<?php

/**
 * Christmas Hat (xmashat.php)
 *
 * Written by Olan Patrick Barnes (patrick a-t opbarnes d-o-t com)
 * Copyright (C) 2008 Olan Patrick Barnes.
 *
 * This software is provided "as is", without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 *
 * Beware of bugs.
 */

$script_self = 'xmashat.php';
$datafile = '/home/pdodger/xmashat_data/xmashat.dat';
$admin_password = 'gravy';
$max_ideal_results_attempts = 1000;
$do_debug = TRUE;

$persons = array(
	'Dave Goodson' => new PersonInfo('dag', 'password1', 1),
	'Sally Goodson' => new PersonInfo('sag', 'pwtwo', 1),
	'Ted Dawson' => new PersonInfo('twd', 'password3', 2),
	'Nelly Dawson' => new PersonInfo('nd', 'pwfour', 2),
	'Phil Dodger' => new PersonInfo('pbd', 'password5', 3),
	'Tina Dodger' => new PersonInfo('tod', 'pwsix', 3)
);

class PersonInfo {
	public $initials = '';
	public $md5 = '';
	public $password = '';
	public $family_id = '';
	public $family_md5 = '';

	public function __construct($initials, $password, $family_id) {
		$this->initials = $initials;
		$this->password = $password;
		$this->family_id = $family_id;
		$this->md5 = md5("{$initials}_{$family_id}");
		$this->family_md5 = md5(get_class($this) . "_{$family_id}");
	}
}

function get_results($persons_array_in, $selections, $is_md5s) {
	$results = array();

	$md5_arr = array();
	$fam_md5_arr = array();
	$name_to_md5 = array();
	foreach ($persons_array_in as $person_name => $person_obj) {
		$md5_arr[] = $person_obj->md5;
		$fam_md5_arr[] = $person_obj->family_md5;
		$name_to_md5[$person_obj->md5] = $person_name;
	}
	sort($md5_arr);
	$fam_md5_arr = array_unique($fam_md5_arr);
	sort($fam_md5_arr);
	$md5_map = array_flip($md5_arr);
	$fam_md5_map = array_flip($fam_md5_arr);

	if ($is_md5s) {
		$tmp = array();
		foreach ($selections as $key_md5 => $val_md5) {
			$tmp[$name_to_md5[$key_md5]] = $name_to_md5[$val_md5];
		}
		$selections = $tmp;
	}

	static $family_ids = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

	foreach ($selections as $giver_name => $recipient_name) {
		$giver = $persons_array_in[$giver_name];
		$recipient = $persons_array_in[$recipient_name];

		$giver_num = $md5_map[$giver->md5] + 1;
		$recipient_num = $md5_map[$recipient->md5] + 1;

		$giver_fam = $fam_md5_map[$giver->family_md5];
		$recipient_fam = $fam_md5_map[$recipient->family_md5];
		if ($giver_fam < strlen($family_ids)) {
			$giver_fam = $family_ids[$fam_md5_map[$giver->family_md5]];
		}
		if ($recipient_fam < strlen($family_ids)) {
			$recipient_fam = $family_ids[$fam_md5_map[$recipient->family_md5]];
		}

		$results[] = "Person #{$giver_num} in family {$giver_fam} is giving to " .
			"person #{$recipient_num} in family {$recipient_fam}.";
	}
	sort($results);
	return $results;
}

function make_picks_file($persons_array_in, $datafile, &$errors, &$successes, &$debug) {
	if (!is_array($errors)) {
		return FALSE;
	}

	if (!is_array($successes)) {
		$errors[] = 'Unexpected successes array.';
		return FALSE;
	}

	if (!is_array($persons_array_in)) {
		$errors[] = 'Unexpected persons array.';
		return FALSE;
	}

	if (!is_string($datafile)) {
		$errors[] = 'Invalid output data file name.';
		return FALSE;
	}

	if (!is_null($debug)) {
		if (!is_array($debug)) {
			$debug = array();
		}
	}

	$selections_with_lowest_interfamily_giving = NULL;
	$num_people_interfamily_giving = NULL;

	global $max_ideal_results_attempts;
	for ($cnt = 0; $cnt < $max_ideal_results_attempts; $cnt++) {	
		$selections = array();
		$persons_array = $persons_array_in;
		$persons_names = array_keys($persons_array);
		$num_left_in_family = 0;
		foreach ($persons_names as $current_person) {
			$pick_is_ok = FALSE;
			while (!$pick_is_ok) {
				$persons_remaining = array_keys($persons_array);
				$random_choice = 0;
				if (count($persons_remaining) > 0) {
					$random_choice = rand(0, count($persons_remaining) - 1);
				}
	
				$person_picked = $persons_remaining[$random_choice];
				$current_person_obj = $persons_array_in[$current_person];
				$picked_person_obj = $persons_array_in[$person_picked];
				if ($current_person_obj->family_id == $picked_person_obj->family_id) {
					$do_try_again = FALSE;
					// If there is only one selection left, and that person is the selector, then
					// go ahead and do it -- but show an error (this should never really happen)
					if ( (count($persons_remaining) == 1) &&
						 ($current_person_obj->md5 == $picked_person_obj->md5) ) {
						$errors[] = 'Data warning:  One person is giving to themselves!';
					}
					// If the selector is the same person as the one selected, and there is more
					// people to choose from, try again
					else if ($current_person_obj->md5 == $picked_person_obj->md5) {
						$do_try_again = TRUE;
						continue;
					}
	
