/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2011 Uwe Hermann <uwe@hermann-uwe.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include <stdlib.h>
#include <string.h>
#include <glib.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"

#define LOG_PREFIX "output/csv"

struct context {
	unsigned int num_enabled_channels;
	uint64_t samplerate;
	char separator;
	gboolean header_done;
	struct sr_channel **channels;

	/* For analog measurements split into frames, not packets. */
	struct sr_channel **analog_channels;
	float *analog_vals; /* Analog values stored until the end of the frame. */
	unsigned int num_analog_channels;
	gboolean inframe;
};

/*
 * TODO:
 *  - Option to specify delimiter character and/or string.
 *  - Option to (not) print metadata as comments.
 *  - Option to specify the comment character(s), e.g. # or ; or C/C++-style.
 *  - Option to (not) print samplenumber / time as extra column.
 *  - Option to "compress" output (only print changed samples, VCD-like).
 *  - Option to print comma-separated bits, or whole bytes/words (for 8/16
 *    channel LAs) as ASCII/hex etc. etc.
 *  - Trigger support.
 */

static int init(struct sr_output *o, GHashTable *options)
{
	struct context *ctx;
	struct sr_channel *ch;
	GSList *l;
	int i, j;

	(void)options;

	if (!o || !o->sdi)
		return SR_ERR_ARG;

	ctx = g_malloc0(sizeof(struct context));
	o->priv = ctx;
	ctx->separator = ',';

	/* Get the number of channels, and the unitsize. */
	for (l = o->sdi->channels; l; l = l->next) {
		ch = l->data;
		if (ch->enabled) {
			if (ch->type == SR_CHANNEL_LOGIC ||
			    ch->type == SR_CHANNEL_ANALOG)
				ctx->num_enabled_channels++;
			if (ch->type == SR_CHANNEL_ANALOG)
				ctx->num_analog_channels++;
		}
	}
	ctx->channels = g_malloc(sizeof(struct sr_channel *)
					* ctx->num_enabled_channels);
	ctx->analog_channels = g_malloc(sizeof(struct sr_channel *)
					* ctx->num_analog_channels);
	ctx->analog_vals = g_malloc(sizeof(float) * ctx->num_analog_channels);

	/* Once more to map the enabled channels. */
	for (i = 0, l = o->sdi->channels, j = 0; l; l = l->next) {
		ch = l->data;
		if (ch->enabled) {
			if (ch->type == SR_CHANNEL_LOGIC ||
			    ch->type == SR_CHANNEL_ANALOG)
				ctx->channels[i++] = ch;
			if (ch->type == SR_CHANNEL_ANALOG)
				ctx->analog_channels[j++] = ch;
		}

	}

	return SR_OK;
}

static GString *gen_header(const struct sr_output *o)
{
	struct context *ctx;
	struct sr_channel *ch;
	GVariant *gvar;
	GString *header;
	GSList *l;
	time_t t;
	int num_channels, i;
	char *samplerate_s;

	ctx = o->priv;
	header = g_string_sized_new(512);

	/* Some metadata */
	t = time(NULL);
	g_string_append_printf(header, "; CSV, generated by %s %s on %s",
			PACKAGE_NAME, SR_PACKAGE_VERSION_STRING, ctime(&t));

	/* Columns / channels */
	num_channels = g_slist_length(o->sdi->channels);
	g_string_append_printf(header, "; Channels (%d/%d):",
			ctx->num_enabled_channels, num_channels);
	for (i = 0, l = o->sdi->channels; l; l = l->next, i++) {
		ch = l->data;
		if (ch->enabled &&
		    (ch->type == SR_CHANNEL_LOGIC ||
		     ch->type == SR_CHANNEL_ANALOG))
			g_string_append_printf(header, " %s,", ch->name);
	}
	if (o->sdi->channels)
		/* Drop last separator. */
		g_string_truncate(header, header->len - 1);
	g_string_append_printf(header, "\n");

	if (ctx->samplerate == 0) {
		if (sr_config_get(o->sdi->driver, o->sdi, NULL, SR_CONF_SAMPLERATE,
				&gvar) == SR_OK) {
			ctx->samplerate = g_variant_get_uint64(gvar);
			g_variant_unref(gvar);
		}
	}
	if (ctx->samplerate != 0) {
		samplerate_s = sr_samplerate_string(ctx->samplerate);
		g_string_append_printf(header, "; Samplerate: %s\n", samplerate_s);
		g_free(samplerate_s);
	}

	return header;
}

static void init_output(GString **out, struct context *ctx,
			const struct sr_output *o)
{
	if (!ctx->header_done) {
		*out = gen_header(o);
		ctx->header_done = TRUE;
	} else {
		*out = g_string_sized_new(512);
	}
}

static void handle_analog_frame(struct context *ctx,
				const struct sr_datafeed_analog *analog)
{
	unsigned int numch, nums, i, j, s;
	GSList *l;

