/*	$OpenBSD: dev.c,v 1.11 2008/11/07 21:01:15 ratchov Exp $	*/
/*
 * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "dev.h"
#include "abuf.h"
#include "aproc.h"
#include "pipe.h"
#include "conf.h"
#include "safile.h"

unsigned dev_bufsz, dev_round, dev_rate;
unsigned dev_rate_div, dev_round_div;
struct aparams dev_ipar, dev_opar;
struct aproc *dev_mix, *dev_sub, *dev_rec, *dev_play;
struct file *dev_file;

/*
 * supported rates
 */
#define NRATES (sizeof(dev_rates) / sizeof(dev_rates[0]))
unsigned dev_rates[] = {
	  6400,   7200,   8000,   9600,  11025,  12000,
	 12800,  14400,  16000,  19200,  22050,  24000,
	 25600,  28800,  32000,  38400,  44100,  48000,
	 51200,  57600,  64000,  76800,  88200,  96000,
	102400, 115200, 128000, 153600, 176400, 192000
};

/*
 * factors of supported rates
 */
#define NPRIMES (sizeof(dev_primes) / sizeof(dev_primes[0]))
unsigned dev_primes[] = {2, 3, 5, 7};

int
dev_setrate(unsigned rate)
{
	unsigned i, r, p;

	r = 1000 * rate;
	for (i = 0; i < NRATES; i++) {
		if (i == NRATES) {
			fprintf(stderr, "dev_setrate: %u, unsupported\n", rate);
			return 0;
		}
		if (r > 996 * dev_rates[i] &&
		    r < 1004 * dev_rates[i]) {
			dev_rate = dev_rates[i];
			break;
		}
	}

	dev_rate_div = dev_rate;
	dev_round_div = dev_round;
	for (i = 0; i < NPRIMES; i++) {
		p = dev_primes[i];
		while (dev_rate_div % p == 0 && dev_round_div % p == 0) {
			dev_rate_div /= p;
			dev_round_div /= p;
		}
	}
	return 1;
}

void
dev_roundrate(unsigned *newrate, unsigned *newround)
{
	*newrate += dev_rate_div - 1;
	*newrate -= *newrate % dev_rate_div;
	*newround = *newrate * dev_round_div / dev_rate_div;
}

/*
 * open the device with the given hardware parameters and create a mixer
 * and a multiplexer connected to it with all necessary conversions
 * setup
 */
void
dev_init(char *devpath,
    struct aparams *dipar, struct aparams *dopar,
    unsigned bufsz, int blkio)
{
	struct aparams ipar, opar;
	struct aproc *conv;
	struct abuf *buf;
	unsigned nfr, ibufsz, obufsz;

	/*
	 * ask for 1/4 of the buffer for the kernel ring and
	 * limit the block size to 1/4 of the requested buffer
	 */
	dev_bufsz = (bufsz + 3) / 4;
	dev_round = (bufsz + 3) / 4;
	dev_file = (struct file *)safile_new(&safile_ops, devpath,
	    dipar, dopar, &dev_bufsz, &dev_round, blkio);
	if (!dev_file)
		exit(1);
	if (!dev_setrate(dipar ? dipar->rate : dopar->rate))
		exit(1);
	if (dipar) {
		dipar->rate = dev_rate;
		if (debug_level > 0) {
			fprintf(stderr, "dev_init: hw recording ");
			aparams_print(dipar);
			fprintf(stderr, "\n");
		}
	}
	if (dopar) {
		dopar->rate = dev_rate;
		if (debug_level > 0) {
			fprintf(stderr, "dev_init: hw playing ");
			aparams_print(dopar);
			fprintf(stderr, "\n");
		}
	}
	ibufsz = obufsz = dev_bufsz;
	bufsz = (bufsz > dev_bufsz) ? bufsz - dev_bufsz : 0;

	/*
	 * use 1/8 of the buffer for the mixer/converters.  Since we
	 * already consumed 1/4 for the device, bufsz represents the
	 * remaining 3/4. So 1/8 is 1/6 of 3/4
	 */
	nfr = (bufsz + 5) / 6;
	nfr += dev_round - 1;
	nfr -= nfr % dev_round;
	if (nfr == 0)
		nfr = dev_round;

	/*
	 * create record chain
	 */
	if (dipar) {
		aparams_init(&ipar, dipar->cmin, dipar->cmax, dipar->rate);
		/*
		 * create the read end
		 */
		dev_rec = rpipe_new(dev_file);
		buf = abuf_new(nfr, dipar);
		aproc_setout(dev_rec, buf);
		ibufsz += nfr;

		/*
		 * append a converter, if needed
		 */
		if (!aparams_eqenc(dipar, &ipar)) {
			conv = dec_new("subin", dipar);
			aproc_setin(conv, buf);
			buf = abuf_new(nfr, &ipar);
			aproc_setout(conv, buf);
			ibufsz += nfr;
		}
		dev_ipar = ipar;

