<?php
# MantisBT - A PHP based bugtracking system

# MantisBT 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.
#
# MantisBT 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.
#
# You should have received a copy of the GNU General Public License
# along with MantisBT.  If not, see <http://www.gnu.org/licenses/>.

/**
 * BugFilterQuery class.
 * @copyright Copyright 2017 MantisBT Team - mantisbt-dev@lists.sourceforge.net
 * @link http://www.mantisbt.org
 * @package MantisBT
 * @subpackage classes
 *
 * @uses access_api.php
 * @uses authentication_api.php
 * @uses config_api.php
 * @uses constant_inc.php
 * @uses custom_field_api.php
 * @uses database_api.php
 * @uses filter_api.php
 * @uses filter_constants_inc.php
 * @uses gpc_api.php
 * @uses helper_api.php
 * @uses logging_api.php
 * @uses project_api.php
 * @uses tag_api.php
 * @uses user_api.php
 * @uses utility_api.php
 */

require_api( 'access_api.php' );
require_api( 'authentication_api.php' );
require_api( 'config_api.php' );
require_api( 'constant_inc.php' );
require_api( 'custom_field_api.php' );
require_api( 'database_api.php' );
require_api( 'filter_api.php' );
require_api( 'filter_constants_inc.php' );
require_api( 'gpc_api.php' );
require_api( 'helper_api.php' );
require_api( 'logging_api.php' );
require_api( 'project_api.php' );
require_api( 'tag_api.php' );
require_api( 'user_api.php' );
require_api( 'utility_api.php' );

/**
 * Bug Filter Query class
 *
 * Allows building a database query based on a filter.
 * Contains logic for translating the filter properties into corresponding sql
 * clauses to retrieve bugs matched by the filter.
 * By inheriting from DbQury class, it can be used transparently as a query object
 * that can be executed and fetched in the same way.
 *
 * With the constructor options, several types of queries can be built, oriented
 * to retrieving a sorted list of bug rows, a single total count, a subquery for
 * only bug ids...
 * See constructor and set_query_type() for details of query type settings.
 * After construction, and after a query type change, the base DbQuery object is
 * ready to be executed.
 *
 * The simplest usage is:
 *   $fq = new BugFilterQuery( $filter );
 *   $fq->execute();
 *
 * Optionally, create with a different type:
 *   $fq = new BugFilterQuery( $filter, BugFilterData::QUERY_TYPE_COUNT );
 *   $bugcount = $fq->value();
 *
 * Or change its type dynamically:
 *   $fq->set_query_type( BugFilterData::QUERY_TYPE_IDS );
 *
 * The query object can be used within other queries:
 *   $subquery = new BugFilterQuery( $some_filter, BugFilterData::QUERY_TYPE_IDS );
 *   $main_query = new DbQuery( 'SELECT * FROM {bug} WHERE id IN :filter_ids' );
 *   $main_query->bind( 'filter_ids', $subquery );
 *   $main_query->execute();
 *
 * Right after the BugFilterQuery object is created, all the internal query parts
 * are constructed based on the filter, and the actual DbQuery sql is built based
 * on the query type.
 * If at a later time, externally new parts are added (where, join, order, etc),
 * the actual sql will be rebuilt once the DbQuery 'execute' method is used, or
 * build_query() is explicitly called.
 */

class BugFilterQuery extends DbQuery {

	const QUERY_TYPE_LIST = 0;
	const QUERY_TYPE_COUNT = 1;
	const QUERY_TYPE_IDS = 2;
	const QUERY_TYPE_DISTINCT_IDS = 3;

	# properties used to build the query
	public $filter;
	public $project_id;
	public $user_id;
	public $use_sticky;

	# internal storage for intermediate data
	protected $query_type;
	protected $parts_select = array();
	protected $parts_from = array();
	protected $parts_join = array();
	protected $parts_where = array(); # these are joined by the filter operator
	protected $parts_order = array();
	protected $fixed_where = array(); # these are joined always by AND
	protected $filter_operator;

	# runtime variables for building the filter query
	protected $rt_stop_build; # flag to stop building the query parts, if there is no need to.
	protected $rt_included_projects; # calculated list of projects in the filter scope, to be reused at each build step
	protected $rt_table_alias_cf; # keep track of the custom field table joins, to reuse them in order by, or serach matching.
	protected $rt_table_alias_bugnote = null; # keep track of the bugnote table joins.
	protected $needs_rebuild; # flag to force a rebuild of the final sql when additions are made after the object is first created.

