#include "NPCManager.hpp"
#include "ItemManager.hpp"
#include "settings.hpp"

#include <cmath>
#include <algorithm>
#include <list>
#include <fstream>
#include <vector>

#include "contrib/JSON.hpp"

std::map<int32_t, BaseNPC> NPCManager::NPCs;
std::map<int32_t, WarpLocation> NPCManager::Warps;
std::vector<WarpLocation> NPCManager::RespawnPoints;

void NPCManager::init() {
    REGISTER_SHARD_PACKET(P_CL2FE_REQ_PC_WARP_USE_NPC, npcWarpHandler);
    REGISTER_SHARD_PACKET(P_CL2FE_REQ_NPC_SUMMON, npcSummonHandler);
    REGISTER_SHARD_PACKET(P_CL2FE_REQ_BARKER, npcBarkHandler);
    REGISTER_SHARD_PACKET(P_CL2FE_REQ_PC_VENDOR_START, npcVendorStart);
    REGISTER_SHARD_PACKET(P_CL2FE_REQ_PC_VENDOR_TABLE_UPDATE, npcVendorTable);
    REGISTER_SHARD_PACKET(P_CL2FE_REQ_PC_VENDOR_ITEM_BUY, npcVendorBuy);
    REGISTER_SHARD_PACKET(P_CL2FE_REQ_PC_VENDOR_ITEM_SELL, npcVendorSell);
}

void NPCManager::npcVendorBuy(CNSocket* sock, CNPacketData* data) {
    if (data->size != sizeof(sP_CL2FE_REQ_PC_VENDOR_ITEM_BUY))
        return; // malformed packet

    sP_CL2FE_REQ_PC_VENDOR_ITEM_BUY* req = (sP_CL2FE_REQ_PC_VENDOR_ITEM_BUY*)data->buf;
    Player *plr = PlayerManager::getPlayer(sock);

    int itemCost = 100; // TODO: placeholder, look up the price of item

    int slot = ItemManager::findFreeSlot(plr);

    if (itemCost > plr->money || slot == -1) {
        // NOTE: VENDOR_ITEM_BUY_FAIL is not actually handled client-side.
        INITSTRUCT(sP_FE2CL_REP_PC_VENDOR_ITEM_BUY_FAIL, failResp);
        failResp.iErrorCode = 0;
        sock->sendPacket((void*)&failResp, P_FE2CL_REP_PC_VENDOR_ITEM_BUY_FAIL, sizeof(sP_FE2CL_REP_PC_VENDOR_ITEM_BUY_FAIL));
        return;
    }

    if (slot != req->iInvenSlotNum) {
        // possible item stacking?
        std::cout << "[WARN] Client and server disagree on bought item slot (" << req->iInvenSlotNum << " vs " << slot << ")" << std::endl;
    }

    INITSTRUCT(sP_FE2CL_REP_PC_VENDOR_ITEM_BUY_SUCC, resp);

    plr->money = plr->money - itemCost;
    plr->Inven[slot] = req->Item;

    resp.iCandy = plr->money;
    resp.iInvenSlotNum = slot;
    resp.Item = req->Item;

    sock->sendPacket((void*)&resp, P_FE2CL_REP_PC_VENDOR_ITEM_BUY_SUCC, sizeof(sP_FE2CL_REP_PC_VENDOR_ITEM_BUY_SUCC));
}

void NPCManager::npcVendorSell(CNSocket* sock, CNPacketData* data) {
    if (data->size != sizeof(sP_CL2FE_REQ_PC_VENDOR_ITEM_SELL))
        return; // malformed packet

    sP_CL2FE_REQ_PC_VENDOR_ITEM_SELL* req = (sP_CL2FE_REQ_PC_VENDOR_ITEM_SELL*)data->buf;
    Player* plr = PlayerManager::getPlayer(sock);

    if (req->iInvenSlotNum < 0 || req->iInvenSlotNum >= AINVEN_COUNT || req->iItemCnt < 0) {
        std::cout << "[WARN] Client failed to sell item in slot " << req->iInvenSlotNum << std::endl;
        INITSTRUCT(sP_FE2CL_REP_PC_VENDOR_ITEM_SELL_FAIL, failResp);
        failResp.iErrorCode = 0;
        sock->sendPacket((void*)&failResp, P_FE2CL_REP_PC_VENDOR_ITEM_SELL_FAIL, sizeof(sP_FE2CL_REP_PC_VENDOR_ITEM_SELL_FAIL));
        return;
    }

    sItemBase* item = &plr->Inven[req->iInvenSlotNum];

