// Copyright 2014-2017 ClassicalSharp | Licensed under BSD-3
using System;
using System.Collections.Generic;
using System.Drawing;
using ClassicalSharp.Entities;
using ClassicalSharp.Events;

namespace ClassicalSharp.Gui.Widgets {
	public class ExtPlayerListWidget : PlayerListWidget {
		
		public ExtPlayerListWidget(Game game, Font font) : base(game, font) {
			textures = new Texture[512];
			titleFont = new Font(game.FontName, font.Size);
			elementOffset = 10;
		}
		
		PlayerInfo[] info = new PlayerInfo[512];
		class PlayerInfo {
			
			public string ListName;
			public string PlayerName;
			public string GroupName;
			public byte GroupRank;
			public byte NameId;
			public bool IsGroup = false;
			
			public PlayerInfo(TabListEntry p) {
				ListName = Utils.StripColours(p.ListName);
				PlayerName = Utils.StripColours(p.PlayerName);
				NameId = p.NameId;
				GroupName = p.GroupName;
				GroupRank = p.GroupRank;
			}
			
			public PlayerInfo(string groupName) {
				GroupName = groupName;
				IsGroup = true;
			}
		}
		
		PlayerInfoComparer comparer = new PlayerInfoComparer();
		class PlayerInfoComparer : IComparer<PlayerInfo> {
			
			public bool JustComparingGroups = true;
			
			public int Compare(PlayerInfo x, PlayerInfo y) {
				if (JustComparingGroups)
					return x.GroupName.CompareTo(y.GroupName);
				
				int rankOrder = x.GroupRank.CompareTo(y.GroupRank);
				return rankOrder != 0 ? rankOrder :
					x.ListName.CompareTo(y.ListName);
			}
		}
		
		protected override bool ShouldOffset(int i) {
			return info[i] == null || !info[i].IsGroup;
		}
		
		Font titleFont;
		public override void Init() {
			base.Init();
			game.EntityEvents.TabListEntryAdded += TabEntryAdded;
			game.EntityEvents.TabListEntryRemoved += TabEntryRemoved;
			game.EntityEvents.TabListEntryChanged += TabEntryChanged;
		}
		
		public override void Dispose() {
			base.Dispose();
			game.EntityEvents.TabListEntryAdded -= TabEntryAdded;
			game.EntityEvents.TabListEntryChanged -= TabEntryChanged;
			game.EntityEvents.TabListEntryRemoved -= TabEntryRemoved;
			titleFont.Dispose();
		}
		
		void TabEntryChanged(object sender, IdEventArgs e) {
			for (int i = 0; i < namesCount; i++) {
				PlayerInfo pInfo = info[i];
				if (!pInfo.IsGroup && pInfo.NameId == e.Id) {
					Texture tex = textures[i];
					gfx.DeleteTexture(ref tex);
					AddPlayerInfo(game.TabList.Entries[e.Id], i);
					SortPlayerInfo();
					return;
				}
			}
		}

		void TabEntryRemoved(object sender, IdEventArgs e) {
			for (int i = 0; i < namesCount; i++) {
				PlayerInfo pInfo = info[i];
				if (!pInfo.IsGroup && pInfo.NameId == e.Id) {
					RemoveInfoAt(info, i);
					return;
				}
			}
		}

		void TabEntryAdded(object sender, IdEventArgs e) {
			AddPlayerInfo(game.TabList.Entries[e.Id], -1);
			SortPlayerInfo();
		}

		protected override void CreateInitialPlayerInfo() {
			TabListEntry[] entries = game.TabList.Entries;
			for (int i = 0; i < entries.Length; i++) {
				TabListEntry e = entries[i];
				if (e != null) AddPlayerInfo(e, -1);
			}
		}
		
		public override string GetNameUnder(int mouseX, int mouseY) {
			for (int i = 0; i < namesCount; i++) {
				Texture texture = textures[i];
				if (texture.IsValid && texture.Bounds.Contains(mouseX, mouseY)
				   && info[i].PlayerName != null)
					return Utils.StripColours(info[i].PlayerName);
			}
			return null;
		}
		
		void AddPlayerInfo(TabListEntry player, int index) {
			DrawTextArgs args = new DrawTextArgs(player.ListName, font, true);
			Texture tex = game.Drawer2D.MakeChatTextTexture(ref args, 0, 0);
			game.Drawer2D.ReducePadding(ref tex, Utils.Floor(font.Size), 3);
			
			if (index < 0) {
				info[namesCount] = new PlayerInfo(player);
				textures[namesCount] = tex;
				namesCount++;
			} else {
				info[index] = new PlayerInfo(player);
				textures[index] = tex;
			}
		}
		
		protected override void SortInfoList() {
			if (namesCount == 0) return;
			
			// Sort the list into groups
			for (int i = 0; i < namesCount; i++) {
				if (info[i].IsGroup) DeleteGroup(ref i);
			}
			comparer.JustComparingGroups = true;
			Array.Sort(info, textures, 0, namesCount, comparer);
			
			// Sort the entries in each group
			comparer.JustComparingGroups = false;
			int index = 0;
			while (index < namesCount) {
				AddGroup(info[index].GroupName, ref index);
				int count = GetGroupCount(index);
				Array.Sort(info, textures, index, count, comparer);
				index += count;
			}
		}
		
		void DeleteGroup(ref int i) {
			gfx.DeleteTexture(ref textures[i]);
			RemoveItemAt(info, i);
			RemoveItemAt(textures, i);
			
			namesCount--;
			i--;
		}
		
		void AddGroup(string group, ref int index) {
			DrawTextArgs args = new DrawTextArgs(group, titleFont, true);
			Texture tex = game.Drawer2D.MakeChatTextTexture(ref args, 0, 0);
			game.Drawer2D.ReducePadding(ref tex, Utils.Floor(titleFont.Size), 3);
			PlayerInfo pInfo = new PlayerInfo(group);
			
			PushDown(info, index, pInfo);
			PushDown(textures, index, tex);
			index++;
			namesCount++;
		}
		
		void PushDown<T>(T[] array, int index, T value) {
			for (int i = array.Length - 1; i > index; i--) {
				array[i] = array[i - 1];
			}
			array[index] = value;
		}
		
		int GetGroupCount(int startIndex) {
			string group = info[startIndex].GroupName;
			int count = 0;
			while (startIndex < namesCount && info[startIndex++].GroupName == group) {
				count++;
			}
			return count;
		}
	}
}