using System.Diagnostics;
using System.Text;
using System.Text.RegularExpressions;
using Discord;
using Discord.WebSocket;
using Microsoft.Extensions.Configuration;
using RestSharp;
using Terminal.Gui;
using Terminal.Gui.Trees;
using Attribute = Terminal.Gui.Attribute;
using Color = Terminal.Gui.Color;

namespace chord
{
	public class Program
	{
		private ListView chatBoxList;
		private List<string> currentChannelMessages;
		private ulong currentSelectedChannel;
		private ulong currentSelectedGuild;
		private SortedDictionary<ulong, List<ulong>> guilds;
		private Settings settings;
		private Window window;

		public static void Main()
		{
			new Program().Start();
		}

		private async void Start()
		{
			try {
#if DEBUG
			var config = new ConfigurationBuilder()
				.AddJsonFile("config.json")
				.Build();
#else
			var config = new ConfigurationBuilder()
					.AddJsonFile($"{Environment.GetEnvironmentVariable("HOME")}/.config/chord/config.json")
					.Build();
#endif

			settings = config.Get<Settings>();

			var client = new DiscordSocketClient(new DiscordSocketConfig
				{ AlwaysDownloadUsers = true, GatewayIntents = GatewayIntents.All });

			await client.LoginAsync(TokenType.Bot, settings.Token);
			await client.StartAsync();

			Application.Init();

			window = new Window("chord")
			{
				X = 0,
				Y = 1,
				Width = Dim.Fill(),
				Height = Dim.Fill(),
				ColorScheme =
				{
					Normal = new Attribute(Color.White, Color.Black)
				}
			};

			client.Ready += () =>
			{
				guilds = new SortedDictionary<ulong, List<ulong>>();

				foreach (var guild in client.Guilds)
				{
					guilds.Add(guild.Id, new List<ulong>());

					foreach (var channel in guild.TextChannels)
					{
						var findGuild = guilds.GetValueOrDefault(guild.Id);

						if (channel.Users.ToList().Find(user => user.Id == client.CurrentUser.Id) == null) continue;
						if (findGuild == null) continue;
						findGuild.Add(channel.Id);

						findGuild.Sort();
					}
				}

				var menuBar = buildMenu();
				var serverList = buildServerList();
				var channelList = buildChannelList(serverList);
				var chatBox = buildChatBox(serverList);
				var messageBox = buildMessageBox(serverList, chatBox);
				var userList = buildUserList(chatBox);

				var serverListList = new ListView
				{
					X = 0,
					Y = 0,
					Width = Dim.Fill(),
					Height = Dim.Fill()
				};

				var guildNames = guilds.Select(guild => client.GetGuild(guild.Key).Name).ToList();

				serverListList.SetSource(guildNames);

				var channelListTree = new TreeView
				{
					X = 0,
					Y = 0,
					Width = Dim.Fill(),
					Height = Dim.Fill()
				};

				chatBoxList = new ListView
				{
					X = 0,
					Y = 0,
					Width = Dim.Fill(),
					Height = Dim.Fill()
				};

				var messageBoxText = new TextView
				{
					X = 0,
					Y = 0,
					Width = Dim.Percent(95),
					Height = Dim.Fill()
				};

				var messageBoxSend = new Button("Send", true)
				{
					X = Pos.Right(messageBoxText) - 2,
					Y = 0
				};

				var userListTree = new TreeView
				{
					X = 0,
					Y = 0,
					Width = Dim.Fill(),
					Height = Dim.Fill()
				};

				serverListList.OpenSelectedItem += args =>
				{
					channelListTree.ClearObjects();

					currentSelectedGuild = guilds.Keys.ToList()[args.Item];

					var channelNames = guilds.GetValueOrDefault(currentSelectedGuild)!
						.Select(channel => client.GetGuild(currentSelectedGuild).GetTextChannel(channel).Name).ToList();

					var categoryDict = new SortedDictionary<ulong, TreeNode>();

					foreach (var categories in client.GetGuild(currentSelectedGuild).CategoryChannels)
					{
						var categoryName = Regex.Replace(categories.Name, @"[^\u0000-\u007F]+", string.Empty);
						var node = new TreeNode(categoryName);

						foreach(var channel in categories.Channels)
						{
							if (channel.GetType().Name == "SocketTextChannel")
							{
								var channelName = Regex.Replace(channel.Name, @"[^\u0000-\u007F]+", string.Empty);
								var channelNode = new TreeNode(channelName);
								channelNode.Tag = new { Id = channel.Id };

