path: root/ctl-lib/ctl-lua.c

/*
 * Copyright (C) 2016 "IoT.bzh"
 * Author Fulup Ar Foll <fulup@iot.bzh>
 *
 * 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.
 * ref:
 *  (manual) https://www.lua.org/manual/5.3/manual.html
 *  (lua->C) http://www.troubleshooters.com/codecorn/lua/lua_c_calls_lua.htm#_Anatomy_of_a_Lua_Call
 *  (lua/C Var) http://acamara.es/blog/2012/08/passing-variables-from-lua-5-2-to-c-and-vice-versa/
 *  (Lua/C Lib)https://john.nachtimwald.com/2014/07/12/wrapping-a-c-library-in-lua/
 *  (Lua/C Table) https://gist.github.com/SONIC3D/10388137
 *  (Lua/C Nested table) https://stackoverflow.com/questions/45699144/lua-nested-table-from-lua-to-c
 *  (Lua/C Wrapper) https://stackoverflow.com/questions/45699950/lua-passing-handle-to-function-created-with-newlib
 *
 */

#define _GNU_SOURCE
#include <stdio.h>
#include <string.h>
#include <sys/time.h>

#include "ctl-config.h"

#define LUA_FIST_ARG 2 // when using luaL_newlib calllback receive libtable as 1st arg
#define LUA_MSG_MAX_LENGTH 512
#define JSON_ERROR (json_object*)-1


static  lua_State* luaState;

#ifndef CTX_MAGIC
 static int CTX_MAGIC;
#endif

#ifndef TIMER_MAGIC
 static int TIMER_MAGIC;
#endif

typedef struct {
    char *name;
    int  count;
    AFB_EventT event;
} LuaAfbEvent;

typedef struct {
    int ctxMagic;
    CtlSourceT *source;
} LuaAfbSourceT;

typedef struct {
  const char *callback;
  json_object *context;
  CtlSourceT *source;
} LuaCbHandleT;


/*
 * Note(Fulup): I fail to use luaL_setmetatable and replaced it with a simple opaque
 * handle while waiting for someone smarter than me to find a better solution
 *  https://stackoverflow.com/questions/45596493/lua-using-lua-newuserdata-from-lua-pcall
*/
STATIC CtlSourceT *LuaSourcePop (lua_State *luaState, int index) {
  LuaAfbSourceT *afbSource;
  luaL_checktype(luaState, index, LUA_TLIGHTUSERDATA);
  afbSource = (LuaAfbSourceT *) lua_touserdata(luaState, index);
  if (afbSource == NULL || afbSource->ctxMagic != CTX_MAGIC) {
      luaL_error(luaState, "(Hoops) Invalid source handle");
      return NULL;
  }
  return afbSource->source;
}

STATIC LuaAfbSourceT *LuaSourcePush (lua_State *luaState, CtlSourceT *source) {
  LuaAfbSourceT *afbSource = (LuaAfbSourceT *)calloc(1, sizeof(LuaAfbSourceT));
  if (!afbSource) {
      AFB_ApiError(source->api, "LuaSourcePush fail to allocate user data context");
      return NULL;
  }

  lua_pushlightuserdata(luaState, afbSource);
  afbSource->ctxMagic=CTX_MAGIC;
  afbSource->source= source;
  return afbSource;
}

// Push a json structure on the stack as a LUA table
STATIC int LuaPushArgument (CtlSourceT *source, json_object *argsJ) {

    //AFB_NOTICE("LuaPushArgument argsJ=%s", json_object_get_string(argsJ));

    json_type jtype= json_object_get_type(argsJ);
    switch (jtype) {
        case json_type_object: {
            lua_newtable (luaState);
            json_object_object_foreach (argsJ, key, val) {
                int done = LuaPushArgument (source, val);
                if (done) {
                    lua_setfield(luaState,-2, key);
                }
            }
            break;
        }
        case json_type_array: {
            int length= json_object_array_length(argsJ);
            lua_newtable (luaState);
            for (int idx=0; idx < length; idx ++) {
                json_object *val=json_object_array_get_idx(argsJ, idx);
                LuaPushArgument (source, val);
                lua_seti (luaState,-2, idx);
            }
            break;
        }
        case json_type_int:
            lua_pushinteger(luaState, json_object_get_int(argsJ));
            break;
        case json_type_string:
            lua_pushstring(luaState, json_object_get_string(argsJ));
            break;
        case json_type_boolean:
            lua_pushboolean(luaState, json_object_get_boolean(argsJ));
            break;
        case json_type_double:
            lua_pushnumber(luaState, json_object_get_double(argsJ));
            break;
        case json_type_null:
            AFB_ApiWarning(source->api, "LuaPushArgument: NULL object type %s", json_object_get_string(argsJ));
            return 0;
            break;

        default:
            AFB_ApiError(source->api, "LuaPushArgument: unsupported Json object type %s", json_object_get_string(argsJ));
            return 0;
    }
    return 1;
}

STATIC  json_object *LuaPopOneArg (CtlSourceT *source, lua_State* luaState, int idx);

// Move a table from Internal Lua representation to Json one
// Numeric table are transformed in json array, string one in object
// Mix numeric/string key are not supported
STATIC json_object *LuaTableToJson (CtlSourceT *source, lua_State* luaState, int index) {
    #define LUA_KEY_INDEX -2
    #define LUA_VALUE_INDEX -1

    int idx;
    int tableType;
    json_object *tableJ= NULL;

    lua_pushnil(luaState); // 1st key
    if (index < 0) index--;
    for (idx=1; lua_next(luaState, index) != 0; idx++) {

        // uses 'key' (at index -2) and 'value' (at index -1)
        if (lua_type(luaState,LUA_KEY_INDEX) == LUA_TSTRING) {

            if (!tableJ) {
                tableJ= json_object_new_object();
                tableType=LUA_TSTRING;
            } else if (tableType != LUA_TSTRING){
                AFB_ApiError(source->api, "MIX Lua Table with key string/numeric not supported");
                return NULL;
            }

            const char *key= lua_tostring(luaState, LUA_KEY_INDEX);
            json_object *argJ= LuaPopOneArg(source, luaState, LUA_VALUE_INDEX);
            json_object_object_add(tableJ, key, argJ);

