path: root/remote_plot.c

// references:
// https://api.libssh.org/stable/libssh_tutorial.html
// https://api.libssh.org/stable/libssh_tutor_guided_tour.html
// https://plplot.sourceforge.net/documentation.php
// https://plplot.sourceforge.net/examples.php
// plplot example 0 and ext-cairo-test.c
// https://docs.gtk.org/gtk4/class.DrawingArea.html
// https://www.gtk.org/docs/getting-started/hello-world/
// https://gitlab.gnome.org/GNOME/gtk/-/blob/main/demos/print-editor/print-editor.c
// https://gitlab.gnome.org/GNOME/gtk/-/blob/main/demos/gtk-demo/main.c

#include <libssh/libssh.h>
#include <stdlib.h>
#include <stdio.h>
#include <libssh/sftp.h>

// verify_knownhost()
#include <errno.h>
#include <string.h>

#include <fcntl.h> // open()

// plplot
#include <plplot/plConfig.h>
#include <plplot/plplot.h>
#include <math.h>
//#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <gtk/gtk.h>
#include "list.h"
#include<stdint.h> //uint32_t

// use double for PLFLT
#define PL_DOUBLE

// max wire unsigned number is 65535
// max wire signed number maybe is -32768 to 32767
// voltage max format 6 bytes ,5.999
// temp max format 6 bytes ,-49.9
// timestamp max 10 bytes 1745742182
// 1 timestamp, 96 voltage, 32 temp, 1 \n
// 10+96*6+32*6+1=779 bytes
#define ENTRY_SIZE 779
// 16 KiB == 16384 bytes
// 16384/ENTRY_SIZE == 21
// 21*ENTRY_SIZE == 16359
// https://api.libssh.org/stable/libssh_tutor_sftp.html
#define MAX_XFER_BUF_SIZE 16384/ENTRY_SIZE*ENTRY_SIZE