								node.Children.Add(channelNode);
							}
						}

						categoryDict.Add(categories.Id, node);
					}

					foreach (var category in categoryDict)
					{
						channelListTree.AddObject(category.Value);
					}
				};

				channelListTree.SelectionChanged += async (arg1, arg2) =>
				{
					userListTree.ClearObjects();

					try {
						currentSelectedChannel = (ulong)arg2.NewValue.Tag.GetType().GetProperty("Id").GetValue(arg2.NewValue.Tag);
					} catch {
						return;
					}

					try {
						var restSharpClient = new RestClient("https://discord.com/api/v9");
						var restSharpReq = new RestRequest($"channels/{currentSelectedChannel}/messages");
						restSharpClient.AddDefaultHeader("Authorization", settings.Token);

						var response = await restSharpClient.GetAsync<List<GetMessagesResponse>>(restSharpReq);

						var messages = new List<string>();

						foreach (var msg in response)
						{
							var msgNewLines = msg.content.Split("\n").ToList();

							var firstMsg = msgNewLines[0];

							msgNewLines.RemoveAt(0);
							msgNewLines.Reverse();

							messages.AddRange(msgNewLines.Select(message => $"{message}"));

							messages.Add($"{msg.author.username}#{msg.author.discriminator} | {firstMsg}");

							if (msg.embeds.Count != 0)
								messages.Add($"{msg.author.username}#{msg.author.discriminator} | [Unable to display embed]");

							if (msg.attachments.Count == 0) continue;
							messages.AddRange(msg.attachments
								.Select(attachment => $"{msg.author.username}#{msg.author.discriminator} | {attachment.url}")
								.Select(dummy => dummy));
						}

						messages.Reverse();

						await chatBoxList.SetSourceAsync(messages);
						currentChannelMessages = messages;

						chatBoxList.ScrollDown(currentChannelMessages.Count - chatBoxList.Bounds.Height);
						chatBoxList.SelectedItem = currentChannelMessages.Count - 1;

						var rolesDict = new SortedDictionary<int, TreeNode>();

						foreach (var roles in client.GetGuild(currentSelectedGuild).Roles)
						{
							var roleName = Regex.Replace(roles.Name, @"[^\u0000-\u007F]+", string.Empty);
							var node = new TreeNode(roleName);

							foreach (var users in roles.Members)
							{
								node.Children.Add(new TreeNode($"{users.Username}#{users.Discriminator} ({users.Nickname})"));
							}

							rolesDict.Add(roles.Position, node);
						}

						foreach (var role in rolesDict)
						{
							userListTree.AddObject(role.Value);
						}
					} catch {
						await chatBoxList.SetSourceAsync(new List<string>());
					}
				};

				messageBoxSend.Clicked += async () =>
				{
					var restSharpClient = new RestClient("https://discord.com/api/v9");
					var restSharpReq = new RestRequest($"channels/{currentSelectedChannel}/messages");
					restSharpClient.AddDefaultHeader("Authorization", settings.Token);
					restSharpReq.AddJsonBody(new { content = Encoding.UTF8.GetString(messageBoxText.Text.ToByteArray()) });

					await restSharpClient.PostAsync<List<object>>(restSharpReq);

					messageBoxText.Text = "";
				};

				chatBoxList.OpenSelectedItem += args =>
				{
					if (currentChannelMessages[args.Item].Split(" | ")[1].Contains("http"))
						for (var i = 0; i < currentChannelMessages[args.Item].Split(" | ")[1].Split(" ").Count(); i++)
							if (currentChannelMessages[args.Item].Split(" | ")[1].Split(" ")[i].Contains("http"))
							{
								var procStartInfo = new ProcessStartInfo("/bin/sh",
									$"-c \"xdg-open {currentChannelMessages[args.Item].Split(" | ")[1].Split(" ")[i]}\"")
								{
									RedirectStandardOutput = true,
									RedirectStandardError = true,
									CreateNoWindow = true,
									UseShellExecute = false
								};

								var proc = new Process();
								proc.StartInfo = procStartInfo;
								proc.Start();
							}
				};