        } else {
            if (!tableJ) {
                tableJ= json_object_new_array();
                tableType=LUA_TNUMBER;
            } else if(tableType != LUA_TNUMBER) {
                AFB_ApiError(source->api, "MIX Lua Table with key numeric/string not supported");
                return NULL;
            }

            json_object *argJ= LuaPopOneArg(source, luaState, LUA_VALUE_INDEX);
            json_object_array_add(tableJ, argJ);
        }


        lua_pop(luaState, 1); // removes 'value'; keeps 'key' for next iteration
    }

    // Query is empty free empty json object
    if (idx == 1) {
        json_object_put(tableJ);
        return NULL;
    }
    return tableJ;
}

STATIC  json_object *LuaPopOneArg (CtlSourceT *source, lua_State* luaState, int idx) {
    json_object *value=NULL;

    int luaType = lua_type(luaState, idx);
    switch(luaType)  {
        case LUA_TNUMBER: {
            lua_Number number= lua_tonumber(luaState, idx);;
            int nombre = (int)number; // evil trick to determine wether n fits in an integer. (stolen from ltcl.c)
            if (number == nombre) {
                value= json_object_new_int((int)number);
            } else {
                value= json_object_new_double(number);
            }
            break;
        }
        case LUA_TBOOLEAN:
            value=  json_object_new_boolean(lua_toboolean(luaState, idx));
            break;
        case LUA_TSTRING:
           value=  json_object_new_string(lua_tostring(luaState, idx));
            break;
        case LUA_TTABLE:
            value= LuaTableToJson(source, luaState, idx);
            break;
        case LUA_TNIL:
            value=json_object_new_string("nil") ;
            break;
        case LUA_TUSERDATA:
            value=json_object_new_int64((int64_t)lua_touserdata(luaState, idx)); // store userdata as int !!!
            break;

        default:
            AFB_ApiNotice (source->api, "LuaPopOneArg: script returned Unknown/Unsupported idx=%d type:%d/%s", idx, luaType, lua_typename(luaState, luaType));
            value=NULL;
    }

    return value;
}

static json_object *LuaPopArgs (CtlSourceT *source, lua_State* luaState, int start) {
    json_object *responseJ;

    int stop = lua_gettop(luaState);
    if(stop-start <0) return NULL;

    // start at 2 because we are using a function array lib
    if (start == stop) {
        responseJ=LuaPopOneArg (source, luaState, start);
    } else {
        // loop on remaining return arguments
        responseJ= json_object_new_array();
        for (int idx=start; idx <= stop; idx++) {
            json_object *argJ=LuaPopOneArg (source, luaState, idx);
            if (!argJ) goto OnErrorExit;
            json_object_array_add(responseJ, argJ);
       }
    }

    return responseJ;

  OnErrorExit:
    return NULL;
}



STATIC int LuaFormatMessage(lua_State* luaState, int verbosity, int level) {
    char *message;

    CtlSourceT *source= LuaSourcePop(luaState, LUA_FIST_ARG);
    if (!source) goto OnErrorExit;
\

    // if log level low then silently ignore message
#ifdef AFB_BINDING_PREV3
    if(source->api->verbosity < verbosity) return 0;
#else
    if(afb_get_verbosity() < verbosity) return 0;
#endif

    json_object *responseJ= LuaPopArgs(source, luaState, LUA_FIST_ARG+1);

    if (!responseJ) {
        luaL_error(luaState,"LuaFormatMessage empty message");
        goto OnErrorExit;
    }

    // if we have only on argument just return the value.
    if (json_object_get_type(responseJ)!=json_type_array || json_object_array_length(responseJ) <2) {
        message= (char*)json_object_get_string(responseJ);
        goto PrintMessage;
    }

    // extract format and push all other parameter on the stack
    message = alloca (LUA_MSG_MAX_LENGTH);
    const char *format = json_object_get_string(json_object_array_get_idx(responseJ, 0));

    int arrayIdx=1;
    int targetIdx=0;

    for (int idx=0; format[idx] !='\0'; idx++) {

        if (format[idx]=='%' && format[idx] !='\0') {
            json_object *slotJ= json_object_array_get_idx(responseJ, arrayIdx);
            //if (slotJ) AFB_NOTICE("**** idx=%d slotJ=%s", arrayIdx, json_object_get_string(slotJ));


            switch (format[++idx]) {
                case 'd':
                    if (slotJ) targetIdx += snprintf (&message[targetIdx], LUA_MSG_MAX_LENGTH-targetIdx,"%d", json_object_get_int(slotJ));
                    else  targetIdx += snprintf (&message[targetIdx], LUA_MSG_MAX_LENGTH-targetIdx,"nil");
                    arrayIdx++;
                    break;
                case 'f':
                    if (slotJ) targetIdx += snprintf (&message[targetIdx], LUA_MSG_MAX_LENGTH-targetIdx,"%f", json_object_get_double(slotJ));
                    else  targetIdx += snprintf (&message[targetIdx], LUA_MSG_MAX_LENGTH-targetIdx,"nil");
                    arrayIdx++;
                    break;

                case'%':
                    message[targetIdx]='%';
                    targetIdx++;
                    break;

                case 'A':
                    targetIdx += snprintf (&message[targetIdx], LUA_MSG_MAX_LENGTH-targetIdx,"level: %s", source->uid);
                    break;

                case 's':
                default:
                    if (slotJ) targetIdx += snprintf (&message[targetIdx], LUA_MSG_MAX_LENGTH-targetIdx,"%s", json_object_get_string(slotJ));
                    else  targetIdx += snprintf (&message[targetIdx], LUA_MSG_MAX_LENGTH-targetIdx,"nil");
                    arrayIdx++;
                }

        } else {
            if (targetIdx >= LUA_MSG_MAX_LENGTH) {
                AFB_ApiWarning (source->api, "LuaFormatMessage: message[%s] owerverflow LUA_MSG_MAX_LENGTH=%d", format, LUA_MSG_MAX_LENGTH);
                targetIdx --; // move backward for EOL
                break;
            } else {
                message[targetIdx++] = format[idx];
            }
        }
    }
    message[targetIdx]='\0';