const char *checkbutton_names[]={
	"0x630_BMS_Cell_4_Voltage",
	"0x630_BMS_Cell_3_Voltage",
	"0x630_BMS_Cell_2_Voltage",
	"0x630_BMS_Cell_1_Voltage",
	"0x631_BMS_Cell_8_Voltage",
	"0x631_BMS_Cell_7_Voltage",
	"0x631_BMS_Cell_6_Voltage",
	"0x631_BMS_Cell_5_Voltage",
	"0x632_BMS_Cell_12_Voltage",
	"0x632_BMS_Cell_11_Voltage",
	"0x632_BMS_Cell_10_Voltage",
	"0x632_BMS_Cell_9_Voltage",
	"0x633_BMS_Cell_4_Voltage",
	"0x633_BMS_Cell_3_Voltage",
	"0x633_BMS_Cell_2_Voltage",
	"0x633_BMS_Cell_1_Voltage",
	"0x634_BMS_Cell_8_Voltage",
	"0x634_BMS_Cell_7_Voltage",
	"0x634_BMS_Cell_6_Voltage",
	"0x634_BMS_Cell_5_Voltage",
	"0x635_BMS_Cell_12_Voltage",
	"0x635_BMS_Cell_11_Voltage",
	"0x635_BMS_Cell_10_Voltage",
	"0x635_BMS_Cell_9_Voltage",
	"0x636_BMS_Cell_4_Voltage",
	"0x636_BMS_Cell_3_Voltage",
	"0x636_BMS_Cell_2_Voltage",
	"0x636_BMS_Cell_1_Voltage",
	"0x637_BMS_Cell_8_Voltage",
	"0x637_BMS_Cell_7_Voltage",
	"0x637_BMS_Cell_6_Voltage",
	"0x637_BMS_Cell_5_Voltage",
	"0x638_BMS_Cell_12_Voltage",
	"0x638_BMS_Cell_11_Voltage",
	"0x638_BMS_Cell_10_Voltage",
	"0x638_BMS_Cell_9_Voltage",
	"0x639_BMS_Cell_4_Voltage",
	"0x639_BMS_Cell_3_Voltage",
	"0x639_BMS_Cell_2_Voltage",
	"0x639_BMS_Cell_1_Voltage",
	"0x63a_BMS_Cell_8_Voltage",
	"0x63a_BMS_Cell_7_Voltage",
	"0x63a_BMS_Cell_6_Voltage",
	"0x63a_BMS_Cell_5_Voltage",
	"0x63b_BMS_Cell_12_Voltage",
	"0x63b_BMS_Cell_11_Voltage",
	"0x63b_BMS_Cell_10_Voltage",
	"0x63b_BMS_Cell_9_Voltage",
	"0x63c_BMS_Cell_4_Voltage",
	"0x63c_BMS_Cell_3_Voltage",
	"0x63c_BMS_Cell_2_Voltage",
	"0x63c_BMS_Cell_1_Voltage",
	"0x63d_BMS_Cell_8_Voltage",
	"0x63d_BMS_Cell_7_Voltage",
	"0x63d_BMS_Cell_6_Voltage",
	"0x63d_BMS_Cell_5_Voltage",
	"0x63e_BMS_Cell_12_Voltage",
	"0x63e_BMS_Cell_11_Voltage",
	"0x63e_BMS_Cell_10_Voltage",
	"0x63e_BMS_Cell_9_Voltage",
	"0x63f_BMS_Cell_4_Voltage",
	"0x63f_BMS_Cell_3_Voltage",
	"0x63f_BMS_Cell_2_Voltage",
	"0x63f_BMS_Cell_1_Voltage",
	"0x640_BMS_Cell_8_Voltage",
	"0x640_BMS_Cell_7_Voltage",
	"0x640_BMS_Cell_6_Voltage",
	"0x640_BMS_Cell_5_Voltage",
	"0x641_BMS_Cell_12_Voltage",
	"0x641_BMS_Cell_11_Voltage",
	"0x641_BMS_Cell_10_Voltage",
	"0x641_BMS_Cell_9_Voltage",
	"0x642_BMS_Cell_4_Voltage",
	"0x642_BMS_Cell_3_Voltage",
	"0x642_BMS_Cell_2_Voltage",
	"0x642_BMS_Cell_1_Voltage",
	"0x643_BMS_Cell_8_Voltage",
	"0x643_BMS_Cell_7_Voltage",
	"0x643_BMS_Cell_6_Voltage",
	"0x643_BMS_Cell_5_Voltage",
	"0x644_BMS_Cell_12_Voltage",
	"0x644_BMS_Cell_11_Voltage",
	"0x644_BMS_Cell_10_Voltage",
	"0x644_BMS_Cell_9_Voltage",
	"0x645_BMS_Cell_4_Voltage",
	"0x645_BMS_Cell_3_Voltage",
	"0x645_BMS_Cell_2_Voltage",
	"0x645_BMS_Cell_1_Voltage",
	"0x646_BMS_Cell_8_Voltage",
	"0x646_BMS_Cell_7_Voltage",
	"0x646_BMS_Cell_6_Voltage",
	"0x646_BMS_Cell_5_Voltage",
	"0x647_BMS_Cell_12_Voltage",
	"0x647_BMS_Cell_11_Voltage",
	"0x647_BMS_Cell_10_Voltage",
	"0x647_BMS_Cell_9_Voltage",
	"0x680_BMS_Section_4_Temp",
	"0x680_BMS_Section_3_Temp",
	"0x680_BMS_Section_2_Temp",
	"0x680_BMS_Section_1_Temp",
	"0x683_BMS_Section_4_Temp",
	"0x683_BMS_Section_3_Temp",
	"0x683_BMS_Section_2_Temp",
	"0x683_BMS_Section_1_Temp",
	"0x686_BMS_Section_4_Temp",
	"0x686_BMS_Section_3_Temp",
	"0x686_BMS_Section_2_Temp",
	"0x686_BMS_Section_1_Temp",
	"0x689_BMS_Section_4_Temp",
	"0x689_BMS_Section_3_Temp",
	"0x689_BMS_Section_2_Temp",
	"0x689_BMS_Section_1_Temp",
	"0x68c_BMS_Section_4_Temp",
	"0x68c_BMS_Section_3_Temp",
	"0x68c_BMS_Section_2_Temp",
	"0x68c_BMS_Section_1_Temp",
	"0x68f_BMS_Section_4_Temp",
	"0x68f_BMS_Section_3_Temp",
	"0x68f_BMS_Section_2_Temp",
	"0x68f_BMS_Section_1_Temp",
	"0x692_BMS_Section_4_Temp",
	"0x692_BMS_Section_3_Temp",
	"0x692_BMS_Section_2_Temp",
	"0x692_BMS_Section_1_Temp",
	"0x695_BMS_Section_4_Temp",
	"0x695_BMS_Section_3_Temp",
	"0x695_BMS_Section_2_Temp",
	"0x695_BMS_Section_1_Temp"
};

typedef struct {
	ssh_session session;
	sftp_session sftp;
	List cans;
	GtkWidget *area;
	GtkWidget *checkbutton[VOLTLEN+TEMPLEN];
	GtkWidget *volt_label;
	GtkWidget *temp_label;
	GtkWidget *live_toggle;
	GtkWidget *from_entry;
	GtkWidget *to_entry;
	// .csv file already read offset
	uint32_t offset;
	uint32_t from_time;
	uint32_t to_time;
	bool from_time_entered;
	// local file name
	char *filename;
	// only read from local .csv file or not
	bool local;
}DATA;

