/*
 * Copyright (C) 2004-2023 ZNC, see the NOTICE file for details.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <znc/Chan.h>
#include <znc/IRCSock.h>
#include <znc/Server.h>
#include <znc/User.h>
#include <znc/IRCNetwork.h>

#include <tcl.h>

using std::vector;
using std::map;

#define STDVAR (ClientData cd, Tcl_Interp * irp, int argc, const char* argv[])

#define BADARGS(nl, nh, example)                                         \
    do {                                                                 \
        if ((argc < (nl)) || (argc > (nh))) {                            \
            Tcl_AppendResult(irp, "wrong # args: should be \"", argv[0], \
                             (example), "\"", nullptr);                  \
            return TCL_ERROR;                                            \
        }                                                                \
    } while (0)

class CModTcl;

class CModTclTimer : public CTimer {
  public:
    CModTclTimer(CModule* pModule, unsigned int uInterval, unsigned int uCycles,
                 const CString& sLabel, const CString& sDescription)
        : CTimer(pModule, uInterval, uCycles, sLabel, sDescription),
          m_pParent(nullptr) {}
    ~CModTclTimer() override {}

  protected:
    void RunJob() override;
    CModTcl* m_pParent;
};

class CModTclStartTimer : public CTimer {
  public:
    CModTclStartTimer(CModule* pModule, unsigned int uInterval,
                      unsigned int uCycles, const CString& sLabel,
                      const CString& sDescription)
        : CTimer(pModule, uInterval, uCycles, sLabel, sDescription),
          m_pParent(nullptr) {}
    ~CModTclStartTimer() override {}

  protected:
    void RunJob() override;
    CModTcl* m_pParent;
};

class CModTcl : public CModule {
  public:
    MODCONSTRUCTOR(CModTcl) { interp = nullptr; }

    ~CModTcl() override {
        if (interp) {
            Tcl_DeleteInterp(interp);
        }
    }

    bool OnLoad(const CString& sArgs, CString& sErrorMsg) override {
#ifndef MOD_MODTCL_ALLOW_EVERYONE
        if (!GetUser()->IsAdmin()) {
            sErrorMsg = "You must be admin to use the modtcl module";
            return false;
        }
#endif

        AddTimer(
            new CModTclStartTimer(this, 1, 1, "ModTclStarter",
                                  "Timer for modtcl to load the interpreter."));
        return true;
    }

    void Start() {
        CString sMyArgs = GetArgs();

        interp = Tcl_CreateInterp();
        Tcl_Init(interp);
        Tcl_CreateCommand(interp, "Binds::ProcessPubm", tcl_Bind, this,
                          nullptr);
        Tcl_CreateCommand(interp, "Binds::ProcessMsgm", tcl_Bind, this,
                          nullptr);
        Tcl_CreateCommand(interp, "Binds::ProcessTime", tcl_Bind, this,
                          nullptr);
        Tcl_CreateCommand(interp, "Binds::ProcessEvnt", tcl_Bind, this,
                          nullptr);
        Tcl_CreateCommand(interp, "Binds::ProcessNick", tcl_Bind, this,
                          nullptr);
        Tcl_CreateCommand(interp, "Binds::ProcessKick", tcl_Bind, this,
                          nullptr);
        Tcl_CreateCommand(interp, "PutIRC", tcl_PutIRC, this, nullptr);
        Tcl_CreateCommand(interp, "PutModule", tcl_PutModule, this, nullptr);
        Tcl_CreateCommand(interp, "PutStatus", tcl_PutStatus, this, nullptr);
        Tcl_CreateCommand(interp, "PutStatusNotice", tcl_PutStatusNotice, this,
                          nullptr);
        Tcl_CreateCommand(interp, "PutUser", tcl_PutUser, this, nullptr);

