/* HF amateur radio communicator
 * 
 * digital HF modes (PSK31, RTTY, MT63, ...)
 * primary server module
 */


/* servermain:
 *
 * opens and initializes sound card
 *
 * initializer encoder and decoder classes (modes/psk31*.C)
 *
 * starts new thread for encoding and decoding
 *
 * offers interface functions for the user interface
 *
 * mutex operations for accesing en-/decoder classes from en/decoding
 *   thread and from user interface thread (==interface functions)
 */

#include <sys/mman.h>

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <time.h>
#include <fcntl.h>
#include <sys/soundcard.h>
#include <sys/ioctl.h>

#ifdef USE_PTHREAD
#include <pthread.h>
#else
#define pthread_mutex_init(x,y)
#define pthread_mutex_lock(x)
#define pthread_mutex_unlock(x)
#endif


#include "../modes/psk31-receiver.h"
#include "../modes/psk31-transmitter.h"
#include "../modes/psk31-fft.h"
#include "../modes/psk31-coder.h"
#include "server.h"

#define USE_REALTIME

// receive / transmit state information
int full_duplex;

static char *audio_path="/dev/audio";
static char *ptt_path=NULL;
static int audiofd=-1, pttfd=-1;
static int ptt_invert=0;

// schedule_transmit: 0=no 1=when dcd goes off, 2=immediately
static int schedule_transmit=0, transmit=0;

static int dcdlevel=0;

/* information: mutex usage:
 * mutex_rx is used for accessing the psk31_receiver objects as well as
 *          the psk31_fft object. this lock is set by the GUI if when
 *          changing configuration parameters.
 * mutex_tx is similar for the psk31_transmitter object.
 * the buffer mutexes are used for the RX buffers, when copying
 *          data to the GUI and when transfering data from the 
 *          psk31 objects in the master loop
 */

/* secondary RX decoders: [limit: N_BUFFERS-3]
 * a secondary can be started by commControl on an unused channel (3..254)
 * with command COMM_MODE and value set to MO_NORMAL
 * it can be disabled by COMM_MODE with value MO_DISABLED
 * if the channel is disable, no other command than COMM_MODE(MO_NORMAL) is
 * accepted.
 */

//static psk31_receiver *psk31rx;  --- now in buffer structure!
static psk31_transmitter *psk31tx;
static psk31_fft *psk31fft;

#ifdef USE_PTHREAD
static pthread_t master_thr;
static pthread_mutex_t mutex_rx = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t mutex_tx = PTHREAD_MUTEX_INITIALIZER;
#endif
/* static pthread_mutex_t mutex_fft= PTHREAD_MUTEX_INITIALIZER; */
/* FFT uses RX mutex! Thus psk31rx also can access the fft */

typedef struct {
	int len;
	int rpos;
	int wpos;
	char *mem;
	psk31_receiver *psk31rx;
#ifdef USE_PTHREAD
	pthread_mutex_t mutex;
#endif
} buffer_t;

// Buffer==Channel: 0=TXdata-Echo 1=FFT-data 2,...=RX-data
#define N_BUFFERS 6
static buffer_t buffers[N_BUFFERS];

static void init_buffer() {
	int i;
	for(i=0; i<N_BUFFERS; i++) {
		buffers[i].len = 16384;
		buffers[i].rpos = buffers[i].wpos = 0;
		buffers[i].mem = (char *)malloc(16384);
		buffers[i].psk31rx = NULL;
		pthread_mutex_init(&buffers[i].mutex, NULL);
	}
}
static int write_buffer(int bufnr, char *data, int cnt) {
	int n, error;
	buffer_t *b = buffers+bufnr;
	if(cnt>b->len) return -1;  // too much data!

	pthread_mutex_lock( &b->mutex );
	if(cnt> ((b->wpos-b->rpos)%b->len)) error=-1; else error=0;
	if(b->wpos+cnt > b->len) n=b->len-b->wpos; else n=cnt;
	bcopy( data, b->mem+b->wpos, n );
	b->wpos += n;
	cnt-=n;
	if(cnt>0) {
		bcopy( data+n, b->mem, cnt);
		b->wpos = cnt;
	}
	pthread_mutex_unlock( &b->mutex);

	return error;
}
static int read_buffer(int bufnr, char *data, int cnt) {
	int n, buflen;
	buffer_t *b = buffers+bufnr;
	
	pthread_mutex_lock( &b->mutex );
	buflen = (b->wpos-b->rpos)%b->len;
	if(buflen<0) buflen+=b->len;

	if(cnt>buflen) cnt=buflen;
	if(b->rpos+cnt > b->len) n=b->len-b->rpos; else n=cnt;
	bcopy( b->mem+b->rpos, data, n );
	b->rpos += n;
	cnt-=n;
	if( cnt>0 ) {
		bcopy( b->mem, data+n, cnt );
		b->rpos = cnt;
	}
	pthread_mutex_unlock( &b->mutex);
	return n;
}