		/*
		 * append a "sub" to which clients will connect
		 */
		dev_sub = sub_new("sub", nfr);
		aproc_setin(dev_sub, buf);
	} else {
		dev_rec = NULL;
		dev_sub = NULL;
	}

	/*
	 * create play chain
	 */
	if (dopar) {
		aparams_init(&opar, dopar->cmin, dopar->cmax, dopar->rate);
		/*
		 * create the write end
		 */
		dev_play = wpipe_new(dev_file);
		buf = abuf_new(nfr, dopar);
		aproc_setin(dev_play, buf);
		obufsz += nfr;
		
		/*
		 * append a converter, if needed
		 */
		if (!aparams_eqenc(&opar, dopar)) {
			conv = enc_new("mixout", dopar);
			aproc_setout(conv, buf);
			buf = abuf_new(nfr, &opar);
			aproc_setin(conv, buf);
			obufsz += nfr;
		}
		dev_opar = opar;

		/*
		 * append a "mix" to which clients will connect
		 */
		dev_mix = mix_new("mix", nfr);
		aproc_setout(dev_mix, buf);
	} else {
		dev_play = NULL;
		dev_mix = NULL;
	}
	dev_bufsz = (dopar) ? obufsz : ibufsz;
	DPRINTF("dev_init: using %u fpb\n", dev_bufsz);
	dev_start();
}

/*
 * cleanly stop and drain everything and close the device
 * once both play chain and record chain are gone
 */
void
dev_done(void)
{
	struct file *f;

	if (dev_mix) {
		/*
		 * generate EOF on all inputs (but not the device), and
		 * put the mixer in ``autoquit'' state, so once buffers
		 * are drained the mixer will terminate and shutdown the
		 * write-end of the device
		 *
		 * NOTE: since file_eof() can destroy the file and
		 * reorder the file_list, we have to restart the loop
		 * after each call to file_eof()
		 */
	restart:
		LIST_FOREACH(f, &file_list, entry) {
			if (f != dev_file && f->rproc) {
				file_eof(f);
				goto restart;
			}
		}
		if (dev_mix)
			dev_mix->u.mix.flags |= MIX_AUTOQUIT;

		/*
		 * wait play chain to terminate
		 */
		while (dev_file->wproc != NULL) {
			if (!file_poll())
				break;
		}
		dev_mix = 0;
	}
	if (dev_sub) {
		/*
		 * same as above, but for the record chain: generate eof
		 * on the read-end of the device and wait record buffers
		 * to desappear.  We must stop the device first, because
		 * play-end will underrun (and xrun correction code will
		 * insert silence on the record-end of the device)
		 */
		dev_stop();
		file_eof(dev_file);
		if (dev_sub)
			dev_sub->u.sub.flags |= SUB_AUTOQUIT;
		for (;;) {
			if (!file_poll())
				break;
		}
		dev_sub = NULL;
	}
}

/*
 * start the (paused) device. By default it's paused
 */
void
dev_start(void)
{
	if (dev_mix)
		dev_mix->u.mix.flags |= MIX_DROP;
	if (dev_sub)
		dev_sub->u.sub.flags |= SUB_DROP;
	dev_file->ops->start(dev_file);
}

/*
 * pause the device
 */
void
dev_stop(void)
{
	dev_file->ops->stop(dev_file);
	if (dev_mix)
		dev_mix->u.mix.flags &= ~MIX_DROP;
	if (dev_sub)
		dev_sub->u.sub.flags &= ~SUB_DROP;
}

/*
 * sync play buffer to rec buffer (for instance when one of
 * them underruns/overruns)
 */
void
dev_sync(struct abuf *ibuf, struct abuf *obuf)
{
	struct abuf *pbuf, *rbuf;
	int delta;

	if (!dev_mix || !dev_sub)
		return;
	pbuf = LIST_FIRST(&dev_mix->obuflist);
	if (!pbuf)
		return;
	rbuf = LIST_FIRST(&dev_sub->ibuflist);
	if (!rbuf)
		return;
	for (;;) {
		if (!ibuf || !ibuf->rproc) {
			DPRINTF("dev_sync: reader desappeared\n");
			return;
		}
		if (ibuf->rproc == dev_mix)
			break;
		ibuf = LIST_FIRST(&ibuf->rproc->obuflist);
	}
	for (;;) {
		if (!obuf || !obuf->wproc) {
			DPRINTF("dev_sync: writer desappeared\n");
			return;
		}
		if (obuf->wproc == dev_sub)
			break;
		obuf = LIST_FIRST(&obuf->wproc->ibuflist);
	}