        Tcl_CreateCommand(interp, "GetCurNick", tcl_GetCurNick, this, nullptr);
        Tcl_CreateCommand(interp, "GetUsername", tcl_GetUsername, this,
                          nullptr);
        Tcl_CreateCommand(interp, "GetNetworkName", tcl_GetNetworkName, this,
                          nullptr);
        Tcl_CreateCommand(interp, "GetRealName", tcl_GetRealName, this,
                          nullptr);
        Tcl_CreateCommand(interp, "GetVHost", tcl_GetBindHost, this, nullptr);
        Tcl_CreateCommand(interp, "GetBindHost", tcl_GetBindHost, this,
                          nullptr);
        Tcl_CreateCommand(interp, "GetChans", tcl_GetChans, this, nullptr);
        Tcl_CreateCommand(interp, "GetChannelUsers", tcl_GetChannelUsers, this,
                          nullptr);
        Tcl_CreateCommand(interp, "GetChannelModes", tcl_GetChannelModes, this,
                          nullptr);
        Tcl_CreateCommand(interp, "GetServer", tcl_GetServer, this, nullptr);
        Tcl_CreateCommand(interp, "GetServerOnline", tcl_GetServerOnline, this,
                          nullptr);
        Tcl_CreateCommand(interp, "GetModules", tcl_GetModules, this, nullptr);
        Tcl_CreateCommand(interp, "GetClientCount", tcl_GetClientCount, this,
                          nullptr);

        Tcl_CreateCommand(interp, "exit", tcl_exit, this, nullptr);

        if (!sMyArgs.empty()) {
            int i = Tcl_EvalFile(interp, sMyArgs.c_str());
            if (i != TCL_OK) {
                PutModule(Tcl_GetStringResult(interp));
            }
        }

        AddTimer(new CModTclTimer(
            this, 1, 0, "ModTclUpdate",
            "Timer for modtcl to process pending events and idle callbacks."));
    }

    void OnModCommand(const CString& sCommand) override {
        CString sResult;
        VCString vsResult;
        CString sCmd = sCommand;

        if (sCmd.Token(0).CaseCmp(".tcl") == 0) sCmd = sCmd.Token(1, true);

        if (sCmd.Left(1).CaseCmp(".") == 0)
            sCmd = "Binds::ProcessDcc - - {" + sCmd + "}";

        Tcl_Eval(interp, sCmd.c_str());

        sResult = CString(Tcl_GetStringResult(interp));
        if (!sResult.empty()) {
            sResult.Split("\n", vsResult);
            unsigned int a = 0;
            for (a = 0; a < vsResult.size(); a++)
                PutModule(vsResult[a].TrimRight_n());
        }
    }

    void TclUpdate() {
        while (Tcl_DoOneEvent(TCL_DONT_WAIT)) {
        }
        int i = Tcl_Eval(interp, "Binds::ProcessTime");
        if (i != TCL_OK) {
            PutModule(Tcl_GetStringResult(interp));
        }
    }

    CString TclEscape(CString sLine) {
        sLine.Replace("\\", "\\\\");
        sLine.Replace("{", "\\{");
        sLine.Replace("}", "\\}");
        return sLine;
    }

    void OnPreRehash() override {
        if (interp) Tcl_Eval(interp, "Binds::ProcessEvnt prerehash");
    }

    void OnPostRehash() override {
        if (interp) {
            Tcl_Eval(interp, "rehash");
            Tcl_Eval(interp, "Binds::ProcessEvnt rehash");
        }
    }

    void OnIRCConnected() override {
        if (interp) Tcl_Eval(interp, "Binds::ProcessEvnt init-server");
    }

    void OnIRCDisconnected() override {
        if (interp) Tcl_Eval(interp, "Binds::ProcessEvnt disconnect-server");
    }

    EModRet OnChanMsg(CNick& Nick, CChan& Channel, CString& sMessage) override {
        CString sMes = TclEscape(sMessage);
        CString sNick = TclEscape(CString(Nick.GetNick()));
        CString sHost =
            TclEscape(CString(Nick.GetIdent() + "@" + Nick.GetHost()));
        CString sChannel = TclEscape(CString(Channel.GetName()));

        CString sCommand = "Binds::ProcessPubm {" + sNick + "} {" + sHost +
                           "} - {" + sChannel + "} {" + sMes + "}";
        int i = Tcl_Eval(interp, sCommand.c_str());
        if (i != TCL_OK) {
            PutModule(Tcl_GetStringResult(interp));
        }
        return CONTINUE;
    }

