<?php
////
// Author: Sean Colombo
// Date: 20080224
//
// This file contains generic utilities that are not specific to this site.
// Since there is no other unifying theme, they should be kept in
// alphabetical order to make the file more managable.
//
// Functions:
//	constrainTo(...)
//	deserialize_nested(...)
//	endsWith(...)
//	getAgeFromDob(...)
//	getCodePath(...)
//	getDomain(...)
//	getImageExts(...)
//	getImageMimes(...)
//	getPost(...)
//	getVal(...)
//	mysql_begin(...)
//	mysql_commit(...)
//	mysql_rollback(...)
//	nextNum(...)
//	scaleMedia(...)
//	startsWith(...)
////

////
// Force the data to fall in the range of minValue to maxValue.  If it is originally less than min, it will become min, if it was originally greater
// than max, it will become max.
////
function constrainTo($data, $minValue, $maxValue){
	if($minValue <= $maxValue){
		if($data < $minValue){
			$data = $minValue;
		} else if($data > $maxValue){
			$data = $maxValue;
		}
	}
	return $data;
} // end constrainTo(...)

////
// Turns a string into an array where the string represents a nested array where the top-level array
// values are separated by a pipe, and the values in the sub-array are separated by two pipes, etc.
//
// See also: serialize_nested.
////
function deserialize_nested($serializedData, $separator=","){
	$retVal = array();
	$matches = array();
	while(0 < preg_match("/^(.*?[^$separator])[$separator]([^$separator].*)$/is", $serializedData, $matches)){
		$retVal[] = $matches[1];
		$serializedData = $matches[2];
	}
	$retVal[] = $serializedData;
	
	// Recursively deserialize all of the sub-arrays.
	for($cnt=0; $cnt < count($retVal); $cnt++){
		if(false !== strpos($retVal[$cnt], $separator)){
			// Instead of making the delimiter longer, just change it so that all remaining delimiters are one character shorter.
			$subData = $retVal[$cnt];
			$subData = preg_replace("/($separator+)$separator/is", "$1", $subData);
			$retVal[$cnt] = deserialize_nested($subData, $separator);
		}
	}

	return $retVal;
} // end deserialize_nested()

////
// Given an array of arbitrary depth, serializes it to a string delimited by groups of 'separator' characters.
// The amount of depth will be equal to the number of sequential separators.   To deserialize these values later,
// use to the deserialize_nested() function.
////
function serialize_nested($arrayData, $separator=","){
	if($separator == ""){return implode($separator, $arrayData);} // not recommended.  the deserializer won't work on this.
	$retVal = "";
	foreach($arrayData as $currValue){
		$retVal .= (($retVal=="")?"":$separator);
		if(is_array($currValue)){
			$retVal .= serialize_nested($currValue, $separator.substr($separator,0,1));
		} else {
			$retVal .= $currValue;
		}
	}
	return $retVal;
} // end serialize_nested()

////
// Returns true if all of suffix is found at the end of haystack.
////
function endsWith($haystack, $suffix){
	return ((strlen($haystack)>=strlen($suffix)) && (substr($haystack, strlen($haystack)-strlen($suffix))==$suffix));
} // end endsWith(...)

////
// Takes a date and and returns the time since that date in years (aka age)
////
function getAgeFromDob($dateStr){
	$daysInYear = 365.242199; // Takes into account leap-years, etc.
	$secondsInYear = (60*60*24*$daysInYear); // seconds*minutes*hours*days
	return floor((strtotime('now')-strtotime($dateStr)) / $secondsInYear);
} // end getAgeFromDob()

////
// Returns the path from the root of the server to the current script.  This is useful in letting the system function even
// if it is put into a subdirectory on a server.
////
function getCodePath(){
	$codePath = preg_replace("/^(.*)\/[^\/]*$/", "$1", $_SERVER['SCRIPT_NAME']); // directory of this file.
	$codePath = str_replace(" ", "%20", $codePath);

	// Subdirectories that are okay to enter into.  These will be chopped off of the path of the running script.
	// WARNING: It is not recommended to run the app in a root directory which is the same as any of these.  For instance, do not run the app in a directory called "/admin".
	$okSubDirs = array(
		"/admin"
	);
	foreach($okSubDirs as $dirName){
		if(endsWith($codePath, $dirName)){
			$codePath = substr($codePath, 0, strlen($codePath) - strlen($dirName));
			break; // once we've found one match, don't keep searching
		}
	}
	return $codePath;
} // end getCodePath()

////
// Returns the domain that the current site is running on (but not the www if that is the subdomain - this helps normalize results).
////
function getDomain(){
	$retVal = $_SERVER['SERVER_NAME'];
	while("www." == substr($retVal, 0, 4)){
		$retVal = substr($retVal, 4);
	}
	$retVal = strtolower($retVal);
	return $retVal;
} // end getDomain()

////
// Returns all allowed file-extensions.  There are some weird-looking extras to account
// for IE's weird mimetypes.
////
function getImageExts(){
	return array("png", "bmp", "gif", "jpg", "jpeg", "tif", "tiff", "pjpeg", "pjpg", "x-png", "x-bmp");
} // end getImageTypes()

////
// Returns mime-types of allowed image types separated by commas.
////
function getImageMimes(){
	return "image/".implode(",image/", getImageExts());
} // end getImageMimes()

////
// Returns the value set in the post array, or empty string on failure.
////
function getPost($key, $default=''){
	return ((isset($_POST[$key]))?$_POST[$key]:$default);
} // end getPost()

////
// Returns the value set in the data array, or empty string on failure.
////
function getVal($dataArray, $key, $default=''){
	return ((isset($dataArray[$key]))?$dataArray[$key]:$default);
} // end getVal

// Functions for handling mysql transactions (requires that the tables are of type innodb).
function mysql_begin(){return sendQuery("BEGIN");}
function mysql_commit(){return sendQuery("COMMIT");}
function mysql_rollback(){return sendQuery("ROLLBACK");}

////
// Returns a number, the results of which are guaranteed to be unique from
// its previous results for any single page-load (ie: it counts up from 1).
////
GLOBAL $NEXT_SEQ_NUMBER;
$NEXT_SEQ_NUMBER = 1;
function nextNum(){
	GLOBAL $NEXT_SEQ_NUMBER;
	return $NEXT_SEQ_NUMBER++;
} // end nextNum

////
// Scales the provided width and height (by reference) to make them fit inside of the default
// MAX_WIDTH and MAX_HEIGHT for the media area of the page.
////
function scaleMedia(&$width, &$height){
	$MAX_WIDTH = 500;
	$MAX_HEIGHT = 900;

	if($width > $MAX_WIDTH){
		$newWidth = ($MAX_WIDTH * $width / $width);
		$newHeight = ($MAX_WIDTH * $height / $width);
		$width = $newWidth;
		$height = $newHeight;
	}
	if($height > $MAX_HEIGHT){
		$newWidth = ($MAX_HEIGHT * $width / $height);
		$newHeight = ($MAX_HEIGHT * $height / $height);
		$width = $newWidth;
		$height = $newHeight;
	}	
} // end scaleMedia(...)

////
// Returns true if all of prefix is found at the beginning of haystack.
////
function startsWith($haystack, $prefix){
	return (strpos($haystack, $prefix) === 0);
} // end startsWith(...)


?>