/*
 * This file is part of the sigrok project.
 *
 * Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/time.h>
#include <inttypes.h>
#include <arpa/inet.h>
#include <glib.h>
#include <libusb.h>
#include "sigrok.h"
#include "sigrok-internal.h"
#include "config.h"
#include "dso.h"


/* Max time in ms before we want to check on events */
#define TICK    1

static int capabilities[] = {
	SR_HWCAP_OSCILLOSCOPE,
	SR_HWCAP_CONTINUOUS,
	0,
};

static const char *probe_names[] = {
	"CH1",
	"CH2",
	NULL,
};

static struct dso_profile dev_profiles[] = {
	{	0x04b4, 0x2090,
		0x04b5, 0x2090,
		"Hantek", "DSO-2090",
		NULL, 2,
		FIRMWARE_DIR "/hantek-dso-2090.fw" },
	{ 0, 0, 0, 0, 0, 0, 0, 0, 0 }
};


SR_PRIV libusb_context *usb_context = NULL;
SR_PRIV GSList *dev_insts = NULL;


static struct sr_dev_inst *dso_dev_new(int index, struct dso_profile *prof)
{
	struct sr_dev_inst *sdi;
	struct context *ctx;

	sdi = sr_dev_inst_new(index, SR_ST_INITIALIZING,
		prof->vendor, prof->model, prof->model_version);
	if (!sdi)
		return NULL;

	if (!(ctx = g_try_malloc0(sizeof(struct context)))) {
		sr_err("hantek-dso: ctx malloc failed");
		return NULL;
	}
	ctx->profile = prof;
	ctx->dev_state = IDLE;
	ctx->timebase = DEFAULT_TIMEBASE;
	ctx->ch1_enabled = TRUE;
	ctx->ch2_enabled = TRUE;
	ctx->voltage_ch1 = DEFAULT_VOLTAGE;
	ctx->voltage_ch2 = DEFAULT_VOLTAGE;
	ctx->coupling_ch1 = DEFAULT_COUPLING;
	ctx->coupling_ch2 = DEFAULT_COUPLING;
	ctx->voffset_ch1 = DEFAULT_VERT_OFFSET;
	ctx->voffset_ch2 = DEFAULT_VERT_OFFSET;
	ctx->voffset_trigger = DEFAULT_VERT_TRIGGERPOS;
	ctx->selected_channel = DEFAULT_SELECTED_CHANNEL;
	ctx->framesize = DEFAULT_FRAMESIZE;
	ctx->triggerslope = SLOPE_POSITIVE;
	ctx->triggersource = DEFAULT_TRIGGER_SOURCE;
	ctx->triggerposition = DEFAULT_HORIZ_TRIGGERPOS;
	sdi->priv = ctx;
	dev_insts = g_slist_append(dev_insts, sdi);

	return sdi;
}

static int configure_probes(struct context *ctx, GSList *probes)
{
	struct sr_probe *probe;
	GSList *l;

	for (l = probes; l; l = l->next) {
		probe = (struct sr_probe *)l->data;
		if (probe->index == 0)
			ctx->ch1_enabled = probe->enabled;
		else if (probe->index == 1)
			ctx->ch2_enabled = probe->enabled;
	}

	return SR_OK;
}

static int hw_init(const char *devinfo)
{
	struct sr_dev_inst *sdi;
	struct libusb_device_descriptor des;
	struct dso_profile *prof;
	struct context *ctx;
	libusb_device **devlist;
	int err, devcnt, i, j;

	/* Avoid compiler warnings. */
	(void)devinfo;

	if (libusb_init(&usb_context) != 0) {
		sr_err("hantek-dso: Failed to initialize USB.");
		return 0;
	}

	/* Find all Hantek DSO devices and upload firmware to all of them. */
	devcnt = 0;
	libusb_get_device_list(usb_context, &devlist);
	for (i = 0; devlist[i]; i++) {
		if ((err = libusb_get_device_descriptor(devlist[i], &des))) {
			sr_err("hantek-dso: failed to get device descriptor: %d", err);
			continue;
		}

