<?php
/*
	Question2Answer by Gideon Greenspan and contributors
	http://www.question2answer.org/

	Description: Common functions for question page viewing, either regular or via Ajax


	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	More about this license: http://www.question2answer.org/license.php
*/

if (!defined('QA_VERSION')) { // don't allow this page to be requested directly from browser
	header('Location: ../../');
	exit;
}


/**
 * Given a $question and its $childposts from the database, return a list of that question's answers
 * @param array $question
 * @param array $childposts
 * @return array
 */
function qa_page_q_load_as($question, $childposts)
{
	$answers = array();

	foreach ($childposts as $postid => $post) {
		switch ($post['type']) {
			case 'A':
			case 'A_HIDDEN':
			case 'A_QUEUED':
				$answers[$postid] = $post;
				break;
		}
	}

	return $answers;
}


/**
 * Given a $question, its $childposts and its answers $achildposts from the database,
 * return a list of comments or follow-on questions for that question or its answers.
 * Follow-on and duplicate questions are now returned, with their visibility determined in qa_page_q_comment_follow_list()
 * @param array $question
 * @param array $childposts
 * @param array $achildposts
 * @param array $duplicateposts
 * @return array
 */
function qa_page_q_load_c_follows($question, $childposts, $achildposts, $duplicateposts = array())
{
	$commentsfollows = array();

	foreach ($childposts as $postid => $post) {
		switch ($post['basetype']) {
			case 'Q':
			case 'C':
				$commentsfollows[$postid] = $post;
				break;
		}
	}

	foreach ($achildposts as $postid => $post) {
		switch ($post['basetype']) {
			case 'Q':
			case 'C':
				$commentsfollows[$postid] = $post;
				break;
		}
	}

	foreach ($duplicateposts as $postid => $post) {
		$commentsfollows[$postid] = $post;
	}

	return $commentsfollows;
}


/**
 * Calculates which operations the current user may perform on a post. This function is a key part of Q2A's logic
 * and is ripe for overriding by plugins. The latter two arrays can contain additional posts retrieved from the
 * database, and these will be ignored.
 * @param array $post The question/answer/comment to check.
 * @param array|null $parentpost The post's parent if there is one.
 * @param array|null $siblingposts The post's siblings (i.e. those with the same type and parent as the post).
 * @param array|null $childposts The post's children (e.g. comments on answers).
 * @return array List of elements that can be added to the post.
 */
function qa_page_q_post_rules($post, $parentpost = null, $siblingposts = null, $childposts = null)
{
	if (qa_to_override(__FUNCTION__)) { $args=func_get_args(); return qa_call_override(__FUNCTION__, $args); }

	$userid = qa_get_logged_in_userid();
	$cookieid = qa_cookie_get();
	$userlevel = qa_user_level_for_post($post);

	$userfields = qa_get_logged_in_user_cache();
	if (!isset($userfields)) {
		$userfields = array(
			'userid' => null,
			'level' => null,
			'flags' => null,
		);
	}

	$rules['isbyuser'] = qa_post_is_by_user($post, $userid, $cookieid);
	$rules['closed'] = $post['basetype'] == 'Q' && (isset($post['closedbyid']) || (isset($post['selchildid']) && qa_opt('do_close_on_select')));

	// Cache some responses to the user permission checks

	$permiterror_post_q = qa_user_permit_error('permit_post_q', null, $userlevel, true, $userfields); // don't check limits here, so we can show error message
	$permiterror_post_a = qa_user_permit_error('permit_post_a', null, $userlevel, true, $userfields);
	$permiterror_post_c = qa_user_permit_error('permit_post_c', null, $userlevel, true, $userfields);

	$edit_option = $post['basetype'] == 'Q' ? 'permit_edit_q' : ($post['basetype'] == 'A' ? 'permit_edit_a' : 'permit_edit_c');
	$permiterror_edit = qa_user_permit_error($edit_option, null, $userlevel, true, $userfields);
	$permiterror_retagcat = qa_user_permit_error('permit_retag_cat', null, $userlevel, true, $userfields);
	$permiterror_flag = qa_user_permit_error('permit_flag', null, $userlevel, true, $userfields);
	$permiterror_hide_show = qa_user_permit_error('permit_hide_show', null, $userlevel, true, $userfields);
	$permiterror_hide_show_self = $rules['isbyuser'] ? qa_user_permit_error(null, null, $userlevel, true, $userfields) : $permiterror_hide_show;

	$close_option = $rules['isbyuser'] && qa_opt('allow_close_own_questions') ? null : 'permit_close_q';
	$permiterror_close_open = qa_user_permit_error($close_option, null, $userlevel, true, $userfields);
	$permiterror_moderate = qa_user_permit_error('permit_moderate', null, $userlevel, true, $userfields);

	// General permissions

	$rules['authorlast'] = !isset($post['lastuserid']) || $post['lastuserid'] === $post['userid'];
	$rules['viewable'] = $post['hidden'] ? !$permiterror_hide_show_self : ($post['queued'] ? ($rules['isbyuser'] || !$permiterror_moderate) : true);

	// Answer, comment and edit might show the button even if the user still needs to do something (e.g. log in)

	$rules['answerbutton'] = $post['type'] == 'Q' && $permiterror_post_a != 'level' && !$rules['closed']
		&& (qa_opt('allow_self_answer') || !$rules['isbyuser']);

	$rules['commentbutton'] = ($post['type'] == 'Q' || $post['type'] == 'A') && $permiterror_post_c != 'level'
		&& qa_opt($post['type'] == 'Q' ? 'comment_on_qs' : 'comment_on_as');
	$rules['commentable'] = $rules['commentbutton'] && !$permiterror_post_c;

	$button_errors = array('login', 'level', 'approve');