static gboolean read_data(gpointer user_data)
//static gboolean sftp_read_sync(gpointer user_data)
//int sftp_read_sync(ssh_session session, sftp_session sftp)
{
	//printf("read_data begin\n");
	DATA *data=user_data;
	bool new_entry=false;

	if(data->local)
	{
		//printf("read_data check local pass\n");
		FILE *fp;
		if((fp=fopen(data->filename,"r"))!=NULL)
		{
			//printf("offset before fseek %d\n",data->offset);
			fseek(fp, data->offset, SEEK_SET);
			//printf("before read_data local for loop\n");
			for(;;)
			{
				//printf("start read_data local for loop\n");
				Item temp;
				int ct=fscanf(fp,"%u,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf,%lf",&(temp.t),&(temp.volt[0]),&(temp.volt[1]),&(temp.volt[2]),&(temp.volt[3]),&(temp.volt[4]),&(temp.volt[5]),&(temp.volt[6]),&(temp.volt[7]),&(temp.volt[8]),&(temp.volt[9]),&(temp.volt[10]),&(temp.volt[11]),&(temp.volt[12]),&(temp.volt[13]),&(temp.volt[14]),&(temp.volt[15]),&(temp.volt[16]),&(temp.volt[17]),&(temp.volt[18]),&(temp.volt[19]),&(temp.volt[20]),&(temp.volt[21]),&(temp.volt[22]),&(temp.volt[23]),&(temp.volt[24]),&(temp.volt[25]),&(temp.volt[26]),&(temp.volt[27]),&(temp.volt[28]),&(temp.volt[29]),&(temp.volt[30]),&(temp.volt[31]),&(temp.volt[32]),&(temp.volt[33]),&(temp.volt[34]),&(temp.volt[35]),&(temp.volt[36]),&(temp.volt[37]),&(temp.volt[38]),&(temp.volt[39]),&(temp.volt[40]),&(temp.volt[41]),&(temp.volt[42]),&(temp.volt[43]),&(temp.volt[44]),&(temp.volt[45]),&(temp.volt[46]),&(temp.volt[47]),&(temp.volt[48]),&(temp.volt[49]),&(temp.volt[50]),&(temp.volt[51]),&(temp.volt[52]),&(temp.volt[53]),&(temp.volt[54]),&(temp.volt[55]),&(temp.volt[56]),&(temp.volt[57]),&(temp.volt[58]),&(temp.volt[59]),&(temp.volt[60]),&(temp.volt[61]),&(temp.volt[62]),&(temp.volt[63]),&(temp.volt[64]),&(temp.volt[65]),&(temp.volt[66]),&(temp.volt[67]),&(temp.volt[68]),&(temp.volt[69]),&(temp.volt[70]),&(temp.volt[71]),&(temp.volt[72]),&(temp.volt[73]),&(temp.volt[74]),&(temp.volt[75]),&(temp.volt[76]),&(temp.volt[77]),&(temp.volt[78]),&(temp.volt[79]),&(temp.volt[80]),&(temp.volt[81]),&(temp.volt[82]),&(temp.volt[83]),&(temp.volt[84]),&(temp.volt[85]),&(temp.volt[86]),&(temp.volt[87]),&(temp.volt[88]),&(temp.volt[89]),&(temp.volt[90]),&(temp.volt[91]),&(temp.volt[92]),&(temp.volt[93]),&(temp.volt[94]),&(temp.volt[95]),&(temp.temp[0]),&(temp.temp[1]),&(temp.temp[2]),&(temp.temp[3]),&(temp.temp[4]),&(temp.temp[5]),&(temp.temp[6]),&(temp.temp[7]),&(temp.temp[8]),&(temp.temp[9]),&(temp.temp[10]),&(temp.temp[11]),&(temp.temp[12]),&(temp.temp[13]),&(temp.temp[14]),&(temp.temp[15]),&(temp.temp[16]),&(temp.temp[17]),&(temp.temp[18]),&(temp.temp[19]),&(temp.temp[20]),&(temp.temp[21]),&(temp.temp[22]),&(temp.temp[23]),&(temp.temp[24]),&(temp.temp[25]),&(temp.temp[26]),&(temp.temp[27]),&(temp.temp[28]),&(temp.temp[29]),&(temp.temp[30]),&(temp.temp[31]));
				if(ct == EOF)
					break;
				else if(ct<(VOLTLEN+TEMPLEN+1))
				{
					fprintf(stderr,"Read less items (%d) than expected from local file\n",ct);
					//exit(1);
					return G_SOURCE_REMOVE;
				}