PrintMessage:
    // TBD: __file__ and __line__ should match LUA source code
    AFB_ApiVerbose(source->api, level,__FILE__,__LINE__,source->uid, "%s", message);
    json_object_put(responseJ);
    return 0;  // nothing return to lua

  OnErrorExit: // on argument to return (the error message)
    json_object_put(responseJ);
    return 1;
}


STATIC int LuaPrintInfo(lua_State* luaState) {
    int err=LuaFormatMessage (luaState, AFB_VERBOSITY_LEVEL_INFO, _AFB_SYSLOG_LEVEL_INFO_);
    return err;
}

STATIC int LuaPrintError(lua_State* luaState) {
    int err=LuaFormatMessage (luaState, AFB_VERBOSITY_LEVEL_ERROR,  _AFB_SYSLOG_LEVEL_ERROR_);
    return err; // no value return
}

STATIC int LuaPrintWarning(lua_State* luaState) {
    int err=LuaFormatMessage (luaState, AFB_VERBOSITY_LEVEL_WARNING,  _AFB_SYSLOG_LEVEL_WARNING_);
    return err;
}

STATIC int LuaPrintNotice(lua_State* luaState) {
    int err=LuaFormatMessage (luaState, AFB_VERBOSITY_LEVEL_NOTICE,  _AFB_SYSLOG_LEVEL_NOTICE_);
    return err;
}

STATIC int LuaPrintDebug(lua_State* luaState) {
    int err=LuaFormatMessage (luaState, AFB_VERBOSITY_LEVEL_DEBUG,  _AFB_SYSLOG_LEVEL_DEBUG_);
    return err;
}

STATIC int LuaAfbSuccess(lua_State* luaState) {
    CtlSourceT *source= LuaSourcePop(luaState, LUA_FIST_ARG);
    if (!source) goto OnErrorExit;

    // ignore context argument
    json_object *responseJ= LuaPopArgs(source, luaState, LUA_FIST_ARG+1);
    if (responseJ == JSON_ERROR) return 1;

    AFB_ReqSucess (source->request, responseJ, NULL);

    json_object_put(responseJ);
    return 0;

 OnErrorExit:
        lua_error(luaState);
        return 1;
}

STATIC int LuaAfbFail(lua_State* luaState) {
    CtlSourceT *source= LuaSourcePop(luaState, LUA_FIST_ARG);
    if (!source) goto OnErrorExit;

    json_object *responseJ= LuaPopArgs(source, luaState, LUA_FIST_ARG+1);
    if (responseJ == JSON_ERROR) return 1;

    AFB_ReqFail(source->request, source->uid, json_object_get_string(responseJ));

    json_object_put(responseJ);
    return 0;

 OnErrorExit:
        lua_error(luaState);
        return 1;
}

#ifdef AFB_BINDING_PREV3
STATIC void LuaAfbServiceCB(void *handle, int iserror, struct json_object *responseJ, AFB_ApiT apiHandle) {
#else
STATIC void LuaAfbServiceCB(void *handle, int iserror, struct json_object *responseJ) {
#endif
    LuaCbHandleT *handleCb= (LuaCbHandleT*)handle;
    int count=1;

    lua_getglobal(luaState, handleCb->callback);

    // Push AFB client context on the stack
    if (iserror) handleCb->source->status = CTL_STATUS_ERR;
    else handleCb->source->status = CTL_STATUS_DONE;
    LuaSourcePush(luaState, handleCb->source);

    // push response
    count+= LuaPushArgument(handleCb->source, responseJ);
    if (handleCb->context) count+= LuaPushArgument(handleCb->source, handleCb->context);

    int err=lua_pcall(luaState, count, LUA_MULTRET, 0);
    if (err) {
        AFB_ApiError(apiHandle, "LUA-SERVICE-CB:FAIL response=%s err=%s", json_object_get_string(responseJ), lua_tostring(luaState,-1) );
    }

    free (handleCb->source);
    free (handleCb);
}


STATIC int LuaAfbService(lua_State* luaState) {
    int count = lua_gettop(luaState);

    CtlSourceT *source= LuaSourcePop(luaState, LUA_FIST_ARG);
    if (!source) {
        lua_pushliteral (luaState, "LuaAfbService-Fail Invalid request handle");
        goto OnErrorExit;
    }

    // note: argument start at 2 because of AFB: table
    if (count <6 || !lua_isstring(luaState, 3) || !lua_isstring(luaState, 4) || !lua_isstring(luaState, 6)) {
        lua_pushliteral (luaState, "ERROR: syntax AFB:service(source, api, verb, {[Lua Table]})");
        goto OnErrorExit;
    }

    // get api/verb+query
    const char *api = lua_tostring(luaState,3);
    const char *verb= lua_tostring(luaState,4);
    json_object *queryJ= LuaTableToJson(source, luaState, 5);
    if (queryJ == JSON_ERROR) return 1;

    LuaCbHandleT *handleCb = calloc (1, sizeof(LuaCbHandleT));
    handleCb->callback= lua_tostring(luaState, 6);
    handleCb->context = LuaPopArgs(source, luaState, 7);

    // source need to be duplicate because request return free it
    handleCb->source  = malloc(sizeof(CtlSourceT));
    handleCb->source  = memcpy (handleCb->source, source, sizeof(CtlSourceT));

    AFB_ServiceCall(source->api, api, verb, queryJ, LuaAfbServiceCB, handleCb);

    return 0; // no value return

  OnErrorExit:
        lua_error(luaState);
        return 1;
}

STATIC int LuaAfbServiceSync(lua_State* luaState) {
    int count = lua_gettop(luaState);
    json_object *responseJ;

    CtlSourceT *source= LuaSourcePop(luaState, LUA_FIST_ARG);
    if (!source) {
        lua_pushliteral (luaState, "LuaAfbServiceSync-Fail Invalid request handle");
        goto OnErrorExit;
    }

    // note: argument start at 2 because of AFB: table
    if (count != 5 || !lua_isstring(luaState, LUA_FIST_ARG+1) || !lua_isstring(luaState, LUA_FIST_ARG+2) || !lua_istable(luaState, LUA_FIST_ARG+3)) {
        lua_pushliteral (luaState, "ERROR: syntax AFB:servsync(api, verb, {[Lua Table]})");
        goto OnErrorExit;
    }