	$rules['editbutton'] = !$post['hidden'] && !$rules['closed']
		&& ($rules['isbyuser'] || (!in_array($permiterror_edit, $button_errors) && (!$post['queued'])));
	$rules['editable'] = $rules['editbutton'] && ($rules['isbyuser'] || !$permiterror_edit);

	$rules['retagcatbutton'] = $post['basetype'] == 'Q' && (qa_using_tags() || qa_using_categories())
		&& !$post['hidden'] && ($rules['isbyuser'] || !in_array($permiterror_retagcat, $button_errors));
	$rules['retagcatable'] = $rules['retagcatbutton'] && ($rules['isbyuser'] || !$permiterror_retagcat);

	if ($rules['editbutton'] && $rules['retagcatbutton']) {
		// only show one button since they lead to the same form
		if ($rules['retagcatable'] && !$rules['editable'])
			$rules['editbutton'] = false; // if we can do this without getting an error, show that as the title
		else
			$rules['retagcatbutton'] = false;
	}

	$rules['aselectable'] = $post['type'] == 'Q' && !qa_user_permit_error($rules['isbyuser'] ? null : 'permit_select_a', null, $userlevel, true, $userfields);

	$rules['flagbutton'] = qa_opt('flagging_of_posts') && !$rules['isbyuser'] && !$post['hidden'] && !$post['queued']
		&& !@$post['userflag'] && !in_array($permiterror_flag, $button_errors);
	$rules['flagtohide'] = $rules['flagbutton'] && !$permiterror_flag && ($post['flagcount'] + 1) >= qa_opt('flagging_hide_after');
	$rules['unflaggable'] = @$post['userflag'] && !$post['hidden'];
	$rules['clearflaggable'] = $post['flagcount'] >= (@$post['userflag'] ? 2 : 1) && !$permiterror_hide_show;

	// Other actions only show the button if it's immediately possible

	$notclosedbyother = !($rules['closed'] && isset($post['closedbyid']) && !$rules['authorlast']);
	$nothiddenbyother = !($post['hidden'] && !$rules['authorlast']);

	$rules['closeable'] = qa_opt('allow_close_questions') && $post['type'] == 'Q' && !$rules['closed'] && $permiterror_close_open === false;
	// cannot reopen a question if it's been hidden, or if it was closed by someone else and you don't have global closing permissions
	$rules['reopenable'] = $rules['closed'] && $permiterror_close_open === false && !$post['hidden']
		&& ($notclosedbyother || !qa_user_permit_error('permit_close_q', null, $userlevel, true, $userfields));

	$rules['moderatable'] = $post['queued'] && !$permiterror_moderate;
	// cannot hide a question if it was closed by someone else and you don't have global hiding permissions
	$rules['hideable'] = !$post['hidden'] && ($rules['isbyuser'] || !$post['queued']) && !$permiterror_hide_show_self
		&& ($notclosedbyother || !$permiterror_hide_show);
	// means post can be reshown immediately without checking whether it needs moderation
	$rules['reshowimmed'] = $post['hidden'] && !$permiterror_hide_show;
	// cannot reshow a question if it was hidden by someone else, or if it has flags - unless you have global hide/show permissions
	$rules['reshowable'] = $post['hidden'] && (!$permiterror_hide_show_self) &&
		($rules['reshowimmed'] || ($nothiddenbyother && !$post['flagcount']));

	$rules['deleteable'] = $post['hidden'] && !qa_user_permit_error('permit_delete_hidden', null, $userlevel, true, $userfields);
	$rules['claimable'] = !isset($post['userid']) && isset($userid) && strlen(@$post['cookieid']) && (strcmp(@$post['cookieid'], $cookieid) == 0)
		&& !($post['basetype'] == 'Q' ? $permiterror_post_q : ($post['basetype'] == 'A' ? $permiterror_post_a : $permiterror_post_c));
	$rules['followable'] = $post['type'] == 'A' ? qa_opt('follow_on_as') : false;

	// Check for claims that could break rules about self answering and multiple answers

	if ($rules['claimable'] && $post['basetype'] == 'A') {
		if (!qa_opt('allow_self_answer') && isset($parentpost) && qa_post_is_by_user($parentpost, $userid, $cookieid))
			$rules['claimable'] = false;

		if (isset($siblingposts) && !qa_opt('allow_multi_answers')) {
			foreach ($siblingposts as $siblingpost) {
				if ($siblingpost['parentid'] == $post['parentid'] && $siblingpost['basetype'] == 'A' && qa_post_is_by_user($siblingpost, $userid, $cookieid))
					$rules['claimable'] = false;
			}
		}
	}

	// Now make any changes based on the child posts

	if (isset($childposts)) {
		foreach ($childposts as $childpost) {
			// Skip the child post if it is a note
			if ($childpost['basetype'] === 'N') {
				continue;
			}

			if ($childpost['parentid'] == $post['postid']) {
				// this post has comments
				$rules['deleteable'] = false;

				if ($childpost['basetype'] == 'A' && qa_post_is_by_user($childpost, $userid, $cookieid)) {
					if (!qa_opt('allow_multi_answers'))
						$rules['answerbutton'] = false;

					if (!qa_opt('allow_self_answer'))
						$rules['claimable'] = false;
				}
			}

			if ($childpost['closedbyid'] == $post['postid']) {
				// other questions are closed as duplicates of this one
				$rules['deleteable'] = false;
			}
		}
	}

	// Return the resulting rules

	return $rules;
}


/**
 * Return the $qa_content['q_view'] element for $question as viewed by the current user. If this question is a
 * follow-on, pass the question for this question's parent answer in $parentquestion, otherwise null. If the question
 * is closed, pass the post used to close this question in $closepost, otherwise null. $usershtml should be an array
 * which maps userids to HTML user representations, including the question's author and (if present) last editor. If a
 * form has been explicitly requested for the page, set $formrequested to true - this will hide the buttons.
 * @param array $question
 * @param array|null $parentquestion
 * @param int|null $closepost
 * @param array $usershtml
 * @param bool $formrequested
 * @return array
 */
function qa_page_q_question_view($question, $parentquestion, $closepost, $usershtml, $formrequested)
{
	require_once QA_INCLUDE_DIR . 'app/posts.php';

