using System;
using System.Collections.Generic;
using System.Linq;

using Gtk;
using Ext.SilentorBit;
using System.Drawing.Imaging;
using System.Runtime.ExceptionServices;

namespace SpritePacker.GUI
{
	public class MainWindow : Window
	{
		private static bool initialised = false;

		private SpriteListView spriteListDisplay;
		private FileChooserDialog spriteListSelector;
		private FileFilter spriteListSelectorFilter;

		private Button openImageButton;
		private Button removeImageButton;

		private SpritePacker spritePacker = new SpritePacker();

		public MainWindow() : base("SpritePacker GUI")
		{
			if (!initialised)
				throw new InvalidOperationException("Error: Gtk hasn't been initialised yet, so you can't create a new window.");

			SetDefaultSize(500, 300);
			SetPosition(WindowPosition.Center);

			// Quit when the close button is pressed
			DeleteEvent += (object o, DeleteEventArgs args) => {
				Application.Quit();
			};

			setupWidgets();
		}

		/// <summary>
		/// Initilise GTK# to make it ready for use.
		/// </summary>
		public static void Init()
		{
			initialised = true;
			Application.Init();
		}

		public void Start()
		{
			ShowAll();
			Application.Run();
		}

		private void setupWidgets()
		{
			// Create the layout containers
			HBox masterContainer = new HBox(false, 10);
			VBox leftPanel = new VBox(false, 0) { MarginRight = 5 };
			HBox controlButtonRow = new HBox();
			VBox rightPanel = new VBox(false, 0) { MarginLeft = 5 };
			Frame leftPanelFrame = new Frame("Sprites") { Child = leftPanel, Margin = 10, MarginRight = 5 };
			Frame rightPanelFrame = new Frame("Preview") { Child = rightPanel, Margin = 10, MarginLeft = 5 };

			// Create the file selector filter
			spriteListSelectorFilter = new FileFilter() { Name = "Images" };
			foreach (ImageCodecInfo currentDecoder in ImageCodecInfo.GetImageDecoders())
				spriteListSelectorFilter.AddMimeType(currentDecoder.MimeType);

			// Create the file selector dialog
			spriteListSelector = new FileChooserDialog("Add Sprite", this, FileChooserAction.Open) {
				Margin = 10,
				PreviewWidgetActive = true,
				Filter = spriteListSelectorFilter
			};
			spriteListSelector.SelectMultiple = true;
			spriteListSelector.AddButton("Add Sprites", ResponseType.Ok);
			spriteListSelector.AddButton("Cancel", ResponseType.Cancel);

			// Create the ListView to display the added sprites
			spriteListDisplay = new SpriteListView() { Margin = 10, MarginTop = 5 };
			spriteListDisplay.EnableSearch = true;

			openImageButton = new Button("Add Sprites") { Margin = 10, MarginTop = 0, MarginBottom = 0 };
			removeImageButton = new Button("Remove Selected Sprites") { Margin = 10, MarginTop = 0, MarginBottom = 0 };
			openImageButton.Released += (object sender, EventArgs e) => {
				ResponseType response = (ResponseType)spriteListSelector.Run();
				spriteListSelector.Hide();
				switch(response)
				{
					case ResponseType.Ok:
						Action_AddSprite(spriteListSelector.Filenames);
						break;
					case ResponseType.DeleteEvent:
					case ResponseType.Cancel:
						Console.Error.WriteLine("Ignoring sprite file chooser response {0}.", response);
						break;
					default:
						throw new Exception($"Unknown sprite file chooser response type {response}.");
				}
			};
			removeImageButton.Released += (object sender, EventArgs e) => {
				foreach(Sprite currentSprite in spriteListDisplay.SelectedItems)
					spritePacker.Remove(currentSprite);
				spriteListDisplay.ClearItems();
				foreach(Sprite currentSprite in spritePacker.CurrentSprites)
					spriteListDisplay.AddItem(currentSprite);
			};

			// Populate the control button row
			controlButtonRow.PackStart(openImageButton, true, false, 0);
			controlButtonRow.PackStart(removeImageButton, true, false, 0);

			// Populate the left panel
			leftPanel.PackStart(controlButtonRow, false, false, 5);
			leftPanel.PackStart(spriteListDisplay, true, true, 0);

			// Pack the master container
			masterContainer.PackStart(leftPanelFrame, true, true, 0);
			masterContainer.PackStart(rightPanelFrame, true, true, 0);

			// Add the master container to the window itself
			Add(masterContainer);
		}

		void Action_AddSprite(string[] selectedFilenames)
		{
			foreach (string filename in selectedFilenames)
			{
				Sprite nextSprite = new Sprite(filename);
				spritePacker.Add(nextSprite);
				spriteListDisplay.AddItem(nextSprite);
			}
		}
	}
}