using System;
using System.Collections.Generic;
using System.Text;
using UnityEngine;

namespace MSCO
{
    /// <summary>
    /// Lieblings-Server mit eigenem Kurznamen (z.B. "mbm"). Gespeichert in den PlayerPrefs, eine Zeile pro Server:
    /// Kurzname, Adresse, Port, Servername (Tab-getrennt). Mit "switch <kurzname>" wechselt man schnell den Server.
    /// </summary>
    public static class Favorites
    {
        public class Favorite
        {
            public string Nickname;
            public string Host;
            public int Port;
            public string ServerName;
            public string Address { get { return Host + ":" + Port; } }
        }

        const string Pref = "MSCO_Favorites";
        const int MaxFavorites = 30;
        static List<Favorite> list;

        public static List<Favorite> All { get { Load(); return list; } }

        static void Load()
        {
            if (list != null) return;
            list = new List<Favorite>();
            string raw = PlayerPrefs.GetString(Pref, "");
            foreach (string line in raw.Split('\n'))
            {
                string[] p = line.Split('\t');
                int port;
                if (p.Length < 3 || p[0].Length == 0 || p[1].Length == 0 || !int.TryParse(p[2], out port)) continue;
                list.Add(new Favorite { Nickname = p[0], Host = p[1], Port = port, ServerName = p.Length > 3 ? p[3] : "" });
            }
        }

        static void Save()
        {
            var sb = new StringBuilder();
            foreach (Favorite f in list)
                sb.Append(Clean(f.Nickname)).Append('\t').Append(Clean(f.Host)).Append('\t').Append(f.Port).Append('\t').Append(Clean(f.ServerName)).Append('\n');
            PlayerPrefs.SetString(Pref, sb.ToString());
            PlayerPrefs.Save();
        }

        static string Clean(string s) { return (s ?? "").Replace("\t", " ").Replace("\n", " ").Trim(); }

        /// <summary>Kurzname: Buchstaben, Zahlen, - und _ (ohne Leerzeichen, damit "switch name" eindeutig ist).</summary>
        public static string CleanNickname(string nickname)
        {
            var sb = new StringBuilder();
            foreach (char c in (nickname ?? "").Trim())
                if (char.IsLetterOrDigit(c) || c == '-' || c == '_') sb.Append(c);
            string s = sb.ToString();
            return s.Length > 20 ? s.Substring(0, 20) : s;
        }

        public static Favorite Find(string nickname)
        {
            Load();
            return list.Find(f => string.Equals(f.Nickname, nickname, StringComparison.OrdinalIgnoreCase));
        }

        public static Favorite FindByAddress(string host, int port)
        {
            Load();
            return list.Find(f => f.Port == port && string.Equals(f.Host, host, StringComparison.OrdinalIgnoreCase));
        }

        /// <summary>Hinzufügen oder (gleiche Adresse) umbenennen. Gibt einen Fehler zurück oder null.</summary>
        public static string Set(string nickname, string host, int port, string serverName)
        {
            Load();
            nickname = CleanNickname(nickname);
            if (nickname.Length == 0) return "Nickname: letters, numbers, - and _";
            if (string.IsNullOrEmpty(host) || port <= 0 || port > 65535) return "Invalid server address";
            Favorite sameName = Find(nickname);
            Favorite existing = FindByAddress(host, port);
            if (sameName != null && sameName != existing) return "The nickname '" + nickname + "' is already used for " + sameName.Address;
            if (existing == null)
            {
                if (list.Count >= MaxFavorites) return "Too many favorites (max " + MaxFavorites + ")";
                existing = new Favorite { Host = host, Port = port };
                list.Add(existing);
            }
            existing.Nickname = nickname;
            if (!string.IsNullOrEmpty(serverName)) existing.ServerName = serverName;
            Save();
            return null;
        }

        public static bool Remove(Favorite f)
        {
            Load();
            if (f == null || !list.Remove(f)) return false;
            Save();
            return true;
        }

        /// <summary>Vorschlag für den Kurznamen aus dem Servernamen (erstes Wort, klein).</summary>
        public static string SuggestNickname(string serverName)
        {
            string first = (serverName ?? "").Trim().Split(' ')[0];
            string nick = CleanNickname(first).ToLower();
            return nick.Length > 0 ? nick : "server";
        }
    }
}