/*
 * This work is licensed under a Creative Commons CCZero 1.0 Universal License.
 * See http://creativecommons.org/publicdomain/zero/1.0/ for more information.
 */
//to compile with single file releases:
// * single-threaded: gcc -std=c99 server.c open62541.c -o server
// * multi-threaded: gcc -std=c99 server.c open62541.c -o server -lurcu-cds -lurcu -lurcu-common -lpthread

#ifdef UA_NO_AMALGAMATION
# include <time.h>
# include "ua_types.h"
# include "ua_server.h"
# include "logger_stdout.h"
# include "networklayer_tcp.h"
#else
# include "open62541.h"
#endif

#include <signal.h>
#include <errno.h> // errno, EINTR
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef _MSC_VER
# include <io.h> //access
#else
# include <unistd.h> //access
#endif

#ifdef UA_MULTITHREADING
# ifdef UA_NO_AMALGAMATION
#  ifndef __USE_XOPEN2K
#   define __USE_XOPEN2K
#  endif
# endif
#include <pthread.h>
#endif

/****************************/
/* Server-related variables */
/****************************/

UA_Boolean running = 1;
UA_Logger logger;

/*************************/
/* Read-only data source */
/*************************/
static UA_StatusCode readTimeData(void *handle, UA_Boolean sourceTimeStamp, const UA_NumericRange *range, UA_DataValue *value) {
    if(range) {
        value->hasStatus = UA_TRUE;
        value->status = UA_STATUSCODE_BADINDEXRANGEINVALID;
        return UA_STATUSCODE_GOOD;
    }
	UA_DateTime *currentTime = UA_DateTime_new();
	if(!currentTime)
		return UA_STATUSCODE_BADOUTOFMEMORY;
	*currentTime = UA_DateTime_now();
	value->value.type = &UA_TYPES[UA_TYPES_DATETIME];
	value->value.arrayLength = -1;
	value->value.data = currentTime;
	value->hasValue = UA_TRUE;
	if(sourceTimeStamp) {
		value->hasSourceTimestamp = UA_TRUE;
		value->sourceTimestamp = *currentTime;
	}
	return UA_STATUSCODE_GOOD;
}

/*****************************/
/* Read-only CPU temperature */
/*      Only on Linux        */
/*****************************/
FILE* temperatureFile = NULL;
static UA_StatusCode readTemperature(void *handle, UA_Boolean sourceTimeStamp, const UA_NumericRange *range, UA_DataValue *value) {
    if(range) {
        value->hasStatus = UA_TRUE;
        value->status = UA_STATUSCODE_BADINDEXRANGEINVALID;
        return UA_STATUSCODE_GOOD;
    }

	UA_Double* currentTemperature = UA_Double_new();

	if(!currentTemperature)
		return UA_STATUSCODE_BADOUTOFMEMORY;

	rewind(temperatureFile);
	fflush(temperatureFile);

	if(fscanf(temperatureFile, "%lf", currentTemperature) != 1){
		UA_LOG_WARNING(logger, UA_LOGCATEGORY_USERLAND, "Can not parse temperature");
		exit(1);
	}

	*currentTemperature /= 1000.0;

	value->sourceTimestamp = UA_DateTime_now();
	value->hasSourceTimestamp = UA_TRUE;
	value->value.type = &UA_TYPES[UA_TYPES_DOUBLE];
	value->value.arrayLength = -1;
	value->value.data = currentTemperature;
	value->value.arrayDimensionsSize = -1;
	value->value.arrayDimensions = NULL;
	value->hasValue = UA_TRUE;
	return UA_STATUSCODE_GOOD;
}

