#!/usr/bin/php -q
<?
// CONFIGURATION
// Enables logging in CSV format, suitable for loading into a spreadsheet
$log_stats = false;
$logfile = "/var/log/asterisk/dspeed.csv";

// Threshold for deciding if dial speed is rising or falling
$threshold = 9.0;

// Use standard Asterisk sounds or text-to-speech?
$tts = true;
$tts_engine = "eSpeak";		// you could use Flite or Festival

// Some PHP implementations don't define these!
if(!defined("STDIN")) {
	define("STDIN", fopen('php://stdin','r'));
}
if(!defined("STDOUT")) {
	define("STDOUT", fopen('php://stdout','w'));
}
if(!defined("STDERR")) {
	define("STDERR", fopen('php://stderr','w'));
}

//   Rotary dial speed tester, for use with Russ Price's dahdi-cnet
//   extended DAHDI drivers.

//   This was inspired by Max Parke's Perl dial speed tester.  The
//   basic test is simpler, since there are never more than 20 hook
//   state transitions in the /proc/dahdi_dial/<channel> log.  Also,
//   the pulse count of the last received digit is provided in the log.

//   This dial speed tester needs no additional audio files or applications.

//   2011-08-20: Added an indication for dial speed run-down/run-up.
//   Since the timing accuracy of the pulse logging isn't as accurate
//   as I would like (remember, normal Linux isn't a hard real time
//   OS, and DAHDI won't compile on RT kernels), I'm using a linear
//   regression to get a better idea of the dial speed trend.  I'm
//   then taking the percentage delta between the LR value for the
//   first and  last pulses; if it is greater than the threshold
//   (default of 9%), indicate run-down or run-up.

//   The 9% threshold was arrived at empirically, by observing the
//   behavior of electronic pulse dials, a WECO Trimline rotary dial,
//   and a WECO 302 dial.  The 302 audibly runs down in speed.
//   The electronic dials and the Trimline typically show deltas in
//   the 2%-5% range, due to system timing inaccuracies.

//   You can log the statistics in CSV format if you please.

//   Text-to-speech is now supported.  The default is not to use it;
//   if enabled, the default is to use eSpeak.  You could use Flite
//   or Festival if you prefer.

//   The standard Asterisk sound library doesn't include the word "steady,"
//   so I'm using tones as indicators if a TTS engine is unavailable.  A
//   steady tone indicates steady  speed, hi-lo indicates dial speed run-down,
//   and lo-hi indicates dial speed run-up.

//   Copyright (C) 2011 Russ Price

//   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

ob_implicit_flush(false);
error_reporting(0);
set_time_limit(300);

/**
 * linear regression function
 * @param $x array x-coords
 * @param $y array y-coords
 * @returns array() m=>slope, b=>intercept
 */
function linear_regression($x, $y) {
  // calculate number points
  $n = count($x);
  // ensure both arrays of points are the same size
  if ($n != count($y)) {
    trigger_error("linear_regression(): Number of elements in coordinate arrays do not match.", E_USER_ERROR);
  }

  // calculate sums
  $x_sum = array_sum($x);
  $y_sum = array_sum($y);

  $xx_sum = 0;
  $xy_sum = 0;

  for($i = 0; $i < $n; $i++) {
    $xy_sum+=($x[$i]*$y[$i]);
    $xx_sum+=($x[$i]*$x[$i]);
  }

  // calculate slope
  $m = (($n * $xy_sum) - ($x_sum * $y_sum)) / (($n * $xx_sum) - ($x_sum * $x_sum));

  // calculate intercept
  $b = ($y_sum - ($m * $x_sum)) / $n;

  // return result
  return array("m"=>$m, "b"=>$b);
}

function execute_agi($command) {
	fputs( STDOUT, $command . "\n" );
	fflush( STDOUT );
	
	$resp = fgets( STDIN, 4096 );
	
	if(preg_match("/^([0-9]{1,3}) (.*)/", $resp, $matches))  {
		if (preg_match('/result=([-0-9a-zA-Z]*)(.*)/', $matches[2], $match))  {
			$arr['code'] = $matches[1];
			$arr['result'] = $match[1];
			if (isset($match[3]) && $match[3])
			$arr['data'] = $match[3];
			return $arr;
		} else {
			$arr['code'] = $matches[1];
			$arr['result'] = 0;
			return $arr;
		}
	} else {
		$arr['code'] = -1;
		$arr['result'] = -1;
		return $arr;
	}
}

function stream($file) {
	execute_agi("STREAM FILE \"$file\" \"\"");
}

function saynumber($number) {
	execute_agi("SAY NUMBER \"$number\" \"\"");
}

function saydigits($digits) {
	execute_agi("SAY DIGITS \"$digits\" \"\"");
}

function calcspeed($chan) {
	global $threshold, $log_stats, $logfile, $tts, $tts_engine;

	$fpPulse = fopen("/proc/dahdi_dial/$chan", "r");
	if(!$fpPulse) {
		execute_agi("EXEC Wait 1");
		stream("error-number");
		saynumber("1");
		return;
	}

	$i = 0;

