#include "esd-server.h"
#include <time.h>
#include <errno.h>

#ifdef HAVE_SYS_IOCTL_H
# include <sys/ioctl.h>
#endif
#ifdef HAVE_SYS_FILIO_H
# include <sys/filio.h>
#endif

#ifdef USE_LIBWRAP
#include <tcpd.h>
#include <syslog.h>

int allow_severity = LOG_INFO;
int deny_severity = LOG_WARNING;
#endif

/*******************************************************************/
/* globals */
extern int esd_use_tcpip; 

/* the list of the currently connected clients */
esd_client_t *esd_clients_list;

/*******************************************************************/
/* prototypes */
void dump_clients(void);
void free_client( esd_client_t *client );


/*******************************************************************/
/* for debugging purposes, dump the list of the clients and data */


void dump_clients()
{
    long addr;
    short port;
    esd_client_t *clients = esd_clients_list;

    if ( !esdbg_trace ) return;

    while ( clients != NULL ) {
	port = ntohs( clients->source.sin_port );
	addr = ntohl( clients->source.sin_addr.s_addr );

	printf( "(%02d) client from: %03u.%03u.%03u.%03u:%05d [%p]\n", 
		clients->fd, (unsigned int) addr >> 24, 
		(unsigned int) (addr >> 16) % 256, 
		(unsigned int) (addr >> 8) % 256, 
		(unsigned int) addr % 256, port, clients );

	clients = clients->next;
    }
    return;
}

/*******************************************************************/
/* deallocate memory for the client */
void free_client( esd_client_t *client )
{
    /* free the client memory */
    free( client );
    return;
}

/*******************************************************************/
/* add a complete new client into the list of clients at head */
void add_new_client( esd_client_t *new_client )
{
    /* printf ( "adding client 0x%08x\n", new_client ); */
    new_client->next = esd_clients_list;
    esd_clients_list = new_client;
    return;
}

/*******************************************************************/
/* erase a client from the client list */
void erase_client( esd_client_t *client )
{
    esd_client_t *previous = NULL;
    esd_client_t *current = esd_clients_list;

    /* iterate until we hit a NULL */
    while ( current != NULL )
    {
	/* see if we hit the target client */
	if ( current == client ) {
	    if( previous != NULL ){
		/* we are deleting in the middle of the list */
		previous->next = current->next;
	    } else { 
		/* we are deleting the head of the list */
		esd_clients_list = current->next;
	    }

	    ESDBG_TRACE( printf ( "(%02d) closing client connection\n", 
				  client->fd ); );

	    close( client->fd );
	    free_client( client );

	    return;
	}

	/* iterate through the list */
	previous = current;
	current = current->next;
    }

    /* hmm, we didn't find the desired client, just get on with life */
    ESDBG_TRACE( printf( "(%02d) client not found\n", client->fd ); );
    return;
}


/*******************************************************************/
/* checks for new connections at listener - zero when done */
int get_new_clients( int sock )
{
    int fd, nbl;
    struct sockaddr_in incoming;
    size_t size_in = sizeof(struct sockaddr_in);
    esd_client_t *new_client = NULL;

    /* see who awakened us */
    do {
	fd = accept( sock, (struct sockaddr*) &incoming, &size_in );
	if ( fd > 0 ) {

	    ESDBG_TRACE( 
	    if (esd_use_tcpip) {
		unsigned long addr;
		short port;

		port = ntohs( incoming.sin_port );
		addr = ntohl( incoming.sin_addr.s_addr );

		printf( "(%02d) new client from: %03u.%03u.%03u.%03u:%05d\n", 
			fd, (unsigned int) addr >> 24, 
			(unsigned int) (addr >> 16) % 256, 
			(unsigned int) (addr >> 8) % 256, 
			(unsigned int) addr % 256, port );
		} );

#ifdef USE_LIBWRAP
	    if (esd_use_tcpip)
	    {
		struct request_info req;
		struct servent *serv;

		request_init( &req, RQ_DAEMON, "esound", RQ_FILE, fd, NULL );
		fromhost( &req );

		if ( !hosts_access( &req )) {
		    ESDBG_TRACE( 
			printf( "connection from %s refused by tcp_wrappers\n",
				eval_client( &req ) ); );

		    close( fd );
		    continue;
		}
	    }
#endif

	    ESDBG_COMMS( printf( "================================\n" ); );

	    /* make sure we have the memory to save the client... */
	    new_client = (esd_client_t*) malloc( sizeof(esd_client_t) );
	    if ( new_client == NULL ) {
		close( fd );
		return -1;
	    }

	    /* It appears that not all systems construct the new socket in
	     * a blocking mode, if the listening socket is non-blocking, so
	     * let's set that here...
	     */
	    nbl = 0;
	    if ( ioctl( fd, FIONBIO, &nbl ) < 0 )
	    {
		ESDBG_TRACE( printf( "(%02d) couldn't turn on blocking for client\n", 
				     fd ); );
		close( fd );
		return -1;
	    }

	    /* Reduce buffers on sockets to the minimum needed */
	    esd_set_socket_buffers( fd, ESD_BITS16, 44100, esd_audio_rate );

