#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <string.h>  
#include <sys/socket.h>  
#include <netinet/in.h>  
#include <arpa/inet.h>  
#include <netdb.h>  
#include <unistd.h>
#include <sys/types.h>
#include <fcntl.h>
#include <pthread.h>
#include <sched.h>
#include <sys/syscall.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/mman.h>





#define NUM_NAL_BUF     (3)
#define NAL_BUF_SIZE    (512*1024)
#define VID_BUF_SIZE    (512*1024)
typedef struct tnal_buf {
    int len;
    uint8_t *buf;
} nal_buf;
int fd_fs;
nal_buf nal_buf_entry[NUM_NAL_BUF];

unsigned char nal_header[4]={0x00,0x00,0x00,0x01};

void assemble_nal(unsigned char* buf, unsigned int len)
{
    static int wr_idx = 0;
    static int nalb_idx = 0;
    uint64_t timestamp;
    int need_sumbit, terminate;
    if((wr_idx + len) >= VID_BUF_SIZE) {
                printf("assemble_nal panic: too many error in pakts\r\n");
                wr_idx = 0;
    }
    need_sumbit = 0;
    terminate = 0;


    if((!memcmp(buf, nal_header , 4)) && (len >= 4)) { //is seperator
                if(wr_idx == 0) { // is new nal item
                        memcpy(nal_buf_entry[nalb_idx].buf + wr_idx, buf, len);
                        wr_idx += len;
                }
                else { //terminate current nal item and submit
                        need_sumbit = 1;
                        terminate = 1;
                }
                if(need_sumbit) {
                      nal_buf_entry[nalb_idx].len = wr_idx;
			if(fd_fs)
				write(fd_fs,nal_buf_entry[nalb_idx].buf,nal_buf_entry[nalb_idx].len);			
            	      wr_idx = 0;
                      nalb_idx = (nalb_idx+1)%NUM_NAL_BUF;
                }
                if(terminate) {
                        memcpy(nal_buf_entry[nalb_idx].buf + wr_idx, buf, len);
                        wr_idx += len;
                }
    }else {
                memcpy(nal_buf_entry[nalb_idx].buf + wr_idx, buf, len);
        	wr_idx += len;
                if(memcmp(nal_buf_entry[nalb_idx].buf, nal_header, 4)) { //wait nal  head
            		wr_idx = 0;
            		return;
        }
    }
}




int main(int argc, char **argv)
{
    int socket_descriptor; 
    int i;
    int len;
    char buffer_nal[2048];
    struct timeval tv;


    struct sockaddr_in address;
    struct sockaddr_in clientAddr;
    

    len = sizeof(clientAddr);
  
    bzero(&address,sizeof(address));  
    address.sin_family=AF_INET;  
    address.sin_addr.s_addr=htonl(INADDR_ANY);
    address.sin_port=htons(20000);  
  
    socket_descriptor=socket(AF_INET,SOCK_DGRAM,0);//IPV4
    
    tv.tv_sec = 1;
    tv.tv_usec = 0;
    if (setsockopt(socket_descriptor, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)) < 0) {
        printf("socket option  SO_RCVTIMEO not support\n");
        return -1;
    }



    if (bind(socket_descriptor, (struct sockaddr *)&address, sizeof(address)) < 0)
    {
        perror("bind");
        exit(1);
    }



	if(argc == 2){

	fd_fs = open(argv[1], O_RDWR | O_CREAT);
    	if(fd_fs < 0) {
        	printf("open %s failed\n", argv[1]);
        	return -1;
    	}
	}


    for(i=0; i<NUM_NAL_BUF; i++) {
        nal_buf_entry[i].buf = (uint8_t *) malloc(NAL_BUF_SIZE);
        if(!nal_buf_entry[i].buf) {
            printf("allocate nal buf failed\r\n");
            return -1;
        }
        memset(nal_buf_entry[i].buf, 0x0, NAL_BUF_SIZE);
    }

	#if 0

    pthread_mutex_init(&pkts_mutex, NULL);
    pthread_cond_init(&pkts_cond, NULL);
    pthread_attr_init(&attr);
    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
    len = pthread_create(&pkts_thread, &attr, pkts_worker, NULL);
    pthread_attr_destroy(&attr);
    pkts_q = dq_create();
	#endif
    while(1) 
    {   
	
	i = recvfrom(socket_descriptor, buffer_nal, 1472, 0, (struct sockaddr*)&clientAddr, &len); 

	if(i>0)
	   assemble_nal(buffer_nal,i);	
		
    }
    close(socket_descriptor);  
    printf("send file finish\r\n");
}