	/*
	 * calculate delta, the number of frames the play chain is ahead
	 * of the record chain. It's necessary to schedule silences (or
	 * drops) in order to start playback and record in sync.
	 */
	delta = 
	    rbuf->bpf * (pbuf->abspos + pbuf->used) - 
	    pbuf->bpf *  rbuf->abspos;
	delta /= pbuf->bpf * rbuf->bpf;
	DPRINTF("dev_sync: delta = %d, ppos = %u, pused = %u, rpos = %u\n",
	    delta, pbuf->abspos, pbuf->used, rbuf->abspos);

	if (delta > 0) {
		/*
		 * if the play chain is ahead (most cases) drop some of
		 * the recorded input, to get both in sync
		 */
		obuf->drop += delta * obuf->bpf;
		abuf_ipos(obuf, -delta);
	} else if (delta < 0) {
		/*
		 * if record chain is ahead (should never happen,
		 * right?) then insert silence to play
		 */
		ibuf->silence += -delta * ibuf->bpf;
		abuf_opos(ibuf, delta);
	} else
		DPRINTF("dev_sync: nothing to do\n");
}

/*
 * attach the given input and output buffers to the mixer and the
 * multiplexer respectively. The operation is done synchronously, so
 * both buffers enter in sync. If buffers do not match play
 * and rec
 */
void
dev_attach(char *name, 
    struct abuf *ibuf, struct aparams *sipar, unsigned underrun, 
    struct abuf *obuf, struct aparams *sopar, unsigned overrun)
{
	struct abuf *pbuf = NULL, *rbuf = NULL;
	struct aparams ipar = *sipar, opar = *sopar;
	struct aproc *conv;
	unsigned nfr;
	
	if (ibuf) {
		pbuf = LIST_FIRST(&dev_mix->obuflist);		
		if (!aparams_eqenc(&ipar, &dev_opar)) {
			nfr = (dev_bufsz + 3) / 4 + dev_round - 1;
			nfr -= nfr % dev_round;
			conv = dec_new(name, &ipar);
			ipar.bps = dev_opar.bps;
			ipar.bits = dev_opar.bits;
			ipar.sig = dev_opar.sig;
			ipar.le = dev_opar.le;
			ipar.msb = dev_opar.msb;
			aproc_setin(conv, ibuf);			
			ibuf = abuf_new(nfr, &ipar);
			aproc_setout(conv, ibuf);
		}
		if (!aparams_subset(&ipar, &dev_opar)) {
			nfr = (dev_bufsz + 3) / 4 + dev_round - 1;
			nfr -= nfr % dev_round;
			conv = cmap_new(name, &ipar, &dev_opar);
			ipar.cmin = dev_opar.cmin;
			ipar.cmax = dev_opar.cmax;
			aproc_setin(conv, ibuf);
			ibuf = abuf_new(nfr, &ipar);
			aproc_setout(conv, ibuf);
		}
		if (!aparams_eqrate(&ipar, &dev_opar)) {
			nfr = (dev_bufsz + 3) / 4 + dev_round - 1;
			nfr -= nfr % dev_round;
			conv = resamp_new(name, &ipar, &dev_opar);
			ipar.rate = dev_opar.rate;
			aproc_setin(conv, ibuf);
			ibuf = abuf_new(nfr, &ipar);
			aproc_setout(conv, ibuf);
		}
		aproc_setin(dev_mix, ibuf);
		abuf_opos(ibuf, -dev_mix->u.mix.lat);
		ibuf->xrun = underrun;
	}
	if (obuf) {
		rbuf = LIST_FIRST(&dev_sub->ibuflist);
		if (!aparams_eqenc(&opar, &dev_ipar)) {
			nfr = (dev_bufsz + 3) / 4 + dev_round - 1;
			nfr -= nfr % dev_round;
			conv = enc_new(name, &opar);
			opar.bps = dev_ipar.bps;
			opar.bits = dev_ipar.bits;
			opar.sig = dev_ipar.sig;
			opar.le = dev_ipar.le;
			opar.msb = dev_ipar.msb;
			aproc_setout(conv, obuf);
			obuf = abuf_new(nfr, &opar);
			aproc_setin(conv, obuf);
		}
		if (!aparams_subset(&opar, &dev_ipar)) {
			nfr = (dev_bufsz + 3) / 4 + dev_round - 1;
			nfr -= nfr % dev_round;
			conv = cmap_new(name, &dev_ipar, &opar);
			opar.cmin = dev_ipar.cmin;
			opar.cmax = dev_ipar.cmax;
			aproc_setout(conv, obuf);
			obuf = abuf_new(nfr, &opar);
			aproc_setin(conv, obuf);
		}
		if (!aparams_eqrate(&opar, &dev_ipar)) {
			nfr = (dev_bufsz + 3) / 4 + dev_round - 1;
			nfr -= nfr % dev_round;
			conv = resamp_new(name, &dev_ipar, &opar);
			opar.rate = dev_ipar.rate;
			aproc_setout(conv, obuf);
			obuf = abuf_new(nfr, &opar);
			aproc_setin(conv, obuf);
		}
		aproc_setout(dev_sub, obuf);
		abuf_ipos(obuf, -dev_sub->u.sub.lat);
		obuf->xrun = overrun;
	}

	/*
	 * sync play to record
	 */
	if (ibuf && obuf) {
		ibuf->duplex = obuf;
		obuf->duplex = ibuf;
		dev_sync(ibuf, obuf);
	}
}