#!/usr/local/bin/perl

# This file contains perl subroutines that handle non-
# specific functions for the server-side functionalities
# of the ProMEM/MealSaver website.
#
# All code written and created by Dan Strife.


use DBI;
require "mysql.pl";


# Check for existance of session ID in sessions table and 
# return corresponding netid.

sub validateSession
{
	my $dbh;
	my $sth;
	my $query;
	my $dis;

	($dbh, $dis) = handleMySQLConnect($_[$#_]);

	my $sessionid = $_[0];
		
	# query club tables for netid
	$query = "SELECT NETID FROM Sessions WHERE SESSIONID='$sessionid'";
	$sth = $dbh->prepare($query);
	$sth->execute();

	my ($netid) = $sth->fetchrow_array();
	
	$sth->finish();
	
	handleMySQLDisconnect($dbh, $dis);

	return $netid;
}


# Compares two exchange records for conflict.

sub compareExchanges
{
	my ($rec1, $rec2) = @_;
	return 1 if (($rec1->[0] eq $rec2->[0]) && ($rec1->[1] eq $rec2->[1]) && ($rec1->[2] eq $rec2->[2]) && ($rec1->[4] eq $rec2->[4]));
	return 1 if (($rec1->[0] eq $rec2->[1]) && ($rec1->[1] eq $rec2->[0]) && ($rec1->[2] eq $rec2->[2]) && ($rec1->[4] eq $rec2->[4]));
  return 0;
}


# Returns the current time in YYYY-MM-DD HH-MM-SS format.

sub getTime
{
  ($second, $minute, $hour, $dayOfMonth, $month, $yearOffset, $dayOfWeek, $dayOfYear, $daylightSavings) = localtime();
  
  $year = 1900 + $yearOffset;
  $month += 1;
  $time = "$year-$month-$dayOfMonth $hour:$minute:$second";
  
  return $time; 
}

1;