<?php

/*
	Question2Answer (c) Gideon Greenspan

	http://www.question2answer.org/

	
	File: qa-include/qa-db-points.php
	Version: See define()s at top of qa-include/qa-base.php
	Description: Database-level access to user points and statistics


	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;
	}


	function qa_db_points_option_names()
/*
	Returns an array of option names required to perform calculations in userpoints table
*/
	{
		if (qa_to_override(__FUNCTION__)) { $args=func_get_args(); return qa_call_override(__FUNCTION__, $args); }
		
		return array(
			'points_post_q', 'points_select_a', 'points_per_q_voted_up', 'points_per_q_voted_down', 'points_q_voted_max_gain', 'points_q_voted_max_loss',
			'points_post_a', 'points_a_selected', 'points_per_a_voted_up', 'points_per_a_voted_down', 'points_a_voted_max_gain', 'points_a_voted_max_loss',
			'points_vote_up_q', 'points_vote_down_q', 'points_vote_up_a', 'points_vote_down_a',
			
			'points_multiple', 'points_base',
		);
	}

	
	function qa_db_points_calculations()
/*
	Returns an array containing all the calculation formulae for the userpoints table. Each element of this
	array is for one column - the key contains the column name, and the value is a further array of two elements.
	The element 'formula' contains the SQL fragment that calculates the columns value for one or more users,
	where the ~ symbol within the fragment is substituted for a constraint on which users we are interested in.
	The element 'multiple' specifies what to multiply each column by to create the final sum in the points column.
*/
	{
		if (qa_to_override(__FUNCTION__)) { $args=func_get_args(); return qa_call_override(__FUNCTION__, $args); }
		
		require_once QA_INCLUDE_DIR.'qa-app-options.php';
		
		$options=qa_get_options(qa_db_points_option_names());
		
		return array(
			'qposts' => array(
				'multiple' => $options['points_multiple']*$options['points_post_q'],
				'formula' => "COUNT(*) AS qposts FROM ^posts AS userid_src WHERE userid~ AND type='Q'",
			),
			
			'aposts' => array(
				'multiple' => $options['points_multiple']*$options['points_post_a'],
				'formula' => "COUNT(*) AS aposts FROM ^posts AS userid_src WHERE userid~ AND type='A'",
			),
			
			'cposts' => array(
				'multiple' => 0,
				'formula' => "COUNT(*) AS cposts FROM ^posts AS userid_src WHERE userid~ AND type='C'",
			),
			
			'aselects' => array(
				'multiple' => $options['points_multiple']*$options['points_select_a'],
				'formula' => "COUNT(*) AS aselects FROM ^posts AS userid_src WHERE userid~ AND type='Q' AND selchildid IS NOT NULL",
			),
			
			'aselecteds' => array(
				'multiple' => $options['points_multiple']*$options['points_a_selected'],
				'formula' => "COUNT(*) AS aselecteds FROM ^posts AS userid_src JOIN ^posts AS questions ON questions.selchildid=userid_src.postid WHERE userid_src.userid~ AND userid_src.type='A' AND NOT (questions.userid<=>userid_src.userid)",
			),
			
			'qupvotes' => array(
				'multiple' => $options['points_multiple']*$options['points_vote_up_q'],
				'formula' => "COUNT(*) AS qupvotes FROM ^uservotes AS userid_src JOIN ^posts ON userid_src.postid=^posts.postid WHERE userid_src.userid~ AND LEFT(^posts.type, 1)='Q' AND userid_src.vote>0",
			),
			
			'qdownvotes' => array(
				'multiple' => $options['points_multiple']*$options['points_vote_down_q'],
				'formula' => "COUNT(*) AS qdownvotes FROM ^uservotes AS userid_src JOIN ^posts ON userid_src.postid=^posts.postid WHERE userid_src.userid~ AND LEFT(^posts.type, 1)='Q' AND userid_src.vote<0",
			),
			
			'aupvotes' => array(
				'multiple' => $options['points_multiple']*$options['points_vote_up_a'],
				'formula' => "COUNT(*) AS aupvotes FROM ^uservotes AS userid_src JOIN ^posts ON userid_src.postid=^posts.postid WHERE userid_src.userid~ AND LEFT(^posts.type, 1)='A' AND userid_src.vote>0",
			),
			
			'adownvotes' => array(
				'multiple' => $options['points_multiple']*$options['points_vote_down_a'],
				'formula' => "COUNT(*) AS adownvotes FROM ^uservotes AS userid_src JOIN ^posts ON userid_src.postid=^posts.postid WHERE userid_src.userid~ AND LEFT(^posts.type, 1)='A' AND userid_src.vote<0",
			),
			