	numch = g_slist_length(analog->channels);
	if ((unsigned int)analog->num_samples > numch)
		nums = analog->num_samples / numch;
	else
		nums = 1;

	s = 0;
	l = analog->channels;
	for (i = 0; i < nums; i++) {
		for (j = 0; j < ctx->num_analog_channels; j++) {
			if (ctx->analog_channels[j] == l->data)
				ctx->analog_vals[j] = analog->data[s++];
		}
		l = l->next;
	}
}

static int receive(const struct sr_output *o, const struct sr_datafeed_packet *packet,
		GString **out)
{
	const struct sr_datafeed_meta *meta;
	const struct sr_datafeed_logic *logic;
	const struct sr_datafeed_analog *analog;
	const struct sr_config *src;
	GSList *l;
	struct context *ctx;
	int idx;
	uint64_t i, j, k, nums, numch;
	gchar *p, c;
	int ret = SR_OK;

	*out = NULL;
	if (!o || !o->sdi)
		return SR_ERR_ARG;
	if (!(ctx = o->priv))
		return SR_ERR_ARG;

	switch (packet->type) {
	case SR_DF_META:
		meta = packet->payload;
		for (l = meta->config; l; l = l->next) {
			src = l->data;
			if (src->key != SR_CONF_SAMPLERATE)
				continue;
			ctx->samplerate = g_variant_get_uint64(src->data);
		}
		break;
	case SR_DF_FRAME_BEGIN:
		/*
		 * Special case - we start gathering data from analog channels
		 * and wait for SR_DF_FRAME_END to dump it.
		 */
		memset(ctx->analog_vals, 0, sizeof(float) * ctx->num_analog_channels);
		ctx->inframe = TRUE;
		ret = SR_OK;
		break;
	case SR_DF_FRAME_END:
		/*
		 * Dump gathered data.
		 */
		init_output(out, ctx, o);

		for (i = 0, j = 0; i < ctx->num_enabled_channels; i++) {
			if (ctx->channels[i]->type == SR_CHANNEL_ANALOG) {
				g_string_append_printf(*out, "%f",
							ctx->analog_vals[j++]);
			}
			g_string_append_c(*out, ctx->separator);
		}
		g_string_truncate(*out, (*out)->len - 1);
		g_string_append_printf(*out, "\n");

		ctx->inframe = FALSE;
		break;
	case SR_DF_LOGIC:
		logic = packet->payload;
		init_output(out, ctx, o);

		for (i = 0; i <= logic->length - logic->unitsize; i += logic->unitsize) {
			for (j = 0; j < ctx->num_enabled_channels; j++) {
				if (ctx->channels[j]->type == SR_CHANNEL_LOGIC) {
					idx = ctx->channels[j]->index;
					p = logic->data + i + idx / 8;
					c = *p & (1 << (idx % 8));
					g_string_append_c(*out, c ? '1' : '0');
				}
				g_string_append_c(*out, ctx->separator);
			}
			if (j) {
				/* Drop last separator. */
				g_string_truncate(*out, (*out)->len - 1);
			}
			g_string_append_printf(*out, "\n");
		}
		break;
	case SR_DF_ANALOG:
		analog = packet->payload;

		if (ctx->inframe) {
			handle_analog_frame(ctx, analog);
			break;
		}

		init_output(out, ctx, o);
		k = 0;
		l = NULL;

		numch = g_slist_length(analog->channels);
		if ((unsigned int)analog->num_samples > numch)
			nums = analog->num_samples / numch;
		else
			nums = 1;

		for (i = 0; i < nums; i++) {
			for (j = 0; j < ctx->num_enabled_channels; j++) {
				if (ctx->channels[j]->type == SR_CHANNEL_ANALOG) {
					if (!l)
						l = analog->channels;

					if (ctx->channels[j] == l->data) {
						g_string_append_printf(*out,
							"%f", analog->data[k++]);
					}

					l = l->next;
				}
				g_string_append_c(*out, ctx->separator);
			}
			g_string_truncate(*out, (*out)->len - 1);
			g_string_append_printf(*out, "\n");
		}
		break;
	/* TODO case SR_DF_ANALOG2: */
	}

	return ret;
}

static int cleanup(struct sr_output *o)
{
	struct context *ctx;

	if (!o || !o->sdi)
		return SR_ERR_ARG;

	if (o->priv) {
		ctx = o->priv;
		g_free(ctx->channels);
		g_free(ctx->analog_channels);
		g_free(ctx->analog_vals);
		g_free(o->priv);
		o->priv = NULL;
	}

	return SR_OK;
}

SR_PRIV struct sr_output_module output_csv = {
	.id = "csv",
	.name = "CSV",
	.desc = "Comma-separated values",
	.exts = (const char*[]){"csv", NULL},
	.flags = 0,
	.options = NULL,
	.init = init,
	.receive = receive,
	.cleanup = cleanup,
};