	$questionid = $question['postid'];
	$userid = qa_get_logged_in_userid();
	$cookieid = qa_cookie_get();

	$htmloptions = qa_post_html_options($question, null, true);
	$htmloptions['answersview'] = false; // answer count is displayed separately so don't show it here
	$htmloptions['avatarsize'] = qa_opt('avatar_q_page_q_size');
	$htmloptions['q_request'] = qa_q_request($question['postid'], $question['title']);
	$q_view = qa_post_html_fields($question, $userid, $cookieid, $usershtml, null, $htmloptions);


	$q_view['main_form_tags'] = 'method="post" action="' . qa_self_html() . '"';
	$q_view['voting_form_hidden'] = array('code' => qa_get_form_security_code('vote'));
	$q_view['buttons_form_hidden'] = array('code' => qa_get_form_security_code('buttons-' . $questionid), 'qa_click' => '');


	// Buttons for operating on the question

	if (!$formrequested) { // don't show if another form is currently being shown on page
		$clicksuffix = ' onclick="qa_show_waiting_after(this, false);"'; // add to operations that write to database
		$buttons = array();

		if ($question['editbutton']) {
			$buttons['edit'] = array(
				'tags' => 'name="q_doedit"',
				'label' => qa_lang_html('question/edit_button'),
				'popup' => qa_lang_html('question/edit_q_popup'),
			);
		}

		$hascategories = qa_using_categories();

		if ($question['retagcatbutton']) {
			$buttons['retagcat'] = array(
				'tags' => 'name="q_doedit"',
				'label' => qa_lang_html($hascategories ? 'question/recat_button' : 'question/retag_button'),
				'popup' => qa_lang_html($hascategories
					? (qa_using_tags() ? 'question/retag_cat_popup' : 'question/recat_popup')
					: 'question/retag_popup'
				),
			);
		}

		if ($question['flagbutton']) {
			$buttons['flag'] = array(
				'tags' => 'name="q_doflag"' . $clicksuffix,
				'label' => qa_lang_html($question['flagtohide'] ? 'question/flag_hide_button' : 'question/flag_button'),
				'popup' => qa_lang_html('question/flag_q_popup'),
			);
		}

		if ($question['unflaggable']) {
			$buttons['unflag'] = array(
				'tags' => 'name="q_dounflag"' . $clicksuffix,
				'label' => qa_lang_html('question/unflag_button'),
				'popup' => qa_lang_html('question/unflag_popup'),
			);
		}

		if ($question['clearflaggable']) {
			$buttons['clearflags'] = array(
				'tags' => 'name="q_doclearflags"' . $clicksuffix,
				'label' => qa_lang_html('question/clear_flags_button'),
				'popup' => qa_lang_html('question/clear_flags_popup'),
			);
		}

		if ($question['closeable']) {
			$buttons['close'] = array(
				'tags' => 'name="q_doclose"',
				'label' => qa_lang_html('question/close_button'),
				'popup' => qa_lang_html('question/close_q_popup'),
			);
		}

		if ($question['reopenable']) {
			$buttons['reopen'] = array(
				'tags' => 'name="q_doreopen"' . $clicksuffix,
				'label' => qa_lang_html('question/reopen_button'),
				'popup' => qa_lang_html('question/reopen_q_popup'),
			);
		}

		if ($question['moderatable']) {
			$buttons['approve'] = array(
				'tags' => 'name="q_doapprove"' . $clicksuffix,
				'label' => qa_lang_html('question/approve_button'),
				'popup' => qa_lang_html('question/approve_q_popup'),
			);

			$buttons['reject'] = array(
				'tags' => 'name="q_doreject"' . $clicksuffix,
				'label' => qa_lang_html('question/reject_button'),
				'popup' => qa_lang_html('question/reject_q_popup'),
			);
		}

		if ($question['hideable']) {
			$buttons['hide'] = array(
				'tags' => 'name="q_dohide"' . $clicksuffix,
				'label' => qa_lang_html('question/hide_button'),
				'popup' => qa_lang_html('question/hide_q_popup'),
			);
		}

		if ($question['reshowable']) {
			$buttons['reshow'] = array(
				'tags' => 'name="q_doreshow"' . $clicksuffix,
				'label' => qa_lang_html('question/reshow_button'),
				'popup' => qa_lang_html('question/reshow_q_popup'),
			);
		}

		if ($question['deleteable']) {
			$buttons['delete'] = array(
				'tags' => 'name="q_dodelete"' . $clicksuffix,
				'label' => qa_lang_html('question/delete_button'),
				'popup' => qa_lang_html('question/delete_q_popup'),
			);
		}

		if ($question['claimable']) {
			$buttons['claim'] = array(
				'tags' => 'name="q_doclaim"' . $clicksuffix,
				'label' => qa_lang_html('question/claim_button'),
				'popup' => qa_lang_html('question/claim_q_popup'),
			);
		}

		if ($question['answerbutton']) {
			// don't show if shown by default
			$buttons['answer'] = array(
				'tags' => 'name="q_doanswer" id="q_doanswer" onclick="return qa_toggle_element(\'anew\')"',
				'label' => qa_lang_html('question/answer_button'),
				'popup' => qa_lang_html('question/answer_q_popup'),
			);
		}

		if ($question['commentbutton']) {
			$buttons['comment'] = array(
				'tags' => 'name="q_docomment" onclick="return qa_toggle_element(\'c' . $questionid . '\')"',
				'label' => qa_lang_html('question/comment_button'),
				'popup' => qa_lang_html('question/comment_q_popup'),
			);
		}