				if(AddItem(temp,&(data->cans))==false)
				{
					fprintf(stderr,"Problem allocating memory\n");
					//exit(1);
					return G_SOURCE_REMOVE;
				}

				if(!new_entry)
					new_entry=true;
				//printf("end read_data local for loop\n");
			}
			//printf("after read_data local for loop\n");
			//printf("offset before ftell %d\n",data->offset);
			data->offset=ftell(fp);
			//printf("offset after ftell %d\n",data->offset);
			fclose(fp);
		}
	}
	else
	{
		int access_type;
		sftp_file file;
		char buffer[MAX_XFER_BUF_SIZE];
		int nbytes, rc;
		access_type = O_RDONLY;

		// This is to represent a loop over time
		// Let's try a random walk process

		file = sftp_open(data->sftp, sftp_expand_path(data->sftp,"~/.local/share/mycan.csv"), access_type, 0);
		if (file == NULL) {
			fprintf(stderr, "Can't open file for reading: %s\n",
					ssh_get_error(data->session));
			//return SSH_ERROR;
			return G_SOURCE_REMOVE;
		}

		if(data->offset != 0)
			sftp_seek(file,data->offset);
		for(;;)
		{
			nbytes = sftp_read(file, buffer, sizeof(buffer));
			//printf("nbytes: %d\n",nbytes);
			//printf("%d\n",MAX_XFER_BUF_SIZE);
			if (nbytes == 0) {
				break; // EOF
			} else if (nbytes < 0) {
				fprintf(stderr, "Error while reading file: %s\n",
						ssh_get_error(data->session));
				sftp_close(file);
				//return SSH_ERROR;
				return G_SOURCE_REMOVE;
			} else if ((nbytes%ENTRY_SIZE) != 0) {
				fprintf(stderr, "sftp read nbytes not a multiple of %d\n",ENTRY_SIZE);
				sftp_close(file);
				//return SSH_ERROR;
				return G_SOURCE_REMOVE;
			}

			// TODO: check strtok return NULL or not
			//printf("before strtok\n");
			for(int i=0;i<(nbytes/ENTRY_SIZE);i++)
			{
				Item temp;
				FILE *fp;
				// TODO: pass endptr and check it and other things to be safe, see https://stackoverflow.com/questions/34206446
				if(i)
					temp.t=strtoul(strtok(NULL,","),NULL,10);
				else
					temp.t=strtoul(strtok(buffer,","),NULL,10);
				for(int j=0;j<VOLTLEN;j++)
					temp.volt[j]=atof(strtok(NULL,","));
				for(int j=0;j<(TEMPLEN-1);j++)
					temp.temp[j]=atof(strtok(NULL,","));
				temp.temp[TEMPLEN-1]=atof(strtok(NULL,"\n"));
				//printf("before AddItem\n");
				if(AddItem(temp,&(data->cans))==false)
				{
					fprintf(stderr,"Problem allocating memory\n");
					return G_SOURCE_REMOVE;
				}
				if(!new_entry)
					new_entry=true;
				//printf("after AddItem\n");

				if((fp=fopen(data->filename,"a"))==NULL)
				{
					fprintf(stderr,"Can't open file \"%s\".\n",data->filename);
					//exit(1);
					return G_SOURCE_REMOVE;
				}
				fprintf(fp,"%u",temp.t);
				for(int j=0;j<VOLTLEN;j++)
					fprintf(fp,",%5.3f",temp.volt[j]);
				for(int j=0;j<TEMPLEN;j++)
					fprintf(fp,",%5.1f",temp.temp[j]);
				fprintf(fp,"\n");
				fclose(fp);
			}
			//printf("after strtok\n");
			data->offset+=nbytes;
		}

		rc = sftp_close(file);
		if (rc != SSH_OK) {
			fprintf(stderr, "Can't close the read file: %s\n",
					ssh_get_error(data->session));
			//return rc;
			return G_SOURCE_REMOVE;
		}
	}

	//printf("after read_data check local if else\n");

	if(new_entry)
	{
		double sum,avg;
		// max 28 char + 1 \0: Average temperature: 6553.5 C
		char str[29];
		sum=avg=0;

		for(int i=0;i<VOLTLEN;i++)
			sum+=data->cans.end->item.volt[i];
		avg=sum/VOLTLEN;
		sprintf(str,"Average voltage: %.3f V",avg);
		gtk_label_set_text(GTK_LABEL(data->volt_label),str);
		sum=0;
		for(int i=0;i<TEMPLEN;i++)
			sum+=data->cans.end->item.temp[i];
		avg=sum/TEMPLEN;
		sprintf(str,"Average temperature: %.1f C",avg);
		gtk_label_set_text(GTK_LABEL(data->temp_label),str);
		new_entry=false;
		gtk_widget_queue_draw(data->area);
	}