	/**
	 * Constructor.
	 * Will build a query based on the provided filter.
	 *
	 * $p_config can be either:
	 * - A single type constant, for easy object creation using default attributes
	 * - An array of options, for more advanced configuration.
	 *
	 * Option array uses "option => value" pairs, supported as:
	 * - 'query_type':	Any of QUERY_TYPE_xxx class constants, meaning:
	 *					QUERY_TYPE_LIST, query listing all fields of matched bugs. This is the default.
	 *					QUERY_TYPE_COUNT, query to return number of matched bugs.
	 *					QUERY_TYPE_IDS, query to return only matched bug ids, which may not
	 *						be unique, but may be faster and convenient for use as a subquery.
	 *					QUERY_TYPE_DISTINCT_IDS, query to return unique matched bug ids .
	 * - 'project_id':	(int) A project id to be used, if needed by the filer. By default,
	 *					current project is used.
	 * - 'user_id':		(int) A user id to be used to determine visibility for the filter.
	 *					By default current user is used.
	 * - 'use_sticky':	(bool) Whether to allow returning the bug list sorted so that sticky
	 *					bugs are placed first in the result order. This is false by default.
	 *
	 * @param array $p_filter			Filter array
	 * @param array|integer $p_config	Options array, or single query type identifier
	 * @return void
	 */
	public function __construct( $p_filter, $p_config = self::QUERY_TYPE_LIST ) {
		# defaults
		$t_query_type = self::QUERY_TYPE_LIST;
		$this->filter = $p_filter;
		$this->use_sticky = false;
		$this->project_id = helper_get_current_project();
		$this->user_id = auth_get_current_user_id();

		# $p_config can be an array or an integer
		if( is_array( $p_config ) ) {
			foreach( $p_config as $t_option => $t_value ) {
				if( null === $t_value ) {
					continue;
				}
				switch( $t_option ) {
					case 'query_type':
						$t_query_type = (int)$t_value;
						break;
					case 'project_id':
						$this->project_id = (int)$t_value;
						break;
					case 'user_id':
						$this->user_id = (int)$t_value;
						break;
					case 'use_sticky':
						$this->use_sticky = (bool)$t_value;
						break;
				}
			}
		} else {
			$t_query_type = $p_config;
		}
		$this->query_type = $t_query_type;
		$this->needs_rebuild = true;

		# The query string must be built here to have a valid DbQuery object ready for use
		$this->build_main();
		$this->set_query_type( $t_query_type );
	}

	/**
	 * Changes the effective database query to be of one of the selected types
	 * See constructor documentation for details about each query type.
	 *
	 * After calling this method, the actual query string is modified and ready to
	 * be used as a DbQuery objet for execution, or subquery composition.
	 *
	 * @param integer $p_query_type	Query type identifier
	 * @return void
	 */
	public function set_query_type( $p_query_type ) {
		$this->query_type = (int)$p_query_type;
		$this->build_query();
	}

	/**
	 * Builds the actual DbQuery object based on the current query type and query parts
	 *
	 * @return void
	 */
	public function build_query() {
		switch( $this->query_type ) {
			case self::QUERY_TYPE_COUNT:
				$this->sql( $this->string_query_count() );
				break;
			case self::QUERY_TYPE_IDS:
				$this->sql( $this->string_query_ids() );
				break;
			case self::QUERY_TYPE_DISTINCT_IDS:
				$this->sql( $this->string_query_dinstinct_ids() );
				break;
			case self::QUERY_TYPE_LIST:
			default:
				$this->sql( $this->string_query_list() );
				break;
		}
		$this->needs_rebuild = false;
		$this->db_result = null;
	}

	/**
	 * Override DbQuery execute method to check first if the query is already buils and up to date
	 * with current query parts.
	 *
	 * @param array $p_bind_array	Array for binding values
	 * @param integer $p_limit		Limit value
	 * @param integer $p_offset		Offset value
	 * @return IteratorAggregate|boolean ADOdb result set or false if the query failed.
	 */
	public function execute( array $p_bind_array = [], $p_limit = null, $p_offset = null ) {
		if( $this->needs_rebuild ) {
			$this->build_query();
		}
		return parent::execute( $p_bind_array, $p_limit, $p_offset );
	}

	/**
	 * Shorthand method to get the total number of issues matched by the filter
	 * It creates a copy of current object, set its type to a count query,
	 * executes it and returns the count value.
	 * This call does not modify current object.
	 *
	 * @return integer	Number of issues matched by the filter
	 */
	public function get_bug_count() {
		# create a copy from current query
		$t_query_count = clone $this;
		# rebuild clauses for count query type
		$t_query_count->set_query_type( self::QUERY_TYPE_COUNT );
		# set defaults
		$t_query_count->set_limit();
		$t_query_count->set_offset();
		$t_query_count->execute();
		return $t_query_count->value();
	}

