using System;
using System.Linq;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Utilities;
using Taloyhtio.CondoUpdate.Common;

namespace CondoUpdate.AddResponsibleUsersToGroupsTallier
{
    public class UpdaterImpl : ICondoUpdater
    {
        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(url);
            }
            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))
            {
                var web = site.RootWeb;
                var list = web.Lists.Cast<SPList>().FirstOrDefault(l => string.Compare(l.Title, "Sivustot", true) == 0);
                if (list == null)
                {
                    warn("List not found");
                    return;
                }

                foreach (SPListItem item in list.Items)
                {
                    string urlFieldTitle = "URL-osoite";
                    var urlField =
                        list.Fields.Cast<SPField>().FirstOrDefault(
                            i => i.Title == urlFieldTitle || i.StaticName == urlFieldTitle);
                    if (urlField == null)
                    {
                        return;
                    }

                    if (item[urlField.Id] == null || string.IsNullOrEmpty(item[urlField.Id].ToString()))
                    {
                        // for some lists on production there are 2 fields with the same title, so 1st field value may contain null
                        foreach (SPField f in item.Fields)
                        {
                            if (f.Title == urlFieldTitle && item[f.Id] != null &&
                                !string.IsNullOrEmpty(item[f.Id].ToString()))
                            {
                                urlField = f;
                                break;
                            }
                        }
                    }
                    if (item[urlField.Id] == null || string.IsNullOrEmpty(item[urlField.Id].ToString()))
                    {
                        return;
                    }
                    string condoUrl = new SPFieldUrlValue(item[urlField.Id].ToString()).Url;

                    SPUser user = null;
                    string userFieldTitle = "Kirjanpitäjä";
                    var userField = list.Fields.Cast<SPField>().FirstOrDefault(f => f.Title == userFieldTitle);
                    if (userField != null && userField.Type == SPFieldType.User && item[userFieldTitle] != null)
                    {
                        var fieldValue = userField.GetFieldValue(item[userFieldTitle].ToString()) as SPFieldUserValue;
                        if (fieldValue != null)
                        {
                            user = fieldValue.User;
                        }
                    }

                    if (SPUrlUtility.IsUrlRelative(condoUrl))
                    {
                        condoUrl = SPUrlUtility.CombineUrl(site.RootWeb.Url, condoUrl);
                    }

                    using (var s = new SPSite(condoUrl))
                    {
                        using (var condoWeb = s.OpenWeb())
                        {
                            if (!condoWeb.Exists)
                            {
                                return;
                            }

                            string groupName = getResponsiblePropertyManagersGroupName(condoWeb);
                            ensureSiteGroup(condoWeb, groupName);
                            if (user != null)
                            {
                                addUserToGroup(condoWeb, user, groupName);
                            }
                            else
                            {
                                // clear the group
                                var group = web.SiteGroups[groupName];
                                group.Users.Cast<SPUser>().ToList().ForEach(u => group.RemoveUser(u));
                            }
                        }
                    }
                }
            }
        }

        private void addUserToGroup(SPWeb web, SPUser user, string groupName)
        {
            if (user == null || string.IsNullOrEmpty(groupName))
            {
                return;
            }

            // don't need to add user in group second time
            if (isUserInGroup(web, user.LoginName, groupName))
            {
                return;
            }

            if (!containsUser(web, user.LoginName))
            {
                web.EnsureUser(user.LoginName);
            }
            var group = web.SiteGroups[groupName];
            group.AddUser(user);
        }

        private bool isUserInGroup(SPWeb web, string loginName, string groupName)
        {
            var group = web.SiteGroups[groupName];
            return group.Users.Cast<SPUser>().Any(u => string.Compare(u.LoginName, loginName, true) == 0);
        }

        public static bool containsUser(SPWeb web, string loginName)
        {
            return web.AllUsers.Cast<SPUser>().Any(u => string.Compare(u.LoginName, loginName, true) == 0);
        }

        private string getResponsiblePropertyManagersGroupName(SPWeb web)
        {
            return string.Format("{0} - Responsible accountants", web.Title);
        }

        private SPGroup ensureSiteGroup(SPWeb web, string groupName)
        {
            if (!isGroupExist(web, groupName))
            {
                web.SiteGroups.Add(groupName, web.SiteAdministrators[0], null, string.Empty);
            }

            return web.SiteGroups[groupName];
        }

        private static bool isGroupExist(SPWeb web, string groupName)
        {
            return web.SiteGroups.Cast<SPGroup>().Any(g => string.Compare(g.Name, groupName, true) == 0);
        }

        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 });
            }
        }
    }
}