	

#if 0
static void atexitfunc() {
	if(audiofd>=0) close(audiofd);
}
#endif


char ibuf[65536];
char *ptr;

static int init_audio() {
	int audio,val;
	audio=open(audio_path, O_RDWR|O_NONBLOCK);
	if(audio<0) return -1;
	
	val=8000;
	if( ioctl(audio, SNDCTL_DSP_SPEED, &val)<0 ) return -1;
	if(val!=8000) {
		fprintf(stderr,"inexact sampling rate: "
			"request for %d resulted in %d",8000,val);
	}

	val=AFMT_S16_LE;
	if( ioctl(audio, SNDCTL_DSP_SETFMT, &val)<0 ) return -1;

	val=DMA_BUF_BITS;
	if( ioctl(audio, SNDCTL_DSP_SETFRAGMENT, &val)<0 ) return -1;

	val=1;
	if( ioctl(audio, SNDCTL_DSP_NONBLOCK, &val)<0 ) return -1;

	val=0;
	if( ioctl(audio, SNDCTL_DSP_STEREO, &val)<0 ) return -1;

	// Check if the device is operating in full duplex mode
	if( ioctl(audio, SNDCTL_DSP_GETCAPS, &val)<0 ) 
		perror("Warning: GETCAPS on audio device failed");
	else
		if(val&DSP_CAP_DUPLEX) full_duplex=1;
	fprintf(stderr,"Using %s mode!\n", full_duplex?"full duplex":"halv duplex");

#if 0
	val = 0;
	if (ioctl(audio, SNDCTL_DSP_SETTRIGGER, &val) == -1)
		perror("ioctl: SNDCTL_DSP_SETTRIGGER");
	val = PCM_ENABLE_INPUT;
	if (ioctl(audio, SNDCTL_DSP_SETTRIGGER, &val) == -1)
		perror("ioctl: SNDCTL_DSP_SETTRIGGER");
#endif

	return audio;
}


static int ctl_ptt(int onoff);

static int init_ptt(void) {
	pttfd = open(ptt_path, O_RDWR);
	if(pttfd>0) {
		if(ctl_ptt(0)<0) return -1;
	}
	return pttfd;
}

static int ctl_ptt(int onoff) {
	//fprintf(stderr,"pttctl[%d]\n",onoff);
	if(pttfd<0) return 0;  // PTT control disabled, nothing to do...
	if(ptt_invert) onoff=!onoff;
	int arg = TIOCM_RTS|TIOCM_DTR;
	if(ioctl(pttfd, onoff?TIOCMBIS:TIOCMBIC, &arg)<0) 
		return -1;
	return 0;
}


#ifdef USE_PTHREAD
void master_handler(void);

static void *master_thr_func(void *dummy) {
	while(1) {
		master_handler();
	}
}
#endif

void master_handler(void) {
	int res;
	fd_set rset, wset, eset;
	struct timeval tm;
	int dcd;

	buffers[COMM_RXCH].psk31rx->get_info(NULL,NULL,NULL,NULL,
					     NULL,&dcd,NULL,NULL);
	if( (schedule_transmit==1&&dcd==0) || schedule_transmit==2) {
		ctl_ptt(1);
		psk31tx->send_char(TX_START);
		transmit=1;
		schedule_transmit=0;
	}
	