		$q_view['form'] = array(
			'style' => 'light',
			'buttons' => $buttons,
		);
	}


	// Information about the question of the answer that this question follows on from (or a question directly)

	if (isset($parentquestion)) {
		$q_view['follows'] = array(
			'label' => qa_lang_html(($question['parentid'] == $parentquestion['postid']) ? 'question/follows_q' : 'question/follows_a'),
			'title' => qa_html(qa_block_words_replace($parentquestion['title'], qa_get_block_words_preg())),
			'url' => qa_q_path_html($parentquestion['postid'], $parentquestion['title'], false,
				($question['parentid'] == $parentquestion['postid']) ? 'Q' : 'A', $question['parentid']),
		);
	}


	// Information about the question that this question is a duplicate of (if appropriate)

	if (isset($closepost) || qa_post_is_closed($question)) {
		if (isset($closepost['basetype']) && $closepost['basetype'] == 'Q') {
			if ($closepost['hidden']) {
				// don't show link for hidden questions
				$q_view['closed'] = array(
					'state' => qa_lang_html('main/closed'),
					'label' => qa_lang_html('main/closed'),
					'content' => '',
				);
			} else {
				$q_view['closed'] = array(
					'state' => qa_lang_html('main/closed'),
					'label' => qa_lang_html('question/closed_as_duplicate'),
					'content' => qa_html(qa_block_words_replace($closepost['title'], qa_get_block_words_preg())),
					'url' => qa_q_path_html($closepost['postid'], $closepost['title']),
				);
			}

		} elseif (isset($closepost['type']) && $closepost['type'] == 'NOTE') {
			$viewer = qa_load_viewer($closepost['content'], $closepost['format']);

			$q_view['closed'] = array(
				'state' => qa_lang_html('main/closed'),
				'label' => qa_lang_html('question/closed_with_note'),
				'content' => $viewer->get_html($closepost['content'], $closepost['format'], array(
					'blockwordspreg' => qa_get_block_words_preg(),
				)),
			);
		} else { // If closed by a selected answer due to the do_close_on_select setting being enabled
			$q_view['closed'] = array(
				'state' => qa_lang_html('main/closed'),
				'label' => qa_lang_html('main/closed'),
				'content' => '',
			);
		}
	}


	// Extra value display

	if (strlen(@$question['extra']) && qa_opt('extra_field_active') && qa_opt('extra_field_display')) {
		$q_view['extra'] = array(
			'label' => qa_html(qa_opt('extra_field_label')),
			'content' => qa_html(qa_block_words_replace($question['extra'], qa_get_block_words_preg())),
		);
	}


	return $q_view;
}


/**
 * Returns an element to add to $qa_content['a_list']['as'] for $answer as viewed by $userid and $cookieid. Pass the
 * answer's $question and whether it $isselected. $usershtml should be an array which maps userids to HTML user
 * representations, including the answer's author and (if present) last editor. If a form has been explicitly requested
 * for the page, set $formrequested to true - this will hide the buttons.
 * @param array $question
 * @param array $answer
 * @param bool $isselected
 * @param array $usershtml
 * @param bool $formrequested
 * @return array
 */
function qa_page_q_answer_view($question, $answer, $isselected, $usershtml, $formrequested)
{
	$answerid = $answer['postid'];
	$userid = qa_get_logged_in_userid();
	$cookieid = qa_cookie_get();

	$htmloptions = qa_post_html_options($answer, null, true);
	$htmloptions['isselected'] = $isselected;
	$htmloptions['avatarsize'] = qa_opt('avatar_q_page_a_size');
	$htmloptions['q_request'] = qa_q_request($question['postid'], $question['title']);
	$a_view = qa_post_html_fields($answer, $userid, $cookieid, $usershtml, null, $htmloptions);

	if ($answer['queued'])
		$a_view['error'] = $answer['isbyuser'] ? qa_lang_html('question/a_your_waiting_approval') : qa_lang_html('question/a_waiting_your_approval');

	$a_view['main_form_tags'] = 'method="post" action="' . qa_self_html() . '"';
	$a_view['voting_form_hidden'] = array('code' => qa_get_form_security_code('vote'));
	$a_view['buttons_form_hidden'] = array('code' => qa_get_form_security_code('buttons-' . $answerid), 'qa_click' => '');


	// Selection/unselect buttons and others for operating on the answer

	if (!$formrequested) { // don't show if another form is currently being shown on page
		$prefix = 'a' . qa_html($answerid) . '_';
		$clicksuffix = ' onclick="return qa_answer_click(' . qa_js($answerid) . ', ' . qa_js($question['postid']) . ', this);"';

		if ($question['aselectable'] && !$answer['hidden'] && !$answer['queued']) {
			if ($isselected)
				$a_view['unselect_tags'] = 'title="' . qa_lang_html('question/unselect_popup') . '" name="' . $prefix . 'dounselect"' . $clicksuffix;
			else
				$a_view['select_tags'] = 'title="' . qa_lang_html('question/select_popup') . '" name="' . $prefix . 'doselect"' . $clicksuffix;
		}

