/*
   Copyright (C) 2002-2010 Karl J. Runge <runge@karlrunge.com> 
   All rights reserved.

This file is part of x11vnc.

x11vnc 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.

x11vnc 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 x11vnc; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA
or see <http://www.gnu.org/licenses/>.

In addition, as a special exception, Karl J. Runge
gives permission to link the code of its release of x11vnc with the
OpenSSL project's "OpenSSL" library (or with modified versions of it
that use the same license as the "OpenSSL" library), and distribute
the linked executables.  You must obey the GNU General Public License
in all respects for all of the code used other than "OpenSSL".  If you
modify this file, you may extend this exception to your version of the
file, but you are not obligated to do so.  If you do not wish to do
so, delete this exception statement from your version.
*/

/* -- rates.c -- */

#include "x11vnc.h"
#include "xwrappers.h"
#include "scan.h"

int measure_speeds = 1;
int speeds_net_rate = 0;
int speeds_net_rate_measured = 0;
int speeds_net_latency = 0;
int speeds_net_latency_measured = 0;
int speeds_read_rate = 0;
int speeds_read_rate_measured = 0;


int get_cmp_rate(void);
int get_raw_rate(void);
void initialize_speeds(void);
int get_read_rate(void);
int link_rate(int *latency, int *netrate);
int get_net_rate(void);
int get_net_latency(void);
void measure_send_rates(int init);


static void measure_display_hook(rfbClientPtr cl);
static int get_rate(int which);
static int get_latency(void);


static void measure_display_hook(rfbClientPtr cl) {
	ClientData *cd = (ClientData *) cl->clientData;
	if (! cd) {
		return;
	}
	dtime0(&cd->timer);
}

static int get_rate(int which) {
	rfbClientIteratorPtr iter;
	rfbClientPtr cl;
	int irate, irate_min = 1;	/* 1 KB/sec */
	int irate_max = 100000;		/* 100 MB/sec */
	int count = 0;
	double slowest = -1.0, rate;
	static double save_rate = 1000 * NETRATE0;

	if (!screen) {
		return 0;
	}

	iter = rfbGetClientIterator(screen);
	while( (cl = rfbClientIteratorNext(iter)) ) {
		ClientData *cd = (ClientData *) cl->clientData;

		if (! cd) {
			continue;
		}
		if (cl->state != RFB_NORMAL) {
			continue;
		}
		if (cd->send_cmp_rate == 0.0 || cd->send_raw_rate == 0.0) {
			continue;
		}
		count++;
		
		if (which == 0) {
			rate = cd->send_cmp_rate;
		} else {
			rate = cd->send_raw_rate;
		}
		if (slowest == -1.0 || rate < slowest) {
			slowest = rate;
		}
		
	}
	rfbReleaseClientIterator(iter);

	if (! count) {
		return NETRATE0;
	}

	if (slowest == -1.0) {
		slowest = save_rate;
	} else {
		save_rate = slowest;
	}

	irate = (int) (slowest/1000.0);
	if (irate < irate_min) {
		irate = irate_min;
	}
	if (irate > irate_max) {
		irate = irate_max;
	}
if (0) fprintf(stderr, "get_rate(%d) %d %.3f/%.3f\n", which, irate, save_rate, slowest); 

	return irate;
}

static int get_latency(void) {
	rfbClientIteratorPtr iter;
	rfbClientPtr cl;
	int ilat, ilat_min = 1;	/* 1 ms */
	int ilat_max = 2000;	/* 2 sec */
	double slowest = -1.0, lat;
	static double save_lat = ((double) LATENCY0)/1000.0;
	int count = 0;
	
	if (!screen) {
		return 0;
	}

	iter = rfbGetClientIterator(screen);
	while( (cl = rfbClientIteratorNext(iter)) ) {
		ClientData *cd = (ClientData *) cl->clientData;
		
		if (! cd) {
			continue;
		}
		if (cl->state != RFB_NORMAL) {
			continue;
		}
		if (cd->latency == 0.0) {
			continue;
		}
		count++;

		lat = cd->latency;
		if (slowest == -1.0 || lat > slowest) {
			slowest = lat;
		}
	}
	rfbReleaseClientIterator(iter);