		prof = NULL;
		for (j = 0; dev_profiles[j].orig_vid; j++) {
			if (des.idVendor == dev_profiles[j].orig_vid
				&& des.idProduct == dev_profiles[j].orig_pid) {
				/* Device matches the pre-firmware profile. */
				prof = &dev_profiles[j];
				sr_dbg("hantek-dso: Found a %s %s.", prof->vendor, prof->model);
				sdi = dso_dev_new(devcnt, prof);
				ctx = sdi->priv;
				if (ezusb_upload_firmware(devlist[i], USB_CONFIGURATION,
						prof->firmware) == SR_OK)
					/* Remember when the firmware on this device was updated */
					g_get_current_time(&ctx->fw_updated);
				else
					sr_err("hantek-dso: firmware upload failed for "
					       "device %d", devcnt);
				/* Dummy USB address of 0xff will get overwritten later. */
				ctx->usb = sr_usb_dev_inst_new(
						libusb_get_bus_number(devlist[i]), 0xff, NULL);
				devcnt++;
				break;
			} else if (des.idVendor == dev_profiles[j].fw_vid
				&& des.idProduct == dev_profiles[j].fw_pid) {
				/* Device matches the post-firmware profile. */
				prof = &dev_profiles[j];
				sr_dbg("hantek-dso: Found a %s %s.", prof->vendor, prof->model);
				sdi = dso_dev_new(devcnt, prof);
				sdi->status = SR_ST_INACTIVE;
				ctx = sdi->priv;
				ctx->usb = sr_usb_dev_inst_new(
						libusb_get_bus_number(devlist[i]),
						libusb_get_device_address(devlist[i]), NULL);
				devcnt++;
				break;
			}
		}
		if (!prof)
			/* not a supported VID/PID */
			continue;
	}
	libusb_free_device_list(devlist, 1);

	return devcnt;
}

static int hw_dev_open(int dev_index)
{
	GTimeVal cur_time;
	struct sr_dev_inst *sdi;
	struct context *ctx;
	int timediff, err;

	if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
		return SR_ERR_ARG;
	ctx = sdi->priv;

	/*
	 * if the firmware was recently uploaded, wait up to MAX_RENUM_DELAY ms
	 * for the FX2 to renumerate
	 */
	err = 0;
	if (GTV_TO_MSEC(ctx->fw_updated) > 0) {
		sr_info("hantek-dso: waiting for device to reset");
		/* takes at least 300ms for the FX2 to be gone from the USB bus */
		g_usleep(300 * 1000);
		timediff = 0;
		while (timediff < MAX_RENUM_DELAY) {
			if ((err = dso_open(dev_index)) == SR_OK)
				break;
			g_usleep(100 * 1000);
			g_get_current_time(&cur_time);
			timediff = GTV_TO_MSEC(cur_time) - GTV_TO_MSEC(ctx->fw_updated);
		}
		sr_info("hantek-dso: device came back after %d ms", timediff);
	} else {
		err = dso_open(dev_index);
	}

	if (err != SR_OK) {
		sr_err("hantek-dso: unable to open device");
		return SR_ERR;
	}

	err = libusb_claim_interface(ctx->usb->devhdl, USB_INTERFACE);
	if (err != 0) {
		sr_err("hantek-dso: Unable to claim interface: %d", err);
		return SR_ERR;
	}

	return SR_OK;
}

static int hw_dev_close(int dev_index)
{
	struct sr_dev_inst *sdi;

	if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
		return SR_ERR_ARG;

	dso_close(sdi);

	return SR_OK;
}

static int hw_cleanup(void)
{
	GSList *l;
	struct sr_dev_inst *sdi;
	struct context *ctx;

	/* Properly close and free all devices. */
	for (l = dev_insts; l; l = l->next) {
		if (!(sdi = l->data)) {
			/* Log error, but continue cleaning up the rest. */
			sr_err("hantek-dso: %s: sdi was NULL, continuing", __func__);
			continue;
		}
		if (!(ctx = sdi->priv)) {
			/* Log error, but continue cleaning up the rest. */
			sr_err("hantek-dso: %s: sdi->priv was NULL, continuing", __func__);
			continue;
		}
		dso_close(sdi);
		sr_usb_dev_inst_free(ctx->usb);
		sr_dev_inst_free(sdi);
	}

	g_slist_free(dev_insts);
	dev_insts = NULL;

	if (usb_context)
		libusb_exit(usb_context);
	usb_context = NULL;

	return SR_OK;
}

static void *hw_get_device_info(int dev_index, int dev_info_id)
{
	struct sr_dev_inst *sdi;
	struct context *ctx;
	void *info;
	uint64_t tmp;

	if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
		return NULL;
	ctx = sdi->priv;