	FD_ZERO(&rset); FD_ZERO(&wset); FD_ZERO(&eset);
	FD_SET(audiofd, &rset);
	//FD_SET(audiofd, &eset);
	if(transmit) FD_SET(audiofd, &wset);
	tm.tv_sec=0; tm.tv_usec=50000; /* 50ms */
	res=select(audiofd+1, &rset, &wset, &eset, &tm);
	/* In my older version I had the problem, that there exist
	 * sound drivers which do not support select correctly. So this
	 * code tries to read/write from/to the audiodevice without
	 * respecting FD_ISSET. This should work with all drivers */
	if( !transmit ) {
		short sample;
		for(;;) {
			res=read(audiofd, &sample, 2);
			if(res==0) {
				break;
			} else if(res!=2) {
				//fprintf(stderr,%d %d\n",res,errno);
				if(errno==EINTR) break; //continue;
				if(errno==EAGAIN||errno==EBUSY) break;
				perror("Audio read failed");
				exit(1);
			}
			for(int r=COMM_RXCH; r<N_BUFFERS; r++) {
				pthread_mutex_lock(&mutex_rx);
				psk31_receiver *rx = buffers[r].psk31rx;
				if(rx==NULL) {
					pthread_mutex_unlock(&mutex_rx);
					continue;
				}
				res = rx->process_rx_sample(sample);
				pthread_mutex_unlock(&mutex_rx);
				if(res!=NO_CHAR) {
					rx->get_info(NULL,NULL,NULL,NULL,
						     NULL,&dcd,NULL,NULL);
					if (dcd||(dcdlevel==-1))  {
						char cd = (char)res;
						write_buffer(r, &cd, 1);
					}
				}
			}
		}
	}

	if(transmit) {
		char cd;
		for(;;) {
			if(full_duplex) {
				// clear buffer if necessary
				char buffer[128];
				for(;;) {
					res=read(audiofd, buffer, 128);
					if(res!=128) break;
				}
			}
			
			pthread_mutex_lock(&mutex_tx);
			res=psk31tx->processor();
			pthread_mutex_unlock(&mutex_tx);
				// echo-characters, including TX_END, 
				// are delivered from psk31tx->processor at the
				// exact end of the transmission!
			if(res==TX_BUSY) {
				break;
			}
			if(res==TX_ERROR) {
				perror("tx error:");
				break;
			}
			if(res==TX_END) { 
				transmit=0; 
				ctl_ptt(0);
				break; 
			}
			cd = (char)(res&0xFF);
			write_buffer(0, &cd, 1);
		}
	}
}


#ifdef USE_PTHREAD
static int run_master_thread() {
	pthread_attr_t attr;
	fprintf(stderr,"run_master_thread()\n");
#ifdef USEREALTIME
	struct sched_param schp;
#endif
        if (pthread_attr_init(&attr)) {
		perror("Cannot initialize pthread attributes");
		exit(4);
	}
	
#ifdef USEREALTIME
	memset(&schp, 0, sizeof(schp));
	if( pthread_attr_setschedpolicy(&attr, SCHED_RR) ) {
		perror("Cannot set realtime scheduling attribute");
		exit(5);
	}
	schp.sched_priority = sched_get_priority_min(SCHED_RR)+1;
        if( pthread_attr_setschedparam(&attr, &schp) ) {
		perror("Cannot set realtime scheduling priority");
		exit(6);
	}
#endif
	if( pthread_create(&master_thr, &attr, master_thr_func, NULL) ) {
		perror("Cannot create IO processing thread");
		exit(7);
	}

	if (pthread_attr_destroy(&attr)) {
		perror("Failed to destroy attribute");
	}
	return 0;
}
#endif

/* audio, ptt:  full path to device
 * data: directory of coder data file (psk31.cod)
 * ptt may be something like "/dev/ttyS0,i"  for inverted PTT
 */
int server_main(char *audio, char *ptt, char *datadir) 
{
	init_buffer();

	if(audio) audio_path = strdup(audio);
	if(ptt) ptt_path = strdup(ptt);

	if(ptt_path!=NULL) {
		int len = strlen(ptt_path);
		if(len>2 && ptt_path[len-2]==',') {
			ptt_invert = (ptt_path[len-1]!='0');
			ptt_path[len-2]=0;
		} else ptt_invert=0;
	}


	if( (audiofd=init_audio())<0 ) {
		fprintf(stderr, "Cannot open audio device ");
		perror(audio_path);
		return -1;
	}

	if( ptt_path && ( (pttfd=init_ptt())<0 ) ) {
		fprintf(stderr, "Cannot open PTT device ");
		perror(ptt_path);
	}

	psk31_coder::init_tables(datadir);
	psk31fft = new psk31_fft();
	psk31fft->set_parameters(1024, 1024, psk31_fft::MODE_RXDATA);
        buffers[COMM_RXCH].psk31rx = new psk31_receiver(psk31fft);
        psk31tx = new psk31_transmitter();
	psk31tx->set_audiofd(audiofd);