	    /* fill in the new_client structure - sockaddr = works!? */
	    new_client->next = NULL;
	    new_client->state = ESD_NEEDS_REQDATA;
	    new_client->request = ESD_PROTO_CONNECT;
	    new_client->fd = fd;
	    new_client->source = incoming; 
	    new_client->proto_data_length = 0;
	    
	    add_new_client( new_client );
	}
    } while ( fd > 0 );

    return 0;
}

void esd_comm_loop( int listen_socket, void *output_buffer, int esd_terminate )
{
    fd_set rd_fds;
    struct timeval timeout;
    struct timeval *timeout_ptr = NULL;
    esd_client_t *client;
    int max_fd = listen_socket, ready;
    int first = 1;
    int is_paused_here = 0;
    int length = 0;

    while ( 1 )
    {
	FD_ZERO( &rd_fds );
	FD_SET( listen_socket, &rd_fds );

	if ((esd_clients_list == NULL) && (!first) && (esd_terminate)
	&& (esd_autostandby_secs<0 || esd_on_autostandby)) {
	    clean_exit(0);
	    exit(0);
	}

	for( client = esd_clients_list ; client ; client = client->next)
	{
	    if ( client->state == ESD_STREAMING_DATA &&
		client->request == ESD_PROTO_STREAM_MON )
		continue;

	    FD_SET( client->fd, &rd_fds );
	    if ( client->fd > max_fd )
		max_fd = client->fd;
	}

	/* if we're doing something useful, make sure we return immediately */
	if ( esd_recorder_list || esd_playing_samples ) {
	    timeout.tv_sec = 0;
	    timeout.tv_usec = 0;
	    timeout_ptr = &timeout;
	} else {
	    if ( is_paused_here && (esd_autostandby_secs<0 || esd_on_standby)) {
		ESDBG_TRACE( printf( "paused, awaiting instructions.\n" ); );
		timeout_ptr = NULL;
	    } else {
		if (is_paused_here && esd_autostandby_secs>=0) {
		    timeout.tv_sec = (esd_last_activity+esd_autostandby_secs+1)-time(NULL);
		    if (timeout.tv_sec < 0 || timeout.tv_sec > esd_autostandby_secs+1)
			timeout.tv_sec = 0;
		    timeout.tv_usec = 0;
		} else {
		    timeout.tv_sec = 0;
		    /* funky math to make sure a long can hold it all, calulate in ms */
		    timeout.tv_usec = (long) esd_buf_size_samples * 1000L
			/ (long) esd_audio_rate;
		    timeout.tv_usec *= 1000/esd_sample_size; 	/* convert to microseconds, sample size */
		}
		timeout_ptr = &timeout;
	    }
	}

	ready = select( max_fd+1, &rd_fds, NULL, NULL, timeout_ptr );

	ESDBG_COMMS( printf( 
	    "paused=%d, samples=%d, auto=%d, standby=%d, record=%d, ready=%d\n",
	    is_paused_here, esd_playing_samples, 
	    esd_autostandby_secs, esd_on_standby, 
	    (esd_recorder_list != 0), ready ); );

	if ( ready < 0 ) {
	    if ( errno == EINTR || errno == EAGAIN )
		continue;
	    perror("select");
	    exit(1);
	} else if ( ready == 0 ) {
	    if ( !is_paused_here && !esd_playing_samples && !esd_recorder_list ) {
		ESDBG_TRACE( printf( "doing nothing, pausing server.\n" ); );
		esd_audio_flush();
		esd_audio_pause();
		esd_last_activity = time( NULL );
		is_paused_here = 1;
	    }
	    if ( is_paused_here && esd_autostandby_secs >= 0
		 && ( time(NULL) > esd_last_activity + esd_autostandby_secs ) ) {
		ESDBG_TRACE( printf( "bored, going to standby mode.\n" ); );
		esd_server_standby();
		esd_on_autostandby = 1;
	    }
	    if (is_paused_here)
		continue;
	}
	is_paused_here = 0;

	if ( FD_ISSET(listen_socket, &rd_fds ) ) {
	    get_new_clients( listen_socket );
	}

	if ( ready || esd_playing_samples || esd_recorder_list ) {
	    /* check for new protocol requests */
	    poll_client_requests();
	    first = 0;

	/* mix new requests, and output to device */
	refresh_mix_funcs(); /* TODO: set a flag to cue when to do this */
	length = mix_players( output_buffer, esd_buf_size_octets );
	
	/* awaken if on autostandby and doing anything */
	if ( esd_on_autostandby && length && !esd_forced_standby ) {
	    ESDBG_TRACE( printf( "stuff to play, waking up.\n" ); );
	    if ( !esd_server_resume()) {
		usleep(100);
	    }
	}

	/* we handle this even when length == 0 because a filter could have
	 * closed, and we don't want to eat the processor if one did.. */
	if ( esd_filter_list && !esd_on_standby ) {
	    length = filter_write( output_buffer, length,
				   esd_audio_format, esd_audio_rate );
	}
	
	if ( length > 0 ) {
	    if ( !esd_on_standby ) {
		/* standby check goes in here, so esd will eat sound data */
		/* TODO: eat a round of data with a better algorithm */
		/*        this will cause guaranteed timing issues */
		/* TODO: on monitor, why isn't this a buffer of zeroes? */
		esd_audio_write( output_buffer, length );
		esd_last_activity = time( NULL );
	    }

	/* if someone's monitoring the sound stream, send them data */
	/* mix_players, above, forces buffer to zero if no players */
	/* this clears out any leftovers from recording, below */
	if ( esd_monitor_list && !esd_on_standby && length ) {
	    monitor_write( output_buffer, length );
	}

	/* if someone's recording the sound stream, send them data */
	if ( esd_recorder_list && !esd_on_standby ) {
	    length = esd_audio_read( output_buffer, esd_buf_size_octets );
	    if ( length ) {
		length = recorder_write( output_buffer, length );
		esd_last_activity = time( NULL );
	    }
	}

	}
	}
    }
}