	info = NULL;
	switch (dev_info_id) {
	case SR_DI_INST:
		info = sdi;
		break;
	case SR_DI_NUM_PROBES:
		info = GINT_TO_POINTER(ctx->profile->num_probes);
		break;
	case SR_DI_PROBE_NAMES:
		info = probe_names;
		break;
	/* TODO remove this */
	case SR_DI_CUR_SAMPLERATE:
		info = &tmp;
		break;
	}

	return info;
}

static int hw_get_status(int device_index)
{
	struct sr_dev_inst *sdi;

	if (!(sdi = sr_dev_inst_get(dev_insts, device_index)))
		return SR_ST_NOT_FOUND;

	return sdi->status;
}

static int *hwcap_get_all(void)
{

	return capabilities;
}

static int hw_dev_config_set(int dev_index, int hwcap, void *value)
{
	struct sr_dev_inst *sdi;
	struct context *ctx;
	int tmp, ret;

	if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
		return SR_ERR;

	if (sdi->status != SR_ST_ACTIVE)
		return SR_ERR;

	ctx = sdi->priv;
	switch (hwcap) {
	case SR_HWCAP_PROBECONFIG:
		ret = configure_probes(ctx, (GSList *) value);
		break;
	case SR_HWCAP_TRIGGERSLOPE:
		tmp = *(int *)value;
		if (tmp != SLOPE_NEGATIVE && tmp != SLOPE_POSITIVE)
			ret = SR_ERR_ARG;
		ctx->triggerslope = tmp;
	default:
		ret = SR_ERR_ARG;
	}

	return ret;
}

/* Called by libusb (as triggered by handle_event()) when a transfer comes in.
 * Only channel data comes in asynchronously, and all transfers for this are
 * queued up beforehand, so this just needs so chuck the incoming data onto
 * the libsigrok session bus.
 */
static void receive_transfer(struct libusb_transfer *transfer)
{
	struct sr_datafeed_packet packet;
	struct sr_datafeed_analog analog;
	struct context *ctx;
	float ch1, ch2;
	int i;

	ctx = transfer->user_data;
	sr_dbg("hantek-dso: receive_transfer(): status %d received %d bytes",
			transfer->status, transfer->actual_length);

	if (transfer->actual_length == 0)
		/* Nothing to send to the bus. */
		return;

	ctx->current_transfer += transfer->actual_length;
	sr_dbg("hantek-dso: got %d of %d in frame", ctx->current_transfer, ctx->framesize * 2);
	if (ctx->current_transfer >= ctx->framesize * 2) {
		ctx->current_transfer = 0;
		ctx->dev_state = NEW_CAPTURE;
	}

	packet.type = SR_DF_ANALOG;
	packet.payload = &analog;
	analog.num_samples = transfer->actual_length / 2;
	analog.data = g_try_malloc(analog.num_samples * sizeof(float) * ctx->profile->num_probes);
	for (i = 0; i < analog.num_samples; i++) {
		/* Hardcoded for two channels, since the order/encoding is specific. */
		/* TODO: support for 5xxx series 9-bit samples */
		ch2 = (*(transfer->buffer + i * 2) / 255.0);
		ch1 = (*(transfer->buffer + i * 2 + 1) / 255.0);
		analog.data[i * ctx->profile->num_probes] = ch1;
		analog.data[i * ctx->profile->num_probes + 1] = ch2;
	}
	g_free(transfer->buffer);
	libusb_free_transfer(transfer);

	sr_session_send(ctx->cb_data, &packet);

}

static int handle_event(int fd, int revents, void *cb_data)
{
	struct timeval tv;
	struct context *ctx;
	int capturestate;

	/* Avoid compiler warnings. */
	(void)fd;
	(void)revents;

	/* Always handle pending libusb events. */
	tv.tv_sec = tv.tv_usec = 0;
	libusb_handle_events_timeout(usb_context, &tv);

	ctx = cb_data;
	/* TODO: ugh */
	if (ctx->dev_state == NEW_CAPTURE) {
		if (dso_capture_start(ctx) != SR_OK)
			return TRUE;
		if (dso_enable_trigger(ctx) != SR_OK)
			return TRUE;
		if (dso_force_trigger(ctx) != SR_OK)
			return TRUE;
		sr_dbg("hantek-dso: successfully requested next chunk");
		ctx->dev_state = CAPTURE;
		return TRUE;
	}
	if (ctx->dev_state != CAPTURE)
		return TRUE;

	if ((capturestate = dso_get_capturestate(ctx)) == CAPTURE_UNKNOWN) {
		/* Generated by the function, not the hardware. */
		return TRUE;
	}