    // get source/api/verb+query
    const char *api = lua_tostring(luaState,LUA_FIST_ARG+1);
    const char *verb= lua_tostring(luaState,LUA_FIST_ARG+2);
    json_object *queryJ= LuaTableToJson(source, luaState, LUA_FIST_ARG+3);

    int iserror=AFB_ServiceSync(source->api, api, verb, queryJ, &responseJ);

    // push error status & response
    count=1; lua_pushboolean(luaState, iserror);
    count+= LuaPushArgument(source, responseJ);

    return count; // return count values

  OnErrorExit:
        lua_error(luaState);
        return 1;
}

STATIC int LuaAfbEventPush(lua_State* luaState) {
    LuaAfbEvent *afbevt;

    CtlSourceT *source= LuaSourcePop(luaState, LUA_FIST_ARG);
    if (!source) {
        lua_pushliteral (luaState, "LuaAfbEventSubscribe-Fail Invalid request handle");
        goto OnErrorExit;
    }

    // if no private event handle then use default binding event
    if (!lua_islightuserdata(luaState, LUA_FIST_ARG+1)) {
        lua_pushliteral (luaState, "LuaAfbMakePush-Fail missing event handle");
        goto OnErrorExit;
    }

    afbevt = (LuaAfbEvent*) lua_touserdata(luaState, LUA_FIST_ARG+1);

    if (!AFB_EventIsValid(afbevt->event)) {
        lua_pushliteral (luaState, "LuaAfbMakePush-Fail invalid event");
        goto OnErrorExit;
    }

    json_object *ctlEventJ= LuaTableToJson(source, luaState, LUA_FIST_ARG+2);
    if (!ctlEventJ) {
        lua_pushliteral (luaState, "LuaAfbEventPush-Syntax is AFB:signal ([evtHandle], {lua table})");
        goto OnErrorExit;
    }

    int done = AFB_EventPush(afbevt->event, ctlEventJ);
    if (!done) {
        lua_pushliteral (luaState, "LuaAfbEventPush-Fail No Subscriber to event");
        AFB_ApiError(source->api, "LuaAfbEventPush-Fail name subscriber event=%s count=%d", afbevt->name, afbevt->count);
        goto OnErrorExit;
    }
    afbevt->count++;
    return 0;

OnErrorExit:
        lua_error(luaState);
        return 1;
}

STATIC int LuaAfbEventSubscribe(lua_State* luaState) {
    LuaAfbEvent *afbevt;

    CtlSourceT *source= LuaSourcePop(luaState, LUA_FIST_ARG);
    if (!source) {
        lua_pushliteral (luaState, "LuaAfbEventSubscribe-Fail Invalid request handle");
        goto OnErrorExit;
    }

    // if no private event handle then use default binding event
    if (!lua_islightuserdata(luaState, LUA_FIST_ARG+1)) {
        lua_pushliteral (luaState, "LuaAfbMakePush-Fail missing event handle");
        goto OnErrorExit;
    }

    afbevt = (LuaAfbEvent*) lua_touserdata(luaState, LUA_FIST_ARG+1);

    if (!AFB_EventIsValid(afbevt->event)) {
        lua_pushliteral (luaState, "LuaAfbMakePush-Fail invalid event handle");
        goto OnErrorExit;
    }

    int err = AFB_ReqSubscribe(source->request, afbevt->event);
    if (err) {
        lua_pushliteral (luaState, "LuaAfbEventSubscribe-Fail No Subscriber to event");
        AFB_ApiError(source->api, "LuaAfbEventPush-Fail name subscriber event=%s count=%d", afbevt->name, afbevt->count);
        goto OnErrorExit;
    }
    afbevt->count++;
    return 0;

  OnErrorExit:
        lua_error(luaState);
        return 1;
}

STATIC int LuaAfbEventMake(lua_State* luaState) {
    int count = lua_gettop(luaState);
    LuaAfbEvent *afbevt=calloc(1,sizeof(LuaAfbEvent));

    CtlSourceT *source= LuaSourcePop(luaState, LUA_FIST_ARG);
    if (!source) {
        lua_pushliteral (luaState, "LuaAfbEventMake-Fail Invalid request handle");
        goto OnErrorExit;
    }

    if (count != LUA_FIST_ARG+1 || !lua_isstring(luaState, LUA_FIST_ARG+1)) {
        lua_pushliteral (luaState, "LuaAfbEventMake-Syntax is evtHandle= AFB:event ('myEventName')");
        goto OnErrorExit;
    }

    // event name should be the only argument
    afbevt->name= strdup (lua_tostring(luaState,LUA_FIST_ARG+1));

    // create a new binder event
    afbevt->event = AFB_EventMake(source->api, afbevt->name);
    if (!AFB_EventIsValid(afbevt->event)) {
        AFB_ApiError (source->api,"Fail to CreateEvent evtname=%s",  afbevt->name);
        lua_pushliteral (luaState, "LuaAfbEventMake-Fail to Create Binder event");
        goto OnErrorExit;
    }

    // push event handler as a LUA opaque handle
    lua_pushlightuserdata(luaState, afbevt);
    return 1;

  OnErrorExit:
        lua_error(luaState);
        return 1;
}

STATIC int LuaAfbGetUid (lua_State* luaState) {

    CtlSourceT *source= LuaSourcePop(luaState, LUA_FIST_ARG);
    if (!source) {
        lua_pushliteral (luaState, "LuaAfbEventSubscribe-Fail Invalid request handle");
        goto OnErrorExit;
    }

    // extract and return afbSource from timer handle
    lua_pushstring(luaState, source->uid);

    return 1; // return argument

OnErrorExit:
    return 0;
}

STATIC int LuaAfbGetStatus (lua_State* luaState) {

    CtlSourceT *source= LuaSourcePop(luaState, LUA_FIST_ARG);
    if (!source) {
        lua_pushliteral (luaState, "LuaAfbEventSubscribe-Fail Invalid request handle");
        goto OnErrorExit;
    }

