using System.IO;
using System.Collections.Generic;
using UnityEngine;

namespace PerfectWorld.Scripts.Task
{
    public struct TASK_PACK_HEADER
    {
        public ulong magic;
        public ulong version;
        public ulong item_count;
    };
    public class ATaskTemplMan
    {
        public const ulong TASK_PACK_MAGIC = 0x93858361;
        public const ulong _task_templ_cur_version = 121;


        private ulong g_ulNewCount = 0;// do we need this?
        private Dictionary<ulong, ATaskTempl> m_TaskTemplMap = new Dictionary<ulong, ATaskTempl>();
        private Dictionary<ulong, ATaskTempl> m_AllTemplMap = new Dictionary<ulong, ATaskTempl>();
        private Dictionary<ulong, ATaskTempl> m_DynTaskMap = new Dictionary<ulong, ATaskTempl>();
        private Dictionary<ulong, ATaskTempl> m_TitleTaskMap = new Dictionary<ulong, ATaskTempl>();
        private Dictionary<ulong, ATaskTempl> m_ExlusiveAwardTaskMap = new Dictionary<ulong, ATaskTempl>();
        private Dictionary<ulong, ATaskTempl> m_ProtectNPCMap = new Dictionary<ulong, ATaskTempl>();
        private Dictionary<ulong, ATaskTempl> m_AutoDelvMap = new Dictionary<ulong, ATaskTempl>();
        private Dictionary<ulong, ATaskTempl> m_DeathTrigMap = new Dictionary<ulong, ATaskTempl>();
        private Dictionary<ulong, ATaskTempl> m_PQTemplMap = new Dictionary<ulong, ATaskTempl>();
        private List<ATaskTempl> m_SkillTaskLst = new List<ATaskTempl>();

#if _TASK_CLIENT
        // char			m_szDynPackPath[512];
        // bool			m_bDynTasksVerified;
        // special_award	m_SpecialAward;
        private List<ATaskTempl> m_TasksCanSeekOut = new List<ATaskTempl>();
        // TaskTemplLst	m_TasksCanDeliver;
        // struct TasksSeekOutDiff
        // {
        // 	ATaskTempl* task;
        // 	TasksSeekOutDiff():task(NULL){}
        // 	TasksSeekOutDiff(ATaskTempl* p):task(p){}

        // 	bool operator < (const TasksSeekOutDiff& rhs) const;
        // 	bool operator == (const TasksSeekOutDiff& rhs) const { return task == rhs.task; }
        // };
        // typedef std::vector<TasksSeekOutDiff> TasksSeekOutDiffList;
        // TasksSeekOutDiffList m_TasksToPush;
#endif

        void Release()
        {

        }
        public bool LoadTasksFromPack(string szPackPath, bool bLoadDescript)
        {
            //TaskInterface::WriteLog(0, 0, 2, "LoadPack begin");
            FileStream fs = new FileStream(szPackPath, FileMode.Open, FileAccess.Read);

            if (fs == null) return false;

            TASK_PACK_HEADER tph;

            // fread(&tph, sizeof(tph), 1, fp);
            tph = ReadStruct<TASK_PACK_HEADER>(fs);

            if (tph.magic != TASK_PACK_MAGIC
             || tph.version != _task_templ_cur_version)
                return false;

            if (tph.item_count == 0) return true;

            long[] pOffs = new long[tph.item_count];
            g_ulNewCount++;

            // fread(pOffs, sizeof(long), tph.item_count, fp);
            // Convert fread(pOffs, sizeof(long), tph.item_count, fp); to C#
            // Read tph.item_count 8-byte integers (long) from the FileStream fs into pOffs array

            byte[] offsBuffer = new byte[tph.item_count * sizeof(long)];
            int bytesRead = fs.Read(offsBuffer, 0, offsBuffer.Length);
            if (bytesRead != offsBuffer.Length)
                throw new EndOfStreamException("Could not read enough bytes for offsets");

            for (ulong i = 0; i < tph.item_count; i++)
            {
                pOffs[i] = System.BitConverter.ToInt64(offsBuffer, (int)(i * sizeof(long)));
            }


            for (ulong i = 0; i < tph.item_count; i++)
            {
                // if (fseek(fp, pOffs[i], SEEK_SET) != 0)
                //     continue;
                if (fs.Seek(pOffs[i], SeekOrigin.Begin) != 0)
                    continue;

                ATaskTempl pTempl = new ATaskTempl();
                g_ulNewCount++;

                if (!pTempl.LoadFromBinFile(fs))
                {
                    // TaskInterface::WriteLog(0, pTempl->m_ID, 0, "Cant Load Task");
                    // LOG_DELETE(pTempl);
                    continue;
                }

                AddOneTaskTempl(pTempl);
                // TaskInterface::WriteLog(0, pTempl->m_ID, 2, "LoadTask");
            }

            // char log[1024];
            // sprintf(log, "LoadTask, Count = %d", m_TaskTemplMap.size());
            // TaskInterface::WriteLog(0, 0, 2, log);