    EModRet OnPrivMsg(CNick& Nick, CString& sMessage) override {
        CString sMes = TclEscape(sMessage);
        CString sNick = TclEscape(CString(Nick.GetNick()));
        CString sHost =
            TclEscape(CString(Nick.GetIdent() + "@" + Nick.GetHost()));

        CString sCommand = "Binds::ProcessMsgm {" + sNick + "} {" + sHost +
                           "} - {" + sMes + "}";
        int i = Tcl_Eval(interp, sCommand.c_str());
        if (i != TCL_OK) {
            PutModule(Tcl_GetStringResult(interp));
        }
        return CONTINUE;
    }

    void OnNick(const CNick& OldNick, const CString& sNewNick,
                const vector<CChan*>& vChans) override {
        CString sOldNick = TclEscape(CString(OldNick.GetNick()));
        CString sNewNickTmp = TclEscape(sNewNick);
        CString sHost =
            TclEscape(CString(OldNick.GetIdent() + "@" + OldNick.GetHost()));

        CString sCommand;
        // Nick change is triggered for each common chan so that binds can be
        // chan specific
        unsigned int nLength = vChans.size();
        for (unsigned int n = 0; n < nLength; n++) {
            sCommand = "Binds::ProcessNick {" + sOldNick + "} {" + sHost +
                       "} - {" + vChans[n]->GetName() + "} {" + sNewNickTmp +
                       "}";
            int i = Tcl_Eval(interp, sCommand.c_str());
            if (i != TCL_OK) {
                PutModule(Tcl_GetStringResult(interp));
            }
        }
    }

    void OnKick(const CNick& OpNick, const CString& sKickedNick, CChan& Channel,
                const CString& sMessage) override {
        CString sOpNick = TclEscape(CString(OpNick.GetNick()));
        CString sNick = TclEscape(sKickedNick);
        CString sOpHost =
            TclEscape(CString(OpNick.GetIdent() + "@" + OpNick.GetHost()));

        CString sCommand = "Binds::ProcessKick {" + sOpNick + "} {" + sOpHost +
                           "} - {" + Channel.GetName() + "} {" + sNick + "} {" +
                           sMessage + "}";
        int i = Tcl_Eval(interp, sCommand.c_str());
        if (i != TCL_OK) {
            PutModule(Tcl_GetStringResult(interp));
        }
    }

  private:
    Tcl_Interp* interp;

    static CString argvit(const char* argv[], unsigned int end,
                          unsigned int begin, CString delim) {
        CString sRet;
        unsigned int i;
        if (begin < end) sRet = CString(argv[begin]);

        for (i = begin + 1; i < end; i++) {
            sRet = sRet + delim + CString(argv[i]);
        }

        return sRet;
    }

    // Placeholder for binds incase binds.tcl isn't used
    static int tcl_Bind STDVAR { return TCL_OK; }

    static int tcl_GetCurNick STDVAR {
        CModTcl* mod = static_cast<CModTcl*>(cd);
        Tcl_SetResult(irp, (char*)mod->GetNetwork()->GetCurNick().c_str(),
                      TCL_VOLATILE);
        return TCL_OK;
    }

    static int tcl_GetUsername STDVAR {
        CModTcl* mod = static_cast<CModTcl*>(cd);
        Tcl_SetResult(irp, (char*)mod->GetUser()->GetUsername().c_str(),
                      TCL_VOLATILE);
        return TCL_OK;
    }

    static int tcl_GetNetworkName STDVAR {
        CModTcl* mod = static_cast<CModTcl*>(cd);
        Tcl_SetResult(irp, (char*)mod->GetNetwork()->GetName().c_str(),
                      TCL_VOLATILE);
        return TCL_OK;
    }

    static int tcl_GetRealName STDVAR {
        CModTcl* mod = static_cast<CModTcl*>(cd);
        Tcl_SetResult(irp, (char*)mod->GetUser()->GetRealName().c_str(),
                      TCL_VOLATILE);
        return TCL_OK;
    }

    static int tcl_GetBindHost STDVAR {
        CModTcl* mod = static_cast<CModTcl*>(cd);
        Tcl_SetResult(irp, (char*)mod->GetUser()->GetBindHost().c_str(),
                      TCL_VOLATILE);
        return TCL_OK;
    }

    static int tcl_GetChans STDVAR {
        char* p;
        const char* l[1];
        CModTcl* mod = static_cast<CModTcl*>(cd);