/*************************/
/* Read-write status led */
/*************************/
#ifdef UA_MULTITHREADING
pthread_rwlock_t writeLock;
#endif
FILE* triggerFile = NULL;
FILE* ledFile = NULL;
UA_Boolean ledStatus = 0;

static UA_StatusCode readLedStatus(void *handle, UA_Boolean sourceTimeStamp, const UA_NumericRange *range, UA_DataValue *value) {
  if(range)
    return UA_STATUSCODE_BADINDEXRANGEINVALID;

  value->hasValue = UA_TRUE;
  UA_StatusCode retval = UA_Variant_setScalarCopy(&value->value, &ledStatus, &UA_TYPES[UA_TYPES_BOOLEAN]);

  if(retval != UA_STATUSCODE_GOOD)
    return retval;
  
  if(sourceTimeStamp) {
          value->sourceTimestamp = UA_DateTime_now();
          value->hasSourceTimestamp = UA_TRUE;
  }
  return UA_STATUSCODE_GOOD;
}

static UA_StatusCode writeLedStatus(void *handle, const UA_Variant *data, const UA_NumericRange *range) {
    if(range)
        return UA_STATUSCODE_BADINDEXRANGEINVALID;

#ifdef UA_MULTITHREADING
	pthread_rwlock_wrlock(&writeLock);
#endif
	if(data->data)
		ledStatus = *(UA_Boolean*)data->data;

	if(triggerFile)
		fseek(triggerFile, 0, SEEK_SET);

	if(ledFile) {
		if(ledStatus == 1)
			fprintf(ledFile, "%s", "1");
		else
			fprintf(ledFile, "%s", "0");
		fflush(ledFile);
	}
#ifdef UA_MULTITHREADING
	pthread_rwlock_unlock(&writeLock);
#endif
	return UA_STATUSCODE_GOOD;
}

#ifdef ENABLE_METHODCALLS
static UA_StatusCode getMonitoredItems(const UA_NodeId objectId, const UA_Variant *input, UA_Variant *output, void *handle) {
    UA_String tmp = UA_STRING("Hello World");
    //UA_Server *theServer = (UA_Server *) handle; // Commented, would result in "unused variable" error
    UA_Variant_setScalarCopy(output, &tmp, &UA_TYPES[UA_TYPES_STRING]);
    printf("getMonitoredItems was called\n");
    return UA_STATUSCODE_GOOD;
}
#endif

static void stopHandler(int sign) {
    UA_LOG_INFO(logger, UA_LOGCATEGORY_SERVER, "Received Ctrl-C\n");
	running = 0;
}

static UA_ByteString loadCertificate(void) {
	UA_ByteString certificate = UA_STRING_NULL;
	FILE *fp = NULL;
	if(!(fp=fopen("server_cert.der", "rb"))) {
        errno = 0; // we read errno also from the tcp layer...
        return certificate;
    }

    fseek(fp, 0, SEEK_END);
    certificate.length = ftell(fp);
    certificate.data = malloc(certificate.length*sizeof(UA_Byte));
	if(!certificate.data){
		fclose(fp);
		return certificate;
	}

    fseek(fp, 0, SEEK_SET);
    if(fread(certificate.data, sizeof(UA_Byte), certificate.length, fp) < (size_t)certificate.length)
        UA_ByteString_deleteMembers(&certificate); // error reading the cert
    fclose(fp);

    return certificate;
}

UA_StatusCode nodeIter(UA_NodeId childId, UA_Boolean isInverse, UA_NodeId referenceTypeId, void *handle);
UA_StatusCode nodeIter(UA_NodeId childId, UA_Boolean isInverse, UA_NodeId referenceTypeId, void *handle) {  
  /*printf("References ns=%d;i=%d using i=%d ", childId.namespaceIndex, childId.identifier.numeric, referenceTypeId.identifier.numeric);
  if (isInverse == UA_TRUE) {
    printf(" (inverse)");
  }
  printf("\n");*/
  
  return UA_STATUSCODE_GOOD;
}

int main(int argc, char** argv) {
  signal(SIGINT, stopHandler); /* catches ctrl-c */
#ifdef UA_MULTITHREADING
  pthread_rwlock_init(&writeLock, 0);
#endif

  UA_Server *server = UA_Server_new(UA_ServerConfig_standard);
  logger = Logger_Stdout_new();
  UA_Server_setLogger(server, logger);
  UA_ByteString certificate = loadCertificate();
  UA_Server_setServerCertificate(server, certificate);
  UA_ByteString_deleteMembers(&certificate);
  UA_Server_addNetworkLayer(server, ServerNetworkLayerTCP_new(UA_ConnectionConfig_standard, 16664));

