/*
buypeeb - a program to track yahoo jp auctions of peebus.
Copyright (C) 2020 lynnesbian

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

using System;
using System.Collections.Generic;
using System.IO;
using System.Text.RegularExpressions;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;
using Gtk;

namespace Buypeeb {
	public struct ItemColumns {
		public const int Name = 0;
		public const int PriceYen = 1;
		public const int PriceAUD = 2;
		public const int Ending = 3;
		public const int Id = 4;
	}

	class MainWindow : Window {

		private string location;

		private ListStore items;
		private Settings settings;
		private TreeView itemTreeView;
		private Label statusLabel;

		static SemaphoreSlim tasklimit = new SemaphoreSlim(4);

		public MainWindow() : this(new Builder("main.glade")) { }

		private MainWindow(Builder builder) : base(builder.GetObject("wndMain").Handle) {
			if (Environment.OSVersion.Platform == PlatformID.Win32NT) {
				// C:\Users\Beebus\AppData\Roaming\Lynnear Software\buypeeb
				this.location = System.IO.Path.Combine(Environment.ExpandEnvironmentVariables("%APPDATA%"), "Lynnear Software", "buypeeb");
			}
			else {
				// ~/.config/Lynnear Software/buypeeb
				this.location = System.IO.Path.Combine(Environment.GetEnvironmentVariable("HOME"), ".config", "Lynnear Software", "buypeeb");
			}

			string userdata = System.IO.Path.Combine(location, "userdata.json");
			if (File.Exists(userdata)) {
				try {
					string j = File.ReadAllText(userdata);
					this.settings = JsonSerializer.Deserialize<Settings>(j);
				}
				catch {
					// ???
					Console.WriteLine("oops");
					Application.Quit();
				}

			}
			else {
				this.settings = new Settings();
			}
			this.SaveSettings();
			this.Title = "Buypeeb";

			builder.Autoconnect(this);

			this.statusLabel = (Label)builder.GetObject("LabelStatus");

			// bind treeview columns to watchlist instead of needing to manually sync its liststore
			this.itemTreeView = (TreeView)builder.GetObject("TreeViewItems");
			this.items = new ListStore(typeof(Listing));
			this.RenderList();

			this.itemTreeView.Model = this.items;
			for (int i = 0; i < this.itemTreeView.Columns.Length; i++) {
				var c = this.itemTreeView.Columns[i];
				TreeCellDataFunc func;

				//TODO: get rid of this awful if statement

				if (i == ItemColumns.Name) {
					func = new TreeCellDataFunc(this.RenderColumnName);
				}
				else if (i == ItemColumns.PriceYen) {
					func = new TreeCellDataFunc(this.RenderColumnPriceYen);
				}
				else if (i == ItemColumns.PriceAUD) {
					func = new TreeCellDataFunc(this.RenderColumnPriceAUD);
				}
				else if (i == ItemColumns.Ending) {
					func = new TreeCellDataFunc(this.RenderColumnEnding);
				}
				else {
					Console.WriteLine($"unexpected value {i}!");
					throw new IndexOutOfRangeException();
				}

				c.SetCellDataFunc(c.Cells[0], func);
			}

			foreach (object[] row in this.items) {
				Console.WriteLine(row[0]);
			}

			DeleteEvent += Window_Shutdown;
		}

		private void Window_Shutdown(object sender, DeleteEventArgs args) {
			Application.Quit();
		}

		// general behaviour

		private void SetStatus(string status) {
			this.statusLabel.Text = status ?? "Buypeeb";
		}

		private void SaveSettings() {
			string j = JsonSerializer.Serialize(this.settings);
			string p = System.IO.Path.Combine(this.location, "userdata.json");
			Console.WriteLine(j);
			if (!File.Exists(p)) {
				File.CreateText(p);
			}
			File.WriteAllText(System.IO.Path.Combine(this.location, "userdata.json"), j);
		}

		private void UpdateThread(string id) {
			var item = this.settings.watchlist[id];
			Console.WriteLine($"Updating {id}...");
			// set item.ready to false to show that it's still being updated
			// this changes a few behaviours, such as displaying the price as "..." instead of whatever's currently stored
			item.ready = false;
			// TODO: actually download the data
			Thread.Sleep(3000);
			string html = "Heeenlo";
			item.name = html;
			item.ready = true;
			Console.WriteLine($"{id} updated.");
			Gtk.Application.Invoke(delegate {
				// TODO: surely there's a better way to do this
				TreeIter iter;
				this.itemTreeView.Model.GetIterFirst(out iter);

				for (int i = 0; i < this.itemTreeView.Model.IterNChildren(); i++) {
					var x = (Listing)this.itemTreeView.Model.GetValue(iter, 0);
					if (x.id == id) {
						this.items.EmitRowChanged(this.itemTreeView.Model.GetPath(iter), iter);
						break;
					}
					else {
						this.itemTreeView.Model.IterNext(ref iter);
					}
				}
			});
		}

		private void UpdateItem(string id) {
			// don't start a new task if there are more than [tasklimit] tasks currently running
			// this makes sure we don't make 1000 simultaneous requests to yahoo auctions if there are 1000 items on the watchlist
			tasklimit.Wait();
			var t = Task.Factory.StartNew(() => {
				this.UpdateThread(id);
			}).ContinueWith(task => { tasklimit.Release(); });
		}

		private void UpdateItems() {
			var t = Task.Factory.StartNew(() => {
				foreach (var item in this.settings.watchlist) {
					this.UpdateItem(item.Key);
				}
			});
		}