	//printf("after check new_entry if\n");

	//return SSH_OK;
	// must return G_SOURCE_CONTINUE to keep polling
	// return G_SOURCE_REMOVE to stop
	return G_SOURCE_CONTINUE;
}

// https://api.libssh.org/stable/libssh_tutor_guided_tour.html
int verify_knownhost(ssh_session session)
{
	enum ssh_known_hosts_e state;
	unsigned char *hash = NULL;
	ssh_key srv_pubkey = NULL;
	size_t hlen;
	char buf[10];
	char *hexa;
	char *p;
	int cmp;
	int rc;

	rc = ssh_get_server_publickey(session, &srv_pubkey);
	if (rc < 0) {
		return -1;
	}

	rc = ssh_get_publickey_hash(srv_pubkey,
			SSH_PUBLICKEY_HASH_SHA1,
			&hash,
			&hlen);
	ssh_key_free(srv_pubkey);
	if (rc < 0) {
		return -1;
	}

	state = ssh_session_is_known_server(session);
	switch (state) {
		case SSH_KNOWN_HOSTS_OK:
			/* OK */

			break;
		case SSH_KNOWN_HOSTS_CHANGED:
			fprintf(stderr, "Host key for server changed: it is now:\n");
			ssh_print_hexa("Public key hash", hash, hlen);
			fprintf(stderr, "For security reasons, connection will be stopped\n");
			ssh_clean_pubkey_hash(&hash);

			return -1;
		case SSH_KNOWN_HOSTS_OTHER:
			fprintf(stderr, "The host key for this server was not found but an other"
					"type of key exists.\n");
			fprintf(stderr, "An attacker might change the default server key to"
					"confuse your client into thinking the key does not exist\n");
			ssh_clean_pubkey_hash(&hash);

			return -1;
		case SSH_KNOWN_HOSTS_NOT_FOUND:
			fprintf(stderr, "Could not find known host file.\n");
			fprintf(stderr, "If you accept the host key here, the file will be"
					"automatically created.\n");

			/* FALL THROUGH to SSH_SERVER_NOT_KNOWN behavior */

		case SSH_KNOWN_HOSTS_UNKNOWN:
			hexa = ssh_get_hexa(hash, hlen);
			fprintf(stderr,"The server is unknown. Do you trust the host key?\n");
			fprintf(stderr, "Public key hash: %s\n", hexa);
			ssh_string_free_char(hexa);
			ssh_clean_pubkey_hash(&hash);
			p = fgets(buf, sizeof(buf), stdin);
			if (p == NULL) {
				return -1;
			}

			cmp = strncasecmp(buf, "yes", 3);
			if (cmp != 0) {
				return -1;
			}

			rc = ssh_session_update_known_hosts(session);
			if (rc < 0) {
				fprintf(stderr, "Error %s\n", strerror(errno));
				return -1;
			}

			break;
		case SSH_KNOWN_HOSTS_ERROR:
			fprintf(stderr, "Error %s", ssh_get_error(session));
			ssh_clean_pubkey_hash(&hash);
			return -1;
	}

	ssh_clean_pubkey_hash(&hash);
	return 0;
}

// https://plplot.sourceforge.net/documentation.php
// https://plplot.sourceforge.net/examples.php
// plplot example 0 and ext-cairo-test.c
static void draw_function (GtkDrawingArea *area,
		cairo_t        *cr,
		int             width,
		int             height,
		gpointer        user_data)
{
	DATA *data=user_data;
	if(!ListIsEmpty(&(data->cans)))
	{
		//printf("draw begin\n");
		//PLFLT xmin=data->cans.head->item.t;
		//PLFLT xmax=data->cans.end->item.t;
		PLFLT xmin,xmax;
		PLFLT ymin, ymax;
		int plot_counts=0;
		gboolean active_checkbutton[VOLTLEN+TEMPLEN];

		if(gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(data->live_toggle)))
			xmax=data->cans.end->item.t;
		else
			xmax=data->to_time;

		if(data->from_time_entered)
			xmin=data->from_time;
		else
			xmin=data->cans.head->item.t;

		for(int i=0;i<(VOLTLEN+TEMPLEN);i++)
			if((active_checkbutton[i]=gtk_check_button_get_active(GTK_CHECK_BUTTON(data->checkbutton[i]))))
				plot_counts++;

		plsdev( "extcairo" );