	// Grab pulse count. If it is less than 10, don't bother.
	$in = fgets($fpPulse);
	list($pcount) = sscanf($in, "Last pulse count: %d");
	if($pcount != 10) {
		execute_agi("EXEC Wait 1");
		stream("bad");
		stream("digit");
		saydigits($pcount);
		fclose($fpPulse);
		return;
	} else {
		for($i = 0, $mcnt = 0, $bcnt = 0; $i < 20; $i++) {
			$in = fgets($fpPulse);
			if($in == "") {
				break;
			}
			list($state, $sec, $usec) = sscanf($in, "zt_hooksig %d: %d:%d");
			if($state) {
				$make[$mcnt++] = $sec + ($usec * .000001);
			} else {
				$break[$bcnt++]  = $sec + ($usec * .000001);
			}
		}
	}
	fclose($fpPulse);

	if($i < 20) {
		execute_agi("EXEC Wait 1");
		stream("bad");
		stream("count");
		return;
	} else {
		for($i = 0; $i < 10; $i++) {
			// need an array of x for regression
			$x[$i] = $i;
			$breaklen[$i] = $make[$i] - $break[$i];
			// Fudge the last "make" length by using the mean
			// of the nine real makes.
			if($i < 9) {
				$makelen[$i] = $break[$i + 1] - $make[$i];
			} else {
				$makelen[$i] = array_sum($makelen) / count($makelen);
			}
			$cycle[$i] = $makelen[$i] + $breaklen[$i];
		}
		$break_length = array_sum($breaklen);
		$make_length = array_sum($makelen);
		$cycle_length = $break_length + $make_length;
		$break_percent = 100 * ($break_length / $cycle_length);
		$make_percent = 100 * ($make_length / $cycle_length);
		$break_percent = round($break_percent);
		$make_percent = round($make_percent);
		$speed = 10 / $cycle_length;
		$strspeed = sprintf("%.1f", $speed);

		$LR = linear_regression($x, $cycle);
		// let's take the regression values for the first and last
		// pulses, and get their percentage delta
		$begin = $LR['b'];		// x=0
		$end = $LR['m']*9+$LR['b'];	// x=9
		$lrdiff = $end - $begin;
		$pctdelta = $lrdiff / $begin * 100;

		if($log_stats) {
			$fp = fopen($logfile, "a");
			fprintf($fp, "Channel,%s\n", $chan);
			fprintf($fp, "Speed,$strspeed\n", $strspeed);
			fprintf($fp, "m,%.6f\n", $LR['m']);
			fprintf($fp, "b,%.6f\n", $LR['b']);
			fprintf($fp, "pctdelta,%.2f\n", $pctdelta);
			fprintf($fp, "x,break,make,breaklen,makelen,cycle,LR\n");
			for($i = 0; $i < 10; $i++) {
				fprintf($fp, "%d,%.6f,%.6f,%.6f,%.6f,%.6f,%.6f\n", $i, $break[$i], $make[$i], $breaklen[$i], $makelen[$i], $cycle[$i], $LR['m'] * $i + $LR['b']);
			}
			fclose($fp);
		}
		execute_agi("EXEC Wait 1");
		if($tts) {
			if($pctdelta > $threshold) {
				$trend = "falling";
			} else if ($pctdelta < -$threshold) {
				$trend = "rising";
			} else {
				$trend = "steady";
			}
			// Commas don't work well in AGI arguments.
			$msg = sprintf("Speed: %s.  %d percent break; %d percent make.  Speed %s.",
				$strspeed, $break_percent, $make_percent, $trend);
			execute_agi("EXEC $tts_engine \"$msg\"");
		} else {
			stream("speed");
			$sp = explode('.', $strspeed);
			saynumber($sp[0]);
			stream("wx/point");
			saydigits($sp[1]);
			execute_agi("EXEC Wait 1");
			stream("period");
			saynumber($break_percent);
			stream("wx/percent");
			saynumber($make_percent);
			stream("wx/percent");
			execute_agi("EXEC Wait 1");
			if($pctdelta > $threshold) {		// indicate run-down
				execute_agi("EXEC Wait 1");
				execute_agi("EXEC PlayTones 620");
				execute_agi("EXEC Wait 0.5");
				execute_agi("EXEC PlayTones 350");
				execute_agi("EXEC Wait 0.5");
				execute_agi("EXEC StopPlayTones");
			} else if($pctdelta < -$threshold) {	// indicate run-up
				execute_agi("EXEC Wait 1");
				execute_agi("EXEC PlayTones 350");
				execute_agi("EXEC Wait 0.5");
				execute_agi("EXEC PlayTones 620");
				execute_agi("EXEC Wait 0.5");
				execute_agi("EXEC StopPlayTones");
			} else {				// indicate steady
				execute_agi("EXEC Wait 1");
				execute_agi("EXEC PlayTones 480");
				execute_agi("EXEC Wait 1");
				execute_agi("EXEC StopPlayTones");
			}
		}
		execute_agi("EXEC Wait 1");
	}
}

 $agivars = array();
 while (!feof(STDIN)) {
     $agivar = trim(fgets(STDIN));
     if ($agivar === '') {
         break;
     }
     $agivar = explode(':', $agivar);
     $agivars[$agivar[0]] = trim($agivar[1]);
 }
 extract($agivars);

if(!preg_match("/(\w+)\/(\d+)/", $agi_channel, $chaninfo)) {
	execute_agi("EXEC Wait 1");
	stream("bad");
	stream("channel");
	exit;
}

if($chaninfo[1] != "DAHDI") {
	execute_agi("EXEC Wait 1");
	stream("bad");
	stream("channel");
	exit;
}

execute_agi("EXEC PlayTones 600*120");
execute_agi("WAIT FOR DIGIT 30000");
execute_agi("EXEC StopPlayTones");
calcspeed($chaninfo[2]);
?>