Poll.php

<?php

/**
 * This receives requests for voting, locking, removing editing polls
 *
 * @package   ElkArte Forum
 * @copyright ElkArte Forum contributors
 * @license   BSD http://opensource.org/licenses/BSD-3-Clause (see accompanying LICENSE.txt file)
 *
 * This file contains code covered by:
 * copyright: 2011 Simple Machines (http://www.simplemachines.org)
 *
 * @version 2.0 dev
 *
 */

namespace ElkArte\Controller;

use ElkArte\AbstractController;
use ElkArte\Errors\ErrorContext;
use ElkArte\Exceptions\Exception;
use ElkArte\Helper\Util;
use ElkArte\Languages\Txt;

/**
 * This receives requests for voting, locking, removing and editing polls.
 * Note that that posting polls is done in Post.controller.php.
 */
class Poll extends AbstractController
{
	/**
	 * Forward to the right action.
	 *
	 * @see AbstractController::action_index
	 */
	public function action_index()
	{
		// Figure out the right action to do.
	}

	/**
	 * Allow the user to vote.
	 *
	 * What it does:
	 *
	 * - It is called to register a vote in a poll.
	 * - Must be called with a topic and option specified.
	 * - Requires the poll_vote permission.
	 * - Upon successful completion of action will direct user back to topic.
	 * - Accessed via ?action=poll;sa=vote.
	 *
	 * @uses Post language file.
	 */
	public function action_vote()
	{
		global $topic, $modSettings;

		require_once(SUBSDIR . '/Poll.subs.php');

		// Make sure you can vote.
		isAllowedTo('poll_vote');

		Txt::load('Post');

		// Check if they have already voted, or voting is locked.
		$row = checkVote($topic);

		if (empty($row))
		{
			throw new Exception('poll_error', false);
		}

		// If this is a guest can they vote?
		if ($this->user->is_guest)
		{
			// Guest voting disabled?
			if (!$row['guest_vote'])
			{
				throw new Exception('guest_vote_disabled');
			}
			// Guest already voted?
			if (!empty($_COOKIE['guest_poll_vote']) && preg_match('~^[0-9,;]+$~', $_COOKIE['guest_poll_vote']) && strpos($_COOKIE['guest_poll_vote'], ';' . $row['id_poll'] . ',') !== false)
			{
				// ;id,timestamp,[vote,vote...]; etc
				$guestinfo = explode(';', $_COOKIE['guest_poll_vote']);
				// Find the poll we're after.
				foreach ($guestinfo as $i => $guestvoted)
				{
					$guestvoted = explode(',', $guestvoted);
					if ($guestvoted[0] == $row['id_poll'])
					{
						break;
					}
				}
				// Has the poll been reset since guest voted?
				if (isset($guestvoted[1]) && $row['reset_poll'] > $guestvoted[1])
				{
					// Remove the poll info from the cookie to allow guest to vote again
					unset($guestinfo[$i]);
					if (!empty($guestinfo))
					{
						$_COOKIE['guest_poll_vote'] = ';' . implode(';', $guestinfo);
					}
					else
					{
						unset($_COOKIE['guest_poll_vote']);
					}
				}
				else
				{
					throw new Exception('poll_error', false);
				}

				unset($guestinfo, $guestvoted, $i);
			}
		}

		// Is voting locked or has it expired?
		if (!empty($row['voting_locked']) || (!empty($row['expire_time']) && time() > $row['expire_time']))
		{
			throw new Exception('poll_error', false);
		}
		// If they have already voted and aren't allowed to change their vote - hence they are outta here!
		if ($this->user->is_guest === false && $row['selected'] != -1 && empty($row['change_vote']))
		{
			throw new Exception('poll_error', false);
		}

		// Otherwise if they can change their vote yet they haven't sent any options... remove their vote and redirect.
		if (!empty($row['change_vote']) && $this->user->is_guest === false && empty($this->_req->post->options))
		{
			checkSession('request');

			// Find out what they voted for before.
			$pollOptions = determineVote($this->user->id, $row['id_poll']);

			// Just skip it if they had voted for nothing before.
			if (!empty($pollOptions))
			{
				// Update the poll totals.
				decreaseVoteCounter($row['id_poll'], $pollOptions);