		{
			char str[12];
			sprintf(str,"%dx%d",
					gtk_widget_get_width(data->area),
					gtk_widget_get_height(data->area));
			plsetopt("geometry", str);
		}

		// change to white background and black foreground, and gray color palette
		// http://plplot.sourceforge.net/docbook-manual/plplot-html-5.15.0/color.html
		// seems should be put before plinit; or need pladv(), plvpor(), plwind() for a new picture?
		// more see example 16
		// http://plplot.sourceforge.net/examples.php?demo=16
		// /usr/share/plplot5.15.0/examples/c/x16c.c
		plspal0("cmap0_black_on_white.pal");
		plspal1("cmap1_gray.pal", 1);

		// Initialize plplot
		if(plot_counts>3)
			plstar(3,(plot_counts+2)/3);
		else
			plstar(1,plot_counts);
		pl_cmd( PLESC_DEVINIT, cr );

		// 10 char unix time: 1745925459
		// set numbers of digits to display x axis labels
		plsxax(10,0);

		for(int i=0;i<(VOLTLEN+TEMPLEN);i++)
		{
			if(active_checkbutton[i])
			{
				if(i<VOLTLEN)
				{
					// according to .dbc file
					ymin=0;
					ymax=6.;
				}
				else
				{
					// according to .dbc file
					ymin=-50;
					ymax=100;
				}

				// Create a labelled box to hold the plot.
				plenv(xmin, xmax, ymin, ymax, 0, 0);
				if(i<VOLTLEN)
					pllab("Time (s)","Voltage (V)",checkbutton_names[i]);
				else
					pllab("Time (s)","Temperature (C)",checkbutton_names[i]);
				// Plot the data that was prepared above.
				// plstring or plptex for scatter
				// #(NNN) is Hershey font code, more see example 5, 6, 21
				// #(727) is centred X symbol; other maybe useful codes: #(728)
				// hershey font code see http://plplot.sourceforge.net/examples.php?demo=07 ?
				{
					Node * pnode = data->cans.head;
					while(pnode!=NULL && ((pnode->item.t <= xmax) || gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(data->live_toggle))) )
					{
						if(pnode->item.t >= xmin)
						{
							if(i<VOLTLEN)
								plptex(pnode->item.t,pnode->item.volt[i],1.,0.,0.5,"#(727)");
							else
								plptex(pnode->item.t,pnode->item.temp[i-VOLTLEN],1.,0.,0.5,"#(727)");
						}
						pnode=pnode->next;
					}
				}
			}
		}

		// Close PLplot library
		plend();
	}
}

static void print_data (GtkWidget *widget, gpointer user_data)
{
	DATA *data=user_data;
	printf("%u",data->cans.end->item.t);
	for(int i=0;i<VOLTLEN;i++)
		printf(",%5.3f",data->cans.end->item.volt[i]);
	for(int i=0;i<TEMPLEN;i++)
		printf(",%5.1f",data->cans.end->item.temp[i]);
	putchar('\n');
}

static void set_from_time (GtkWidget *widget, gpointer user_data)
{
	DATA *data=user_data;
	if(!(data->from_time_entered))
		data->from_time_entered=true;
	data->from_time=strtoul(gtk_editable_get_text(GTK_EDITABLE(data->from_entry)),NULL,10);
	gtk_widget_queue_draw(data->area);
}

static void set_to_time (GtkWidget *widget, gpointer user_data)
{
	DATA *data=user_data;
	gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(data->live_toggle),FALSE);
	data->to_time=strtoul(gtk_editable_get_text(GTK_EDITABLE(data->to_entry)),NULL,10);
	gtk_widget_queue_draw(data->area);
}

static void activate (GtkApplication *app, gpointer user_data)
{
	DATA *data=user_data;
	GtkWidget *window;
	data->area = gtk_drawing_area_new ();
	GtkWidget *button;
	GtkWidget *box = gtk_box_new(GTK_ORIENTATION_VERTICAL,1);
	GtkWidget *scrolled_window;
	GtkWidget *flowbox_volt = gtk_flow_box_new();
	GtkWidget *flowbox_temp = gtk_flow_box_new();
	GtkWidget *expander_volt = gtk_expander_new("Choose cell voltages to plot");
	GtkWidget *expander_temp = gtk_expander_new("Choose cell temperatures to plot");
	GtkWidget *from_box = gtk_box_new(GTK_ORIENTATION_HORIZONTAL,0);
	GtkWidget *to_box = gtk_box_new(GTK_ORIENTATION_HORIZONTAL,0);
	GtkWidget *from_button = gtk_button_new_with_label ("Enter from time");
	GtkWidget *to_button = gtk_button_new_with_label ("Enter to time");