		$buttons = array();

		if ($answer['editbutton']) {
			$buttons['edit'] = array(
				'tags' => 'name="' . $prefix . 'doedit"',
				'label' => qa_lang_html('question/edit_button'),
				'popup' => qa_lang_html('question/edit_a_popup'),
			);
		}

		if ($answer['flagbutton']) {
			$buttons['flag'] = array(
				'tags' => 'name="' . $prefix . 'doflag"' . $clicksuffix,
				'label' => qa_lang_html($answer['flagtohide'] ? 'question/flag_hide_button' : 'question/flag_button'),
				'popup' => qa_lang_html('question/flag_a_popup'),
			);
		}

		if ($answer['unflaggable']) {
			$buttons['unflag'] = array(
				'tags' => 'name="' . $prefix . 'dounflag"' . $clicksuffix,
				'label' => qa_lang_html('question/unflag_button'),
				'popup' => qa_lang_html('question/unflag_popup'),
			);
		}

		if ($answer['clearflaggable']) {
			$buttons['clearflags'] = array(
				'tags' => 'name="' . $prefix . 'doclearflags"' . $clicksuffix,
				'label' => qa_lang_html('question/clear_flags_button'),
				'popup' => qa_lang_html('question/clear_flags_popup'),
			);
		}

		if ($answer['moderatable']) {
			$buttons['approve'] = array(
				'tags' => 'name="' . $prefix . 'doapprove"' . $clicksuffix,
				'label' => qa_lang_html('question/approve_button'),
				'popup' => qa_lang_html('question/approve_a_popup'),
			);

			$buttons['reject'] = array(
				'tags' => 'name="' . $prefix . 'doreject"' . $clicksuffix,
				'label' => qa_lang_html('question/reject_button'),
				'popup' => qa_lang_html('question/reject_a_popup'),
			);
		}

		if ($answer['hideable']) {
			$buttons['hide'] = array(
				'tags' => 'name="' . $prefix . 'dohide"' . $clicksuffix,
				'label' => qa_lang_html('question/hide_button'),
				'popup' => qa_lang_html('question/hide_a_popup'),
			);
		}

		if ($answer['reshowable']) {
			$buttons['reshow'] = array(
				'tags' => 'name="' . $prefix . 'doreshow"' . $clicksuffix,
				'label' => qa_lang_html('question/reshow_button'),
				'popup' => qa_lang_html('question/reshow_a_popup'),
			);
		}

		if ($answer['deleteable']) {
			$buttons['delete'] = array(
				'tags' => 'name="' . $prefix . 'dodelete"' . $clicksuffix,
				'label' => qa_lang_html('question/delete_button'),
				'popup' => qa_lang_html('question/delete_a_popup'),
			);
		}

		if ($answer['claimable']) {
			$buttons['claim'] = array(
				'tags' => 'name="' . $prefix . 'doclaim"' . $clicksuffix,
				'label' => qa_lang_html('question/claim_button'),
				'popup' => qa_lang_html('question/claim_a_popup'),
			);
		}

		if ($answer['followable']) {
			$buttons['follow'] = array(
				'tags' => 'name="' . $prefix . 'dofollow"',
				'label' => qa_lang_html('question/follow_button'),
				'popup' => qa_lang_html('question/follow_a_popup'),
			);
		}

		if ($answer['commentbutton']) {
			$buttons['comment'] = array(
				'tags' => 'name="' . $prefix . 'docomment" onclick="return qa_toggle_element(\'c' . $answerid . '\')"',
				'label' => qa_lang_html('question/comment_button'),
				'popup' => qa_lang_html('question/comment_a_popup'),
			);
		}

		$a_view['form'] = array(
			'style' => 'light',
			'buttons' => $buttons,
		);
	}

	return $a_view;
}


/**
 * Returns an element to add to the appropriate $qa_content[...]['c_list']['cs'] array for $comment as viewed by the
 * current user. Pass the comment's $parent post and antecedent $question. $usershtml should be an array which maps
 * userids to HTML user representations, including the comments's author and (if present) last editor. If a form has
 * been explicitly requested for the page, set $formrequested to true - this will hide the buttons.
 * @param array $question
 * @param array $parent
 * @param array $comment
 * @param array $usershtml
 * @param bool $formrequested
 * @return array
 */
function qa_page_q_comment_view($question, $parent, $comment, $usershtml, $formrequested)
{
	$commentid = $comment['postid'];
	$questionid = ($parent['basetype'] == 'Q') ? $parent['postid'] : $parent['parentid'];
	$userid = qa_get_logged_in_userid();
	$cookieid = qa_cookie_get();

	$htmloptions = qa_post_html_options($comment, null, true);
	$htmloptions['avatarsize'] = qa_opt('avatar_q_page_c_size');
	$htmloptions['q_request'] = qa_q_request($question['postid'], $question['title']);
	$c_view = qa_post_html_fields($comment, $userid, $cookieid, $usershtml, null, $htmloptions);

	if ($comment['queued'])
		$c_view['error'] = $comment['isbyuser'] ? qa_lang_html('question/c_your_waiting_approval') : qa_lang_html('question/c_waiting_your_approval');

	$c_view['main_form_tags'] = 'method="post" action="' . qa_self_html() . '"';
	$c_view['voting_form_hidden'] = array('code' => qa_get_form_security_code('vote'));
	$c_view['buttons_form_hidden'] = array('code' => qa_get_form_security_code('buttons-' . $parent['postid']), 'qa_click' => '');


	// Buttons for operating on this comment

	if (!$formrequested) { // don't show if another form is currently being shown on page
		$prefix = 'c' . qa_html($commentid) . '_';
		$clicksuffix = ' onclick="return qa_comment_click(' . qa_js($commentid) . ', ' . qa_js($questionid) . ', ' . qa_js($parent['postid']) . ', this);"';

