<?php

define('FILTER_EXTREME_DIFF', 500);

function _strtotime($x) {
	# Mo, 29 Nov 2010 05:49:20 +0100

	$x = str_replace('Mo,', 'Mon,', $x);
	$x = str_replace('Di,', 'Tue,', $x);
	$x = str_replace('Mi,', 'Wed,', $x);
	$x = str_replace('Do,', 'Thu,', $x);
	$x = str_replace('Fr,', 'Fri,', $x);
	$x = str_replace('Sa,', 'Sat,', $x);
	$x = str_replace('So,', 'Sun,', $x);

	$x = str_replace('Mär ', 'Mar ', $x);
	$x = str_replace('Mai ', 'May ', $x);
	$x = str_replace('Dez ', 'Dec ', $x);

	return strtotime($x);
}

function immort_get_timestamps($fn) {
	$immort_stats = file_get_contents($fn);

	preg_match_all("@Testbegin:\s+([^\n]+)\nSavetime:\s+([^\n]+)\n@ismU", $immort_stats, $m);
	$first_step_time = _strtotime($m[2][0]) - _strtotime($m[1][0]);

	preg_match_all("@Unix time:\s+(\d+)\s+@ismU", $immort_stats, $m);

	$out = array();
	$out[] = $m[1][0]-$first_step_time;
	foreach ($m[1] as &$t) {
		$out[] = $t;
	}
	return $out;
}

function immort_slowdown_factor($fn) { // slow down factor per step (10,000 digits = 1 step)
	$ary = immort_get_timestamps($fn);

	$sa = 0;
	$sn = 0;
	for ($i=2; $i<count($ary); $i++) {

		// Filtern von Extremwerten, sonst kommt seltsamerweise MW(d'') immer 3,1... raus bei 2010, 2012 und 2013!
		if (abs($ary[$i] - $ary[$i-1]) > FILTER_EXTREME_DIFF) continue;
		if (abs($ary[$i-1] - $ary[$i-2]) > FILTER_EXTREME_DIFF) continue;

		$diff_diff = $ary[$i] - 2*$ary[$i-1] + $ary[$i-2]; // zweite numerische ableitung, erinnert an binomische formel
		$sa += $diff_diff; $sn++;
	}
	$diff_diff_mittelwert = $sa/$sn;

	return $diff_diff_mittelwert;
}

function immort_estimate_finishtime($fn, $n) {
	$ary = immort_get_timestamps($fn);
	$t0 = $ary[0];

	$z = immort_slowdown_factor($fn);

	$s = 0;
	for ($i=1; $i<=$n; $i++) {
		$s += $i;
	}
	return $t0 + round($z*$s);
}

function immort_read_r_array($fn) {
        $immort_stats = file_get_contents($fn);

        preg_match_all("@Digit count:\s+(\d+)\s+Param r:\s+(\d+)\s+@ismU", $immort_stats, $m);

        $out = array();
        foreach ($m[2] as $n => &$x) {
                $out[$n+1] = $x;
        }
        return $out;
}