	if (! count) {
		return LATENCY0;
	}

	if (slowest == -1.0) {
		slowest = save_lat;
	} else {
		save_lat = slowest;
	}

	ilat = (int) (slowest * 1000.0);
	if (ilat < ilat_min) {
		ilat = ilat_min;
	}
	if (ilat > ilat_max) {
		ilat = ilat_max;
	}

	return ilat;
}

int get_cmp_rate(void) {
	return get_rate(0);
}

int get_raw_rate(void) {
	return get_rate(1);
}

void initialize_speeds(void) {
	char *s, *s_in, *p;
	int i;

	speeds_read_rate = 0;
	speeds_net_rate = 0;
	speeds_net_latency = 0;
	if (! speeds_str || *speeds_str == '\0') {
		s_in = strdup("");
	} else {
		s_in = strdup(speeds_str);
	}

	if (!strcmp(s_in, "modem")) {
		s = strdup("6,4,200");
	} else if (!strcmp(s_in, "dsl")) {
		s = strdup("6,100,50");
	} else if (!strcmp(s_in, "lan")) {
		s = strdup("6,5000,1");
	} else {
		s = strdup(s_in);
	}

	p = strtok(s, ",");
	i = 0;
	while (p) {
		double val;
		if (*p != '\0') {
			val = atof(p);
			if (i==0) {
				speeds_read_rate = (int) 1000000 * val;
			} else if (i==1) {
				speeds_net_rate = (int) 1000 * val;
			} else if (i==2) {
				speeds_net_latency = (int) val;
			}
		}
		i++;
		p = strtok(NULL, ",");
	}
	free(s);
	free(s_in);

	if (! speeds_read_rate) {
		int n = 0;
		double dt, timer;
#ifdef MACOSX
		if (macosx_console && macosx_read_opengl && fullscreen) {
			copy_image(fullscreen, 0, 0, 0, 0);
			usleep(10 * 1000);
		}
#endif

		dtime0(&timer);
		if (fullscreen) {
			copy_image(fullscreen, 0, 0, 0, 0);
			n = fullscreen->bytes_per_line * fullscreen->height;
		} else if (scanline) {
			copy_image(scanline, 0, 0, 0, 0);
			n = scanline->bytes_per_line * scanline->height;
		}
		dt = dtime(&timer);
		if (n && dt > 0.0) {
			double rate = ((double) n) / dt;
			speeds_read_rate_measured = (int) (rate/1000000.0);
			if (speeds_read_rate_measured < 1) {
				speeds_read_rate_measured = 1;
			} else {
				rfbLog("fb read rate: %d MB/sec\n",
				    speeds_read_rate_measured);
			}
		}
	}
}

int get_read_rate(void) {
	if (speeds_read_rate) {
		return speeds_read_rate;
	}
	if (speeds_read_rate_measured) {
		return speeds_read_rate_measured;
	}
	return 0;
}

int link_rate(int *latency, int *netrate) {
	*latency = get_net_latency();
	*netrate = get_net_rate();

	if (speeds_str) {
		if (!strcmp(speeds_str, "modem")) {
			return LR_DIALUP;
		} else if (!strcmp(speeds_str, "dsl")) {
			return LR_BROADBAND;
		} else if (!strcmp(speeds_str, "lan")) {
			return LR_LAN;
		}
	}

	if (*latency == LATENCY0 && *netrate == NETRATE0)  {
		return LR_UNSET;
	} else if (*latency > 150 || *netrate < 20) {
		return LR_DIALUP;
	} else if (*latency > 50 || *netrate < 150) {
		return LR_BROADBAND;
	} else if (*latency < 10 && *netrate > 300) {
		return LR_LAN;
	} else {
		return LR_UNKNOWN;
	}
}

int get_net_rate(void) {
	int spm = speeds_net_rate_measured;
	if (speeds_net_rate) {
		return speeds_net_rate;
	}
	if (! spm || spm == NETRATE0) {
		speeds_net_rate_measured = get_cmp_rate();
	}
	if (speeds_net_rate_measured) {
		return speeds_net_rate_measured;
	}
	return 0;
}