				// Delete off the log.
				removeVote($this->user->id, $row['id_poll']);
			}
			// Redirect back to the topic so the user can vote again!
			if (empty($this->_req->post->options))
			{
				redirectexit('topic=' . $topic . '.' . $this->_req->post->start);
			}
		}

		checkSession('request');

		// Make sure the option(s) are valid.
		if (empty($this->_req->post->options))
		{
			throw new Exception('didnt_select_vote', false);
		}

		// Too many options checked!
		if (count($this->_req->post->options) > $row['max_votes'])
		{
			throw new Exception('poll_too_many_votes', false, array($row['max_votes']));
		}

		$pollOptions = array();
		$inserts = array();
		foreach ($this->_req->post->options as $id)
		{
			$id = (int) $id;

			$pollOptions[] = $id;
			$inserts[] = array($row['id_poll'], $this->user->id, $id);
		}

		// Add their vote to the tally.
		addVote($inserts);
		increaseVoteCounter($row['id_poll'], $pollOptions);

		// If it's a guest don't let them vote again.
		if ($this->user->is_guest && $pollOptions !== [])
		{
			// Time is stored in case the poll is reset later, plus what they voted for.
			$_COOKIE['guest_poll_vote'] = empty($_COOKIE['guest_poll_vote']) ? '' : $_COOKIE['guest_poll_vote'];

			// ;id,timestamp,[vote,vote...]; etc
			$_COOKIE['guest_poll_vote'] .= ';' . $row['id_poll'] . ',' . time() . ',' . (count($pollOptions) > 1 ? implode(',', $pollOptions) : $pollOptions[0]);

			// Increase num guest voters count by 1
			increaseGuestVote($row['id_poll']);

			// Set the guest cookie so we can track the voting
			require_once(SUBSDIR . '/Auth.subs.php');
			$cookie_url = url_parts(!empty($modSettings['localCookies']), !empty($modSettings['globalCookies']));
			elk_setcookie('guest_poll_vote', $_COOKIE['guest_poll_vote'], time() + 2500000, $cookie_url[1], $cookie_url[0], false, false);
		}

		// Maybe let a social networking mod log this, or something?
		call_integration_hook('integrate_poll_vote', array(&$row['id_poll'], &$pollOptions));

		// Return to the post...
		redirectexit('topic=' . $topic . '.' . $this->_req->post->start);
	}

	/**
	 * Lock the voting for a poll.
	 *
	 * What it does:
	 *
	 * - Must be called with a topic specified in the URL.
	 * - An admin always has over riding permission to lock a poll.
	 * - If not an admin must have poll_lock_any permission, otherwise must
	 * be poll starter with poll_lock_own permission.
	 * - Upon successful completion of action will direct user back to topic.
	 * - Accessed via ?action=lockvoting.
	 */
	public function action_lockvoting()
	{
		global $topic;

		require_once(SUBSDIR . '/Poll.subs.php');

		checkSession('get');

		// Get the poll starter, ID, and whether or not it is locked.
		$poll = pollInfoForTopic($topic);

		// If the user _can_ modify the poll....
		if (!allowedTo('poll_lock_any'))
		{
			isAllowedTo('poll_lock_' . ($this->user->id == $poll['id_member_started'] ? 'own' : 'any'));
		}

		// It's been locked by a non-moderator.
		if ($poll['locked'] == '1')
		{
			$poll['locked'] = '0';
		}
		// Locked by a moderator, and this is a moderator.
		elseif ($poll['locked'] == '2' && allowedTo('moderate_board'))
		{
			$poll['locked'] = '0';
		}
		// Sorry, a moderator locked it.
		elseif ($poll['locked'] == '2' && !allowedTo('moderate_board'))
		{
			throw new Exception('locked_by_admin', 'user');
		}
		// A moderator *is* locking it.
		elseif ($poll['locked'] == '0' && allowedTo('moderate_board'))
		{
			$poll['locked'] = '2';
		}
		// Well, it's gonna be locked one way or another otherwise...
		else
		{
			$poll['locked'] = '1';
		}