    // extract and return afbSource from timer handle
    lua_pushinteger(luaState, source->status);

    return 1; // return argument

OnErrorExit:
    return 0;
}

// Function call from LUA when lua2c plugin L2C is used
// Rfor: Not using LUA_FIRST_ARG here because we didn't use
// luaL_newlib function, so first args is on stack at first
// position.
PUBLIC int Lua2cWrapper(void* luaHandle, char *funcname, Lua2cFunctionT callback) {
    lua_State* luaState = (lua_State*)luaHandle;
    json_object *responseJ=NULL;

    CtlSourceT *source= LuaSourcePop(luaState, 1);

    json_object *argsJ= LuaPopArgs(source, luaState, 2);
    int err= (*callback) (source, argsJ, &responseJ);

    // push error code and eventual response to LUA
    int count=1;
    lua_pushinteger (luaState, err);
    count += LuaPushArgument (source, responseJ);

    return count;
}

// Call a Lua function from a control action
PUBLIC int LuaCallFunc (CtlSourceT *source, CtlActionT *action, json_object *queryJ) {

    int err, count;

    json_object* argsJ  = action->argsJ;
    const char*  func   = action->exec.lua.funcname;

    // load function (should exist in CONTROL_PATH_LUA
    lua_getglobal(luaState, func);

    // push source on the stack
    count=1;
    // Push AFB client context on the stack
    LuaAfbSourceT *afbSource= LuaSourcePush(luaState, source);
    if (!afbSource) goto OnErrorExit;

    // push argsJ on the stack
    if (!argsJ) {
        lua_pushnil(luaState); count++;
    } else {
        count+= LuaPushArgument (source, argsJ);
    }

    // push queryJ on the stack
    if (!queryJ) {
        lua_pushnil(luaState);
        count++;
    } else {
        count+= LuaPushArgument (source, queryJ);
    }

    // effectively exec LUA script code
    err=lua_pcall(luaState, count, 1, 0);
    if (err)  {
        AFB_ApiError(source->api, "LuaCallFunc Fail calling %s error=%s", func, lua_tostring(luaState,-1));
        goto OnErrorExit;
    }

    // return LUA script value
    int rc= (int)lua_tointeger(luaState, -1);
    return rc;

  OnErrorExit:
    return -1;
}


// Execute LUA code from received API request
STATIC void LuaDoAction (LuaDoActionT action, AFB_ReqT request) {

    int err, count=0;
    CtlSourceT *source = alloca(sizeof(CtlSourceT));
    source->request = request;

    json_object* queryJ = AFB_ReqJson(request);


    switch (action) {

        case LUA_DOSTRING: {
            const char *script = json_object_get_string(queryJ);
            err=luaL_loadstring(luaState, script);
            if (err) {
                AFB_ApiError(source->api, "LUA-DO-COMPILE:FAIL String=%s err=%s", script, lua_tostring(luaState,-1) );
                goto OnErrorExit;
            }
            // Push AFB client context on the stack
            LuaAfbSourceT *afbSource= LuaSourcePush(luaState, source);
            if (!afbSource) goto OnErrorExit;

            break;
        }

        case LUA_DOCALL: {
            const char *func;
            json_object *argsJ=NULL;

            err= wrap_json_unpack (queryJ, "{s:s, s?o !}", "target", &func, "args", &argsJ);
            if (err) {
                AFB_ApiError(source->api, "LUA-DOCALL-SYNTAX missing target|args query=%s", json_object_get_string(queryJ));
                goto OnErrorExit;
            }

            // load function (should exist in CONTROL_PATH_LUA
            lua_getglobal(luaState, func);

            // Push AFB client context on the stack
            LuaAfbSourceT *afbSource= LuaSourcePush(luaState, source);
            if (!afbSource) goto OnErrorExit;

            // push query on the stack
            if (!argsJ) {
                lua_pushnil(luaState);
                count++;
            } else {
                count+= LuaPushArgument (source, argsJ);
            }

            break;
        }

        case LUA_DOSCRIPT: {   // Fulup need to fix argument passing
            char *filename; char*fullpath;
            char luaScriptPath[CONTROL_MAXPATH_LEN];
            int index;

            // scan luascript search path once
            static json_object *luaScriptPathJ =NULL;

            // extract value from query
            const char *target=NULL,*func=NULL;
            json_object *argsJ=NULL;
            err= wrap_json_unpack (queryJ, "{s:s,s?s,s?s,s?o !}",
                "target", &target,
                "path",&luaScriptPathJ,
                "function",&func,
                "args",&argsJ);
            if (err) {
                AFB_ApiError(source->api, "LUA-DOSCRIPT-SYNTAX:missing target|[path]|[function]|[args] query=%s", json_object_get_string(queryJ));
                goto OnErrorExit;
            }

            // search for filename=script in CONTROL_LUA_PATH
            if (!luaScriptPathJ)  {
                strncpy(luaScriptPath,CONTROL_DOSCRIPT_PRE, strlen(CONTROL_DOSCRIPT_PRE)+1);
                strncat(luaScriptPath,"-", strlen("-"));
                strncat(luaScriptPath,target, strlen(target));
                luaScriptPathJ= ScanForConfig(CONTROL_LUA_PATH , CTL_SCAN_RECURSIVE,luaScriptPath,".lua");
            }
            for (index=0; index < json_object_array_length(luaScriptPathJ); index++) {
                json_object *entryJ=json_object_array_get_idx(luaScriptPathJ, index);

                err= wrap_json_unpack (entryJ, "{s:s, s:s !}", "fullpath",  &fullpath,"filename", &filename);
                if (err) {
                    AFB_ApiError(source->api, "LUA-DOSCRIPT-SCAN:HOOPs invalid config file path = %s", json_object_get_string(entryJ));
                    goto OnErrorExit;
                }

                if (index > 0) AFB_ApiWarning(source->api, "LUA-DOSCRIPT-SCAN:Ignore second script=%s path=%s", filename, fullpath);
                else {
                    strncpy (luaScriptPath, fullpath, strlen(fullpath)+1);
                    strncat (luaScriptPath, "/", strlen("/"));
                    strncat (luaScriptPath, filename, strlen(filename));
                }
            }

            err= luaL_loadfile(luaState, luaScriptPath);
            if (err) {
                AFB_ApiError(source->api, "LUA-DOSCRIPT HOOPs Error in LUA loading scripts=%s err=%s", luaScriptPath, lua_tostring(luaState,-1));
                goto OnErrorExit;
            }