int get_net_latency(void) {
	int spm = speeds_net_latency_measured;
	if (speeds_net_latency) {
		return speeds_net_latency;
	}
	if (! spm || spm == LATENCY0) {
		speeds_net_latency_measured = get_latency();
	}
	if (speeds_net_latency_measured) {
		return speeds_net_latency_measured;
	}
	return 0;
}

void measure_send_rates(int init) {
	double cmp_rate, raw_rate;
	static double now, start = 0.0;
	static rfbDisplayHookPtr orig_display_hook = NULL;
	double cmp_max = 1.0e+08;	/* 100 MB/sec */
	double cmp_min = 1000.0;	/* 9600baud */
	double lat_max = 5.0;		/* 5 sec */
	double lat_min = .0005;		/* 0.5 ms */
	int min_cmp = 10000, nclients;
	rfbClientIteratorPtr iter;
	rfbClientPtr cl0, cl;
	int msg = 0, clcnt0 = 0, cc;
	int db = 0, ouch_db = 0, ouch = 0;

	if (! measure_speeds) {
		return;
	}
	if (speeds_net_rate && speeds_net_latency) {
		return;
	}
	if (!client_count) {
		return;
	}

	if (! orig_display_hook) {
		orig_display_hook = screen->displayHook;
	}

	if (start == 0.0) {
		dtime(&start);
	}

	dtime0(&now);
	if (now < last_client_gone+4.0) {
		return;
	}
	now = now - start;

	nclients = 0;

	if (!screen) {
		return;
	}

	cl0 = NULL;
	iter = rfbGetClientIterator(screen);
	while( (cl = rfbClientIteratorNext(iter)) ) {
		ClientData *cd = (ClientData *) cl->clientData;

		if (! cd) {
			continue;
		}
		if (cd->send_cmp_rate > 0.0) {
			continue;
		}
		if (cl->onHold) {
			continue;
		}
		nclients++;
		if (cl0 == NULL)  {
			cl0 = cl;
		}
	}
	rfbReleaseClientIterator(iter);

	cl = cl0;
	cc = 0;

	while (cl != NULL && cc++ == 0) {
		int defer, i, cbs, rbs;
		char *httpdir;
		double dt, dt1 = 0.0, dt2, dt3;
		double tm, spin_max = 15.0, spin_lat_max = 1.5;
		int got_t2 = 0, got_t3 = 0;
		ClientData *cd = (ClientData *) cl->clientData;

#if 0
		for (i=0; i<MAX_ENCODINGS; i++) {
			cbs += cl->bytesSent[i];
		}
		rbs = cl->rawBytesEquivalent;
#else
#if LIBVNCSERVER_HAS_STATS
		cbs = rfbStatGetSentBytes(cl);
		rbs = rfbStatGetSentBytesIfRaw(cl);
#endif
#endif

		if (init) {

if (db) fprintf(stderr, "%d client num rects req: %d  mod: %d  cbs: %d  "
    "rbs: %d  dt1: %.3f  t: %.3f\n", init,
    (int) sraRgnCountRects(cl->requestedRegion),
    (int) sraRgnCountRects(cl->modifiedRegion), cbs, rbs, dt1, now);

			cd->timer = dnow();
			cd->cmp_bytes_sent = cbs;
			cd->raw_bytes_sent = rbs;
			continue;
		}

		/* first part of the bulk transfer of initial screen */
		dt1 = dtime(&cd->timer);

if (db) fprintf(stderr, "%d client num rects req: %d  mod: %d  cbs: %d  "
    "rbs: %d  dt1: %.3f  t: %.3f\n", init,
    (int) sraRgnCountRects(cl->requestedRegion),
    (int) sraRgnCountRects(cl->modifiedRegion), cbs, rbs, dt1, now);

		if (dt1 <= 0.0) {
			continue;
		}

		cbs = cbs - cd->cmp_bytes_sent;
		rbs = rbs - cd->raw_bytes_sent;

		if (cbs < min_cmp) {
			continue;
		}

		if (ouch_db) fprintf(stderr, "START-OUCH: %d\n", client_count);
		clcnt0 = client_count;
#define OUCH ( ouch || (ouch = (!client_count || client_count != clcnt0 || dnow() < last_client_gone+4.0)) )