		// Lock!  *Poof* - no one can vote.
		lockPoll($poll['id_poll'], $poll['locked']);

		redirectexit('topic=' . $topic . '.' . $this->_req->post->start);
	}

	/**
	 * Update the settings for a poll, or add a new one.
	 *
	 * What it does:
	 *
	 * - Must be called with a topic specified in the URL.
	 * - The user must have poll_edit_any/poll_add_any permission for the relevant action. Otherwise
	 * they must be poll starter with poll_edit_own permission for editing, or be topic starter
	 * with poll_add_any permission for adding.
	 * - In the case of an error, this function will redirect back to action_editpoll and
	 * display the relevant error message.
	 * - Upon successful completion of action will direct user back to topic.
	 * - Accessed via ?action=editpoll2.
	 */
	public function action_editpoll2()
	{
		global $topic, $board;

		// Sneaking off, are we?
		if (empty($this->_req->post))
		{
			redirectexit('action=editpoll;topic=' . $topic . '.0');
		}

		$poll_errors = ErrorContext::context('poll');

		if (checkSession('post', '', false) !== '')
		{
			$poll_errors->addError('session_timeout');
		}

		// HACKERS (!!) can't edit :P.
		if (empty($topic))
		{
			throw new Exception('no_access', false);
		}

		// Is this a new poll, or editing an existing?
		$isEdit = isset($this->_req->post->add) ? 0 : 1;

		// Make sure we have our stuff.
		require_once(SUBSDIR . '/Poll.subs.php');

		// Get the starter and the poll's ID - if it's an edit.
		$bcinfo = getPollStarter($topic);
		// Check their adding/editing is valid.
		if (!$isEdit && !empty($bcinfo['id_poll']))
		{
			throw new Exception('poll_already_exists');
		}

		// Are we editing a poll which doesn't exist?
		if ($isEdit && empty($bcinfo['id_poll']))
		{
			throw new Exception('poll_not_found');
		}

		// Check if they have the power to add or edit the poll.
		if ($isEdit && !allowedTo('poll_edit_any'))
		{
			isAllowedTo('poll_edit_' . ($this->user->id == $bcinfo['id_member_started'] || ($bcinfo['poll_starter'] != 0 && $this->user->id == $bcinfo['poll_starter']) ? 'own' : 'any'));
		}
		elseif (!$isEdit && !allowedTo('poll_add_any'))
		{
			isAllowedTo('poll_add_' . ($this->user->id == $bcinfo['id_member_started'] ? 'own' : 'any'));
		}

		$optionCount = 0;
		$idCount = 0;

		// Ensure the user is leaving a valid amount of options - there must be at least two.
		foreach ($this->_req->post->options as $k => $option)
		{
			if (trim($option) !== '')
			{
				$optionCount++;
				$idCount = max($idCount, $k);
			}
		}

		if ($optionCount < 2)
		{
			$poll_errors->addError('poll_few');
		}
		elseif ($optionCount > 256 || $idCount > 255)
		{
			$poll_errors->addError('poll_many');
		}

		// Also - ensure they are not removing the question.
		if ($this->_req->getPost('question', 'trim') === '')
		{
			$poll_errors->addError('no_question');
		}

		// Got any errors to report?
		if ($poll_errors->hasErrors())
		{
			$this->action_editpoll();
		}

		// Prevent double submission of this form.
		checkSubmitOnce('check');

		// Now we've done all our error checking, let's get the core poll information cleaned... question first.
		$question = Util::htmlspecialchars($this->_req->getPost('question', 'trim'));
		$question = Util::substr($question, 0, 255);

		$poll_hide = $this->_req->getPost('poll_hide', 'intval', 0);
		$poll_expire = $this->_req->getPost('poll_expire', 'intval', 0);
		$poll_change_vote = isset($this->_req->post->poll_change_vote) ? 1 : 0;
		$poll_guest_vote = isset($this->_req->post->poll_guest_vote) ? 1 : 0;
		$poll_max_votes = 0;

		// Make sure guests are actually allowed to vote generally.
		if ($poll_guest_vote !== 0)
		{
			require_once(SUBSDIR . '/Members.subs.php');
			$allowedGroups = groupsAllowedTo('poll_vote', $board);
			if (!in_array(-1, $allowedGroups['allowed']))
			{
				$poll_guest_vote = 0;
			}
		}