	sr_dbg("hantek-dso: capturestate %d", capturestate);
	switch (capturestate) {
	case CAPTURE_EMPTY:
		if (++ctx->capture_empty_count >= MAX_CAPTURE_EMPTY) {
			ctx->capture_empty_count = 0;
			if (dso_capture_start(ctx) != SR_OK)
				break;
			if (dso_enable_trigger(ctx) != SR_OK)
				break;
			if (dso_force_trigger(ctx) != SR_OK)
				break;
			sr_dbg("hantek-dso: successfully requested next chunk");
		}
		break;
	case CAPTURE_FILLING:
		/* no data yet */
		break;
	case CAPTURE_READY_8BIT:
		/* Tell the scope to send us the first frame. */
		if (dso_get_channeldata(ctx, receive_transfer) != SR_OK)
			break;
//		/* Current frame is on the way, make sure the scope
//		 * sends us the next one. */
//		if (dso_capture_start(ctx) != SR_OK)
//			break;
//		if (dso_enable_trigger(ctx) != SR_OK)
//			break;
//		if (dso_force_trigger(ctx) != SR_OK)
//			break;
		ctx->dev_state = FETCH_DATA;
		break;
	case CAPTURE_READY_9BIT:
		/* TODO */
		sr_err("not yet supported");
		break;
	case CAPTURE_TIMEOUT:
		/* Doesn't matter, we'll try again next time. */
		break;
	default:
		sr_dbg("unknown capture state");
	}

	return TRUE;
}

static int hw_start_acquisition(int device_index, void *cb_data)
{
	const struct libusb_pollfd **lupfd;
	struct sr_datafeed_packet packet;
	struct sr_datafeed_header header;
	struct sr_datafeed_meta_analog meta;
	struct sr_dev_inst *sdi;
	struct context *ctx;
	int i;

	if (!(sdi = sr_dev_inst_get(dev_insts, device_index)))
		return SR_ERR;

	if (sdi->status != SR_ST_ACTIVE)
		return SR_ERR;

	ctx = sdi->priv;
	ctx->cb_data = cb_data;

	if (dso_init(ctx) != SR_OK)
		return SR_ERR;

	if (dso_capture_start(ctx) != SR_OK)
		return SR_ERR;

	ctx->dev_state = CAPTURE;
	lupfd = libusb_get_pollfds(usb_context);
	for (i = 0; lupfd[i]; i++)
		sr_source_add(lupfd[i]->fd, lupfd[i]->events, TICK, handle_event,
			      ctx);
	free(lupfd);

	/* Send header packet to the session bus. */
	packet.type = SR_DF_HEADER;
	packet.payload = (unsigned char *)&header;
	header.feed_version = 1;
	gettimeofday(&header.starttime, NULL);
	sr_session_send(cb_data, &packet);

	/* Send metadata about the SR_DF_ANALOG packets to come. */
	packet.type = SR_DF_META_ANALOG;
	packet.payload = &meta;
	meta.num_probes = ctx->profile->num_probes;
	sr_session_send(cb_data, &packet);

	return SR_OK;
}

/* TODO: doesn't really cancel pending transfers so they might come in after
 * SR_DF_END is sent.
 */
static int hw_stop_acquisition(int device_index, gpointer session_device_id)
{
	struct sr_datafeed_packet packet;
	struct sr_dev_inst *sdi;
	struct context *ctx;

	if (!(sdi = sr_dev_inst_get(dev_insts, device_index)))
		return SR_ERR;

	if (sdi->status != SR_ST_ACTIVE)
		return SR_ERR;

	ctx = sdi->priv;
	ctx->dev_state = IDLE;

	packet.type = SR_DF_END;
	sr_session_send(session_device_id, &packet);

	return SR_OK;
}

SR_PRIV struct sr_dev_driver hantek_dso_plugin_info = {
	.name = "hantek-dso",
	.longname = "Hantek DSO",
	.api_version = 1,
	.init = hw_init,
	.cleanup = hw_cleanup,
	.dev_open = hw_dev_open,
	.dev_close = hw_dev_close,
	.dev_info_get = hw_get_device_info,
	.dev_status_get = hw_get_status,
	.hwcap_get_all = hwcap_get_all,
	.dev_config_set = hw_dev_config_set,
	.dev_acquisition_start = hw_start_acquisition,
	.dev_acquisition_stop = hw_stop_acquisition,
};