		rfbPE(1000);
		if (OUCH && ouch_db) fprintf(stderr, "***OUCH-A\n");
		if (OUCH) continue;

		if (use_threads) LOCK(cl->updateMutex);

		if (sraRgnCountRects(cl->modifiedRegion)) {
			rfbPE(1000);
			if (OUCH && ouch_db) fprintf(stderr, "***OUCH-B\n");
			if (use_threads) UNLOCK(cl->updateMutex);
			if (OUCH) continue;
		}

		if (use_threads) UNLOCK(cl->updateMutex);

		defer = screen->deferUpdateTime;
		httpdir = screen->httpDir;
		screen->deferUpdateTime = 0;
		screen->httpDir = NULL;

		/* mark a small rectangle: */
		mark_rect_as_modified(0, 0, 16, 16, 1);

		dtime0(&tm);

		dt2 = 0.0;
		dt3 = 0.0;

		if (dt1 < 0.25) {
			/* try to cut it down to avoid long pauses. */
			spin_max = 5.0;
		}

		/* when req1 = 1 mod1 == 0, end of 2nd part of bulk transfer */
		while (1) {
			int req0, req1, mod0, mod1;

			if (OUCH && ouch_db) fprintf(stderr, "***OUCH-C1\n");
			if (OUCH) break;

			if (use_threads) LOCK(cl->updateMutex);

			req0 = sraRgnCountRects(cl->requestedRegion);
			mod0 = sraRgnCountRects(cl->modifiedRegion);

			if (use_threads) UNLOCK(cl->updateMutex);

			if (use_threads) {
				usleep(1000);
			} else {
				if (mod0) {
					rfbPE(1000);
				} else {
					rfbCFD(1000);
				}
			}
			dt = dtime(&tm);
			dt2 += dt;
			if (dt2 > spin_max) {
				break;
			}

			if (OUCH && ouch_db) fprintf(stderr, "***OUCH-C2\n");
			if (OUCH) break;

			if (use_threads) LOCK(cl->updateMutex);

			req1 = sraRgnCountRects(cl->requestedRegion);
			mod1 = sraRgnCountRects(cl->modifiedRegion);

			if (use_threads) UNLOCK(cl->updateMutex);

if (db) fprintf(stderr, "dt2 calc: num rects req: %d/%d mod: %d/%d  "
    "fbu-sent: %d  dt: %.4f dt2: %.4f  tm: %.4f\n",
    req0, req1, mod0, mod1,
#if 0
    cl->framebufferUpdateMessagesSent,
#else
#if LIBVNCSERVER_HAS_STATS
    rfbStatGetMessageCountSent(cl, rfbFramebufferUpdate),
#endif
#endif
    dt, dt2, tm);
			if (req1 != 0 && mod1 == 0) {
				got_t2 = 1;
				break;
			}
		}
		if (OUCH && ouch_db) fprintf(stderr, "***OUCH-D\n");
		if (OUCH) goto ouch;

		if (! got_t2) {
			dt2 = 0.0;
		} else {
			int tr, trm = 3;
			double dts[10];
			
			/*
			 * Note: since often select(2) cannot sleep
			 * less than 1/HZ (e.g. 10ms), the resolution
			 * of the latency may be messed up by something
			 * of this order.  Effect may occur on both ends,
			 * i.e. the viewer may not respond immediately.
			 */
		
			for (tr = 0; tr < trm; tr++) {
				usleep(5000);

				/* mark a 2nd small rectangle: */
				mark_rect_as_modified(0, 0, 16, 16, 1);
				i = 0;
				dtime0(&tm);
				dt3 = 0.0;