		// Ensure that the number options allowed makes sense, and the expiration date is valid.
		if (!$isEdit || allowedTo('moderate_board'))
		{
			$poll_expire = $poll_expire > 9999 ? 9999 : ($poll_expire < 0 ? 0 : $poll_expire);

			if (empty($poll_expire) && $poll_hide == 2)
			{
				$poll_hide = 1;
			}
			elseif (!$isEdit || $poll_expire != ceil($bcinfo['expire_time'] <= time() ? -1 : ($bcinfo['expire_time'] - time()) / (3600 * 24)))
			{
				$poll_expire = empty($poll_expire) ? 0 : time() + $_POST['poll_expire'] * 3600 * 24;
			}
			else
			{
				$poll_expire = $bcinfo['expire_time'];
			}

			if (empty($this->_req->post->poll_max_votes) || $this->_req->post->poll_max_votes <= 0)
			{
				$poll_max_votes = 1;
			}
			else
			{
				$poll_max_votes = $this->_req->getPost('poll_max_votes', 'intval', 0);
			}
		}

		// If we're editing, let's commit the changes.
		if ($isEdit !== 0)
		{
			modifyPoll($bcinfo['id_poll'], $question,
				empty($poll_max_votes) ? 0 : $poll_max_votes,
				$poll_hide,
				empty($poll_expire) ? 0 : $poll_expire,
				$poll_change_vote, $poll_guest_vote
			);
		}
		// Otherwise, let's get our poll going!
		else
		{
			// Create the poll.
			$bcinfo['id_poll'] = createPoll($question, $this->user->id, $this->user->username,
				$poll_max_votes, $poll_hide, $poll_expire,
				$poll_change_vote, $poll_guest_vote
			);

			// Link the poll to the topic.
			associatedPoll($topic, $bcinfo['id_poll']);
		}

		// Get all the choices.  (no better way to remove all emptied and add previously non-existent ones.)
		$choices = array_keys(pollOptions($bcinfo['id_poll']));

		$add_options = array();
		$update_options = array();
		$delete_options = array();
		foreach ($this->_req->post->options as $k => $option)
		{
			// Make sure the key is numeric for sanity's sake.
			$k = (int) $k;

			// They've cleared the box.  Either they want it deleted, or it never existed.
			if (trim($option) === '')
			{
				// They want it deleted.  Bye.
				if (in_array($k, $choices))
				{
					$delete_options[] = $k;
				}

				// Skip the rest...
				continue;
			}

			// Dress the option up for its big date with the database.
			$option = Util::htmlspecialchars($option);

			// If it's already there, update it.  If it's not... add it.
			if (in_array($k, $choices))
			{
				$update_options[] = array($bcinfo['id_poll'], $k, $option);
			}
			else
			{
				$add_options[] = array($bcinfo['id_poll'], $k, $option, 0);
			}
		}

		if (!empty($update_options))
		{
			modifyPollOption($update_options);
		}

		if (!empty($add_options))
		{
			insertPollOptions($add_options);
		}

		// I'm sorry, but... well, no one was choosing you. Poor options, I'll put you out of your misery.
		if (!empty($delete_options))
		{
			deletePollOptions($bcinfo['id_poll'], $delete_options);
		}

		// Shall I reset the vote count, sir?
		if (isset($this->_req->post->resetVoteCount))
		{
			resetVotes($bcinfo['id_poll']);
		}

		call_integration_hook('integrate_poll_add_edit', array($bcinfo['id_poll'], $isEdit));

		// Off we go.
		redirectexit('topic=' . $topic . '.' . $this->_req->post->start);
	}

	/**
	 * Display screen for editing or adding a poll.
	 *
	 * What it does:
	 *
	 * - Must be called with a topic specified in the URL.
	 * - If the user is adding a poll to a topic, must contain the variable
	 * 'add' in the url.
	 * - User must have poll_edit_any/poll_add_any permission for the relevant action,
	 * otherwise must be poll starter with poll_edit_own permission for editing, or
	 * be topic starter with poll_add_any permission for adding.
	 * - Accessed via ?action=editpoll.
	 *
	 * @uses Post language file.
	 * @uses template_poll_edit() sub-template in Poll.template,
	 */
	public function action_editpoll()
	{
		global $txt, $context, $topic, $board;