            // script was loaded we need to parse to make it executable
            err=lua_pcall(luaState, 0, 0, 0);
            if (err) {
                AFB_ApiError(source->api, "LUA-DOSCRIPT:FAIL to load %s", luaScriptPath);
                goto OnErrorExit;
            }

            // if no func name given try to deduct from filename
            if (!func && (func=(char*)GetMidleName(filename))!=NULL) {
                strncpy(luaScriptPath,"_", strlen("_")+1);
                strncat(luaScriptPath,func, strlen(func));
                func=luaScriptPath;
            }
            if (!func) {
                AFB_ApiError(source->api, "LUA-DOSCRIPT:FAIL to deduct funcname from %s", filename);
                goto OnErrorExit;
            }

            // load function (should exist in CONTROL_PATH_LUA
            lua_getglobal(luaState, func);

            // Push AFB client context on the stack
            LuaAfbSourceT *afbSource= LuaSourcePush(luaState, source);
            if (!afbSource) goto OnErrorExit;

            // push function arguments
            if (!argsJ) {
                lua_pushnil(luaState);
                count++;
            } else {
                count+= LuaPushArgument(source, argsJ);
            }

            break;
        }

        default:
            AFB_ApiError(source->api, "LUA-DOSCRIPT-ACTION unknown query=%s", json_object_get_string(queryJ));
            goto OnErrorExit;
    }

    // effectively exec LUA code (afb_reply/fail done later from callback)
    err=lua_pcall(luaState, count+1, 0, 0);
    if (err) {
        AFB_ApiError(source->api, "LUA-DO-EXEC:FAIL query=%s err=%s", json_object_get_string(queryJ), lua_tostring(luaState,-1));
        goto OnErrorExit;
    }
    return;

 OnErrorExit:
    AFB_ReqFail(request,"LUA:ERROR", lua_tostring(luaState,-1));
    return;
}

PUBLIC void ctlapi_execlua (AFB_ReqT request) {
    LuaDoAction (LUA_DOSTRING, request);
}

PUBLIC void ctlapi_request (AFB_ReqT request) {
    LuaDoAction (LUA_DOCALL, request);
}

PUBLIC void ctlapi_debuglua (AFB_ReqT request) {
    LuaDoAction (LUA_DOSCRIPT, request);
}


STATIC TimerHandleT *LuaTimerPop (lua_State *luaState, int index) {
  TimerHandleT *timerHandle;

  luaL_checktype(luaState, index, LUA_TLIGHTUSERDATA);
  timerHandle = (TimerHandleT *) lua_touserdata(luaState, index);

  if (timerHandle == NULL && timerHandle->magic != TIMER_MAGIC) {
      luaL_error(luaState, "Invalid source handle");
      fprintf(stderr, "LuaSourcePop error retrieving afbSource");
      return NULL;
  }
  return timerHandle;
}

STATIC int LuaTimerClear (lua_State* luaState) {

    // retrieve useful information opaque handle
    TimerHandleT *timerHandle = LuaTimerPop(luaState, LUA_FIST_ARG);
    if (!timerHandle) goto OnErrorExit;

#ifdef AFB_BINDING_PREV3
    // API handle does not exit in API-V2
    LuaCbHandleT *luaCbHandle = (LuaCbHandleT*) timerHandle->context;
#endif
    AFB_ApiNotice (luaCbHandle->source->api,"LuaTimerClear timer=%s", timerHandle->uid);
    TimerEvtStop(timerHandle);

    return 0; //happy end

OnErrorExit:
    return 1;
}
STATIC int LuaTimerGet (lua_State* luaState) {

    // retrieve useful information opaque handle
    TimerHandleT *timerHandle = LuaTimerPop(luaState, LUA_FIST_ARG);
    if (!timerHandle) goto OnErrorExit;
    LuaCbHandleT *luaCbHandle = (LuaCbHandleT*) timerHandle->context;

    // create response as a JSON object
    json_object *responseJ= json_object_new_object();
    json_object_object_add(responseJ,"uid", json_object_new_string(timerHandle->uid));
    json_object_object_add(responseJ,"delay", json_object_new_int(timerHandle->delay));
    json_object_object_add(responseJ,"count", json_object_new_int(timerHandle->count));

    // return JSON object as Lua table
    int count=LuaPushArgument(luaCbHandle->source, responseJ);

    // free json object
    json_object_put(responseJ);

    return count; // return argument

OnErrorExit:
    return 0;
}

// Timer Callback

// Set timer
STATIC int LuaTimerSetCB (TimerHandleT *timer) {
    LuaCbHandleT *LuaCbHandle = (LuaCbHandleT*) timer->context;
    int count;

    // push timer handle and user context on Lua stack
    lua_getglobal(luaState, LuaCbHandle->callback);

    // Push AFB client context on the stack
    count=1;
    LuaAfbSourceT *afbSource= LuaSourcePush(luaState, LuaCbHandle->source);
    if (!afbSource) goto OnErrorExit;

    // Push AFB client context on the stack
    count ++;
    lua_pushlightuserdata(luaState, timer);
    if (!afbSource) goto OnErrorExit;

    // Push user Context
    count+= LuaPushArgument(LuaCbHandle->source, LuaCbHandle->context);

    int err=lua_pcall(luaState, count, LUA_MULTRET, 0);
    if (err) {
        AFB_ApiError (LuaCbHandle->source->api,"LUA-TIMER-CB:FAIL response=%s err=%s", json_object_get_string(LuaCbHandle->context), lua_tostring(luaState,-1));
        goto OnErrorExit;
    }

    // get return parameter
    if (!lua_isboolean(luaState, -1)) {
        return (lua_toboolean(luaState, -1));
    }

    return 0;  // By default we are happy

 OnErrorExit:
    return 1;  // stop timer
}

// Free Timer context handle
STATIC int LuaTimerCtxFree(void *handle) {
    LuaCbHandleT *LuaCbHandle = (LuaCbHandleT*) handle;

    free (LuaCbHandle->source);
    free (LuaCbHandle);

    return 0;
}

STATIC int LuaTimerSet(lua_State* luaState) {
    const char *uid=NULL, *info=NULL;
    int delay=0, count=0;