	data->from_entry = gtk_entry_new();
	data->to_entry = gtk_entry_new();
	// TODO: gtk_entry_set_placeholder_text()
	//gtk_entry_set_placeholder_text(GTK_ENTRY(data->from_entry),"...");
	// unix time now is about 10 char
	gtk_entry_set_max_length(GTK_ENTRY(data->from_entry),10);
	gtk_entry_set_max_length(GTK_ENTRY(data->to_entry),10);
	gtk_box_append(GTK_BOX(from_box), data->from_entry);
	gtk_box_append(GTK_BOX(from_box), from_button);
	gtk_box_append(GTK_BOX(to_box), data->to_entry);
	gtk_box_append(GTK_BOX(to_box), to_button);
	g_signal_connect (from_button, "clicked", G_CALLBACK (set_from_time), user_data);
	g_signal_connect (to_button, "clicked", G_CALLBACK (set_to_time), user_data);

	data->volt_label=gtk_label_new("Average voltage:");
	data->temp_label=gtk_label_new("Average temperature:");
	data->live_toggle = gtk_toggle_button_new_with_label("Live");
	gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(data->live_toggle),TRUE);

	for(int i=0;i<(VOLTLEN+TEMPLEN);i++)
		data->checkbutton[i]=gtk_check_button_new_with_label(checkbutton_names[i]);
	gtk_check_button_set_active(GTK_CHECK_BUTTON(data->checkbutton[0]),TRUE);
	gtk_check_button_set_active(GTK_CHECK_BUTTON(data->checkbutton[VOLTLEN]),TRUE);

	window = gtk_application_window_new (app);
	gtk_window_set_title (GTK_WINDOW (window), "remote_plot");
	gtk_window_set_default_size (GTK_WINDOW (window), 1000, 1000);

	//gtk_drawing_area_set_content_width (GTK_DRAWING_AREA (data->area), 600);
	//gtk_drawing_area_set_content_height (GTK_DRAWING_AREA (data->area), 600);
	gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (data->area),
			draw_function,
			user_data, NULL);
	gtk_widget_set_vexpand(data->area,TRUE);
	gtk_widget_set_hexpand(data->area,TRUE);

	button = gtk_button_new_with_label ("Print last second data");
	g_signal_connect (button, "clicked", G_CALLBACK (print_data), user_data);

	// https://gitlab.gnome.org/GNOME/gtk/-/blob/main/demos/print-editor/print-editor.c
	scrolled_window=gtk_scrolled_window_new();
	gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (scrolled_window),GTK_POLICY_AUTOMATIC,GTK_POLICY_AUTOMATIC);
	gtk_scrolled_window_set_has_frame (GTK_SCROLLED_WINDOW (scrolled_window), TRUE);
	gtk_widget_set_vexpand (scrolled_window, TRUE);
	gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (scrolled_window), box);

	for(int i=0;i<(VOLTLEN+TEMPLEN);i++)
	{
		if(i<VOLTLEN)
			gtk_flow_box_append(GTK_FLOW_BOX(flowbox_volt), data->checkbutton[i]);
		else
			gtk_flow_box_append(GTK_FLOW_BOX(flowbox_temp), data->checkbutton[i]);
	}
	gtk_expander_set_child (GTK_EXPANDER (expander_volt), flowbox_volt);
	gtk_expander_set_child (GTK_EXPANDER (expander_temp), flowbox_temp);

	gtk_box_append(GTK_BOX(box), button);
	gtk_box_append(GTK_BOX(box), data->volt_label);
	gtk_box_append(GTK_BOX(box), data->temp_label);
	gtk_box_append(GTK_BOX(box), data->live_toggle);
	gtk_box_append(GTK_BOX(box), from_box);
	gtk_box_append(GTK_BOX(box), to_box);
	gtk_box_append(GTK_BOX(box), expander_volt);
	gtk_box_append(GTK_BOX(box), expander_temp);
	gtk_box_append(GTK_BOX(box), data->area);
	gtk_window_set_child (GTK_WINDOW (window), scrolled_window);

	gtk_window_present (GTK_WINDOW (window));

	//printf("before g_timeout_add\n");
	g_timeout_add(1000,read_data,user_data);
	//printf("after g_timeout_add\n");
}