				/*
				 * when req1 > 0 and mod1 == 0, we say
				 * that is the "ping" time.
				 */
				while (1) {
					int req0, req1, mod0, mod1;

					if (use_threads) LOCK(cl->updateMutex);

					req0 = sraRgnCountRects(cl->requestedRegion);
					mod0 = sraRgnCountRects(cl->modifiedRegion);

					if (use_threads) UNLOCK(cl->updateMutex);

					if (i == 0) {
						rfbPE(0);
					} else {
						if (use_threads) {
							usleep(1000);
						} else {
							/* try to get it all */
							rfbCFD(1000*1000);
						}
					}
					if (OUCH && ouch_db) fprintf(stderr, "***OUCH-E\n");
					if (OUCH) goto ouch;
					dt = dtime(&tm);
					i++;

					dt3 += dt;
					if (dt3 > spin_lat_max) {
						break;
					}

					if (use_threads) LOCK(cl->updateMutex);

					req1 = sraRgnCountRects(cl->requestedRegion);
					mod1 = sraRgnCountRects(cl->modifiedRegion);

					if (use_threads) UNLOCK(cl->updateMutex);

if (db) fprintf(stderr, "dt3 calc: num rects req: %d/%d mod: %d/%d  "
    "fbu-sent: %d  dt: %.4f dt3: %.4f  tm: %.4f\n",
    req0, req1, mod0, mod1,
#if 0
    cl->framebufferUpdateMessagesSent,
#else
#if LIBVNCSERVER_HAS_STATS
    rfbStatGetMessageCountSent(cl, rfbFramebufferUpdate),
#endif
#endif
    dt, dt3, tm);

					if (req1 != 0 && mod1 == 0) {
						dts[got_t3++] = dt3;
						break;
					}
				}
			}
		
			if (! got_t3) {
				dt3 = 0.0;
			} else {
				if (got_t3 == 1) {
					dt3 = dts[0];
				} else if (got_t3 == 2) {
					dt3 = dts[1];
				} else {
					if (dts[2] > 0.0) {
						double rat = dts[1]/dts[2];
						if (rat > 0.5 && rat < 2.0) {
							dt3 = dts[1]+dts[2];
							dt3 *= 0.5;
						} else {
							dt3 = dts[1];
						}
					} else {
						dt3 = dts[1];
					}
				}
			}
		}

		ouch:
		
		screen->deferUpdateTime = defer;
		screen->httpDir = httpdir;

		if (OUCH && ouch_db) fprintf(stderr, "***OUCH-F\n");
		if (OUCH) break;

		dt = dt1 + dt2;


		if (dt3 <= dt2/2.0) {
			/* guess only 1/2 a ping for reply... */
			dt = dt - dt3/2.0;
		}

		cmp_rate = cbs/dt;
		raw_rate = rbs/dt;

		if (cmp_rate > cmp_max) {
			cmp_rate = cmp_max;
		}
		if (cmp_rate <= cmp_min) {
			cmp_rate = cmp_min;
		}

		cd->send_cmp_rate = cmp_rate;
		cd->send_raw_rate = raw_rate;

		if (dt3 > lat_max) {
			dt3 = lat_max;
		}
		if (dt3 <= lat_min) {
			dt3 = lat_min;
		}

		cd->latency = dt3;
		
		rfbLog("client %d network rate %.1f KB/sec (%.1f eff KB/sec)\n",
		    cd->uid, cmp_rate/1000.0, raw_rate/1000.0);
		rfbLog("client %d latency:  %.1f ms\n", cd->uid, 1000.0*dt3);
		rfbLog("dt1: %.4f, dt2: %.4f dt3: %.4f bytes: %d\n",
		    dt1, dt2, dt3, cbs);
		msg = 1;
	}

	if (msg) {
		int link, latency, netrate;
		char *str = "error";

		link = link_rate(&latency, &netrate);
		if (link == LR_UNSET) {
			str = "LR_UNSET";
		} else if (link == LR_UNKNOWN) {
			str = "LR_UNKNOWN";
		} else if (link == LR_DIALUP) {
			str = "LR_DIALUP";
		} else if (link == LR_BROADBAND) {
			str = "LR_BROADBAND";
		} else if (link == LR_LAN) {
			str = "LR_LAN";
		}
		rfbLog("link_rate: %s - %d ms, %d KB/s\n", str, latency,
		    netrate);
	}

	if (init) {
		if (nclients) {
			screen->displayHook = measure_display_hook;
		}
	} else {
		screen->displayHook = orig_display_hook;
	}
}