  // add node with the datetime data source
  UA_NodeId nodeId_currentTime;
  UA_DataSource dateDataSource = (UA_DataSource) {.handle = NULL, .read = readTimeData, .write = NULL};
  const UA_QualifiedName dateName = UA_QUALIFIEDNAME(1, "current time");
  const UA_LocalizedText dateNameBrowseName = UA_LOCALIZEDTEXT("en_US","current time");
  UA_Server_addDataSourceVariableNode(server, UA_NODEID_NULL, dateName, dateNameBrowseName, dateNameBrowseName, 0, 0,

                                  UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER),
                                  UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES),

                                  dateDataSource,

                                  &nodeId_currentTime);

  // Get and reattach the datasource
  UA_DataSource *dataSourceCopy = NULL;
  UA_Server_getAttribute_DataSource(server, nodeId_currentTime, &dataSourceCopy);
  if (dataSourceCopy == NULL)
    UA_LOG_WARNING(logger, UA_LOGCATEGORY_USERLAND, "The returned dataSource is invalid");
  else if (dataSourceCopy->read != dateDataSource.read)
    UA_LOG_WARNING(logger, UA_LOGCATEGORY_USERLAND, "The returned dataSource is not the same as we set?");
  else
    UA_Server_setAttribute_DataSource(server, nodeId_currentTime, dataSourceCopy);
  free(dataSourceCopy);
#ifndef _WIN32
  //cpu temperature monitoring for linux machines
  if((temperatureFile = fopen("/sys/class/thermal/thermal_zone0/temp", "r"))) {
          // add node with the data source
          UA_DataSource temperatureDataSource = (UA_DataSource) {.handle = NULL, .read = readTemperature, .write = NULL};
          const UA_QualifiedName tempName = UA_QUALIFIEDNAME(1, "cpu temperature");
          const UA_LocalizedText tempNameBrowseName = UA_LOCALIZEDTEXT("en_US","temperature");
          UA_Server_addDataSourceVariableNode(server, UA_NODEID_NULL, tempName, tempNameBrowseName, tempNameBrowseName, 0, 0,

                                            UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER),
                                            UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES),

                                            temperatureDataSource,

                                            NULL);
  }

  //LED control for rpi
  if(access("/sys/class/leds/led0/trigger", F_OK ) != -1 || access("/sys/class/leds/led0/brightness", F_OK ) != -1) {
    if((triggerFile = fopen("/sys/class/leds/led0/trigger", "w")) && (ledFile = fopen("/sys/class/leds/led0/brightness", "w"))) {
      //setting led mode to manual
      fprintf(triggerFile, "%s", "none");
      fflush(triggerFile);

      //turning off led initially
      fprintf(ledFile, "%s", "1");
      fflush(ledFile);

      // add node with the LED status data source
      UA_DataSource ledStatusDataSource = (UA_DataSource) {.handle = NULL, .read = readLedStatus, .write = writeLedStatus};
      const UA_QualifiedName statusName = UA_QUALIFIEDNAME(0, "status LED");
      const UA_LocalizedText statusNameBrowseName = UA_LOCALIZEDTEXT("en_US","status LED");
      UA_Server_addDataSourceVariableNode(server, UA_NODEID_NULL, statusName, statusNameBrowseName, statusNameBrowseName, 0, 0,

                                        UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER),
                                        UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES),

                                        ledStatusDataSource,

                                        NULL);
    } else {
      UA_LOG_WARNING(logger, UA_LOGCATEGORY_USERLAND, "[Raspberry Pi] LED file exist, but I have no access (try to run server with sudo)");
    }
  }
#endif

  // add a static variable node to the adresspace
  UA_Variant *myIntegerVariant = UA_Variant_new();
  UA_Int32 myInteger = 42;
  UA_Variant_setScalarCopy(myIntegerVariant, &myInteger, &UA_TYPES[UA_TYPES_INT32]);
  const UA_QualifiedName myIntegerName = UA_QUALIFIEDNAME(1, "the answer");
  const UA_NodeId myIntegerNodeId = UA_NODEID_STRING(1, "the.answer");
  UA_NodeId parentNodeId = UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER);
  UA_NodeId parentReferenceNodeId = UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES);
  UA_Server_addVariableNode(server, myIntegerNodeId, myIntegerName, UA_LOCALIZEDTEXT("en_US", "the answer"), UA_LOCALIZEDTEXT("en_US", "the answer"),  0, 0,
                            parentNodeId, parentReferenceNodeId, myIntegerVariant, NULL);
  /**************/
  /* Demo Nodes */
  /**************/

