/*
 * 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, something express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 * Reference:
 *   Json load using json_unpack https://jansson.readthedocs.io/en/2.9/apiref.html#parsing-and-validating-values
 */

#define _GNU_SOURCE
#include <stdio.h>
#include <string.h>
#include <dlfcn.h>


#include <json-c/json_object.h> 

#include "wrap-json.h"
#include "ctl-binding.h"


typedef struct {
    const char* label;
    const char *info;
    const char *version;
    DispatchActionT *actions;
} DispatchHandleT;


typedef struct {
    const char* label;
    const char *info;
    const char *version;
    char *plugin;
    void *dlHandle;
    DispatchHandleT *onload;
    DispatchHandleT *events;
    DispatchHandleT *controls;
} DispatchConfigT;

STATIC DispatchConfigT *ctlHandle = NULL;

PUBLIC void ctlapi_dispatch (DispatchCtlEnumT control, afb_req request) {
    json_object*tmpJ;
    
    json_object* argsJ= afb_req_json(request);
    int done=json_object_object_get_ex(argsJ, "closing", &tmpJ);
    if (done) return;
    
}

// List Avaliable Configuration Files
PUBLIC void ctlapi_config (struct afb_req request) {
    json_object*tmpJ;
    char *dirList;
    
    json_object* argsJ = afb_req_json(request);
    if (argsJ && json_object_object_get_ex (argsJ, "cfgpath" , &tmpJ)) {
        dirList = strdup (json_object_get_string(tmpJ));
    } else {    
        dirList = strdup (CONTROL_DISPATCH_PATH); 
        AFB_NOTICE ("CONFIG-MISSING: use default CONTROL_DISPATCH_PATH=%s", CONTROL_DISPATCH_PATH);
    }
   
    // get list of config file
    struct json_object *responseJ = ScanForConfig(dirList, "onload", "json");
    
    if (json_object_array_length(responseJ) == 0) {
       afb_req_fail(request, "CONFIGPATH:EMPTY", "No Config Found in CONTROL_DISPATCH_PATH"); 
    } else {
        afb_req_success(request, responseJ, NULL);
    }
    
    return;
}

// unpack individual action object
STATIC int DispatchLoadOneAction (json_object *actionJ,  DispatchActionT *action) {
    char *api, *verb, *callback, *lua;
    int err, modeCount=0;

    err= wrap_json_unpack(actionJ, "{ss,s?s,s?s,s?o,s?s,s?s,s?s !}"
        , "label",&action->label, "info",&action->info, "callback",&callback, "lua", &lua, "args",&action->argsJ, "api",&api, "verb", &verb);
    if (err) {
        AFB_ERROR ("DISPATCH-LOAD-ACTION Missing something label|info|callback|lua|(api+verb)|args in %s", json_object_get_string(actionJ));
        goto OnErrorExit;
    }

    if (lua) {
        action->mode = CTL_MODE_LUA;
        action->call=lua;
        modeCount++;
    }

    if (api && verb) {
        action->mode = CTL_MODE_API;
        action->api=api;
        action->call=verb;
        modeCount++;
    }

    if (callback) {
        action->mode = CTL_MODE_CB;
        action->call=callback;
        modeCount++;

        action->actionCB = dlsym(ctlHandle->dlHandle, callback);
        if (!action->actionCB) {
            AFB_ERROR ("DISPATCH-LOAD-ACTION fail to find calbback=%s in %s", callback, ctlHandle->plugin);
            goto OnErrorExit;
        }
    }

    // make sure at least one mode is selected
    if (modeCount == 0) {
        AFB_ERROR ("DISPATCH-LOAD-ACTION Missing something lua|callback|(api+verb) in %s", json_object_get_string(actionJ));            
        goto OnErrorExit;
    } 

    if (modeCount > 1) {
        AFB_ERROR ("DISPATCH-LOAD-ACTION ToMany lua|callback|(api+verb) in %s", json_object_get_string(actionJ));            
        goto OnErrorExit;
   } 
   return 0;
   
OnErrorExit:
   return -1;   
};