#ifdef USE_PTHREAD
	if( run_master_thread()<0 ) 
		return -1;
#endif
	return 0;
}


int commWaitUpdate(unsigned long timeout)
{
	return -1;
}

int commGetData(int channel, char *buffer, int buflen)
{
	if(channel<0||channel>=N_BUFFERS) return -1;

	
	if(channel==COMM_FFTCH) {
		if(psk31fft->has_new_data()) {
			int len;
			psk31fft->get_parameters(&len, NULL, NULL);
			if(buflen<(int)(len*sizeof(float))) {
				fprintf(stderr,"no space in buffer for FFT data\n");
				return 0;
			}
			psk31fft->get_abs_data((float *)buffer, 0, len, 1);
#if 0
			for(int i=0; i<1024; i++)
				fprintf(stderr,"%d ",((float *)buffer)[i]);
#endif
			return len;
		}
		else return 0;
	} else {
		return read_buffer(channel, buffer, buflen);
	}
}

int commPutData(char *buffer, int buflen)
{
	if(buflen<=0) buflen=strlen(buffer);
	pthread_mutex_lock(&mutex_tx);
	for(int i=0; i<buflen; i++) {
		psk31tx->send_char((unsigned char)(buffer[i]));
	}
	pthread_mutex_unlock(&mutex_tx);
	return buflen;
}

static int txControl(int spec, int value)
{
	int retval=0;
	static int mq=0, ml=0, mcw=0; 

	pthread_mutex_lock(&mutex_tx);
	switch(spec) {
	case COMM_PTT:
		// if(transmit == (value&PTTON)) break; // nothing to do!
		switch(value) {
		case PTTON:
			// schedule TX start on DCD off
			schedule_transmit=1;
			break;
		case PTTON|PTTFORCE:
			// schedule TX start now
			schedule_transmit=2;
			break;
		case PTTOFF:
			// schedule TX end!
			psk31tx->send_char(TX_END);
			break;
		case PTTOFF|PTTFORCE:
			// shall we just clear the internal buffer and send
			// a postamble before aborting? should be the right
			// thing to do! TX_END|TX_URGENT does this job!
			// However, this does not allow "instant" abort
			// for emergency cases when something really goes
			// wrong... (TODO: clarify this matter...)
			psk31tx->send_char(TX_END|TX_URGENT);
#if 0
			transmit=0;
			ctl_ptt(0);
#endif		       
			break;
		}
		break;
	case COMM_QPSK:
		mq=value;
		psk31tx->send_char(TX_MODE|(value?TXM_QPSK:0)|(ml?TXM_LSB:0));
		break;
	case COMM_LSB:
		ml=value;
		psk31tx->send_char(TX_MODE|(mq?TXM_QPSK:0)|(value?TXM_LSB:0));
		break;
	case COMM_MODE:
		//fprintf(stderr,"mode: value=%d\n",value);
		if(value==MO_TUNE) {
			psk31tx->send_char(TX_MODE|TXM_TUNE);
			mcw = 2;
		}
		else if(value==MO_CWSEND) {
			psk31tx->send_char(TX_MODE|TXM_CW);
			mcw = 1;
		}
		else {
			psk31tx->send_char( TX_MODE | (mq?TXM_QPSK:0)
					    | (ml?TXM_LSB:0) );
			mcw = 0;
		}
		break;
	case COMM_FREQ:
		psk31tx->send_char( TX_FREQ|(0xFFFFF&value) );
		break;
	default:
		retval=-1;
	}
	pthread_mutex_unlock(&mutex_tx);
	return retval;
}

static int rxControl(int channel, int spec, int value)
{
	int retval=0;
	int mqpsk, mlsb, mafc, musedcd, mdcd; float mfreq;
	int lastdelta, strength;

	psk31_receiver *rx = buffers[channel].psk31rx;
	if(rx==NULL) {
		if(spec==COMM_MODE && value==MO_NORMAL) {
			// start new decoder object
#if 0
			fprintf(stderr,"info: starting new decoder object"
				"on channel %d\n",channel);
#endif
			buffers[channel].psk31rx = new psk31_receiver(NULL);
			return 0;
		}
		fprintf(stderr,"warning: rxControl on disabled RX channel\n"
			"channel=%d spec=%d value=%d\n",channel,spec,value);
		return -1;
	}