					// See if everyone who is left in persons_remaining are in the same family, if
					// so, let this go as long as they current person and the picked person aren't
					// the same person.
					foreach ($persons_remaining as $person_remaining_item) {
						$person_remaining_item_obj = $persons_array_in[$person_remaining_item];
						if ($person_remaining_item_obj->family_id == $current_person_obj->family_id) {
							$num_left_in_family++;
						}
						else {
							$num_left_in_family = 0;
							$do_try_again = TRUE;
							break;
						}
					}
					if ($do_try_again) {
						continue;
					}
				}
	
				$selections[$current_person] = $person_picked;
				unset($persons_array[$person_picked]);
				$pick_is_ok = TRUE;
			}
		}

		if (!is_null($debug)) {
			$debug[] = "Attempt {$cnt} resulted in {$num_left_in_family} persons interfamily giving.";
		}

		if ( (is_null($num_people_interfamily_giving)) ||
		     ($num_left_in_family < $num_people_interfamily_giving) ) {
			$num_people_interfamily_giving = $num_left_in_family;
			$selections_with_lowest_interfamily_giving = $selections;
		}

		if ($num_left_in_family == 0) {
			break;
		}
	}

	assert(is_array($selections_with_lowest_interfamily_giving));
	assert(is_int($num_people_interfamily_giving));

	$selections = $selections_with_lowest_interfamily_giving;
	$num_left_in_family = $num_people_interfamily_giving;

	if ($num_left_in_family > 0) {
		// If some selections had to be made in the same family, show an error about it
		$errors[] = "Data warning: {$num_left_in_family} people in the same family are " .
			' giving to another in the same family.';
	}

	$selections_for_file = array();
	foreach ($selections as $giver_name => $recipient_name) {
		$giver = $persons_array_in[$giver_name];
		$recipient = $persons_array_in[$recipient_name];
		$selections_for_file[$giver->md5] = $recipient->md5;
	}

	if (!is_null($debug)) {
		$debug = array_merge($debug, get_results($persons_array_in, $selections, FALSE));
	}

	if (file_put_contents($datafile, json_encode($selections_for_file)) === FALSE) {
		$errors[] = 'Unable to save to data file.';
		return FALSE;
	}
	$successes[] = 'Data file successfully created.';
	return TRUE;
}
		
$errors = array();
$successes = array();
$debug_msgs = ($do_debug) ? array() : NULL;

//Test for any md5 collisions
$md5_tests = array();
foreach ($persons as $tmp_name => $person_tmp) {
	if (isset($md5_tests[$person_tmp->md5])) {
		$errors[] = "Person name md5 collision for {$tmp_name}.  Please change name to resolve.";
	}
	else {
		$md5_tests[$person_tmp->md5] = 1;
	}
}
foreach ($persons as $tmp_name => $person_tmp) {
	if ( (isset($md5_tests[$person_tmp->family_md5])) &&
	     ($md5_tests[$person_tmp->family_md5] != $person_tmp->family_id) ) {
		$errors[] = "Family ID md5 collision for {$person_tmp->family_id}.  Please family ID to resolve.";
	}
	else {
		$md5_tests[$person_tmp->family_md5] = $person_tmp->family_id;
	}
}

$person_initials = NULL;
$person_name = '';
$person_recipient = '';
if ( (isset($_REQUEST['action'])) && ($_REQUEST['action'] == 'submit') ) {
	if ( (isset($_REQUEST['person'])) && (!empty($_REQUEST['person'])) ) {
		$person_name = $_REQUEST['person'];
		if (isset($persons[$person_name])) {
			if ((isset($_POST['userpw'])) && ($_POST['userpw'] == $persons[$person_name]->password)) {
				$person_initials = $persons[$person_name]->initials;
				if (($picks_json = file_get_contents($datafile)) === FALSE) {
					$errors[] = 'Unable to read data file.';
					return FALSE;
				}
				$selections = json_decode($picks_json, TRUE);
				$person_md5 = $persons[$person_name]->md5;
				$recipient_md5 = $selections[$person_md5];
				foreach ($persons as $person_iter_name => $person_iter_obj) {
					if ($recipient_md5 == $person_iter_obj->md5) {
						$person_recipient = $person_iter_name;
						break;
					}
				}
			}
			else {
				$errors[] = "Invalid password for {$person_name}.";
			}
		}
		else {
			$errors[] = 'Unknown person.';
		}
	}
	else {
		$errors[] = 'You must select a person from the list.';
	}
}

$is_admin = FALSE;
if ( (isset($_REQUEST['action'])) &&
     ($_REQUEST['action'] == 'admin') &&
     (isset($_POST['pw'])) ) {
	if ($_POST['pw'] == $admin_password) {
		$is_admin = TRUE;
	}
	else {
		$errors[] = 'Admin password incorrect.';
	}
}