#define DEMOID 50000
  UA_Server_addObjectNode(server, UA_NODEID_NUMERIC(1, DEMOID), UA_QUALIFIEDNAME(1, "Demo"), UA_LOCALIZEDTEXT("en_US","Demo"),
                          UA_LOCALIZEDTEXT("en_US","Demo"), 0, 0, UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER), UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES),
                          UA_EXPANDEDNODEID_NUMERIC(0, UA_NS0ID_FOLDERTYPE), NULL);

#define SCALARID 50001
  UA_Server_addObjectNode(server, UA_NODEID_NUMERIC(1, SCALARID), UA_QUALIFIEDNAME(1, "Scalar"), UA_LOCALIZEDTEXT("en_US","Demo"), 
                          UA_LOCALIZEDTEXT("en_US","Demo"), 0, 0, UA_NODEID_NUMERIC(1, DEMOID), UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES),
                          UA_EXPANDEDNODEID_NUMERIC(0, UA_NS0ID_FOLDERTYPE), NULL);

#define ARRAYID 50002
  UA_Server_addObjectNode(server, UA_NODEID_NUMERIC(1, ARRAYID), UA_QUALIFIEDNAME(1, "Array"), UA_LOCALIZEDTEXT("en_US","Demo"), 
                          UA_LOCALIZEDTEXT("en_US","Demo"), 0, 0, UA_NODEID_NUMERIC(1, DEMOID), UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES),
                          UA_EXPANDEDNODEID_NUMERIC(0, UA_NS0ID_FOLDERTYPE), NULL);

#define MATRIXID 50003
  UA_Server_addObjectNode(server, UA_NODEID_NUMERIC(1, MATRIXID), UA_QUALIFIEDNAME(1, "Matrix"), UA_LOCALIZEDTEXT("en_US","Demo"), 
                          UA_LOCALIZEDTEXT("en_US","Demo"), 0, 0, UA_NODEID_NUMERIC(1, DEMOID), UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES),
                          UA_EXPANDEDNODEID_NUMERIC(0, UA_NS0ID_FOLDERTYPE), NULL);

  UA_UInt32 id = 51000; //running id in namespace 0
  for(UA_UInt32 type = 0; UA_IS_BUILTIN(type); type++) {
    if(type == UA_TYPES_VARIANT || type == UA_TYPES_DIAGNOSTICINFO)
        continue;
    //add a scalar node for every built-in type
    void *value = UA_new(&UA_TYPES[type]);
    UA_Variant *variant = UA_Variant_new();
    UA_Variant_setScalar(variant, value, &UA_TYPES[type]);
    char name[15];
    sprintf(name, "%02d", type);
    UA_QualifiedName qualifiedName = UA_QUALIFIEDNAME(1, name);
    UA_Server_addVariableNode(server, UA_NODEID_NUMERIC(1, ++id), qualifiedName, UA_LOCALIZEDTEXT("en_US",""), UA_LOCALIZEDTEXT("en_US",""), 0, 0,
                              UA_NODEID_NUMERIC(1, SCALARID), UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES), variant, NULL);

    //add an array node for every built-in type
    UA_Variant *arrayvar = UA_Variant_new();
    UA_Variant_setArray(arrayvar, UA_Array_new(&UA_TYPES[type], 10), 10, &UA_TYPES[type]);
    UA_Server_addVariableNode(server, UA_NODEID_NUMERIC(1, ++id), qualifiedName, UA_LOCALIZEDTEXT("en_US",""), UA_LOCALIZEDTEXT("en_US",""), 0, 0,
                              UA_NODEID_NUMERIC(1, ARRAYID), UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES), arrayvar, NULL);

