#define _GNU_SOURCE

#include <ctype.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <netdb.h>
#include <sys/syscall.h>
#include <sched.h>
#include <stdatomic.h>
#include <sys/types.h>
#include <dirent.h>

#include <sys/stat.h>
#include <sched.h>
#include <mqueue.h>

#define DEVMQPATH    "/dev/mqueue/"
#define AGNIPATH_IN  "agni-%d-in"
#define AGNIPATH_OUT "agni-%d-out"

//------------------------------------------------------------------------------
int main(int argc, char **argv)
{
	//generic variables
	int c;
	int i,j;
	int iRet; //any func return param

	//for directory listing
	DIR *dirPath;
  	struct dirent *entryPath;

	//list all mqs
	int flagListAll = 0;
	//show mq param
	int flagMqParam = 0;
	char* mqName = NULL;
	//clear message queue
	int flagClear = 0;
	char* mqNameClear = NULL;
	//clear print extra info if there is
	int flagExtra = 0;
	//send string to queue
	int flagSendQueue = 0;
	char *mqNameSend = NULL; //mq name where to send
	//argument value that to send into queue
	int flagSendStr = 0;
	char *sStrSend = NULL; //mq string that should be push'ed in queue
	//print help
	int flagHelp = 0;

	//get arguments
	while ((c = getopt(argc, argv, "elp:c:s:q:h")) != -1)
	switch(c)
	{
	//list all mqueue's
	case 'l':
		flagListAll = 1;
		break;
	//show param of mq
	case 'p':
		flagMqParam = 1;
		mqName = optarg;
		break;
	//get all messages, print out and clean queue
	case 'c':
		flagClear = 1;
		mqNameClear = optarg;
		break;
	//send string to queue
	case 's':
		flagSendQueue = 1;
		mqNameSend = optarg;
		break;
	case 'q':
		flagSendStr = 1;
		sStrSend = optarg;
		break;
	//show extra information if avaliable
	case 'e':
		flagExtra = 1;
		break;
	case 'h':
		flagHelp = 1;
		break;
	default:
		break;
	}

	//----------------------------------------------------------------------
	//main logic

	//list all
	if (flagListAll)
	{
		dirPath = opendir(DEVMQPATH);
		if (dirPath != NULL)
		{
			while (entryPath = readdir(dirPath))
			{
				int id;
				if (entryPath->d_type == DT_REG)
				{
					if(sscanf(entryPath->d_name, "agni-%d", &id) == 1)
					{
						printf("/%s\n",entryPath->d_name);
					}
				}
				//should free entryPath? maybe
			}
			closedir(dirPath);
		} else
		{
			perror("Cant open directory");
		}

		exit(0);
	}

	//get mqueue params
	if (flagMqParam)
	{
		struct mq_attr mqAttr;
		int mqFd = -1;
		
		mqFd = mq_open(mqName, O_RDWR, 0666, NULL);
		if (mqFd != -1)
		{
			iRet = mq_getattr(mqFd, &mqAttr);
			if (iRet != -1)
			{
				printf("FLAGS    %8ld, ", mqAttr.mq_flags);
				printf("MSG SIZE %8ld, ", mqAttr.mq_msgsize);
				printf("CUR MSGS %ld/%ld\n", mqAttr.mq_curmsgs,mqAttr.mq_maxmsg);
			}
		} else {
			printf("Cant open %s\n", mqName);
		}
		exit(0);
	}

	//clear mq from messages
	if (flagClear)
	{
		struct mq_attr mqAttr;
		int mqFd = -1;
		char *cBuf = NULL;
		int numRead = -1;
		int prio = 0;
		int iCountMsg = 0;

		mqFd = mq_open(mqNameClear, O_RDWR, 0666, NULL);
		if (mqFd == -1)
		{
			printf("Cant open %s\n", mqName);
			exit(1);
		}

		iRet = mq_getattr(mqFd, &mqAttr);
		if (iRet == -1)
		{
			perror("Cant get attributes");
			exit(1);
		}

		cBuf = malloc(mqAttr.mq_msgsize);
		if (cBuf == NULL)
		{
			perror("cant alloc memory");
			exit(1);
		}

		for (i=0; i<mqAttr.mq_curmsgs; i++)
		{
			numRead = mq_receive(mqFd, cBuf, mqAttr.mq_msgsize, &prio);
			if (numRead == -1)
			{
				free(cBuf);
				exit(0);
			}
			iCountMsg += 1;

			//extra output of message value
			if (flagExtra)
			{
				for (j=0; j<numRead; j++)
				{
					printf("%c",cBuf[j]);
				}
				printf("\n");
			}
		}

		free(cBuf);

		printf("Readed %d messages from %ld\n", iCountMsg, mqAttr.mq_curmsgs);


		exit(0);
	}
	if (flagSendQueue && flagSendStr)
	{
		size_t szStr=0;
		int mqFd = -1;
		int numRead = -1;
		int prio = 0;
		struct mq_attr mqAttr;

		mqFd = mq_open(mqNameSend, O_RDWR, 0666, NULL);
		if (mqFd == -1)
		{
			printf("Cant open %s\n", mqName);
			exit(1);
		}

		iRet = mq_getattr(mqFd, &mqAttr);
		if (iRet == -1)
		{
			perror("Cant get attributes");
			exit(1);
		}

		iRet = mq_send(mqFd, sStrSend, strlen(sStrSend), prio);
		if (iRet == -1)
		{
			perror("Cant send message");
			exit(1);
		}

		exit(0);
	}

	if (flagHelp)
	{
		printf("""Help: ./mqtool\n\
-l           - list all avaliable mq's\n\
-p [MQ_NAME] - show params of mq\n\
-c [MQ_NAME] - clear mq, and print all messages\n\
-s [MQ_NAME] - mq name, \"/mq-name\"\n\
-q [STR]     - string to send, combined with -s \n\
-e           - print extra info if there is\n\
-h           - print this help\n\
""");
		exit(0);
	}

}