        BADARGS(1, 1, "");

        const vector<CChan*>& Channels = mod->GetNetwork()->GetChans();
        for (unsigned int c = 0; c < Channels.size(); c++) {
            CChan* pChan = Channels[c];
            l[0] = pChan->GetName().c_str();
            p = Tcl_Merge(1, l);
            Tcl_AppendElement(irp, p);
            Tcl_Free((char*)p);
        }

        return TCL_OK;
    }

    static int tcl_GetChannelUsers STDVAR {
        char* p;
        const char* l[4];
        CModTcl* mod = static_cast<CModTcl*>(cd);

        BADARGS(2, 999, " channel");

        CString sChannel = argvit(argv, argc, 1, " ");
        CChan* pChannel = mod->GetNetwork()->FindChan(sChannel);

        if (!pChannel) {
            CString sMsg = "invalid channel: " + sChannel;
            Tcl_SetResult(irp, (char*)sMsg.c_str(), TCL_VOLATILE);
            return TCL_ERROR;
        }

        const map<CString, CNick>& msNicks = pChannel->GetNicks();
        for (map<CString, CNick>::const_iterator it = msNicks.begin();
             it != msNicks.end(); ++it) {
            const CNick& Nick = it->second;
            l[0] = (Nick.GetNick()).c_str();
            l[1] = (Nick.GetIdent()).c_str();
            l[2] = (Nick.GetHost()).c_str();
            l[3] = (Nick.GetPermStr()).c_str();
            p = Tcl_Merge(4, l);
            Tcl_AppendElement(irp, p);
            Tcl_Free((char*)p);
        }

        return TCL_OK;
    }

    static int tcl_GetChannelModes STDVAR {
        CModTcl* mod = static_cast<CModTcl*>(cd);

        BADARGS(2, 999, " channel");

        CString sChannel = argvit(argv, argc, 1, " ");
        CChan* pChannel = mod->GetNetwork()->FindChan(sChannel);
        CString sMsg;

        if (!pChannel) {
            sMsg = "invalid channel: " + sChannel;
            Tcl_SetResult(irp, (char*)sMsg.c_str(), TCL_VOLATILE);
            return TCL_ERROR;
        }

        sMsg = pChannel->GetModeString();
        Tcl_SetResult(irp, (char*)sMsg.c_str(), TCL_VOLATILE);
        return TCL_OK;
    }

    static int tcl_GetServer STDVAR {
        CModTcl* mod = static_cast<CModTcl*>(cd);
        CServer* pServer = mod->GetNetwork()->GetCurrentServer();
        CString sMsg;
        if (pServer)
            sMsg = pServer->GetName() + ":" + CString(pServer->GetPort());
        Tcl_SetResult(irp, (char*)sMsg.c_str(), TCL_VOLATILE);
        return TCL_OK;
    }

    static int tcl_GetServerOnline STDVAR {
        CModTcl* mod = static_cast<CModTcl*>(cd);
        CIRCSock* pIRCSock = mod->GetNetwork()->GetIRCSock();
        CString sMsg = "0";
        if (pIRCSock) sMsg = CString(pIRCSock->GetStartTime());
        Tcl_SetResult(irp, (char*)sMsg.c_str(), TCL_VOLATILE);
        return TCL_OK;
    }

    static int tcl_GetModules STDVAR {
        char* p;
        const char* l[3];
        CModTcl* mod = static_cast<CModTcl*>(cd);

        BADARGS(1, 1, "");

