using System;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.Linq;
using System.Threading;
using System.Web;
using System.Web.Script.Serialization;
using System.Web.Security;
using CamlexNET;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Utilities;
using Taloyhtio.CustomFBADataSource.CodeFiles;

namespace Taloyhtio.CustomFBADataSource
{
    public class sitecolls : IHttpHandler
    {
        private const string QUERY_STRING_KEY_USER_NAME = "UserName";
        private const string QUERY_STRING_KEY_OP = "op";
        private const string QUERY_STRING_KEY_OP_NEW = "new";
        private const string QUERY_STRING_KEY_OP_OLD = "old";

        public void ProcessRequest(HttpContext context)
        {
            try
            {
                var web = SPContext.Current.Web;
                if (web.CurrentUser == null || !web.CurrentUser.IsSiteAdmin)
                {
                    throw new Exception("Current user is not site admin");
                }

                string userName = context.Request.QueryString[QUERY_STRING_KEY_USER_NAME];
                if (string.IsNullOrEmpty(userName))
                {
                    throw new Exception("User name is empty");
                }
                userName = HttpUtility.UrlDecode(userName);

                string op = context.Request.QueryString[QUERY_STRING_KEY_OP];
                if (string.IsNullOrEmpty(op))
                {
                    throw new Exception("Operation is empty");
                }
                op = op.ToLower();

                if (op != QUERY_STRING_KEY_OP_NEW && op != QUERY_STRING_KEY_OP_OLD)
                {
                    throw new Exception("Operation is not supported");
                }

                var siteColls = new List<string>();
                if (op == QUERY_STRING_KEY_OP_NEW)
                {
                    // currently new algorithm can be used only for Taloytio
                    if (this.isTaloyhtio())
                    {
                        siteColls = this.getSiteCollectionsUsingNewMethod(userName);
                    }
                }
                else if (op == QUERY_STRING_KEY_OP_OLD)
                {
                    siteColls = this.getSiteCollectionsUsingOldMethod(userName);
                }

                this.sendResponse(context, siteColls, false, string.Empty);
            }
            catch (ThreadAbortException)
            {
                throw;
            }
            catch (Exception x)
            {
                this.sendError(context, x.Message);
            }
        }

        private List<string> getSiteCollectionsUsingNewMethod(string userName)
        {
            try
            {
                var result = new List<string>();
                // run code under elevated priveleges in order to connect to db using account of application pool. In this case we need
                // to grant permissions to db only to single account, not to all users under which this code will be executed
                SPSecurity.RunWithElevatedPrivileges(
                    () =>
                        {
                            string url = string.Empty;
                            using (var rootSite = new SPSite(SPContext.Current.Site.WebApplication.Sites[0].ID, SPContext.Current.Site.Zone))
                            {
                                url = rootSite.Url;
                            }

                            if (string.IsNullOrEmpty(userName))
                            {
                                return;
                            }

                            string connStr = this.getConnectionString();
                            if (string.IsNullOrEmpty(connStr))
                            {
                                return;
                            }

                            var r = new CredentialsRepository(connStr);
                            var userId = r.GetUserId(userName);
                            if (userId == Guid.Empty)
                            {
                                return;
                            }
                            var condos = r.GetUserCondos(userId);
                            if (condos.IsNullOrEmpty())
                            {
                                return;
                            }
                            result = condos.Select(c => SPUrlUtility.CombineUrl(url, c.PmcRelativeUrl)).Distinct().ToList();
                        });
                return result;
            }
            catch (Exception x)
            {
                this.log("Error occured in new method (user name '{0}'): {1}\n{2}", userName, x.Message, x.StackTrace);
                return new List<string>();
            }
        }

        private string getConnectionString()
        {
            string connStringName = this.isTaloyhtio() ? Constants.FBA_CONNECTION_STRING_TALOYHTIO : Constants.FBA_CONNECTION_STRING_TALLIER;
            if (ConfigurationManager.ConnectionStrings == null || ConfigurationManager.ConnectionStrings[connStringName] == null)
            {
                return string.Empty;
            }
            return ConfigurationManager.ConnectionStrings[connStringName].ConnectionString;
        }

        private bool isTaloyhtio()
        {
            string url = SPContext.Current.Site.Url.ToLower();
            return url.Contains("taloyhtio");
        }

        private List<string> getSiteCollectionsUsingOldMethod(string userName)
        {
            var siteColls = new List<string>();
            try
            {
                SPSecurity.RunWithElevatedPrivileges(
                    () =>
                        {
                            string url = string.Empty;
                            using (var rootSite = new SPSite(SPContext.Current.Site.WebApplication.Sites[0].ID, SPContext.Current.Site.Zone))
                            {
                                url = rootSite.Url;
                            }

                            using (var elevatedSite = new SPSite(SPContext.Current.Site.ID, SPContext.Current.Site.Zone))
                            {
                                var settings = Utils.GetFBAIisSettings(elevatedSite);
                                if (settings == null)
                                {
                                    this.log("FBA IIS settings can't be retrieved");
                                    return;
                                }
                                var membershipProvider = Membership.Providers[settings.FormsClaimsAuthenticationProvider.MembershipProvider];
                                string prefixOld = membershipProvider.Name.ToLower() + ":";
                                string prefixClaims = "i:0#.f|" + membershipProvider.Name.ToLower() + "|";

                                var sites = elevatedSite.WebApplication.Sites;
                                foreach (SPSite site in sites)
                                {
                                    if (this.userBelongsToSite(prefixClaims, prefixOld, userName, site))
                                    {
                                        siteColls.Add(SPUrlUtility.CombineUrl(url, site.ServerRelativeUrl));
                                    }
                                }
                            }
                        });
                return siteColls;
            }
            catch (Exception x)
            {
                this.log("Error occured in old method (user name '{0}'): {1}\n{2}", userName, x.Message, x.StackTrace);
                return new List<string>();
            }
        }

        private void sendError(HttpContext context, string error)
        {
            this.sendResponse(context, new List<string>(), true, error);
        }

        private void sendResponse(HttpContext context, List<string> siteColls, bool isError, string error)
        {
            var response = context.Response;
            response.Clear();
            var s = new JavaScriptSerializer();
            string result = s.Serialize(new { SiteColls = siteColls, IsError = isError, ErrorMessage = error });
            response.ContentType = "application/json";
            response.Write(result);
            response.Flush();
            response.End();
        }

        private bool userBelongsToSite(string prefixClaims, string prefixOld, string userName, SPSite site)
        {
            if (string.IsNullOrEmpty(userName) || site == null)
            {
                return false;
            }
            var query = new SPQuery();
            query.Query = Camlex.Query().Where(x => ((string)x["Name"] == prefixClaims + userName || (string)x["Name"] == prefixOld + userName) && (string)x["ContentType"] == "Person").ToString();
            //query.ViewFields = Camlex.Query().ViewFields(x => new[] { x["Name"] });
            var itemsCount = site.RootWeb.SiteUserInfoList.GetItems(query).Count;
            return (itemsCount > 0);
        }

        public bool IsReusable
        {
            get { return true; }
        }

        private void log(string msg, params object[] args)
        {
            try
            {
                msg = string.Format(msg, args);
                msg = string.Format("{0} (thread id: {1})\t{2}\n", DateTime.Now.ToString("yyyy.MM.dd HH:mm:ss"), Thread.CurrentThread.ManagedThreadId, msg);
                File.AppendAllText(string.Format("c://temp/_fbauserssearch_{0}.txt", isTaloyhtio() ? "taloyhtio" : "tallier"), msg);
            }
            catch { }
        }
    }
}