using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using HutongGames.PlayMaker;
using UnityEngine;

namespace MSCO
{
    /// <summary>
    /// Jobs, Aufträge und Laden: deren Fortschritt steht in PlayMaker-FSMs (z.B. "Auftrag angenommen", Anzahl
    /// geleerter Klärgruben, bestellte Teile). Übertragen werden nur Ganzzahlen und Schalter - keine Kommazahlen
    /// (Timer, Positionen), die jeder selbst weiterzählt. Wer etwas ändert, schickt es; Werte, die ständig hin und her
    /// springen (interne Zähler), werden nach kurzer Zeit nicht mehr übertragen.
    /// </summary>
    public class WorldVarSync
    {
        /// <summary>Wurzelobjekte mit Jobs/Aufträgen/Laden.</summary>
        public static readonly string[] Roots = { "JOBS", "STORE", "REPAIRSHOP", "INSPECTION", "LANDFILL", "DANCEHALL", "COTTAGE", "RALLY" };

        const float ScanInterval = 15f;
        const float CheckInterval = 0.5f;
        const float MinResend = 2f;       // höchstens so oft pro Wert
        const int FlipLimit = 6;          // so viele Änderungen ...
        const float FlipWindow = 30f;     // ... in dieser Zeit = interner Zähler, nicht mehr übertragen
        const int MaxPerMessage = 200;

        class Var
        {
            public int Key;
            public NamedVariable Variable;
            public byte Type;   // 2 int, 3 bool
            public int LastI;
            public bool LastB;
            public float LastSent = -100f;
            public float WindowStart;
            public int Flips;
            public bool Muted;
        }

        readonly Dictionary<int, Var> vars = new Dictionary<int, Var>();
        readonly HashSet<PlayMakerFSM> scanned = new HashSet<PlayMakerFSM>();
        readonly List<Var> outgoing = new List<Var>();
        float nextScan, nextCheck;

        public int Count { get { return vars.Count; } }

        public void Reset()
        {
            vars.Clear();
            scanned.Clear();
            nextScan = -1f; // erster Suchlauf verteilt, siehe Update
        }

        public void Update(Action<MsgType, byte[]> send)
        {
            if (nextScan < 0f) nextScan = Time.time + 3.8f; // nicht alle Sync-Teile im selben Frame suchen lassen
            if (Time.time >= nextScan)
            {
                nextScan = Time.time + ScanInterval;
                Scan();
            }
            if (Time.time < nextCheck) return;
            nextCheck = Time.time + CheckInterval;

            outgoing.Clear();
            foreach (Var v in vars.Values)
            {
                if (v.Muted || !Changed(v)) continue;
                if (Time.time - v.LastSent < MinResend) continue; // später nochmal prüfen
                Remember(v);
                if (Time.time - v.WindowStart > FlipWindow) { v.WindowStart = Time.time; v.Flips = 0; }
                if (++v.Flips > FlipLimit) { v.Muted = true; continue; }
                v.LastSent = Time.time;
                outgoing.Add(v);
            }

            for (int start = 0; start < outgoing.Count; start += MaxPerMessage)
            {
                int from = start, count = Math.Min(MaxPerMessage, outgoing.Count - start);
                send(MsgType.WorldVars, NetSession.Build(w =>
                {
                    w.Write(count);
                    for (int i = from; i < from + count; i++)
                    {
                        Var v = outgoing[i];
                        w.Write(v.Key);
                        w.Write(v.Type);
                        if (v.Type == 2) w.Write(v.LastI); else w.Write(v.LastB);
                    }
                }));
            }
        }

        public void Handle(BinaryReader r)
        {
            int count = r.ReadInt32();
            for (int i = 0; i < count; i++)
            {
                int key = r.ReadInt32();
                byte type = r.ReadByte();
                int iv = 0; bool bv = false;
                if (type == 2) iv = r.ReadInt32(); else if (type == 3) bv = r.ReadBoolean(); else return;
                Var v;
                if (!vars.TryGetValue(key, out v) || v.Type != type) continue;
                if (type == 2) ((FsmInt)v.Variable).Value = iv; else ((FsmBool)v.Variable).Value = bv;
                Remember(v); // nicht zurückschicken
            }
        }

        void Scan()
        {
            int before = vars.Count;
            foreach (PlayMakerFSM fsm in SceneCache.Fsms(5f))
            {
                if (fsm == null || !scanned.Add(fsm)) continue;
                if (Array.IndexOf(Roots, fsm.transform.root.name) < 0) continue;
                string prefix = FsmSync.PathOf(fsm.transform) + "|" + fsm.FsmName + "|";
                FsmVariables fv = fsm.FsmVariables;
                foreach (FsmInt n in fv.IntVariables) Register(prefix, n, 2);
                foreach (FsmBool b in fv.BoolVariables) Register(prefix, b, 3);
            }
            if (vars.Count != before) MscoLog.Info("[MSCO] Jobs/shop: " + vars.Count + " values synced");
        }

        void Register(string prefix, NamedVariable variable, byte type)
        {
            if (variable == null || string.IsNullOrEmpty(variable.Name)) return;
            int key = Hash(prefix + variable.Name);
            if (vars.ContainsKey(key)) return;
            var v = new Var { Key = key, Variable = variable, Type = type };
            Remember(v);
            vars[key] = v;
        }

        static bool Changed(Var v)
        {
            return v.Type == 2 ? ((FsmInt)v.Variable).Value != v.LastI : ((FsmBool)v.Variable).Value != v.LastB;
        }

        static void Remember(Var v)
        {
            if (v.Type == 2) v.LastI = ((FsmInt)v.Variable).Value; else v.LastB = ((FsmBool)v.Variable).Value;
        }

        static int Hash(string s)
        {
            unchecked
            {
                uint h = 2166136261;
                foreach (byte c in Encoding.UTF8.GetBytes(s)) { h ^= c; h *= 16777619; }
                return (int)h;
            }
        }
    }
}