using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Threading;

using System.Windows.Forms;

using Html.Downloader.Engine;

using Html.Downloader.Extensions;

using Melon.Commons.Aspects.WinForms;

using Melon.Commons.Aspects.WinForms.Asynchronousity;

using Melon.Commons.Aspects.WinForms.ExceptionHandling;

using Melon.Commons.Aspects.WinForms.Synchronization;



namespace Html.Downloader.Forms

{

    public partial class AddLinksForm : Form, IExceptionHandler, IAsynchronous

    {

        #region Private Fields

        private ILinkPreparationService service;

        #endregion

        #region Constructors

        public AddLinksForm(ILinkPreparationService service)

        {

            this.service = service;

            this.InitializeComponent();

        }

        #endregion



        [ExceptionHandled]

        private void OnQueueRequest(object sender, EventArgs e)

        {

            var query = from item in this.lvLinks.Items.OfType<ListViewItem>()

                        where item.Checked && item.Tag is DownloadItem

                        select item.Tag as DownloadItem;



            this.service.Queue(query.ToArray());

        }



        private void OnManualLinksAreaChanged(object sender, EventArgs e)

        {

            this.btnManualFind.Enabled = this.tbLinkPasteArea.TextLength > 0;

        }



        private void OnFinalLinkChecked(object sender, ItemCheckedEventArgs e)

        {

            this.OnFinalLinksContentChanged();

        }



        private void OnFinalLinksContentChanged()

        {

            var unrecognized = from item in this.lvLinks.Items.OfType<ListViewItem>()

                               where item.Tag is DownloadLink

                               select item;



            var selectedAndRecognized = from item in this.lvLinks.Items.OfType<ListViewItem>()

                                        where item.Checked && item.Tag is DownloadItem

                                        select item;



            this.btnRecognize.Enabled = unrecognized.Any();

            this.btnQueue.Enabled = selectedAndRecognized.Any();

        }



        private void OnFoundLinksContentChanged()

        {

            var selected = from item in this.lvFoundLinks.Items.OfType<ListViewItem>()

                           where item.Checked

                           select item;



            this.btnFoundAddSelected.Enabled = selected.Any();

        }



        private void OnFindManuallyEnteredLinks(object sender, EventArgs e)

        {

            this.AddLinksToRecognizingStage(this.service.FindInText(this.tbLinkPasteArea.Text));

        }



        private void OnAnalyzePage(object sender, EventArgs e)

        {

            this.OnAnalyzePage(this.tbPageLink.Text);

        }



        [ExceptionHandled, Asynchronous(AsynchronousMode.Real, "Analyzing page...")]

        private void OnAnalyzePage(string link)

        {

            var links = this.service.FindAtPage(link);

            this.OnAnalyzePageComplete(links);

        }



        [MethodSynchronizer]

        private void OnAnalyzePageComplete(DownloadLink[] links)

        {

            this.AddLinksToFoundStage(links);



            this.lblStatus.ResetText();

            this.Enabled = true;

        }



        private void AddLinksToRecognizingStage(DownloadLink[] links)

        {

            var list = new List<ListViewItem>();



            foreach (var link in links)

            {

                var current = link;

                var provider = String.Empty;

                var linkname = current.Target;

                var item = new ListViewItem(new[] { linkname, provider }) { Tag = current };



                list.Add(item);

            }



            this.lvLinks.Items.AddRange(list.ToArray());

            this.OnFinalLinksContentChanged();

        }



        private void AddLinksToFoundStage(DownloadLink[] links)

        {

            foreach (var link in links)

            {

                var current = link;

                var linkname = current.Target;

                var item = new ListViewItem(new[] { linkname }) { Tag = current, Checked = true };



                this.lvFoundLinks.Items.Add(item);

            }



            this.OnFoundLinksContentChanged();

        }



        private void OnRecognizeAvailableLinks(object sender, EventArgs e)

        {

            this.OnRecognizeAvailableLinks(this.lvLinks.Items.OfType<ListViewItem>().ToArray());

        }



        [ExceptionHandled, Asynchronous(AsynchronousMode.Real, "Querying servers...")]

        private void OnRecognizeAvailableLinks(ListViewItem[] items)

        {

            var selected = from item in items

                           where item.Tag is DownloadLink

                           select new

                           {

                               Item = item,

                               Link = item.Tag as DownloadLink

                           };



            var recognized = this.service.Recognize(selected.Select(x => x.Link).ToArray());



            var updated = from item in selected

                          join element in recognized on item.Link.Target equals element.GetSources().First().Link into elements

                          from element in elements.DefaultIfEmpty()

                          select new

                          {

                              Item = item.Item,

                              Link = element

                          };



            this.OnRecognizeAvailableLinksComplete(updated.ToDictionary(x => x.Item, x => x.Link));

        }



        [MethodSynchronizer]

        private void OnRecognizeAvailableLinksComplete(IDictionary<ListViewItem, DownloadItem> updated)

        {

            foreach (var item in updated)

            {

                if (item.Value == null)

                {

                    item.Key.Remove();

                }

                else

                {

                    item.Key.Checked = true;

                    item.Key.Tag = item.Value;

                    item.Key.SubItems[0].Text = item.Value.Filename;

                    item.Key.SubItems[1].Text = item.Value.GetSources().First().Info.Name;

                }

            }



            this.OnFinalLinksContentChanged();

        }



        private void OnAddSelectedLinks(object sender, EventArgs e)

        {

            var selected = from item in this.lvFoundLinks.Items.OfType<ListViewItem>()

                           where item.Checked

                           select new

                           {

                               Item = item,

                               Link = item.Tag as DownloadLink

                           };



            this.AddLinksToRecognizingStage(selected.Select(x => x.Link).ToArray());



            this.lvFoundLinks.SuspendLayout();

            foreach (var item in selected.ToArray())

                item.Item.Remove();

            this.lvFoundLinks.ResumeLayout();



            this.OnFoundLinksContentChanged();

        }



        private void OnPageLinkChanged(object sender, EventArgs e)

        {

            Uri dummy;

            this.btnAnalyzePage.Enabled = Uri.TryCreate(this.tbPageLink.Text, UriKind.Absolute, out dummy) && dummy.Scheme == Uri.UriSchemeHttp;

        }



        #region IExceptionHandler Members

        [MethodSynchronizer]

        void IExceptionHandler.Handle(Exception ex)

        {

            this.lblStatus.ResetText();

            this.Enabled = true;



            MessageBox.Show(this, ex.Message, this.Text, MessageBoxButtons.OK, MessageBoxIcon.Error);

        }

        #endregion

        #region IAsynchronous Members

        [MethodSynchronizer]

        void IAsynchronous.OnStart(string message)

        {

            this.lblStatus.Text = message;

            this.Enabled = false;

        }



        [MethodSynchronizer]

        void IAsynchronous.OnComplete()

        {

            this.lblStatus.ResetText();

            this.Enabled = true;

        }

        #endregion

    }

}