    // Get source handle
    CtlSourceT *source= LuaSourcePop(luaState, LUA_FIST_ARG);
    if (!source) goto OnErrorExit;

    json_object *timerJ = LuaPopOneArg(source, luaState, LUA_FIST_ARG+1);
    const char *callback = lua_tostring(luaState, LUA_FIST_ARG + 2);
    json_object *contextJ = LuaPopOneArg(source, luaState, LUA_FIST_ARG + 3);

    if (lua_gettop(luaState) != LUA_FIST_ARG+3 || !timerJ || !callback || !contextJ) {
        lua_pushliteral(luaState, "LuaTimerSet: Syntax timerset (source, timerT, 'callback', contextT)");
        goto OnErrorExit;
    }

    int err = wrap_json_unpack(timerJ, "{ss, s?s si, si !}",
        "uid", &uid,
        "info", &info,
        "delay", &delay,
        "count", &count);
    if (err) {

        lua_pushliteral(luaState, "LuaTimerSet: Syntax timerT={uid:xxx delay:ms, count:xx}");
        goto OnErrorExit;
    }

    // Allocate handle to store context and callback
    LuaCbHandleT *handleCb = calloc (1, sizeof(LuaCbHandleT));
    handleCb->callback= callback;
    handleCb->context = contextJ;
    handleCb->source  = malloc(sizeof(CtlSourceT));
    memcpy (handleCb->source, source, sizeof(CtlSourceT));  // Fulup need to be free when timer is done

    // everything look fine create timer structure
    TimerHandleT *timerHandle = malloc (sizeof (TimerHandleT));
    timerHandle->magic= TIMER_MAGIC;
    timerHandle->delay=delay;
    timerHandle->count=count;
    timerHandle->uid=uid;
    timerHandle->freeCB=LuaTimerCtxFree;

    // fire timer
    TimerEvtStart (source->api, timerHandle, LuaTimerSetCB, handleCb);

    // Fulup finir les timers avec handle

    // return empty error code plus timer handle
    lua_pushnil(luaState);
    lua_pushlightuserdata(luaState, timerHandle);
    return 2;

OnErrorExit:
    lua_error(luaState);
    return 1; // return error code
}

typedef struct {
    const char *callback;
    json_object *clientCtxJ;
    CtlSourceT *source;
} LuaClientCtxT;


STATIC void *LuaClientCtxNew (void * handle) {

    LuaClientCtxT *clientCtx = (LuaClientCtxT*) handle;
    int count=1;

    // push callback and client context on Lua stack
    lua_getglobal(luaState, clientCtx->callback);

    // let's Lua script know about new/free
    clientCtx->source->status = CTL_STATUS_DONE;

    // Push AFB client context on the stack
    LuaAfbSourceT *afbSource= LuaSourcePush(luaState, clientCtx->source);
    if (!afbSource) goto OnErrorExit;

    // Push user Context
    count+= LuaPushArgument(clientCtx->source, clientCtx->clientCtxJ);

    int err=lua_pcall(luaState, count, 1, 0);
    if (err) {
        AFB_ApiError (clientCtx->source->api,"LuaClientCtxNew:FAIL response=%s err=%s", json_object_get_string(clientCtx->clientCtxJ), lua_tostring(luaState,-1));
        goto OnErrorExit;
    }

    // If function return an error status then free client context
    if (lua_tointeger(luaState, -1)) {
        free (clientCtx);
        goto OnErrorExit;
    }

    return handle;  // By default we are happy

OnErrorExit:
    return NULL;

}

STATIC void LuaClientCtxFree (void * handle) {

    LuaClientCtxT *clientCtx = (LuaClientCtxT*) handle;
    int count=1;

    if (!handle) return;

    // let's Lua script know about new/free
    lua_getglobal(luaState, clientCtx->callback);

    // set source status to notify lua script about free
    clientCtx->source->status = CTL_STATUS_FREE;

    // Push AFB client context on the stack
    LuaAfbSourceT *afbSource= LuaSourcePush(luaState, clientCtx->source);
    if (!afbSource) goto OnErrorExit;

    // Push user Context
    count+= LuaPushArgument(clientCtx->source, clientCtx->clientCtxJ);

    int err=lua_pcall(luaState, count, LUA_MULTRET, 0);
    if (err) {
        AFB_ApiError (clientCtx->source->api,"LuaClientCtxFree:FAIL response=%s err=%s", json_object_get_string(clientCtx->clientCtxJ), lua_tostring(luaState,-1));
        goto OnErrorExit;
    }

    // If function return an error status then free client context
    if (lua_toboolean(luaState, -1)) {
        free (clientCtx);
        goto OnErrorExit;
    }

    return;  // No return status

OnErrorExit:
    return;

}

// set a context that will be free when WS is closed
STATIC int LuaClientCtx(lua_State* luaState) {

    // Get source handle
    CtlSourceT *source= LuaSourcePop(luaState, LUA_FIST_ARG);
    if (!source) goto OnErrorExit;

    if (!AFB_ReqIsValid (source->request)) {
        lua_pushliteral(luaState, "LuaSessionSet-Syntax should be called within client request context");
        goto OnErrorExit;
    }

    // in only one arg then we should free the clientCtx
    if (lua_gettop(luaState) == LUA_FIST_ARG) {
        AFB_ClientCtxClear(source->request);
        goto OnSuccessExit;
    }

    const char *callback = lua_tostring(luaState, LUA_FIST_ARG + 1);
    json_object *clientCtxJ = LuaPopOneArg(source, luaState, LUA_FIST_ARG + 2);

    if (lua_gettop(luaState) != LUA_FIST_ARG+2 || !clientCtxJ || !callback) {
        lua_pushliteral(luaState, "LuaClientCtx-Syntax clientCtx (source, callback, clientCtx)");
        goto OnErrorExit;
    }