    //add an matrix node for every built-in type
    arrayvar = UA_Variant_new();
    void* myMultiArray = UA_Array_new(&UA_TYPES[type],9);
    arrayvar->arrayDimensions = UA_Array_new(&UA_TYPES[UA_TYPES_INT32],2);
    arrayvar->arrayDimensions[0] = 3;
    arrayvar->arrayDimensions[1] = 3;
    arrayvar->arrayDimensionsSize = 2;
    arrayvar->arrayLength = 9;
    arrayvar->data = myMultiArray;
    arrayvar->type = &UA_TYPES[type];
    UA_Server_addVariableNode(server, UA_NODEID_NUMERIC(1, ++id), qualifiedName, UA_LOCALIZEDTEXT("en_US",""), UA_LOCALIZEDTEXT("en_US",""),
                              0, 0, UA_NODEID_NUMERIC(1, MATRIXID), UA_NODEID_NUMERIC(0, UA_NS0ID_ORGANIZES), arrayvar, NULL);
  }

#ifdef ENABLE_METHODCALLS
  UA_Argument inputArguments;
  UA_Argument_init(&inputArguments);
  inputArguments.arrayDimensionsSize = -1;
  inputArguments.arrayDimensions = NULL;
  inputArguments.dataType = UA_TYPES[UA_TYPES_STRING].typeId;
  inputArguments.description = UA_LOCALIZEDTEXT("en_US", "A String");
  inputArguments.name = UA_STRING("Input an integer");
  inputArguments.valueRank = -1;

  UA_Argument outputArguments;
  UA_Argument_init(&outputArguments);
  outputArguments.arrayDimensionsSize = -1;
  outputArguments.arrayDimensions = NULL;
  outputArguments.dataType = UA_TYPES[UA_TYPES_STRING].typeId;
  outputArguments.description = UA_LOCALIZEDTEXT("en_US", "A String");
  outputArguments.name = UA_STRING("Input an integer");
  outputArguments.valueRank = -1;

  UA_NodeId methodId; // Retrieve the actual ID if this node if a random id as in UA_NODEID_NUMERIC(1,0) is used
  UA_Server_addMethodNode(server, UA_NODEID_NUMERIC(1,62541), UA_QUALIFIEDNAME(1,"ping"), UA_LOCALIZEDTEXT("en_US", "ping"),
                          UA_LOCALIZEDTEXT("en_US", "Return a single argument as passed by the caller"),
                          UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER), UA_NODEID_NUMERIC(0, UA_NS0ID_HASCOMPONENT),
                          0, 0,
                          &getMonitoredItems, // Call this method
                          (void *) server,    // Pass our server pointer as a handle to the method
                          1, &inputArguments, 1, &outputArguments, &methodId);
  
  // Dettach the method from the methodNode
  UA_Server_setAttribute_method(server, UA_NODEID_NUMERIC(1,62541), NULL, NULL);
  
  // Reaettach the method from the methodNode
  UA_Server_setAttribute_method(server, UA_NODEID_NUMERIC(1,62541), &getMonitoredItems, (void *) server);
#endif
   
  // Example for iterating over all nodes referenced by "Objects":
  //printf("Nodes connected to 'Objects':\n=============================\n");
  UA_Server_forEachChildNodeCall(server, UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER), nodeIter, NULL);
  
  // Some easy localization
  UA_LocalizedText objectsName = UA_LOCALIZEDTEXT("de_DE", "Objekte");
  UA_Server_setAttribute_displayName(server, UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER), &objectsName);
  
  //start server
  UA_StatusCode retval = UA_Server_run(server, 1, &running); //blocks until running=false

  //ctrl-c received -> clean up
  UA_Server_delete(server);

  if(temperatureFile)
          fclose(temperatureFile);

  if(triggerFile) {
          fseek(triggerFile, 0, SEEK_SET);
          //setting led mode to default
          fprintf(triggerFile, "%s", "mmc0");
          fclose(triggerFile);
  }
  
  if(ledFile)
    fclose(ledFile);

#ifdef UA_MULTITHREADING
  pthread_rwlock_destroy(&writeLock);
#endif

  return retval;
}