using System;
using System.Globalization;
using System.Linq;
using System.Threading;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Utilities;
using SPSolutions.SharePoint.Alerts;
using Taloyhtio.CondoUpdate.Common;

namespace CondoUpdate.ChangeDiscussionBoardAlertTemplates
{
    public class UpdaterImpl : ICondoUpdater
    {
     private const string ALERT_TEMPLATE_BODY_PROPERTY_NAME = "NotificationMessage";

        public event EventHandler<LogEventArgs> OnNotify;
        public void Update(object args)
        {
            string url = args as string;
            if (string.IsNullOrEmpty(url))
            {
                this.warn("Url is empty");
                return;
            }

            try
            {
                this.updateImpl(SPUrlUtility.CombineUrl(url, "hallitukselle"));
            }
            catch(Exception x)
            {
                this.error("Error occured during updating of Condo '{0}':\n{1}\n{2}", url, x.Message, x.StackTrace);
            }
        }

        private void updateImpl(string url)
        {
            using (var site = new SPSite(url))
            {
                using (var web = site.OpenWeb())
                {
                    if (!web.Exists || string.Compare(web.Url, url, true) != 0)
                    {
                        return;
                    }
                    var list = web.Lists.Cast<SPList>().FirstOrDefault(l => l.Title == "Keskustelupalsta");
                    if (list == null)
                    {
                        this.warn("Keskustelupalsta list not found");
                        return;
                    }
                    this.ensureText(list);
                }
            }
        }

        private void ensureText(SPList l)
        {
            try
            {
                //var alertTemplate = l.AlertTemplate;
                var alert = getFirstListAlert(l);
                if (alert == null)
                {
                    //error("There are no alerts in the list");
                    return;
                }

                // get alert template from this list
                var alertTemplate = alert.AlertTemplate;
                if (alertTemplate == null)
                {
                    //error("Alert's alert template is null (list '{0}')", l.DefaultViewUrl);
                    return;
                }

                if (!isCustom(alertTemplate))
                {
                    //error("Alert template '{0}' is not custom (list '{1}')", alertTemplate.DisplayName, l.DefaultViewUrl);
                    return;
                }

                if (alertTemplate.Properties == null || !alertTemplate.Properties.ContainsKey(ALERT_TEMPLATE_BODY_PROPERTY_NAME))
                {
                    //error("Alert template '{0}' doesn't have {1} property (list '{2}')", alertTemplate.DisplayName, ALERT_TEMPLATE_BODY_PROPERTY_NAME, l.DefaultViewUrl);
                    return;
                }

                string body = alertTemplate.Properties[ALERT_TEMPLATE_BODY_PROPERTY_NAME] as string;
                if (string.IsNullOrEmpty(body))
                {
                    //error("{0} property is empty (list '{1}')", ALERT_TEMPLATE_BODY_PROPERTY_NAME, l.DefaultViewUrl);
                    return;
                }

                if (body.Contains("{ParentDiscussionTitle}"))
                {
                    //info("Body already contains ParentDiscussionTitle placeholder");
                    return;
                }

                if (!body.Contains("&lt;p&gt;&lt;strong&gt;{Title}&lt;/strong&gt;&lt;/p&gt;"))
                {
                    //error("Body doesn't contain Title placeholder");
                    return;
                }

                alertTemplate.Properties[ALERT_TEMPLATE_BODY_PROPERTY_NAME] =
                    body.Replace("&lt;p&gt;&lt;strong&gt;{Title}&lt;/strong&gt;&lt;/p&gt;", "&lt;p&gt;&lt;strong&gt;{ParentDiscussionTitle}&lt;/strong&gt;&lt;/p&gt;");
                alertTemplate.Update();
            }
            catch (Exception x)
            {
                this.error("Error occured when try to update alert template for list '{0}': {1}\n{2}", l.DefaultViewUrl, x.Message, x.StackTrace);
            }
        }

        private static SPAlert getFirstListAlert(SPList list)
        {
            var web = list.ParentWeb;
            var alerts = web.Alerts.Cast<SPAlert>();
            return alerts.FirstOrDefault(a => a.ListID == list.ID);
        }

        // This is copy of Alert template's AlertTemplateManager.IsCustom property implementation
        private static bool isCustom(SPAlertTemplate t)
        {
            return (((t.Properties["Custom"] != null) && (t.Properties["Custom"] is string)) && (((string)t.Properties["Custom"]) == SPAlertTemplateUtil.CustomAlertTemplateIdentifier));
        }

        private void info(string msg, params object[] args)
        {
            this.notify(LogLevel.Info, msg, args);
        }

        private void warn(string msg, params object[] args)
        {
            this.notify(LogLevel.Warn, msg, args);
        }

        private void error(string msg, params object[] args)
        {
            this.notify(LogLevel.Error, msg, args);
        }

        private void notify(LogLevel level, string msg, params object[] args)
        {
            this.notify(level, string.Format(msg, args));
        }

        private void notify(LogLevel level, string msg)
        {
            if (this.OnNotify != null)
            {
                this.OnNotify(this, new LogEventArgs { LogLevel = level, Message = msg });
            }
        }
    }
}