using System.Reflection;
using System.Text.Json;
using System.Text.Json.Nodes;
using System.Text.Json.Serialization;
using CounterStrikeSharp.API;
using CounterStrikeSharp.API.Core;
using CounterStrikeSharp.API.Core.Attributes;
using CounterStrikeSharp.API.Core.Attributes.Registration;
using CounterStrikeSharp.API.Modules.Admin;
using CounterStrikeSharp.API.Modules.Commands;
using CounterStrikeSharp.API.Modules.Entities;
using CounterStrikeSharp.API.Modules.Timers;
using CounterStrikeSharp.API.Modules.Utils;
using Microsoft.Extensions.Logging;

namespace CS2_Tags;

public class Tag
{
	[JsonPropertyName("prefix")] public string Prefix { get; set; } = "";
	[JsonPropertyName("nick_color")] public string NickColor { get; set; } = "";
	[JsonPropertyName("message_color")] public string MessageColor { get; set; } = "";
	[JsonPropertyName("scoreboard")] public string Scoreboard { get; set; } = "";

	// A tag with nothing to show in chat leaves the player's messages to the game.
	[JsonIgnore]
	public bool AffectsChat => Prefix != "" || NickColor != "" || MessageColor != "";
}

[MinimumApiVersion(375)]
public class CS2_Tags : BasePlugin
{
	public override string ModuleName => "CS2-Tags";
	public override string ModuleDescription => "Add player tags easily in cs2 game";
	public override string ModuleAuthor => "daffyy";
	public override string ModuleVersion => "1.0.4c-zio1";

	private static string TagsPath => Path.Combine(Server.GameDirectory, "csgo", "addons", "counterstrikesharp",
		"configs", "plugins", "CS2-Tags", "tags.json");

	// Checked in file order after the SteamID64 entries, first match wins, so list higher ranks first.
	private List<KeyValuePair<string, Tag>> _tags = new();

	public override void Load(bool hotReload)
	{
		LoadTags();

		RegisterListener<Listeners.OnClientAuthorized>(OnClientAuthorized);
		RegisterEventHandler<EventPlayerConnectFull>(OnPlayerConnectFull);
		RegisterEventHandler<EventPlayerSpawn>(OnPlayerSpawn);
		RegisterEventHandler<EventPlayerDeath>(OnPlayerDeath);
		AddCommandListener("say", OnPlayerChat);
		AddCommandListener("say_team", OnPlayerChatTeam);

		if (hotReload)
			ApplyAllClanTags();
	}

	private void LoadTags()
	{
		try
		{
			if (!File.Exists(TagsPath))
			{
				Directory.CreateDirectory(Path.GetDirectoryName(TagsPath)!);
				File.WriteAllText(TagsPath, DefaultTagsJson);
			}

			var root = JsonNode.Parse(File.ReadAllText(TagsPath),
				documentOptions: new JsonDocumentOptions { CommentHandling = JsonCommentHandling.Skip, AllowTrailingCommas = true });
			var tags = new List<KeyValuePair<string, Tag>>();
			if (root?["tags"] is JsonObject tagsObject)
			{
				foreach (var (key, value) in tagsObject)
				{
					var tag = value?.Deserialize<Tag>();
					if (tag != null)
						tags.Add(new(key, tag));
				}
			}

			_tags = tags;
			Logger.LogInformation("Loaded {Count} tags from {Path}", _tags.Count, TagsPath);
		}
		catch (Exception ex)
		{
			// Keep the previous tags, so a typo in the file doesn't strip everyone's tags.
			Logger.LogError(ex, "Failed to load {Path}", TagsPath);
		}
	}

	[ConsoleCommand("css_tags_reload", "Reload tags.json and reapply scoreboard tags")]
	[CommandHelper(whoCanExecute: CommandUsage.CLIENT_AND_SERVER)]
	[RequiresPermissions("@css/root")]
	public void OnReloadConfig(CCSPlayerController? player, CommandInfo info)
	{
		LoadTags();
		ApplyAllClanTags();
		info.ReplyToCommand($"[CS2-Tags] Reloaded {_tags.Count} tags.");
	}

	private void OnClientAuthorized(int playerSlot, SteamID steamId)
	{
		var player = Utilities.GetPlayerFromSlot(playerSlot);
		if (player == null || !player.IsValid || player.IsBot || player.IsHLTV) return;