$is_admin_submit = FALSE;
$is_admin_submit_iam = '';
$results_output = NULL;

if ( (isset($_REQUEST['action'])) &&
     ($_REQUEST['action'] == 'admin_submit') &&
     (isset($_POST['pw'])) ) {
	if ($_POST['pw'] == $admin_password) {
		$is_admin_submit = TRUE;
		if (isset($_POST['admin_action'])) {
			switch ($_POST['admin_action']) {
			case 'reset':
				$is_admin_submit_iam = ' resetting the picks list data file...';
				make_picks_file($persons, $datafile, $errors, $successes, $debug_msgs);
				break;
			case 'seelist':
				if (($picks_json = file_get_contents($datafile)) === FALSE) {
					$errors[] = 'Unable to read data file.';
					return FALSE;
				}
				$selections = json_decode($picks_json, TRUE);
				$results_output = get_results($persons, $selections, TRUE);
				break;
			}
		}
	}
	else {
		$errors[] = 'Admin password incorrect.';
	}
}

$is_login = FALSE;
if ( (isset($_REQUEST['action'])) && ($_REQUEST['action'] == 'login') ) {
	$is_login = TRUE;
}

$for_person = '';
if (!is_null($person_initials)) {
	$for_person = " for {$person_name}";
}

$iam_person =':';
if ($is_login) {
	$iam_person = ' logging in as administrator:';
}
else if ($is_admin) {
	$iam_person = ' logged in as administrator:';
}
else if (!is_null($person_initials)) {
	$iam_person = " {$person_name}";
}

print <<<EOHTML
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Christmas Hat{$for_person}</title>
</head>
<body>
<div class="header">
<h1>Christmas Hat</h1>
EOHTML;

$status_types = array('errors', 'successes', 'debug_msgs');
foreach ($status_types as $status_type) {
	if (!empty($$status_type)) {
		print "<div class=\"{$status_type}\">\n";
		foreach ($$status_type as $item) {
			print "<span class=\"{$status_type}_item\">{$item}</span><br />\n";
		}
		print "</div><br />\n";
	}
}

if (!empty($results_output)) {
	print "<div class=\"pick_results\">\n";
	print "<h3>Pick Results:</h3>\n";
	print implode('<br />', $results_output);
	print "</div><br />";
}

print <<<EOHTML
<p>&quot;Christmas Hat&quot; already randomly picked the name of your Christmas gift recepient out
 of a hat, so let's see who you got!</p>
<div class="person_list">
<h2>I am{$iam_person}</h2>
EOHTML;

if ($is_login) {
	print <<<EOHTML
<form name="login_form" method="post" action="{$script_self}">
<input type="hidden" name="action" value="admin" />
<p>
Admin password:&nbsp;&nbsp;<input type="password" name="pw" />
<br />
<input type="submit" value="Log in" />
</p>
</form>
EOHTML;
}
else if ($is_admin) {
	print <<<EOHTML
<h3>What do you want to do?</h3>
<form name="login_form" method="post" action="{$script_self}">
<input type="hidden" name="action" value="admin_submit" />
<p>
<input type="radio" name="admin_action" value="reset">Reset all hat picks</input><br />
<input type="radio" name="admin_action" value="seelist">See obfuscated pick list</input>
</p><p>
Password is required to do any action:
</p><p>
Admin password:&nbsp;&nbsp;<input type="password" name="pw" />
<br />
<input type="submit" value="Submit" />
</p></form>
EOHTML;
}
else if (is_null($person_initials)) {
	print <<<EOHTML
<form name="person_list_form" method="post" action="{$script_self}">
<input type="hidden" name="action" value="submit" />
<p>
EOHTML;

	$radio_outputs = array();
	foreach ($persons as $person_name => $person_info) {
		$name_parts = explode(' ', $person_name, 2);
		$last_name = isset($name_parts[1]) ? $name_parts[1] : $person_name;
		$person_name = htmlentities($person_name);
		$radio_outputs[$last_name . $person_name] =
			"<input type=\"radio\" name=\"person\" value=\"{$person_name}\">" .
			"&nbsp;{$person_name}</input><br />";
	}

	ksort($radio_outputs);
	print "\n";
	foreach ($radio_outputs as $ro_key => $ro_val) {
		print $ro_val . "\n";
	}

	print <<<EOHTML
</p><p>
And my password is:&nbsp;&nbsp;<input type="password" name="userpw" />
</p><p>
<input type="submit" value="Continue" />
</p>
</form>
EOHTML;
}
else if (!empty($person_recipient)) {
	print <<<EOHTML
	<div class="your_pick">
	<h3>Your Pick:</h3>
	<p>
	{$person_recipient}
	</p>
	<p>
	<a href="{$script_self}">Done</a>
	</p>
	</div>

EOHTML;
}

print <<<EOHTML
</div>
<div class="footer">
Copyright &copy;2008 O. Patrick Barnes.  All rights reserved.&nbsp;&nbsp;&nbsp&nbsp;[<a 
href="{$script_self}?action=login">admin</a>]
</div>
</body>
</html>
EOHTML;

?>