				Application.Top.KeyPress += async args =>
				{
					switch (ShortcutHelper.GetModifiersKey(args.KeyEvent)) {
						case Key.CtrlMask | Key.S:
							serverListList.SetFocus();
							break;
						case Key.CtrlMask | Key.C:
							channelListTree.SetFocus();
							break;
						case Key.CtrlMask | Key.AltMask | Key.C:
							chatBoxList.SetFocus();
							break;
						case Key.CtrlMask | Key.U:
							userListTree.SetFocus();
							break;
						case Key.CtrlMask | Key.Enter:
							var restSharpClient = new RestClient("https://discord.com/api/v9");
							var restSharpReq = new RestRequest($"channels/{currentSelectedChannel}/messages");
							restSharpClient.AddDefaultHeader("Authorization", settings.Token);
							restSharpReq.AddJsonBody(new { content = Encoding.UTF8.GetString(messageBoxText.Text.ToByteArray()) });

							await restSharpClient.PostAsync<List<object>>(restSharpReq);

							messageBoxText.Text = "";
							break;
					}
				};

				Application.Top.Add(window, menuBar);
				window.Add(serverList, channelList, messageBox, chatBox, userList);
				serverList.Add(serverListList);
				channelList.Add(channelListTree);
				chatBox.Add(chatBoxList);
				messageBox.Add(messageBoxText, messageBoxSend);
				userList.Add(userListTree);

				return Task.CompletedTask;
			};

			client.MessageReceived += async msg =>
			{
				if (msg.Channel.Id != currentSelectedChannel) return;

				var restSharpClient = new RestClient("https://discord.com/api/v9");
				var restSharpReq = new RestRequest($"channels/{currentSelectedChannel}/messages");
				restSharpReq.AddQueryParameter("limit", "1");
				restSharpClient.AddDefaultHeader("Authorization", settings.Token);

				var response = await restSharpClient.GetAsync<List<GetMessagesResponse>>(restSharpReq);

				currentChannelMessages.Add(
					$"{response.First().author.username}#{response.First().author.discriminator} | {response.First().content}");
				await chatBoxList.SetSourceAsync(currentChannelMessages);

				chatBoxList.ScrollDown(currentChannelMessages.Count - chatBoxList.Bounds.Height);
				chatBoxList.SelectedItem = currentChannelMessages.Count - 1;
			};

			Application.MainLoop.AddTimeout(TimeSpan.FromMilliseconds(100), caller => true);

			Application.Run();
			Application.Shutdown();
			} catch (System.Exception err) {
				Console.WriteLine(err);
			}
		}

		private Window buildChatBox(Window serverList)
		{
			return new Window("Chat Box")
			{
				X = Pos.Right(serverList),
				Y = 0,
				Width = Dim.Percent(60),
				Height = Dim.Percent(90)
			};
		}

		private Window buildChannelList(Window serverList)
		{
			return new Window("Channel List")
			{
				X = 0,
				Y = Pos.Bottom(serverList),
				Width = Dim.Percent(30),
				Height = Dim.Percent(50)
			};
		}

		private MenuBar buildMenu()
		{
			return new MenuBar(new[]
			{
				new MenuBarItem("File", new[]
				{
					new MenuItem("_Quit", "Quit the Application", () => { Application.Top.Running = false; })
				}),
				new MenuBarItem("Help", new[]
				{
					new MenuItem("_License", "See the Application License", () => {
						MessageBox.Query("License", "chord Copyright (C) 2021 Daryl Ronningen\nThis program comes with ABSOLUTELY NO WARRANTY; for details see section `15` of the GPL license\nThis is free software, and you are welcome to redistribute it under certain conditions; for details see section `2` of the GPL license", "Close");
					})
				})
			});
		}

		private Window buildMessageBox(Window serverList, Window chatBox)
		{
			return new Window("Message Box")
			{
				X = Pos.Right(serverList),
				Y = Pos.Bottom(chatBox),
				Width = Dim.Percent(60),
				Height = Dim.Percent(10)
			};
		}

		private Window buildUserList(Window chatBox)
		{
			return new Window("User List")
			{
				X = Pos.Right(chatBox),
				Y = 0,
				Width = Dim.Percent(10),
				Height = Dim.Fill()
			};
		}

		private Window buildServerList()
		{
			return new Window("Server List")
			{
				X = 0,
				Y = 0,
				Width = Dim.Percent(30),
				Height = Dim.Percent(50)
			};
		}
	}
}

public class Settings
{
	public string Token { get; set; }
}

public class GetMessagesResponse
{
	public string content { get; set; }
	public MessageAuthor author { get; set; }
	public List<object> embeds { get; set; }
	public List<MessageAttachments> attachments { get; set; }
}

public class MessageAuthor
{
	public string username { get; set; }
	public string discriminator { get; set; }
}

public class MessageAttachments
{
	public string url { get; set; }
}