#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <stdarg.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <errno.h>
#include <vector>
#include <strings.h>
#include <sys/sem.h>
#include <semaphore.h>
#include <fcntl.h>
#include <vector>



struct file_lock
{
    char filename[255];
    sem_t *sem;
};
std::vector<file_lock> lock;




int read_line(int fd, void *buffer, size_t n)
{
    int numRead;                    /* # of bytes fetched by last read() */
    int totRead;                     /* Total bytes read so far */
    char *buf;
    char ch;

    if (n <= 0 || buffer == NULL) {
        errno = EINVAL;
        return -1;
    }

    buf = (char*)buffer;                       /* No pointer arithmetic on "void *" */

    totRead = 0;
    for (;;) {
        numRead = read(fd, &ch, 1);

        if (numRead == -1) {
            if (errno == EINTR)         /* Interrupted --> restart read() */
                continue;
            else
                return -1;              /* Some other error */

        } else if (numRead == 0) {      /* EOF */
            if (totRead == 0)           /* No bytes read; return 0 */
                return 0;
            else                        /* Some bytes read; add '\0' */
                break;

        } else {                        /* 'numRead' must be 1 if we get here */
            if (totRead < n - 1) {      /* Discard > (n - 1) bytes */
                totRead++;
                *buf++ = ch;
            }

            if (ch == '\n')
                break;
        }
    }

    *buf = '\0';
    return totRead;
}

struct name_samphore {
  char filename[256];
  bool semaphore;
} ;


int main(int argc, char *argv[])
{

	char content_type[24] = "Content-Type: text/html";

	sockaddr_in inadr;
	inadr.sin_family = AF_INET;
	inadr.sin_port = htons( 12345 );
	inadr.sin_addr.s_addr = INADDR_ANY;
	int sd = socket( AF_INET, SOCK_STREAM, 0 );
	int err = bind( sd, ( sockaddr * ) &inadr, sizeof( inadr ) );
	if ( err < 0 ) printf( "bind selhal\n" );
	err = listen( sd, 1 );


	while(1)
	{
		sockaddr_in peeradr;
		socklen_t len_adr = sizeof( peeradr );
		int newsock = accept( sd, ( sockaddr * ) &peeradr, &len_adr );

		char data[ 256 ];
		char request_path[256];
		while((read_line( newsock, &data, sizeof( data )) > 0))
		{
			//printf("Reading the file\n");
			//printf(data);
			char *location = strstr(data,"GET");

			if (((int)location-(int)data+1) == 1)
			{

					// starts with GET
					//printf("Request starts with GET\n");
				char *location2 = strchr(data,'/');
				int index = (int)(location2 - data);
				int iter = 0;

				memset ( request_path, 0, 256 );

				do {

						request_path[iter] = data[index];
						iter++;
						index++;
					}
					while( data[index] != ' ' );

				printf("Requested path is %s\n", request_path);

			}
			if ( data[0] == '\n' || data[0] == '\r')
			{
					printf("New line delimiter\n");
					break;

			}

			bool isInList = false;
			// check if file exists in vector
			for (int i = 0; i < lock.size(); i++)
			{
				if(strcmp(lock[i].filename, request_path) == 0)
				{
					printf("file name of the sema match . . alread in vector \n");
					isInList = true;
					break;
				}
			}

			if(!isInList)
			{
				// if file does not exists add that semaphore into vector
				char sem_name[100];
				memset ( sem_name, 0, 100 );
				sprintf(sem_name,"%s", request_path);

				printf("Create semaphore %s \n", sem_name);

				sem_t *semik = sem_open(sem_name, O_CREAT | O_RDWR, 0660, 1);
				sem_init(semik, 1,1);
				file_lock new_lock;
				new_lock.sem = semik;
				sprintf(new_lock.filename, request_path);
				lock.push_back(new_lock);
			}

		}

		if (fork() == 0)
		{


			// creating response



			char response[255] = {0};
			printf("trzing to open %s", request_path+1);
			int fp = open(request_path+1, O_RDONLY);

			if (fp < 0)
			{
				printf("Cannot read file\n");
				sprintf(response, "HTTP/1.1 404 Not Found\r\nContent-Type: text/html\r\nConnection: Closed\r\n\r\n");
				write(newsock, response, strlen(response));

				close(newsock);
				exit(0);
			}

			// HTTP response
			sprintf(response, "HTTP/1.1 200 OK\r\nContent-Type: text/html\r\nConnection: Closed\r\n\r\n");
			write(newsock, response, strlen(response));

			char w_buff[64];
			int ret = 0;
			while((ret = read(fp, w_buff, 64)) > 0)
			{
				int res = write(newsock, w_buff, ret);
				if (res < 0)
				{
					printf("writing error\n");
				}
			}
			close(fp);

			printf("All data send. Closing socket.\n");
			close(newsock);
			exit(0);


		}
		else
		{
			printf("Closing parent socks\n");
			close( newsock );
		}


		usleep( 10 );
	}

	return 0;
}