			'qvoteds' => array(
				'multiple' => $options['points_multiple'],
				'formula' => "COALESCE(SUM(".
					"LEAST(".((int)$options['points_per_q_voted_up'])."*upvotes,".((int)$options['points_q_voted_max_gain']).")".
					"-".
					"LEAST(".((int)$options['points_per_q_voted_down'])."*downvotes,".((int)$options['points_q_voted_max_loss']).")".
					"), 0) AS qvoteds FROM ^posts AS userid_src WHERE LEFT(type, 1)='Q' AND userid~",
			),
			
			'avoteds' => array(
				'multiple' => $options['points_multiple'],
				'formula' => "COALESCE(SUM(".
					"LEAST(".((int)$options['points_per_a_voted_up'])."*upvotes,".((int)$options['points_a_voted_max_gain']).")".
					"-".
					"LEAST(".((int)$options['points_per_a_voted_down'])."*downvotes,".((int)$options['points_a_voted_max_loss']).")".
					"), 0) AS avoteds FROM ^posts AS userid_src WHERE LEFT(type, 1)='A' AND userid~",
			),
			
			'upvoteds' => array(
				'multiple' => 0,
				'formula' => "COALESCE(SUM(upvotes), 0) AS upvoteds FROM ^posts AS userid_src WHERE userid~",
			),

			'downvoteds' => array(
				'multiple' => 0,
				'formula' => "COALESCE(SUM(downvotes), 0) AS downvoteds FROM ^posts AS userid_src WHERE userid~",
			),
		);
	}

	
	function qa_db_points_update_ifuser($userid, $columns)
/*
	Update the userpoints table in the database for $userid and $columns, plus the summary points column.
	Set $columns to true for all, empty for none, an array for several, or a single value for one.
	This dynamically builds some fairly crazy looking SQL, but it works, and saves repeat calculations.
*/
	{
		if (qa_to_override(__FUNCTION__)) { $args=func_get_args(); return qa_call_override(__FUNCTION__, $args); }
		
		if (qa_should_update_counts() && isset($userid)) {
			require_once QA_INCLUDE_DIR.'qa-app-options.php';

			$calculations=qa_db_points_calculations();
			
			if ($columns===true)
				$keycolumns=$calculations;
			elseif (empty($columns))
				$keycolumns=array();
			elseif (is_array($columns))
				$keycolumns=array_flip($columns);
			else
				$keycolumns=array($columns => true);
			
			$insertfields='userid, ';
			$insertvalues='$, ';
			$insertpoints=(int)qa_opt('points_base');

			$updates='';
			$updatepoints=$insertpoints;
			
			foreach ($calculations as $field => $calculation) {
				$multiple=(int)$calculation['multiple'];
				
				if (isset($keycolumns[$field])) {
					$insertfields.=$field.', ';
					$insertvalues.='@_'.$field.':=(SELECT '.$calculation['formula'].'), ';
					$updates.=$field.'=@_'.$field.', ';
					$insertpoints.='+('.(int)$multiple.'*@_'.$field.')';
				}
				
				$updatepoints.='+('.$multiple.'*'.(isset($keycolumns[$field]) ? '@_' : '').$field.')';
			}
			
			$query='INSERT INTO ^userpoints ('.$insertfields.'points) VALUES ('.$insertvalues.$insertpoints.') '.
				'ON DUPLICATE KEY UPDATE '.$updates.'points='.$updatepoints.'+bonus';
			
			qa_db_query_raw(str_replace('~', "='".qa_db_escape_string($userid)."'", qa_db_apply_sub($query, array($userid))));
				// build like this so that a #, $ or ^ character in the $userid (if external integration) isn't substituted
			
			if (qa_db_insert_on_duplicate_inserted())
				qa_db_userpointscount_update();
		}
	}


	function qa_db_points_set_bonus($userid, $bonus)
/*
	Set the number of explicit bonus points for $userid to $bonus
*/
	{
		qa_db_query_sub(
			"INSERT INTO ^userpoints (userid, bonus) VALUES ($, #) ON DUPLICATE KEY UPDATE bonus=#",
			$userid, $bonus, $bonus
		);
	}
	
	
	function qa_db_userpointscount_update()
/*
	Update the cached count in the database of the number of rows in the userpoints table
*/
	{
		if (qa_should_update_counts())
			qa_db_query_sub("REPLACE ^options (title, content) SELECT 'cache_userpointscount', COUNT(*) FROM ^userpoints");
	}


/*
	Omit PHP closing tag to help avoid accidental output
*/