using System;
using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;
using Microsoft.TeamFoundation.Client;
using Pinwheel;
using Pinwheel.SCM;
using Pinwheel.SCM.AwardContexts;

namespace TFS_Notification_Service
{
    public class TfsAwardContextFactory
    {
        protected internal static TfsAwardContextFactory Current { get; set; }
        
        static TfsAwardContextFactory()
        {
            Current = new TfsAwardContextFactory();
        }

        public static AwardContext CreateFromXml(string eventXml, string tfsIdentityXml)
        {
            return Current.GetContextFromXml(eventXml, tfsIdentityXml);
        }

        protected internal virtual AwardContext GetContextFromXml(string eventXml, string tfsIdentityXml)
        {
            ScmAwardContext context = null;

            var sourceDetails = XDocument.Parse(eventXml);
            switch (sourceDetails.Root.Name.ToString())
            {
                case "CheckinEvent":
                    context = new CheckinAwardContext();
                    break;
                case "BuildCompleteEvent":
                    context = new BuildAwardContext { BuildSuccessful = true };
                    break;
            }

            if (context != null)
            {
                context.AwardService = IocContainer.Resolve<IAwardService>();
                context.ChangesetID = GetChangesetId(sourceDetails);
                context.Server = GetTfsServer(tfsIdentityXml);
                context.Timestamp = DateTime.Now;
                context.User = GetUser(sourceDetails);
                context.WorkItemIDs = GetWorkItemIds(sourceDetails);
            }

            return context;
        }

        protected internal virtual int? GetChangesetId(XContainer sourceDetails)
        {
            return 1000;
        }

        protected internal virtual IEnumerable<int> GetWorkItemIds(XDocument sourceDetails)
        {
            return new[] { 1, 2, 3 };
        }

        protected internal virtual User GetUser(XContainer sourceDetails)
        {
            var username = (from e in sourceDetails.Elements("CheckinEvent")
                            select e.Element("Committer").Value).FirstOrDefault();
            return new ScmUser { Username = username };
        }

        protected internal virtual IScmServer GetTfsServer(string tfsIdentityXml)
        {
            var serverUrl = XDocument.Parse(tfsIdentityXml)
                .Element("TeamFoundationServer")
                .Attribute("url").Value;
            return new TfsServer(TeamFoundationServerFactory.GetServer(serverUrl));
        }

    }
}