STATIC DispatchActionT *DispatchLoadActions (json_object *actionsJ) {
    int err;
    DispatchActionT *actions;
                
    // action array is close with a nullvalue;
    if (json_object_get_type(actionsJ) == json_type_array) {
        int count = json_object_array_length(actionsJ);
        actions = calloc (count+1, sizeof(DispatchActionT));
        
        for (int idx=0; idx < count; idx++) {
            json_object *actionJ = json_object_array_get_idx(actionsJ, idx);
            err = DispatchLoadOneAction (actionJ, &actions[idx]);
            if (err) goto OnErrorExit;
        }
        
    } else {
        actions = calloc (2, sizeof(DispatchActionT));  
        err = DispatchLoadOneAction (actionsJ, &actions[0]);
        if (err) goto OnErrorExit;
    }
    
    return actions;
    
 OnErrorExit:
    return NULL;
    
}

STATIC DispatchConfigT *DispatchLoadConfig (const char* filepath) {
    json_object *dispatchConfigJ, *ignoreJ;
    int err;
    
    // Load JSON file
    dispatchConfigJ= json_object_from_file(filepath);
    if (!dispatchConfigJ) goto OnErrorExit;
    
    AFB_INFO ("DISPATCH-LOAD-CONFIG: loading config filepath=%s", filepath);
    
    json_object *metadataJ=NULL, *onloadJ=NULL, *controlsJ=NULL, *eventsJ=NULL;
    err= wrap_json_unpack(dispatchConfigJ, "{s?o,so,s?o,s?o,s?o !}", "$schema", &ignoreJ, "metadata",&metadataJ, "onload",&onloadJ, "controls",&controlsJ, "events",&eventsJ);
    if (err) {
        AFB_ERROR ("DISPATCH-LOAD-CONFIG Missing something metadata|[onload]|[controls]|[events] in %s", json_object_get_string(dispatchConfigJ));
        goto OnErrorExit;
    }
    
    DispatchConfigT *dispatchConfig = calloc (1, sizeof(DispatchConfigT));
    if (metadataJ) {
        err= wrap_json_unpack(metadataJ, "{so,s?s,ss !}", "label", &dispatchConfig->label, "info",&dispatchConfig->info, "version",&dispatchConfig->version);
        if (err) {
            AFB_ERROR ("DISPATCH-LOAD-CONFIG:METADATA Missing something label|version|[label] in %s", json_object_get_string(metadataJ));
            goto OnErrorExit;
        }
    } 
    
    if (onloadJ) {
        json_object * actionsJ;
        DispatchHandleT *dispatchHandle = calloc (1, sizeof(DispatchHandleT));

        err= wrap_json_unpack(onloadJ, "{so,s?s,s?s,s?o !}", "label",&dispatchHandle->label, "info",&dispatchHandle->info, "plugin", &dispatchConfig->plugin, "actions",&actionsJ);
        if (err) {
            AFB_ERROR ("DISPATCH-LOAD-CONFIG:ONLOAD Missing something label|[info]|[plugin]|[actions] in %s", json_object_get_string(onloadJ));
            goto OnErrorExit;
        }
        
        if (dispatchConfig->plugin) {
            
            // search for default policy config file
            json_object *pluginPathJ = ScanForConfig(CONTROL_PLUGIN_PATH , dispatchConfig->plugin, NULL);
            if (!pluginPathJ || json_object_array_length(pluginPathJ) == 0) {
                AFB_ERROR ("DISPATCH-LOAD-CONFIG:PLUGIN Missing plugin=%s in path=%s", dispatchConfig->plugin, CONTROL_PLUGIN_PATH);
                goto OnErrorExit;                
            }
            
            char *filename; char*dirpath;
            err= wrap_json_unpack (json_object_array_get_idx(pluginPathJ,1), "{s:s, s:s !}", "dirpath",  &dirpath,"filename", &filename);
            if (err) {
                AFB_ERROR ("DISPATCH-LOAD-CONFIG:PLUGIN HOOPs invalid plugin file path = %s", json_object_get_string(pluginPathJ));
                goto OnErrorExit;
            }
            