		AddTimer(2.0f, () => SetPlayerClanTag(player), TimerFlags.STOP_ON_MAPCHANGE);
	}

	private HookResult OnPlayerConnectFull(EventPlayerConnectFull @event, GameEventInfo info)
	{
		var player = @event.Userid;
		if (player == null || !player.IsValid || player.IsBot || player.IsHLTV) return HookResult.Continue;

		AddTimer(2.0f, () => SetPlayerClanTag(player), TimerFlags.STOP_ON_MAPCHANGE);
		return HookResult.Continue;
	}

	private HookResult OnPlayerSpawn(EventPlayerSpawn @event, GameEventInfo info)
	{
		var player = @event.Userid;
		if (player == null || !player.IsValid || player.IsBot) return HookResult.Continue;

		AddTimer(1.5f, () => SetPlayerClanTag(player), TimerFlags.STOP_ON_MAPCHANGE);
		return HookResult.Continue;
	}

	private HookResult OnPlayerDeath(EventPlayerDeath @event, GameEventInfo info)
	{
		var player = @event.Userid;
		if (player == null || !player.IsValid || player.IsBot) return HookResult.Continue;

		AddTimer(1.5f, () => SetPlayerClanTag(player), TimerFlags.STOP_ON_MAPCHANGE);
		return HookResult.Continue;
	}

	// Gags and "@" admin chat are CS2-SimpleAdmin's job: its catch-all command listener runs before
	// these and stops the command, so a gagged player's message never reaches here.
	private static bool IsCommandOrTrigger(string message) =>
		message.StartsWith('!') || message.StartsWith('@') || message.StartsWith('/') || message.StartsWith('.') || message == "rtv";

	private HookResult OnPlayerChat(CCSPlayerController? player, CommandInfo info)
	{
		var message = info.GetArg(1);
		if (player == null || !player.IsValid || message.Length == 0 || IsCommandOrTrigger(message)) return HookResult.Continue;

		var tag = FindTag(player);
		if (tag == null || !tag.AffectsChat) return HookResult.Continue;

		var line = FormatChat(player, tag, message, player.TeamNum);
		Server.PrintToChatAll($" {line}");
		return HookResult.Handled;
	}

	private HookResult OnPlayerChatTeam(CCSPlayerController? player, CommandInfo info)
	{
		var message = info.GetArg(1);
		if (player == null || !player.IsValid || message.Length == 0 || IsCommandOrTrigger(message)) return HookResult.Continue;

		var tag = FindTag(player);
		if (tag == null || !tag.AffectsChat) return HookResult.Continue;

		var line = $"{TeamName(player.TeamNum)} {ChatColors.Default}{FormatChat(player, tag, message, player.TeamNum)}";
		foreach (var p in Utilities.GetPlayers().Where(p => p is { IsValid: true, IsBot: false } && p.TeamNum == player.TeamNum))
		{
			p.PrintToChat($" {line}");
		}

		return HookResult.Handled;
	}

	private string FormatChat(CCSPlayerController player, Tag tag, string message, int teamNum)
	{
		string deadIcon = player.TeamNum > (int)CsTeam.Spectator && !player.PawnIsAlive ? $"{ChatColors.White}☠ {ChatColors.Default}" : "";
		string prefix = tag.Prefix == "" ? "" : ReplaceTags(tag.Prefix, teamNum).TrimEnd() + " ";
		string nickColor = tag.NickColor == "" ? TeamColor(teamNum) : ReplaceTags(tag.NickColor, teamNum);
		string messageColor = tag.MessageColor == "" ? ChatColors.Default.ToString() : ReplaceTags(tag.MessageColor, teamNum);

		// Colour tags are only replaced in the config's strings, never in the player's name or message.
		return $"{deadIcon}{prefix}{ChatColors.Default}{nickColor}{player.PlayerName}{ChatColors.Default}: {messageColor}{message}";
	}