		// No topic, means you can't edit the poll
		if (empty($topic))
		{
			throw new Exception('no_access', false);
		}

		// We work hard with polls.
		require_once(SUBSDIR . '/Poll.subs.php');

		Txt::load('Post');
		theme()->getTemplates()->load('Poll');
		loadJavascriptFile('post.js', array(), 'post_scripts');

		$context['sub_template'] = 'poll_edit';
		$context['start'] = $this->_req->getQuery('start', 'intval');
		$context['is_edit'] = isset($this->_req->post->add) ? 0 : 1;

		$poll_errors = ErrorContext::context('poll');
		$pollinfo = pollInfoForTopic($topic);

		// Assume it all exists, right?
		if (empty($pollinfo))
		{
			throw new Exception('no_board');
		}

		// If we are adding a new poll - make sure that there isn't already a poll there.
		if (!$context['is_edit'] && !empty($pollinfo['id_poll']))
		{
			throw new Exception('poll_already_exists');
		}

		// Otherwise, if we're editing it, it does exist I assume?
		if ($context['is_edit'] && empty($pollinfo['id_poll']))
		{
			throw new Exception('poll_not_found');
		}

		// Can you do this?
		if ($context['is_edit'] && !allowedTo('poll_edit_any'))
		{
			isAllowedTo('poll_edit_' . ($this->user->id == $pollinfo['id_member_started'] || ($pollinfo['poll_starter'] != 0 && $this->user->id == $pollinfo['poll_starter']) ? 'own' : 'any'));
		}
		elseif (!$context['is_edit'] && !allowedTo('poll_add_any'))
		{
			isAllowedTo('poll_add_' . ($this->user->id == $pollinfo['id_member_started'] ? 'own' : 'any'));
		}

		$context['can_moderate_poll'] = isset($this->_req->post->add) ? true : allowedTo('poll_edit_' . ($this->user->id == $pollinfo['id_member_started'] || ($pollinfo['poll_starter'] != 0 && $this->user->id == $pollinfo['poll_starter']) ? 'own' : 'any'));

		// Do we enable guest voting?
		require_once(SUBSDIR . '/Members.subs.php');
		$groupsAllowedVote = groupsAllowedTo('poll_vote', $board);

		// Want to make sure before you actually submit?  Must be a lot of options, or something.
		if ($poll_errors->hasErrors())
		{
			$question = Util::htmlspecialchars($this->_req->post->question);

			// Basic theme info...
			$context['poll'] = array(
				'id' => $pollinfo['id_poll'],
				'question' => $question,
				'hide_results' => empty($this->_req->post->poll_hide) ? 0 : $this->_req->post->poll_hide,
				'change_vote' => isset($this->_req->post->poll_change_vote),
				'guest_vote' => isset($this->_req->post->poll_guest_vote),
				'guest_vote_allowed' => in_array(-1, $groupsAllowedVote['allowed']),
				'max_votes' => empty($this->_req->post->poll_max_votes) ? '1' : max(1, $this->_req->post->poll_max_votes),
			);

			// Start at number one with no last id to speak of.
			$number = 1;
			$last_id = 0;

			// Get all the choices - if this is an edit.
			if ($context['is_edit'])
			{
				$pollOptions = pollOptions($pollinfo['id_poll']);
				$context['poll']['choices'] = array();

				foreach ($pollOptions as $option)
				{
					// Get the highest id so we can add more without reusing.
					if ($option['id_choice'] >= $last_id)
					{
						$last_id = $option['id_choice'] + 1;
					}

					// They cleared this by either omitting it or emptying it.
					if (!isset($this->_req->post->options[$option['id_choice']]) || $this->_req->post->options[$option['id_choice']] == '')
					{
						continue;
					}

					// Add the choice!
					$context['poll']['choices'][$option['id_choice']] = array(
						'id' => $option['id_choice'],
						'number' => $number++,
						'votes' => $option['votes'],
						'label' => $option['label'],
						'is_last' => false
					);
				}
			}

			// Work out how many options we have, so we get the 'is_last' field right...
			$totalPostOptions = 0;
			foreach ($this->_req->post->options as $id => $label)
			{
				if ($label !== '')
				{
					$totalPostOptions++;
				}
			}