		$buttons = array();

		if ($comment['editbutton']) {
			$buttons['edit'] = array(
				'tags' => 'name="' . $prefix . 'doedit"',
				'label' => qa_lang_html('question/edit_button'),
				'popup' => qa_lang_html('question/edit_c_popup'),
			);
		}

		if ($comment['flagbutton']) {
			$buttons['flag'] = array(
				'tags' => 'name="' . $prefix . 'doflag"' . $clicksuffix,
				'label' => qa_lang_html($comment['flagtohide'] ? 'question/flag_hide_button' : 'question/flag_button'),
				'popup' => qa_lang_html('question/flag_c_popup'),
			);
		}

		if ($comment['unflaggable']) {
			$buttons['unflag'] = array(
				'tags' => 'name="' . $prefix . 'dounflag"' . $clicksuffix,
				'label' => qa_lang_html('question/unflag_button'),
				'popup' => qa_lang_html('question/unflag_popup'),
			);
		}

		if ($comment['clearflaggable']) {
			$buttons['clearflags'] = array(
				'tags' => 'name="' . $prefix . 'doclearflags"' . $clicksuffix,
				'label' => qa_lang_html('question/clear_flags_button'),
				'popup' => qa_lang_html('question/clear_flags_popup'),
			);
		}

		if ($comment['moderatable']) {
			$buttons['approve'] = array(
				'tags' => 'name="' . $prefix . 'doapprove"' . $clicksuffix,
				'label' => qa_lang_html('question/approve_button'),
				'popup' => qa_lang_html('question/approve_c_popup'),
			);

			$buttons['reject'] = array(
				'tags' => 'name="' . $prefix . 'doreject"' . $clicksuffix,
				'label' => qa_lang_html('question/reject_button'),
				'popup' => qa_lang_html('question/reject_c_popup'),
			);
		}

		if ($comment['hideable']) {
			$buttons['hide'] = array(
				'tags' => 'name="' . $prefix . 'dohide"' . $clicksuffix,
				'label' => qa_lang_html('question/hide_button'),
				'popup' => qa_lang_html('question/hide_c_popup'),
			);
		}

		if ($comment['reshowable']) {
			$buttons['reshow'] = array(
				'tags' => 'name="' . $prefix . 'doreshow"' . $clicksuffix,
				'label' => qa_lang_html('question/reshow_button'),
				'popup' => qa_lang_html('question/reshow_c_popup'),
			);
		}

		if ($comment['deleteable']) {
			$buttons['delete'] = array(
				'tags' => 'name="' . $prefix . 'dodelete"' . $clicksuffix,
				'label' => qa_lang_html('question/delete_button'),
				'popup' => qa_lang_html('question/delete_c_popup'),
			);
		}

		if ($comment['claimable']) {
			$buttons['claim'] = array(
				'tags' => 'name="' . $prefix . 'doclaim"' . $clicksuffix,
				'label' => qa_lang_html('question/claim_button'),
				'popup' => qa_lang_html('question/claim_c_popup'),
			);
		}

		if ($parent['commentbutton'] && qa_opt('show_c_reply_buttons') && $comment['type'] == 'C') {
			$buttons['comment'] = array(
				'tags' => 'name="' . (($parent['basetype'] == 'Q') ? 'q' : ('a' . qa_html($parent['postid']))) .
					'_docomment" onclick="return qa_toggle_element(\'c' . qa_html($parent['postid']) . '\')"',
				'label' => qa_lang_html('question/reply_button'),
				'popup' => qa_lang_html('question/reply_c_popup'),
			);
		}

		$c_view['form'] = array(
			'style' => 'light',
			'buttons' => $buttons,
		);
	}

	return $c_view;
}


/**
 * Return an array for $qa_content[...]['c_list'] to display all of the comments and follow-on questions in
 * $commentsfollows which belong to post $parent with antecedent $question, as viewed by the current user. If
 * $alwaysfull then all comments will be included, otherwise the list may be shortened with a 'show previous x
 * comments' link. $usershtml should be an array which maps userids to HTML user representations, including all
 * comments' and follow on questions' authors and (if present) last editors. If a form has been explicitly requested
 * for the page, set $formrequested to true and pass the postid of the post for the form in $formpostid - this will
 * hide the buttons and remove the $formpostid comment from the list.
 * @param array $question
 * @param array $parent
 * @param array $commentsfollows
 * @param bool $alwaysfull
 * @param array $usershtml
 * @param bool $formrequested
 * @param int $formpostid
 * @return array
 */
function qa_page_q_comment_follow_list($question, $parent, $commentsfollows, $alwaysfull, $usershtml, $formrequested, $formpostid)
{
	$parentid = $parent['postid'];
	$userid = qa_get_logged_in_userid();
	$cookieid = qa_cookie_get();

	$commentlist = array(
		'tags' => 'id="c' . qa_html($parentid) . '_list"',
		'cs' => array(),
	);

	$showcomments = array();

	// $commentsfollows contains ALL comments on the question and all answers, so here we filter the comments viewable for this context
	foreach ($commentsfollows as $commentfollowid => $commentfollow) {
		$showcomment = $commentfollow['parentid'] == $parentid && $commentfollow['viewable'] && $commentfollowid != $formpostid;
		// show hidden follow-on questions only if the parent is hidden
		if ($showcomment && $commentfollow['basetype'] == 'Q' && $commentfollow['hidden']) {
			$showcomment = $parent['hidden'];
		}
		// show questions closed as duplicate of this one, only if this question is hidden
		$showduplicate = $question['hidden'] && $commentfollow['closedbyid'] == $parentid;

		if ($showcomment || $showduplicate) {
			$showcomments[$commentfollowid] = $commentfollow;
		}
	}

	$countshowcomments = count($showcomments);

	if (!$alwaysfull && $countshowcomments > qa_opt('show_fewer_cs_from'))
		$skipfirst = $countshowcomments - qa_opt('show_fewer_cs_count');
	else
		$skipfirst = 0;

	if ($skipfirst == $countshowcomments) { // showing none
		if ($skipfirst == 1)
			$expandtitle = qa_lang_html('question/show_1_comment');
		else
			$expandtitle = qa_lang_html_sub('question/show_x_comments', $skipfirst);

	} else {
		if ($skipfirst == 1)
			$expandtitle = qa_lang_html('question/show_1_previous_comment');
		else
			$expandtitle = qa_lang_html_sub('question/show_x_previous_comments', $skipfirst);
	}

	if ($skipfirst > 0) {
		$commentlist['cs'][$parentid] = array(
			'url' => qa_html('?state=showcomments-' . $parentid . '&show=' . $parentid . '#' . urlencode(qa_anchor($parent['basetype'], $parentid))),