            if (json_object_array_length(pluginPathJ) > 1) {
                AFB_WARNING ("DISPATCH-LOAD-CONFIG:PLUGIN plugin multiple instances in searchpath will use %s/%s", dirpath, filepath);
            }
    
            char filepath[255];
            strncpy(filepath, dirpath, sizeof(filepath)); 
            strncat(filepath, "/", sizeof(filepath)); 
            strncat(filepath, filename, sizeof(filepath)); 
            dispatchConfig->dlHandle = dlopen(filepath, RTLD_NOW);
            if (!dispatchConfig->dlHandle) {
                AFB_ERROR ("DISPATCH-LOAD-CONFIG:PLIUGIN Fail to load filepath=%s err= %s", filepath, dlerror());
                goto OnErrorExit;
            }
        }
        
        dispatchHandle->actions= DispatchLoadActions(actionsJ);
        dispatchConfig->onload= dispatchHandle;
    }
    
    if (controlsJ) {
        json_object * actionsJ;
        DispatchHandleT *dispatchHandle = calloc (1, sizeof(DispatchHandleT));

        err= wrap_json_unpack(controlsJ, "{so,s?s,so !}", "label",&dispatchHandle->label, "info",&dispatchHandle->info, "actions",&actionsJ);
        if (err) {
            AFB_ERROR ("DISPATCH-LOAD-CONFIG:CONTROLS Missing something label|[info]|actions in %s", json_object_get_string(controlsJ));
            goto OnErrorExit;
        }
        dispatchHandle->actions= DispatchLoadActions(actionsJ);
        dispatchConfig->onload= dispatchHandle;
    }
    
    if (eventsJ) {
        json_object * actionsJ;
        DispatchHandleT *dispatchHandle = calloc (1, sizeof(DispatchHandleT));

        err= wrap_json_unpack(eventsJ, "{so,s?s,so !}", "label",&dispatchHandle->label, "info",&dispatchHandle->info, "actions",&actionsJ);
        if (err) {
            AFB_ERROR ("DISPATCH-LOAD-CONFIG:EVENTS Missing something label|[info]|actions in %s", json_object_get_string(eventsJ));
            goto OnErrorExit;
        }
        dispatchHandle->actions= DispatchLoadActions(actionsJ);
        dispatchConfig->onload= dispatchHandle;
    }
    
    return dispatchConfig;
    
OnErrorExit:
    return NULL;
}

// Load default config file at init
PUBLIC int DispatchInit () {
    int index, err;
    
    
    // search for default dispatch config file
    json_object* responseJ = ScanForConfig(CONTROL_DISPATCH_PATH, "onload", "json");
    
    for (index=0; index < json_object_array_length(responseJ); index++) {
        json_object *entryJ=json_object_array_get_idx(responseJ, index);
        
        char *filename; char*dirpath;
        err= wrap_json_unpack (entryJ, "{s:s, s:s !}", "dirpath",  &dirpath,"filename", &filename);
        if (err) {
            AFB_ERROR ("DISPATCH-INIT HOOPs invalid config file path = %s", json_object_get_string(entryJ));
            goto OnErrorExit;
        }
        
        if (strcasestr(filename, CONTROL_DISPATCH_FILE)) {
            char filepath[255];
            strncpy(filepath, dirpath, sizeof(filepath)); 
            strncat(filepath, "/", sizeof(filepath)); 
            strncat(filepath, filename, sizeof(filepath)); 
            ctlHandle = DispatchLoadConfig (filepath);
            if (!ctlHandle) {
                AFB_ERROR ("DISPATCH-INIT:ERROR No File to load [%s]", filepath);
                goto OnErrorExit;
            }
            break;
        }
    }
    
    // no dispatch config found remove control API from binder
    if (index == 0)  {
        AFB_WARNING ("DISPATCH-INIT:WARNING No Control dispatch file [%s]", CONTROL_DISPATCH_FILE);
    }
    
    AFB_NOTICE ("DISPATCH-INIT:SUCCES: Audio Control Dispatch Init");
    return 0;
    
OnErrorExit:
    AFB_NOTICE ("DISPATCH-INIT:ERROR: Audio Control Dispatch Init");
    return 1;    
}