    // Allocate handle to store clientCtx and callback
    LuaClientCtxT *clientCtx = calloc (1, sizeof(LuaCbHandleT));
    clientCtx->callback = callback;
    clientCtx->clientCtxJ= clientCtxJ;
    clientCtx->source  = malloc(sizeof(CtlSourceT));
    memcpy (clientCtx->source, source, sizeof(CtlSourceT));  // source if free when command return

    // push client context within session
    void *done = AFB_ClientCtxSet (source->request, 1, LuaClientCtxNew, LuaClientCtxFree, clientCtx);
    if (!done) {
        lua_pushliteral(luaState, "LuaClientCtx-Fail to allocate client context)");
        goto OnErrorExit;
    }

OnSuccessExit:
    lua_pushnil(luaState);
    return 1;

OnErrorExit:
    lua_error(luaState);
    return 1; // return error code
}


// Register a new L2c list of LUA user plugin commands
PUBLIC void LuaL2cNewLib(luaL_Reg *l2cFunc, int count) {
    // luaL_newlib(luaState, l2cFunc); macro does not work with pointer :(
    luaL_checkversion(luaState);
    lua_createtable(luaState, 0, count+1);
    luaL_setfuncs(luaState,l2cFunc,0);
    lua_setglobal(luaState, "_lua2c");
}

static const luaL_Reg afbFunction[] = {
    {"timerclear", LuaTimerClear},
    {"timerget"  , LuaTimerGet},
    {"timerset"  , LuaTimerSet},
    {"notice"    , LuaPrintNotice},
    {"info"      , LuaPrintInfo},
    {"warning"   , LuaPrintWarning},
    {"debug"     , LuaPrintDebug},
    {"error"     , LuaPrintError},
    {"servsync"  , LuaAfbServiceSync},
    {"service"   , LuaAfbService},
    {"success"   , LuaAfbSuccess},
    {"fail"      , LuaAfbFail},
    {"subscribe" , LuaAfbEventSubscribe},
    {"evtmake"   , LuaAfbEventMake},
    {"evtpush"   , LuaAfbEventPush},
    {"getuid"    , LuaAfbGetUid},
    {"status"    , LuaAfbGetStatus},
    {"context"   , LuaClientCtx},

    {NULL, NULL}  /* sentinel */
};

// Load Lua Interpreter
PUBLIC int LuaConfigLoad (AFB_ApiT apiHandle) {
    static int luaLoaded=0;

    // Lua loads only once
    if (luaLoaded) return 0;
    luaLoaded=1;

    // open a new LUA interpretor
    luaState = luaL_newstate();
    if (!luaState)  {
        AFB_ApiError(apiHandle, "LUA_INIT: Fail to open lua interpretor");
        goto OnErrorExit;
    }

    // load auxiliary libraries
    luaL_openlibs(luaState);

    // redirect print to AFB_NOTICE
    luaL_newlib(luaState, afbFunction);
    lua_setglobal(luaState, "AFB");

    // initialise static magic for context
    #ifndef CTX_MAGIC
        CTX_MAGIC=CtlConfigMagicNew();
    #endif

    #ifndef TIMER_MAGIC
        TIMER_MAGIC=CtlConfigMagicNew();
    #endif

    return 0;

 OnErrorExit:
    free(luaState);
    return 1;
}

// Create Binding Event at Init Exec Time
PUBLIC int LuaConfigExec (AFB_ApiT apiHandle, const char* prefix) {

    int err, index;

    // search for default policy config files
    char fullprefix[CONTROL_MAXPATH_LEN];
    if(prefix)
        strncpy (fullprefix, prefix, strlen(prefix)+1);
    else
        strncat (fullprefix, GetBinderName(), strlen(GetBinderName()));

    strncat (fullprefix, "-", strlen("-"));

    const char *dirList= getenv("CONTROL_LUA_PATH");
    if (!dirList) dirList=CONTROL_LUA_PATH;

    // special case for no lua even when avaliable
    if (!strcasecmp ("/dev/null", dirList)) {
        return 0;
    }

    json_object *luaScriptPathJ = ScanForConfig(dirList , CTL_SCAN_RECURSIVE, fullprefix, "lua");

    // load+exec any file found in LUA search path
    if(luaScriptPathJ) {
        for (index=0; index < json_object_array_length(luaScriptPathJ); index++) {
            json_object *entryJ=json_object_array_get_idx(luaScriptPathJ, index);

            char *filename; char*fullpath;
            err= wrap_json_unpack (entryJ, "{s:s, s:s !}", "fullpath",  &fullpath,"filename", &filename);
            if (err) {
                AFB_ApiError(apiHandle, "LUA-INIT HOOPs invalid config file path = %s", json_object_get_string(entryJ));
                goto OnErrorExit;
            }

            char filepath[CONTROL_MAXPATH_LEN];
            strncpy(filepath, fullpath, strlen(fullpath)+1);
            strncat(filepath, "/", strlen("/"));
            strncat(filepath, filename, strlen(filename));
            err= luaL_loadfile(luaState, filepath);
            if (err) {
                AFB_ApiError(apiHandle, "LUA-LOAD HOOPs Error in LUA loading scripts=%s err=%s", filepath, lua_tostring(luaState,-1));
                goto OnErrorExit;
            }

            // exec/compil script
            err = lua_pcall(luaState, 0, 0, 0);
            if (err) {
                AFB_ApiError(apiHandle, "LUA-LOAD HOOPs Error in LUA exec scripts=%s err=%s", filepath, lua_tostring(luaState,-1));
                goto OnErrorExit;
            } else {
                AFB_ApiNotice(apiHandle, "LUA-LOAD '%s'", filepath);
            }
        }

        json_object_put(luaScriptPathJ);
        // no policy config found remove control API from binder
        if (index == 0)  {
            AFB_ApiWarning (apiHandle, "POLICY-INIT:WARNING (setenv CONTROL_LUA_PATH) No LUA '%s*.lua' in '%s'", fullprefix, dirList);
        }
    }
    else AFB_ApiWarning (apiHandle, "POLICY-INIT:WARNING (setenv CONTROL_LUA_PATH) No LUA '%s*.lua' in '%s'", fullprefix, dirList);

    AFB_ApiDebug (apiHandle, "Audio control-LUA Init Done");
    return 0;

 OnErrorExit:
    return 1;
}