	// SteamID64 entries win, then groups ("#...") and permissions ("@...") in file order, then "everyone".
	private Tag? FindTag(CCSPlayerController player)
	{
		if (player.IsBot || player.IsHLTV || player.AuthorizedSteamID == null) return null;

		string steamid = player.AuthorizedSteamID.SteamId64.ToString();
		foreach (var (key, tag) in _tags)
		{
			if (key == steamid) return tag;
		}

		foreach (var (key, tag) in _tags)
		{
			if (key.StartsWith('#') && AdminManager.PlayerInGroup(player, key)) return tag;
			if (key.StartsWith('@') && AdminManager.PlayerHasPermissions(player, key)) return tag;
		}

		foreach (var (key, tag) in _tags)
		{
			if (key == "everyone") return tag;
		}

		return null;
	}

	private void ApplyAllClanTags()
	{
		foreach (var player in Utilities.GetPlayers())
		{
			SetPlayerClanTag(player);
		}
	}

	private void SetPlayerClanTag(CCSPlayerController? player)
	{
		if (player == null || !player.IsValid) return;

		var tag = FindTag(player);
		if (tag == null || tag.Scoreboard == "" || player.Clan == tag.Scoreboard) return;

		player.Clan = tag.Scoreboard;
		Utilities.SetStateChanged(player, "CCSPlayerController", "m_szClan");
	}

	private static string TeamName(int teamNum)
	{
		return teamNum switch
		{
			(int)CsTeam.Spectator => "(SPEC)",
			(int)CsTeam.Terrorist => $"{ChatColors.Yellow}(T)",
			(int)CsTeam.CounterTerrorist => $"{ChatColors.Blue}(CT)",
			_ => "(NONE)",
		};
	}

	private static string TeamColor(int teamNum)
	{
		return teamNum switch
		{
			(int)CsTeam.Terrorist => ChatColors.Gold.ToString(),
			(int)CsTeam.CounterTerrorist => ChatColors.Blue.ToString(),
			_ => "",
		};
	}

	private static string ReplaceTags(string text, int teamNum = 0)
	{
		if (!text.Contains('{')) return text;

		foreach (FieldInfo field in typeof(ChatColors).GetFields(BindingFlags.Public | BindingFlags.Static))
		{
			if (field.FieldType == typeof(char))
				text = text.Replace($"{{{field.Name}}}", field.GetValue(null)!.ToString(), StringComparison.OrdinalIgnoreCase);
		}

		return text.Replace("{TEAMCOLOR}", TeamColor(teamNum), StringComparison.OrdinalIgnoreCase);
	}

	// Written to configs/plugins/CS2-Tags/tags.json on first load. Our CS2-SimpleAdmin rank groups,
	// highest first; guardian (VIP) comes after staff so a staff member's rank tag wins.
	private const string DefaultTagsJson = """
		{
		  "tags": {
		    "#rank/owner":       { "prefix": "{DarkRed}[Owner]",        "nick_color": "{LightRed}", "message_color": "", "scoreboard": "[Owner]" },
		    "#rank/senioradmin": { "prefix": "{Red}[Senior Admin]",     "nick_color": "{LightRed}", "message_color": "", "scoreboard": "[Sr. Admin]" },
		    "#rank/admin":       { "prefix": "{Red}[Admin]",            "nick_color": "{LightRed}", "message_color": "", "scoreboard": "[Admin]" },
		    "#rank/trialadmin":  { "prefix": "{LightRed}[Trial Admin]", "nick_color": "",           "message_color": "", "scoreboard": "[T. Admin]" },
		    "#rank/mod":         { "prefix": "{Blue}[Mod]",             "nick_color": "",           "message_color": "", "scoreboard": "[Mod]" },
		    "#rank/trialmod":    { "prefix": "{LightBlue}[Trial Mod]",  "nick_color": "",           "message_color": "", "scoreboard": "[T. Mod]" },
		    "#rank/helper":      { "prefix": "{Green}[Helper]",         "nick_color": "",           "message_color": "", "scoreboard": "[Helper]" },
		    "#rank/guardian":    { "prefix": "{Gold}[Guardian]",        "nick_color": "",           "message_color": "", "scoreboard": "[Guardian]" },
		    "everyone":          { "prefix": "",                        "nick_color": "",           "message_color": "", "scoreboard": "" }
		  }
		}
		""";
}