// https://gitlab.gnome.org/GNOME/gtk/-/blob/main/demos/gtk-demo/main.c
static int command_line (GApplication *app, GApplicationCommandLine *cmdline, gpointer user_data)
{
	DATA *data=user_data;
	int rc;
	GVariantDict *options = g_application_command_line_get_options_dict (cmdline);
	// not sure if using char * here is ok
	char *dest="Spartan_Racing_Charger@10.0.0.9";
	// https://docs.gtk.org/glib/gvariant-format-strings.html#pointers
	// &s copy the pointer
	g_variant_dict_lookup (options, "destination", "&s", &dest);
	g_variant_dict_lookup (options, "local", "b", &(data->local));

	if(!(data->local))
	{
		// Open session and set options
		data->session = ssh_new();
		if (data->session == NULL)
			exit(-1);
		ssh_options_set(data->session, SSH_OPTIONS_HOST, dest);

		// Connect to server
		rc = ssh_connect(data->session);
		if (rc != SSH_OK)
		{
			fprintf(stderr, "Error connecting to %s: %s\n",
					dest, ssh_get_error(data->session));
			ssh_free(data->session);
			exit(-1);
		}

		// Verify the server's identity
		// For the source code of verify_knownhost(), check previous example
		if (verify_knownhost(data->session) < 0)
		{
			ssh_disconnect(data->session);
			ssh_free(data->session);
			exit(-1);
		}

		// Authenticate ourselves
		// https://api.libssh.org/stable/libssh_tutor_authentication.html
		rc = ssh_userauth_publickey_auto(data->session, NULL, NULL);
		if (rc != SSH_AUTH_SUCCESS)
		{
			fprintf(stderr, "Error authenticating with key: %s\n",
					ssh_get_error(data->session));
			ssh_disconnect(data->session);
			ssh_free(data->session);
			exit(-1);
		}

		data->sftp = sftp_new(data->session);
		if (data->sftp == NULL)
		{
			fprintf(stderr, "Error allocating SFTP session: %s\n",
					ssh_get_error(data->session));
			return SSH_ERROR;
		}

		rc = sftp_init(data->sftp);
		if (rc != SSH_OK)
		{
			fprintf(stderr, "Error initializing SFTP session: code %d.\n",
					sftp_get_error(data->sftp));
			sftp_free(data->sftp);
			return rc;
		}
	}


	// https://discourse.gnome.org/t/gio-application-commandline-does-trigger-activate-signal/2988/22
	// > If you pass G_APPLICATION_HANDLES_COMMAND_LINE in the flags, the
	// > command-line args are passed to the primary instance and ::activate is
	// > not emitted. An example again is an something like --hide-window or
	// > --do-without-disturbing-user which wouldn’t work if the default were to
	// > trigger ::activate and open the window. So just pass
	// > G_APPLICATION_HANDLES_COMMAND_LINE and then call
	// > g_application_activate() in your ::command-line handler
	g_application_activate(app);

	return 0;
}

int main (int argc, char **argv)
{
	DATA data;
	GtkApplication *app;
	int status;

	{
		// usually ~/.local/share
		const char *dir=getenv("XDG_DATA_HOME");
		const char *str;
		if(dir != NULL)
			str="/mycan.csv";
		else
		{
			str="/.local/share/mycan.csv";
			dir=getenv("HOME");
		}
		data.filename=malloc((strlen(dir)+strlen(str)+1)*sizeof(char));
		sprintf(data.filename,"%s%s",dir,str);
	}

	InitializeList(&(data.cans));
	if(ListIsFull(&(data.cans)))
	{
		fprintf(stderr,"No memory available! Bye!\n");
		exit(1);
	}
	data.from_time_entered=false;
	data.offset=0;
	data.local=false;

	//printf("after init\n");

	// if I don't handle command line
	//app = gtk_application_new ("org.gtk.example", G_APPLICATION_DEFAULT_FLAGS);
	// if I handle command line
	app = gtk_application_new ("org.gtk.example", G_APPLICATION_HANDLES_COMMAND_LINE);

	g_application_add_main_option(G_APPLICATION(app),"destination",'d',0,G_OPTION_ARG_STRING,"ssh destination","Spartan_Racing_Charger@10.0.0.9");
	g_application_add_main_option(G_APPLICATION(app),"local",'l',0,G_OPTION_ARG_NONE,"Only read from local .csv file",NULL);

	g_signal_connect (app, "activate", G_CALLBACK (activate), &data);
	g_signal_connect (app, "command-line", G_CALLBACK (command_line), &data);
	//printf("before g_app run\n");
	status = g_application_run (G_APPLICATION (app), argc, argv);
	g_object_unref (app);

	//printf("before ssh free\n");

	if(data.local==false)
	{
		ssh_disconnect(data.session);
		ssh_free(data.session);
	}
	// Segmentation fault (core dumped) error, why? maybe double free? so no free is ok?
	//sftp_free(sftp);

	EmptyTheList(&(data.cans));

	free(data.filename);

	return status;
}