    INITSTRUCT(sP_FE2CL_REP_PC_VENDOR_ITEM_SELL_SUCC, resp);

    int sellValue = 100 * req->iItemCnt; // TODO: lookup item price

    // increment taros
    plr->money = plr->money + sellValue;

    // empty the slot; probably needs to be changed for stacks
    item->iID = 0;
    item->iOpt = 0;
    item->iType = 0;
    item->iTimeLimit = 0;

    // response parameters
    resp.iInvenSlotNum = req->iInvenSlotNum;
    resp.iCandy = plr->money;
    resp.Item = *item;

    sock->sendPacket((void*)&resp, P_FE2CL_REP_PC_VENDOR_ITEM_SELL_SUCC, sizeof(sP_FE2CL_REP_PC_VENDOR_ITEM_SELL_SUCC));
}

void NPCManager::npcVendorTable(CNSocket* sock, CNPacketData* data) {
    if (data->size != sizeof(sP_CL2FE_REQ_PC_VENDOR_TABLE_UPDATE))
        return; // malformed packet

    sP_CL2FE_REQ_PC_VENDOR_TABLE_UPDATE* req = (sP_CL2FE_REQ_PC_VENDOR_TABLE_UPDATE*)data->buf;
    
    if (req->iVendorID != req->iNPC_ID || ItemManager::VendorTables.find(req->iNPC_ID) == ItemManager::VendorTables.end())
        return;

    std::vector<VendorListing> listings = ItemManager::VendorTables[req->iNPC_ID]; // maybe use iVendorID instead...?

    INITSTRUCT(sP_FE2CL_REP_PC_VENDOR_TABLE_UPDATE_SUCC, resp);

    for (int i = 0; i < 20; i++) { // 20 is the max

        if (i < listings.size()) { // check to make sure listing exists first
            sItemBase base;
            base.iID = listings[i].iID;
            base.iOpt = 0;
            base.iTimeLimit = 0;
            base.iType = listings[i].type;

            sItemVendor vItem;
            vItem.item = base;
            vItem.iSortNum = listings[i].sort;
            vItem.iVendorID = req->iVendorID;
            vItem.fBuyCost = listings[i].price;

            resp.item[i] = vItem;
        }
    }

    sock->sendPacket((void*)&resp, P_FE2CL_REP_PC_VENDOR_TABLE_UPDATE_SUCC, sizeof(sP_FE2CL_REP_PC_VENDOR_TABLE_UPDATE_SUCC));
}

void NPCManager::npcVendorStart(CNSocket* sock, CNPacketData* data) {
    if (data->size != sizeof(sP_CL2FE_REQ_PC_VENDOR_START))
        return; // malformed packet

    sP_CL2FE_REQ_PC_VENDOR_START* req = (sP_CL2FE_REQ_PC_VENDOR_START*)data->buf;
    INITSTRUCT(sP_FE2CL_REP_PC_VENDOR_START_SUCC, resp);

    resp.iNPC_ID = req->iNPC_ID;
    resp.iVendorID = req->iVendorID;

    sock->sendPacket((void*)&resp, P_FE2CL_REP_PC_VENDOR_START_SUCC, sizeof(sP_FE2CL_REP_PC_VENDOR_START_SUCC));
}

void NPCManager::updatePlayerNPCS(CNSocket* sock, PlayerView& view) {
    std::list<int32_t> yesView;
    std::list<int32_t> noView;

    for (auto& pair : NPCs) {
        int diffX = abs(view.plr->x - pair.second.appearanceData.iX);
        int diffY = abs(view.plr->y - pair.second.appearanceData.iY);

        if (diffX < settings::NPCDISTANCE && diffY < settings::NPCDISTANCE) {
            yesView.push_back(pair.first);
        }
        else {
            noView.push_back(pair.first);
        }
    }