			'expand_tags' => 'onclick="return qa_show_comments(' . qa_js($question['postid']) . ', ' . qa_js($parentid) . ', this);"',

			'title' => $expandtitle,
		);
	}

	foreach ($showcomments as $commentfollowid => $commentfollow) {
		if ($skipfirst > 0) {
			$skipfirst--;
		} elseif ($commentfollow['basetype'] == 'C') {
			$commentlist['cs'][$commentfollowid] = qa_page_q_comment_view($question, $parent, $commentfollow, $usershtml, $formrequested);
		} elseif ($commentfollow['basetype'] == 'Q') {
			$htmloptions = qa_post_html_options($commentfollow);
			$htmloptions['avatarsize'] = qa_opt('avatar_q_page_c_size');
			$htmloptions['voteview'] = false;

			$commentlist['cs'][$commentfollowid] = qa_post_html_fields($commentfollow, $userid, $cookieid, $usershtml, null, $htmloptions);
		}
	}

	if (empty($commentlist['cs']))
		$commentlist['hidden'] = true;

	return $commentlist;
}


/**
 * Return a $qa_content form for adding an answer to $question. Pass an HTML element id to use for the form in $formid
 * and the result of qa_user_captcha_reason() in $captchareason. Pass previous inputs from a submitted version of this
 * form in the array $in and resulting errors in $errors. If $loadnow is true, the form will be loaded immediately. Set
 * $formrequested to true if the user explicitly requested it, as opposed being shown automatically.
 * @param array $qa_content
 * @param string $formid
 * @param string $captchareason
 * @param array $question
 * @param array $in
 * @param array $errors
 * @param bool $loadnow
 * @param bool $formrequested
 * @return array
 */
function qa_page_q_add_a_form(&$qa_content, $formid, $captchareason, $question, $in, $errors, $loadnow, $formrequested)
{
	// The 'approve', 'login', 'confirm', 'limit', 'userblock', 'ipblock' permission errors are reported to the user here
	// The other option ('level') prevents the answer button being shown, in qa_page_q_post_rules(...)

	switch (qa_user_post_permit_error('permit_post_a', $question, QA_LIMIT_ANSWERS)) {
		case 'login':
			$form = array(
				'title' => qa_insert_login_links(qa_lang_html('question/answer_must_login'), qa_request()),
			);
			break;

		case 'confirm':
			$form = array(
				'title' => qa_insert_login_links(qa_lang_html('question/answer_must_confirm'), qa_request()),
			);
			break;

		case 'approve':
			$form = array(
				'title' => strtr(qa_lang_html('question/answer_must_be_approved'), array(
					'^1' => '<a href="' . qa_path_html('account') . '">',
					'^2' => '</a>',
				)),
			);
			break;

		case 'limit':
			$form = array(
				'title' => qa_lang_html('question/answer_limit'),
			);
			break;

		default:
			$form = array(
				'title' => qa_lang_html('users/no_permission'),
			);
			break;

		case false:
			$editorname = isset($in['editor']) ? $in['editor'] : qa_opt('editor_for_as');
			$editor = qa_load_editor(@$in['content'], @$in['format'], $editorname);

			if (method_exists($editor, 'update_script'))
				$updatescript = $editor->update_script('a_content');
			else
				$updatescript = '';

			$custom = qa_opt('show_custom_answer') ? trim(qa_opt('custom_answer')) : '';

			$form = array(
				'tags' => 'method="post" action="' . qa_self_html() . '" name="a_form"',

				'title' => qa_lang_html('question/your_answer_title'),

				'fields' => array(
					'custom' => array(
						'type' => 'custom',
						'note' => $custom,
					),

					'content' => array_merge(
						qa_editor_load_field($editor, $qa_content, @$in['content'], @$in['format'], 'a_content', 12, $formrequested, $loadnow),
						array(
							'error' => qa_html(@$errors['content']),
						)
					),
				),

				'buttons' => array(
					'answer' => array(
						'tags' => 'onclick="' . $updatescript . ' return qa_submit_answer(' . qa_js($question['postid']) . ', this);"',
						'label' => qa_lang_html('question/add_answer_button'),
					),
				),

				'hidden' => array(
					'a_editor' => qa_html($editorname),
					'a_doadd' => '1',
					'code' => qa_get_form_security_code('answer-' . $question['postid']),
				),
			);

			if (!strlen($custom))
				unset($form['fields']['custom']);

			if ($formrequested || !$loadnow)
				$form['buttons']['cancel'] = array(
					'tags' => 'name="docancel"',
					'label' => qa_lang_html('main/cancel_button'),
				);

			if (!qa_is_logged_in() && qa_opt('allow_anonymous_naming'))
				qa_set_up_name_field($qa_content, $form['fields'], @$in['name'], 'a_');

			qa_set_up_notify_fields($qa_content, $form['fields'], 'A', qa_get_logged_in_email(),
				isset($in['notify']) ? $in['notify'] : qa_opt('notify_users_default'), @$in['email'], @$errors['email'], 'a_');

			$onloads = array();

			if ($captchareason) {
				$captchaloadscript = qa_set_up_captcha_field($qa_content, $form['fields'], $errors, qa_captcha_reason_note($captchareason));

				if (strlen($captchaloadscript))
					$onloads[] = 'document.getElementById(' . qa_js($formid) . ').qa_show = function() { ' . $captchaloadscript . ' };';
			}

			if (!$loadnow) {
				if (method_exists($editor, 'load_script'))
					$onloads[] = 'document.getElementById(' . qa_js($formid) . ').qa_load = function() { ' . $editor->load_script('a_content') . ' };';

