute, error.HandlerType);
			// We are succeeded
			return true;
		}

		private int FindHttpError(ConfigurationElementCollection collection, HttpError error)
		{
			for (int i = 0; i < collection.Count; i++)
			{
				var item = collection[i];
				//
				if ((Int64)item.GetAttributeValue(StatusCodeAttribute) == Int64.Parse(error.ErrorCode)
					&& (Int32)item.GetAttributeValue(SubStatusCodeAttribute) == Int32.Parse(error.ErrorSubcode))
				{
					return i;
				}
			}
			//
			return -1;
		}
    }
}