			$count = 1;

			// If an option exists, update it.  If it is new, add it - but don't reuse ids!
			foreach ($this->_req->post->options as $id => $label)
			{
				$label = censor(Util::htmlspecialchars($label));

				if (isset($context['poll']['choices'][$id]))
				{
					$context['poll']['choices'][$id]['label'] = $label;
				}
				elseif ($label !== '')
				{
					$context['poll']['choices'][] = array(
						'id' => $last_id++,
						'number' => $number++,
						'label' => $label,
						'votes' => -1,
						'is_last' => $count++ === $totalPostOptions && $totalPostOptions > 1,
					);
				}
			}

			// Make sure we have two choices for sure!
			if ($totalPostOptions < 2)
			{
				// Need two?
				if ($totalPostOptions === 0)
				{
					$context['poll']['choices'][] = array(
						'id' => $last_id++,
						'number' => $number++,
						'label' => '',
						'votes' => -1,
						'is_last' => false
					);
				}

				$poll_errors->addError('poll_few');
			}

			// Always show one extra box...
			$context['poll']['choices'][] = array(
				'id' => $last_id++,
				'number' => $number,
				'label' => '',
				'votes' => -1,
				'is_last' => true
			);

			$context['last_choice_id'] = $last_id;

			if ($context['can_moderate_poll'])
			{
				$context['poll']['expiration'] = (int) $this->_req->post->poll_expire;
			}

			// Check the question/option count for errors.
			// @todo: why !$poll_errors->hasErrors()?
			if (trim($this->_req->post->question) === '' && !$poll_errors->hasErrors())
			{
				$poll_errors->addError('no_question');
			}

			// No check is needed, since nothing is really posted.
			checkSubmitOnce('free');

			// Take a check for any errors... assuming we haven't already done so!
			$context['poll_error'] = array(
				'errors' => $poll_errors->prepareErrors(),
				'type' => $poll_errors->getErrorType() == 0 ? 'minor' : 'serious',
				'title' => $context['is_edit'] ? $txt['error_while_editing_poll'] : $txt['error_while_adding_poll'],
			);
		}
		else
		{
			// Basic theme info...
			$context['poll'] = array(
				'id' => $pollinfo['id_poll'],
				'question' => $pollinfo['question'],
				'hide_results' => $pollinfo['hide_results'],
				'max_votes' => $pollinfo['max_votes'],
				'change_vote' => !empty($pollinfo['change_vote']),
				'guest_vote' => !empty($pollinfo['guest_vote']),
				'guest_vote_allowed' => in_array(-1, $groupsAllowedVote['allowed']),
			);

			// Poll expiration time?
			$context['poll']['expiration'] = empty($pollinfo['expire_time']) || !$context['can_moderate_poll'] ? '' : ceil($pollinfo['expire_time'] <= time() ? -1 : ($pollinfo['expire_time'] - time()) / (3600 * 24));

			// Get all the choices - if this is an edit.
			if ($context['is_edit'])
			{
				$context['poll']['choices'] = getPollChoices($pollinfo['id_poll']);

				$last_id = max(array_keys($context['poll']['choices'])) + 1;

				// Add an extra choice...
				$context['poll']['choices'][] = array(
					'id' => $last_id,
					'number' => $context['poll']['choices'][$last_id - 1]['number'] + 1,
					'votes' => -1,
					'label' => '',
					'is_last' => true
				);
				$context['last_choice_id'] = $last_id;
			}
			// New poll?
			else
			{
				// Setup the default poll options.
				$context['poll'] = array(
					'id' => 0,
					'question' => '',
					'hide_results' => 0,
					'max_votes' => 1,
					'change_vote' => 0,
					'guest_vote' => 0,
					'guest_vote_allowed' => in_array(-1, $groupsAllowedVote['allowed']),
					'expiration' => '',
				);