    INITSTRUCT(sP_FE2CL_NPC_EXIT, exitData);
    std::list<int32_t>::iterator i = view.viewableNPCs.begin();
    while (i != view.viewableNPCs.end()) {
        int32_t id = *i;

        if (std::find(noView.begin(), noView.end(), id) != noView.end()) {
            // it shouldn't be visible, send NPC_EXIT

            exitData.iNPC_ID = id;
            sock->sendPacket((void*)&exitData, P_FE2CL_NPC_EXIT, sizeof(sP_FE2CL_NPC_EXIT));

            // remove from view
            view.viewableNPCs.erase(i++);
        }
        else {
            i++;
        }
    }

    INITSTRUCT(sP_FE2CL_NPC_ENTER, enterData);
    for (int32_t id : yesView) {
        if (std::find(view.viewableNPCs.begin(), view.viewableNPCs.end(), id) == view.viewableNPCs.end()) {
            // needs to be added to viewableNPCs! send NPC_ENTER

            enterData.NPCAppearanceData = NPCs[id].appearanceData;
            sock->sendPacket((void*)&enterData, P_FE2CL_NPC_ENTER, sizeof(sP_FE2CL_NPC_ENTER));

            // add to viewable
            view.viewableNPCs.push_back(id);
        }
    }

    PlayerManager::players[sock].viewableNPCs = view.viewableNPCs;
}

void NPCManager::npcBarkHandler(CNSocket* sock, CNPacketData* data) {} // stubbed for now

void NPCManager::npcSummonHandler(CNSocket* sock, CNPacketData* data) {
    if (data->size != sizeof(sP_CL2FE_REQ_NPC_SUMMON))
        return; // malformed packet

    sP_CL2FE_REQ_NPC_SUMMON* req = (sP_CL2FE_REQ_NPC_SUMMON*)data->buf;
    INITSTRUCT(sP_FE2CL_NPC_ENTER, resp);
    Player* plr = PlayerManager::getPlayer(sock);

    // permission & sanity check
    if (!plr->IsGM || req->iNPCType >= 3314)
        return;

    resp.NPCAppearanceData.iNPC_ID = rand(); // cpunch-style
    resp.NPCAppearanceData.iNPCType = req->iNPCType;
    resp.NPCAppearanceData.iHP = 1000; // TODO: placeholder
    resp.NPCAppearanceData.iX = plr->x;
    resp.NPCAppearanceData.iY = plr->y;
    resp.NPCAppearanceData.iZ = plr->z;

    sock->sendPacket((void*)&resp, P_FE2CL_NPC_ENTER, sizeof(sP_FE2CL_NPC_ENTER));
    for (CNSocket *s : PlayerManager::players[sock].viewable)
        s->sendPacket((void*)&resp, P_FE2CL_NPC_ENTER, sizeof(sP_FE2CL_NPC_ENTER));
}

void NPCManager::npcWarpHandler(CNSocket* sock, CNPacketData* data) {
    if (data->size != sizeof(sP_CL2FE_REQ_PC_WARP_USE_NPC))
        return; // malformed packet

    sP_CL2FE_REQ_PC_WARP_USE_NPC* warpNpc = (sP_CL2FE_REQ_PC_WARP_USE_NPC*)data->buf;
    PlayerView& plrv = PlayerManager::players[sock];

    // sanity check
    if (Warps.find(warpNpc->iWarpID) == Warps.end())
        return;

    // send to client
    INITSTRUCT(sP_FE2CL_REP_PC_WARP_USE_NPC_SUCC, resp);
    resp.iX = Warps[warpNpc->iWarpID].x;
    resp.iY = Warps[warpNpc->iWarpID].y;
    resp.iZ = Warps[warpNpc->iWarpID].z;

    // force player & NPC reload
    plrv.viewable.clear();
    plrv.viewableNPCs.clear();

    sock->sendPacket((void*)&resp, P_FE2CL_REP_PC_WARP_USE_NPC_SUCC, sizeof(sP_FE2CL_REP_PC_WARP_USE_NPC_SUCC));
}