				$form['buttons']['cancel']['tags'] .= ' onclick="return qa_toggle_element();"';
			}

			if (!$formrequested) {
				if (method_exists($editor, 'focus_script'))
					$onloads[] = 'document.getElementById(' . qa_js($formid) . ').qa_focus = function() { ' . $editor->focus_script('a_content') . ' };';
			}

			if (count($onloads)) {
				$qa_content['script_onloads'][] = $onloads;
			}

			break;
	}

	$form['id'] = $formid;
	$form['collapse'] = !$loadnow;
	$form['style'] = 'tall';

	return $form;
}


/**
 * Returns a $qa_content form for adding a comment to post $parent which is part of $question. Pass an HTML element id
 * to use for the form in $formid and the result of qa_user_captcha_reason() in $captchareason. Pass previous inputs
 * from a submitted version of this form in the array $in and resulting errors in $errors. If $loadfocusnow is true,
 * the form will be loaded and focused immediately.
 * @param array $qa_content
 * @param array $question
 * @param array $parent
 * @param string $formid
 * @param string $captchareason
 * @param array $in
 * @param array $errors
 * @param bool $loadfocusnow
 * @return array
 */
function qa_page_q_add_c_form(&$qa_content, $question, $parent, $formid, $captchareason, $in, $errors, $loadfocusnow)
{
	// The 'approve', 'login', 'confirm', 'userblock', 'ipblock' permission errors are reported to the user here
	// The other option ('level') prevents the comment button being shown, in qa_page_q_post_rules(...)

	switch (qa_user_post_permit_error('permit_post_c', $parent, QA_LIMIT_COMMENTS)) {
		case 'login':
			$form = array(
				'title' => qa_insert_login_links(qa_lang_html('question/comment_must_login'), qa_request()),
			);
			break;

		case 'confirm':
			$form = array(
				'title' => qa_insert_login_links(qa_lang_html('question/comment_must_confirm'), qa_request()),
			);
			break;

		case 'approve':
			$form = array(
				'title' => strtr(qa_lang_html('question/comment_must_be_approved'), array(
					'^1' => '<a href="' . qa_path_html('account') . '">',
					'^2' => '</a>',
				)),
			);
			break;

		case 'limit':
			$form = array(
				'title' => qa_lang_html('question/comment_limit'),
			);
			break;

		default:
			$form = array(
				'title' => qa_lang_html('users/no_permission'),
			);
			break;

		case false:
			$prefix = 'c' . $parent['postid'] . '_';

			$editorname = isset($in['editor']) ? $in['editor'] : qa_opt('editor_for_cs');
			$editor = qa_load_editor(@$in['content'], @$in['format'], $editorname);

			if (method_exists($editor, 'update_script'))
				$updatescript = $editor->update_script($prefix . 'content');
			else
				$updatescript = '';

			$custom = qa_opt('show_custom_comment') ? trim(qa_opt('custom_comment')) : '';

			$form = array(
				'tags' => 'method="post" action="' . qa_self_html() . '" name="c_form_' . qa_html($parent['postid']) . '"',

				'title' => qa_lang_html(($question['postid'] == $parent['postid']) ? 'question/your_comment_q' : 'question/your_comment_a'),

				'fields' => array(
					'custom' => array(
						'type' => 'custom',
						'note' => $custom,
					),

					'content' => array_merge(
						qa_editor_load_field($editor, $qa_content, @$in['content'], @$in['format'], $prefix . 'content', 4, $loadfocusnow, $loadfocusnow),
						array(
							'error' => qa_html(@$errors['content']),
						)
					),
				),

				'buttons' => array(
					'comment' => array(
						'tags' => 'onclick="' . $updatescript . ' return qa_submit_comment(' . qa_js($question['postid']) . ', ' . qa_js($parent['postid']) . ', this);"',
						'label' => qa_lang_html('question/add_comment_button'),
					),

					'cancel' => array(
						'tags' => 'name="docancel"',
						'label' => qa_lang_html('main/cancel_button'),
					),
				),

				'hidden' => array(
					$prefix . 'editor' => qa_html($editorname),
					$prefix . 'doadd' => '1',
					$prefix . 'code' => qa_get_form_security_code('comment-' . $parent['postid']),
				),
			);

			if (!strlen($custom))
				unset($form['fields']['custom']);

			if (!qa_is_logged_in() && qa_opt('allow_anonymous_naming'))
				qa_set_up_name_field($qa_content, $form['fields'], @$in['name'], $prefix);

			qa_set_up_notify_fields($qa_content, $form['fields'], 'C', qa_get_logged_in_email(),
				isset($in['notify']) ? $in['notify'] : qa_opt('notify_users_default'), @$in['email'], @$errors['email'], $prefix);

			$onloads = array();

			if ($captchareason) {
				$captchaloadscript = qa_set_up_captcha_field($qa_content, $form['fields'], $errors, qa_captcha_reason_note($captchareason));

				if (strlen($captchaloadscript))
					$onloads[] = 'document.getElementById(' . qa_js($formid) . ').qa_show = function() { ' . $captchaloadscript . ' };';
			}

			if (!$loadfocusnow) {
				if (method_exists($editor, 'load_script'))
					$onloads[] = 'document.getElementById(' . qa_js($formid) . ').qa_load = function() { ' . $editor->load_script($prefix . 'content') . ' };';
				if (method_exists($editor, 'focus_script'))
					$onloads[] = 'document.getElementById(' . qa_js($formid) . ').qa_focus = function() { ' . $editor->focus_script($prefix . 'content') . ' };';

				$form['buttons']['cancel']['tags'] .= ' onclick="return qa_toggle_element()"';
			}

			if (count($onloads)) {
				$qa_content['script_onloads'][] = $onloads;
			}

			break;
	}

	$form['id'] = $formid;
	$form['collapse'] = !$loadfocusnow;
	$form['style'] = 'tall';

	return $form;
}