				// Make all five poll choices empty.
				$context['poll']['choices'] = array(
					array('id' => 0, 'number' => 1, 'votes' => -1, 'label' => '', 'is_last' => false),
					array('id' => 1, 'number' => 2, 'votes' => -1, 'label' => '', 'is_last' => false),
					array('id' => 2, 'number' => 3, 'votes' => -1, 'label' => '', 'is_last' => false),
					array('id' => 3, 'number' => 4, 'votes' => -1, 'label' => '', 'is_last' => false),
					array('id' => 4, 'number' => 5, 'votes' => -1, 'label' => '', 'is_last' => true)
				);
				$context['last_choice_id'] = 4;
			}
		}

		$context['page_title'] = $context['is_edit'] ? $txt['poll_edit'] : $txt['add_poll'];
		$context['form_url'] = getUrl('action', ['action' => 'editpoll2'] + ($context['is_edit'] ? [] : ['add']) + ['topic' => $context['current_topic'] . '.' . $context['start']]);

		// Build the link tree.
		$pollinfo['subject'] = censor($pollinfo['subject']);
		$context['linktree'][] = array(
			'url' => getUrl('topic', ['topic' => $topic, 'start' => '0', 'subject' => $pollinfo['subject']]),
			'name' => $pollinfo['subject'],
		);
		$context['linktree'][] = array(
			'name' => $context['page_title'],
		);

		// Register this form in the session variables.
		checkSubmitOnce('register');
	}

	/**
	 * Remove a poll from a topic without removing the topic.
	 *
	 * What it does:
	 *
	 * - Must be called with a topic specified in the URL.
	 * - Requires poll_remove_any permission, unless it's the poll starter
	 * with poll_remove_own permission.
	 * - Upon successful completion of action will direct user back to topic.
	 * - Accessed via ?action=poll;sa=remove.
	 */
	public function action_remove()
	{
		global $topic;

		// Make sure the topic is not empty.
		if (empty($topic))
		{
			throw new Exception('no_access', false);
		}

		// Verify the session.
		checkSession('get');

		// We need to work with them polls.
		require_once(SUBSDIR . '/Poll.subs.php');

		// Check permissions.
		if (!allowedTo('poll_remove_any'))
		{
			$pollStarters = pollStarters($topic);
			if (empty($pollStarters))
			{
				throw new Exception('no_access', false);
			}

			[$topicStarter, $pollStarter] = $pollStarters;
			if ($topicStarter == $this->user->id || ($pollStarter != 0 && $pollStarter == $this->user->id))
			{
				isAllowedTo('poll_remove_own');
			}
		}

		// Retrieve the poll ID.
		$pollID = associatedPoll($topic);

		// Remove the poll!
		removePoll($pollID);

		// Finally set the topic poll ID back to 0!
		associatedPoll($topic, 0);

		// A mod might have logged this (social network?), so let them remove, it too
		call_integration_hook('integrate_poll_remove', array($pollID));

		// Take the moderator back to the topic.
		redirectexit('topic=' . $topic . '.' . $this->_req->post->start);
	}

	/**
	 * The only reason of this function is to build the poll UI and send it back in an XML form
	 */
	public function action_interface()
	{
		global $context, $board, $db_show_debug;

		theme()->getLayers()->removeAll();
		theme()->getTemplates()->load('Poll');
		Txt::load('Post');

		$db_show_debug = false;

		$context['sub_template'] = 'poll_edit';

		require_once(SUBSDIR . '/Members.subs.php');
		$allowedVoteGroups = groupsAllowedTo('poll_vote', $board);

		// Set up the poll options.
		$context['poll'] = array(
			'max_votes' => 1,
			'hide_results' => 0,
			'expiration' => '',
			'change_vote' => false,
			'guest_vote' => false,
			'guest_vote_allowed' => in_array(-1, $allowedVoteGroups['allowed']),
		);

		$context['can_moderate_poll'] = true;

		// Make all five poll choices empty.
		$context['poll']['choices'] = array(
			array('id' => 0, 'number' => 1, 'label' => '', 'is_last' => false),
			array('id' => 1, 'number' => 2, 'label' => '', 'is_last' => false),
			array('id' => 2, 'number' => 3, 'label' => '', 'is_last' => false),
			array('id' => 3, 'number' => 4, 'label' => '', 'is_last' => false),
			array('id' => 4, 'number' => 5, 'label' => '', 'is_last' => true)
		);
		$context['last_choice_id'] = 4;
	}
}