		// show a simple entry dialogue that allows the user to enter text and either cancel or submit it
		private (Boolean accepted, string response) EntryDialogue(string title = "Buypeeb", string message = "Hi there!") {
			Dialog ed = new Dialog(title, null, Gtk.DialogFlags.DestroyWithParent, "Cancel", ResponseType.Cancel, "OK", ResponseType.Ok);
			ed.DefaultResponse = ResponseType.Ok;

			Label edLabel = new Label(message);
			Entry edEntry = new Entry();
			edEntry.ActivatesDefault = true;

			ed.ContentArea.PackStart(edLabel, true, true, 2);
			edLabel.Show();
			ed.ContentArea.PackStart(edEntry, true, true, 10);
			edEntry.Show();

			ResponseType accepted = (ResponseType)ed.Run();
			string response = edEntry.Text;
			ed.Dispose();
			return (accepted == ResponseType.Ok, response);
		}

		private void RenderList() {
			this.items.Clear();
			foreach (var item in this.settings.watchlist) {
				items.AppendValues(item.Value);
			}
		}

		// button handlers

		private void ButtonAddClicked(object sender, EventArgs a) {
			// Console.WriteLine("ButtonAddClicked");
			AddItemDialogue aid = new AddItemDialogue();
			ResponseType accepted = (ResponseType)aid.Run();
			string url = aid.GetURL();
			string name = aid.GetName();
			aid.Dispose();

			// vry simpl url validation for simpol creachers
			Regex rx = new Regex(@"^http.+yahoo.+");
			if (rx.IsMatch(url)) {
				Console.WriteLine("{0} will be added", url);
				this.settings.Watch(url, name);
				this.RenderList();
			}
			else {
				Console.WriteLine("{0} is an invalid url", url);
			}
		}

		private void ButtonUpdateAllClicked(object sender, EventArgs a) {
			this.UpdateItems();
		}

		private void ButtonClearEndedClicked(object sender, EventArgs a) {
			Console.WriteLine("ButtonClearEndedClicked");
		}

		private void ButtonClearAllClicked(object sender, EventArgs a) {
			Console.WriteLine("ButtonClearAllClicked");
		}

		private void ButtonSaveClicked(object sender, EventArgs a) {
			Console.WriteLine("ButtonSaveClicked");
		}

		private void ButtonQuitClicked(object sender, EventArgs a) {
			MessageDialog md = new MessageDialog(null, DialogFlags.DestroyWithParent, MessageType.Question, ButtonsType.OkCancel, "Are you sure you want to quit?");
			ResponseType response = (ResponseType)md.Run();
			md.Dispose();
			if (response == ResponseType.Ok) {
				Application.Quit();
			}
		}

		private void tveItemsSelectionChanged(object sender, EventArgs a) {
			Console.WriteLine("tveItemsSelectionChanged");
		}

		private void ButtonViewBuyeeClicked(object sender, EventArgs a) {
			Console.WriteLine("ButtonViewBuyeeClicked");
		}

		private void ButtonViewYahooClicked(object sender, EventArgs a) {
			Console.WriteLine("ButtonViewYahooClicked");
		}

		private void ButtonSelectedRemoveClicked(object sender, EventArgs a) {
			Console.WriteLine("ButtonSelectedRemoveClicked");
		}

		private void ButtonSelectedRenameClicked(object sender, EventArgs a) {
			Console.WriteLine("ButtonSelectedRenameClicked");
		}

		// column renderers

		private void RenderColumnName(Gtk.TreeViewColumn column, Gtk.CellRenderer cell, Gtk.ITreeModel model, Gtk.TreeIter iter) {
			Listing item = (Listing)model.GetValue(iter, 0);
			(cell as Gtk.CellRendererText).Text = item.name ?? "Loading...";
		}

		private void RenderColumnPriceYen(Gtk.TreeViewColumn column, Gtk.CellRenderer cell, Gtk.ITreeModel model, Gtk.TreeIter iter) {
			Listing item = (Listing)model.GetValue(iter, 0);
			(cell as Gtk.CellRendererText).Text = item.PriceJPY();
		}

		private void RenderColumnPriceAUD(Gtk.TreeViewColumn column, Gtk.CellRenderer cell, Gtk.ITreeModel model, Gtk.TreeIter iter) {
			Listing item = (Listing)model.GetValue(iter, 0);
			(cell as Gtk.CellRendererText).Text = item.PriceAUD();
		}

		private void RenderColumnEnding(Gtk.TreeViewColumn column, Gtk.CellRenderer cell, Gtk.ITreeModel model, Gtk.TreeIter iter) {
			Listing item = (Listing)model.GetValue(iter, 0);
			(cell as Gtk.CellRendererText).Text = "whatever";
		}

	}
}