	pthread_mutex_lock(&mutex_rx);
	rx->get_info(&mqpsk, &mlsb, &mfreq, &musedcd, &mafc, &mdcd,
		     &lastdelta, &strength);
	switch(spec) {
	case COMM_SWAP:
		/* exchange psk31_receiver objects of current channel and
		 * channel <value> */
		// TODO: keep IQ FFT data reference on COMM_RXCH!!
		// (currently not used, so not a big issue)
		if(value<COMM_RXCH||value>=N_BUFFERS) {
			retval=-1; break;
		}
		{
		 psk31_receiver *rx2 = buffers[value].psk31rx;
		 buffers[channel].psk31rx = rx2;
		 buffers[value].psk31rx = rx;
		 if(value==COMM_RXCH) {
			 rx->set_fft(psk31fft); rx2->set_fft(NULL);
		 }
		 else if(channel==COMM_RXCH) {
			 rx2->set_fft(psk31fft); rx->set_fft(NULL);
		 }
		}
		break;
	case COMM_DCD:
		rx->set_dcd(value);
		break;
	case COMM_DCDLEVEL:
		dcdlevel = value;
		rx->set_dcdlevel(value);
		break;
	case COMM_QPSK:
		rx->set_mode(value, mlsb);
		break;
	case COMM_LSB:
		rx->set_mode(mqpsk, value);
		break;
	case COMM_AFC:
		rx->set_afc(value);
		break;
	case COMM_MODE:
		if(value==MO_DISABLED) {
			if(channel==COMM_RXCH) {
				// do not delete master RX channel. won't work
				// as base FFT depends on this master channel
				retval=-1;
				break;
			}
#if 0
			fprintf(stderr,"info: deleting decoder object"
				"on channel %d\n",channel);
#endif
			delete rx;
			buffers[channel].psk31rx=NULL;
			buffers[channel].rpos = buffers[channel].wpos = 0;
		} else {
			fprintf(stderr,"warning: active channel %d: "
				"COMM_MODE %d\n",channel,value);
		}
		break;
	case COMM_FREQ:
		rx->set_freq(0.01*value);
		break;
	default:
		retval=-1;
	}
	pthread_mutex_unlock(&mutex_rx);
	return retval;
}

int fftControl(int spec, int value)
{
	int len, overlap, mode;

	int retval=0;
	pthread_mutex_lock(&mutex_rx);
	psk31fft->get_parameters(&len, &overlap, &mode);
	switch(spec) {
	case COMM_FFTN:
		len = value;
		psk31fft->set_parameters(len, overlap, mode);
		break;
	case COMM_FFTOVERLAP:
		overlap = value;
		psk31fft->set_parameters(len, overlap, mode);
		break;
	default:
		retval=-1;
	}
	pthread_mutex_unlock(&mutex_rx);
	return retval;
}

int commControl(int channel, int spec, int value)
{
	if(channel==255) {
		// transmit channel
		return txControl(spec, value);
	} else if(channel==0) {
		// echo channel
		return 0;  // no control here!
	} else if(channel==1) {
		// fft channel
		return fftControl(spec, value);
	} else if(channel>=COMM_RXCH&&channel<N_BUFFERS) {
		// rx data chennal
		return rxControl(channel, spec, value);
	} else {
		return -1;  // invalid channel
	}
}

int commGetInfo(int channel, void *buffer, int buflen)
{
	float freq;
	PSK31info *info;

	if(channel==COMM_TXCH) {
		// transmit channel
		if(buflen<(int)sizeof(PSK31info)) return -1;
		info = (PSK31info *)buffer;
		info->ptt = transmit;
		pthread_mutex_lock(&mutex_tx);
		psk31tx->get_info(&info->qpsk, &info->lsb, &info->cw, &freq);
		info->freq = (int)(100*freq);
		pthread_mutex_unlock(&mutex_tx);
	} else if(channel==COMM_ECHOCH) {
		// echo channel
		return -1;  // no info on echo channel
	} else if(channel==COMM_FFTCH) {
		// fft channel
		return -1;  // no info in fft channel (TODO)
	} else if(channel>=COMM_RXCH&&channel<N_BUFFERS) {
		// rx channel
		int retval=0;
		if(buflen<(int)sizeof(PSK31info)) return -1;
		info = (PSK31info *)buffer;
		info->ptt = transmit;
		pthread_mutex_lock(&mutex_rx);
		psk31_receiver *rx = buffers[channel].psk31rx;
		if(rx==NULL) {
			// TODO: different return value for invalid channel
			// vs disabled channel
			retval=-1;
		} else {
			rx->get_info(&info->qpsk, &info->lsb, &freq,
				     &info->dcdlevel, &info->afc, &info->dcd,
				     &info->phdelta, &info->strength );
			info->freq = (int)(100*freq);
		}
		pthread_mutex_unlock(&mutex_rx);
		return retval;
	} else {
		return -1;  // invalid channel
	}
	return 0;   // or what should we return here?
}