        CModules& GModules = CZNC::Get().GetModules();
        CModules& Modules = mod->GetUser()->GetModules();

        for (unsigned int b = 0; b < GModules.size(); b++) {
            l[0] = GModules[b]->GetModName().c_str();
            l[1] = GModules[b]->GetArgs().c_str();
            l[2] = "1";  // IsGlobal
            p = Tcl_Merge(3, l);
            Tcl_AppendElement(irp, p);
            Tcl_Free((char*)p);
        }
        for (unsigned int b = 0; b < Modules.size(); b++) {
            l[0] = Modules[b]->GetModName().c_str();
            l[1] = Modules[b]->GetArgs().c_str();
            l[2] = "0";  // IsGlobal
            p = Tcl_Merge(3, l);
            Tcl_AppendElement(irp, p);
            Tcl_Free((char*)p);
        }

        return TCL_OK;
    }

    static int tcl_GetClientCount STDVAR {
        CModTcl* mod = static_cast<CModTcl*>(cd);
        Tcl_SetResult(
            irp, (char*)CString(mod->GetNetwork()->GetClients().size()).c_str(),
            TCL_VOLATILE);
        return TCL_OK;
    }

    static int tcl_PutIRC STDVAR {
        CString sMsg;
        CModTcl* mod = static_cast<CModTcl*>(cd);

        BADARGS(2, 999, " string");
        sMsg = argvit(argv, argc, 1, " ");
        mod->GetNetwork()->PutIRC(sMsg);
        return TCL_OK;
    }

    static int tcl_PutModule STDVAR {
        CString sMsg;
        VCString vsMsg;
        CModTcl* mod = static_cast<CModTcl*>(cd);

        BADARGS(2, 999, " string");
        sMsg = argvit(argv, argc, 1, " ");
        // mod->PutModule(sMsg);
        sMsg.Split("\n", vsMsg);
        unsigned int a = 0;
        for (a = 0; a < vsMsg.size(); a++)
            mod->PutModule(vsMsg[a].TrimRight_n());
        return TCL_OK;
    }

    static int tcl_PutStatus STDVAR {
        CString sMsg;
        CModTcl* mod = static_cast<CModTcl*>(cd);

        BADARGS(2, 999, " string");
        sMsg = argvit(argv, argc, 1, " ");
        mod->PutStatus(sMsg);
        return TCL_OK;
    }

    static int tcl_PutStatusNotice STDVAR {
        CString sMsg;
        CModTcl* mod = static_cast<CModTcl*>(cd);

        BADARGS(2, 999, " string");
        sMsg = argvit(argv, argc, 1, " ");
        mod->GetUser()->PutStatusNotice(sMsg);
        return TCL_OK;
    }

    static int tcl_PutUser STDVAR {
        CString sMsg;
        CModTcl* mod = static_cast<CModTcl*>(cd);

        BADARGS(2, 999, " string");
        sMsg = argvit(argv, argc, 1, " ");
        mod->GetUser()->PutUser(sMsg);
        return TCL_OK;
    }

    static int tcl_exit STDVAR {
        CString sMsg;
        CModTcl* mod = static_cast<CModTcl*>(cd);

        BADARGS(1, 2, " ?reason?");

        if (!mod->GetUser()->IsAdmin()) {
            sMsg = "You need to be administrator to shutdown the bnc.";
            Tcl_SetResult(irp, (char*)sMsg.c_str(), TCL_VOLATILE);
            return TCL_ERROR;
        }
        if (argc > 1) {
            sMsg = argvit(argv, argc, 1, " ");
            CZNC::Get().Broadcast(sMsg);
            usleep(100000);  // Sleep for 10ms to attempt to allow the previous
                             // Broadcast() to go through to all users
        }

        throw CException(CException::EX_Shutdown);

        return TCL_OK;
    }
};

void CModTclTimer::RunJob() {
    CModTcl* p = (CModTcl*)GetModule();
    if (p) p->TclUpdate();
}

void CModTclStartTimer::RunJob() {
    CModTcl* p = (CModTcl*)GetModule();
    if (p) p->Start();
}

template <>
void TModInfo<CModTcl>(CModInfo& Info) {
    Info.SetWikiPage("modtcl");
    Info.SetHasArgs(true);
    Info.SetArgsHelpText("Absolute path to modtcl.tcl file");
}

NETWORKMODULEDEFS(CModTcl, "Loads Tcl scripts as ZNC modules")