            //todo: check
            // LOG_DELETE_ARR(pOffs);
            fs.Close();

            //todo: check UpdateTimeLimitCheckList
            // #if _TASK_CLIENT
            UpdateTimeLimitCheckList();
            // #else
            SortTasksCanSeekOut();
            // #endif

#if _ELEMENTCLIENT
                    _task_err.Release();
                    _task_err.Init("Configs\\task_err.txt", true);
#endif

            return true;
        }

        // General method to read a struct from a FileStream
        private T ReadStruct<T>(FileStream stream) where T : struct
        {
            int size = System.Runtime.InteropServices.Marshal.SizeOf(typeof(T));
            byte[] buffer = new byte[size];
            int bytesRead = stream.Read(buffer, 0, size);
            if (bytesRead != size)
                throw new EndOfStreamException("Could not read enough bytes for struct");
            var handle = System.Runtime.InteropServices.GCHandle.Alloc(buffer, System.Runtime.InteropServices.GCHandleType.Pinned);
            try
            {
                return (T)System.Runtime.InteropServices.Marshal.PtrToStructure(handle.AddrOfPinnedObject(), typeof(T));
            }
            finally
            {
                handle.Free();
            }
        }
        public bool LoadNPCInfoFromPack(string szPath)
        {
            return true;
        }
        public void VerifyDynTasksPack(string szPath)
        {

        }

        private void AddOneTaskTempl(ATaskTempl pTask)
        {
            //todo: recheck - wrong logic
            if (m_AllTemplMap.ContainsKey(pTask.m_ID))
            {
                CECTaskInterface.WriteLog(0, (int)pTask.m_ID, 0, "Dup Task Found");
                // Optionally log duplicate task found, e.g.:
                // Debug.LogWarning($"Duplicate Task Found: {pTempl.m_ID}");
                return;
            }

            m_TaskTemplMap[pTask.m_ID] = pTask;

            if (pTask.m_bDeathTrig) m_DeathTrigMap[pTask.m_ID] = pTask;
            else if (pTask.m_bAutoDeliver) m_AutoDelvMap[pTask.m_ID] = pTask;

            if (pTask.m_bPQTask) m_PQTemplMap[pTask.m_ID] = pTask;

            if (pTask.m_bSkillTask) m_SkillTaskLst.Add(pTask);

            //todo: recheck m_DynTaskType type
            if (pTask.m_DynTaskType)
            {
                TaskTemplMap::iterator itDyn = m_DynTaskMap.find(pTask.m_ID);
                if (itDyn != m_DynTaskMap.end())
                    TaskInterface::WriteLog(0, pTask.m_ID, 0, "Dup Dyn Task Found");

                m_DynTaskMap[pTask.m_ID] = pTask;
            }
            if (pTask.m_bDisplayInTitleTaskUI)
                m_TitleTaskMap[pTask.m_ID] = pTask;
            if (pTask.m_bAutoDeliver && pTask.m_bDisplayInExclusiveUI)
                m_ExlusiveAwardTaskMap[pTask.m_ID] = pTask;

# if _TASK_CLIENT
            if (pTask.m_ulDelvNPC != 0 && pTask.m_bCanSeekOut)
                m_TasksCanSeekOut.push_back(pTask);
#endif

            AddTaskToMap(pTask);
        }

        private void AddTaskToMap(ATaskTempl pTempl)
        {
            if (pTempl.m_enumMethod == (ulong)TaskMethod.enumTMProtectNPC && pTempl.m_ulNPCToProtect > 0)
                m_ProtectNPCMap[pTempl.m_ulNPCToProtect] = pTempl;

            m_AllTemplMap[pTempl.m_ID] = pTempl;
            ATaskTempl pChild = pTempl.m_pFirstChild;

            while (pChild != null)
            {
                AddTaskToMap(pChild);
                pChild = pChild.m_pNextSibling;
            }
        }

        private void SortTasksCanSeekOut()
        {
            m_TasksCanSeekOut.Sort((lhs, rhs) =>
            {
                if (lhs.m_ulPremItems != 0 && rhs.m_ulPremItems == 0)
                    return -1; // lhs comes before rhs
                else if (lhs.m_ulPremItems == 0 && rhs.m_ulPremItems != 0)
                    return 1; // rhs comes before lhs
                else if (lhs.m_ulPremItems != 0 && rhs.m_ulPremItems != 0)
                    return rhs.m_ID.CompareTo(lhs.m_ID); // descending by ID
                else
                    return rhs.m_ulPremise_Lev_Min.CompareTo(lhs.m_ulPremise_Lev_Min); // descending by Premise_Lev_Min
            });
        }

        void UpdateTimeLimitCheckList()
        {
            m_TmLmtChkLst.clear();

            TaskTemplMap::iterator it = m_TaskTemplMap.begin();
            for (; it != m_TaskTemplMap.end(); ++it)
                if (it->second->m_ulMaxReceiver) m_TmLmtChkLst.push_back(it->second);
        }
    }
}