	/**
	 * Adds a query part to the "select" elements
	 * @param string $p_string
	 * @return void
	 */
	public function add_select( $p_string ) {
		$this->parts_select[] = $p_string;
		$this->needs_rebuild = true;
	}

	/**
	 * Adds a query part to the "from" elements
	 * @param string $p_string
	 * @return void
	 */
	public function add_from( $p_string ) {
		$this->parts_from[] = $p_string;
		$this->needs_rebuild = true;
	}

	/**
	 * Adds a query part to the "join" elements
	 * @param string $p_string
	 * @return void
	 */
	public function add_join( $p_string ) {
		$this->parts_join[] = $p_string;
		$this->needs_rebuild = true;
	}

	/**
	 * Adds a query part to the "where" elements.
	 * These elements will be combined with the operator (and/or) defined by the filter
	 * @param string $p_string
	 * @return void
	 */
	public function add_where( $p_string ) {
		$this->parts_where[] = $p_string;
		$this->needs_rebuild = true;
	}

	/**
	 * Adds a query part to the "fixed where" elements.
	 * The elements will always be ANDed in the query.
	 * @param string $p_string
	 * @return void
	 */
	public function add_fixed_where( $p_string ) {
		$this->fixed_where[] = $p_string;
		$this->needs_rebuild = true;
	}

	/**
	 * Adds a query part to the "order by" elements
	 * @param string $p_string
	 * @return void
	 */
	public function add_order( $p_string ) {
		$this->parts_order[] = $p_string;
		$this->needs_rebuild = true;
	}

	/**
	 * Builds the query string block which is common to other query constructions,
	 * based on the from, join, and where parts
	 * @return string	The constructed query string block
	 */
	protected function helper_string_query_inner() {
		$t_from_string = ' FROM ' . implode( ', ', $this->parts_from );
		$t_join_string = count( $this->parts_join ) > 0 ? ' ' . implode( ' ', $this->parts_join ) : '';
		$t_where_string = ' WHERE '. implode( ' AND ', $this->fixed_where );
		if( count( $this->parts_where ) > 0 ) {
			$t_where_string .= ' AND ( ';
			$t_where_string .= implode( $this->filter_operator, $this->parts_where );
			$t_where_string .= ' )';
		}
		return $t_from_string . $t_join_string . $t_where_string;
	}

	/**
	 * Builds a query string destinated to listing the issues with all the selected fields
	 * @return string	The constructed query string
	 */
	protected function string_query_list() {
		if( empty( $this->parts_order ) ) {
			$this->build_order_by();
			$this->unique_query_parts();
		}
		$t_select_string = 'SELECT DISTINCT ' . implode( ', ', $this->parts_select );
		$t_order_string = ' ORDER BY ' . implode( ', ', $this->parts_order );
		return $t_select_string . $this->helper_string_query_inner() . $t_order_string;
	}

	/**
	 * Builds a query string destinated to listing the matched issues count
	 * @return string	The constructed query string
	 */
	protected function string_query_count() {
		$t_select_string = 'SELECT COUNT( DISTINCT {bug}.id )';
		return $t_select_string . $this->helper_string_query_inner();
	}

	/**
	 * Builds a query string destinated to listing the matched issue ids.
	 * The values returned by this query are not unique.
	 * @return string	The constructed query string
	 */
	protected function string_query_ids() {
		$t_select_string = 'SELECT {bug}.id';
		return $t_select_string . $this->helper_string_query_inner();
	}

	/**
	 * Builds a query string destinated to listing the matched issue ids
	 * The values returned by this query are unique ids
	 * @return string	The constructed query string
	 */
	protected function string_query_dinstinct_ids() {
		$t_select_string = 'SELECT DISTINCT {bug}.id';
		return $t_select_string . $this->helper_string_query_inner();
	}

	/**
	 * Build all the query parts needed based on the filter
	 * @return void
	 */
	protected function build_main() {
		$this->rt_stop_build = false;
		$this->add_from( '{bug}' );
		$this->add_select( '{bug}.*' );

		if( $this->filter[FILTER_PROPERTY_MATCH_TYPE] == FILTER_MATCH_ANY ) {
			$this->filter_operator = ' OR ';
		} else {
			$this->filter_operator = ' AND ';
		}

		$this->build_projects();
		# if no projects where found, stop here
		if( $this->rt_stop_build ) {
			return;
		}

		foreach( $this->filter as $t_prop => $t_value ) {
			# These are the main entries for filter properties
			switch( $t_prop ) {
				case FILTER_PROPERTY_REPORTER_ID:
					$this->build_prop_reporter();
					break;
				case FILTER_PROPERTY_HANDLER_ID:
					$this->build_prop_handler();
					break;
				case FILTER_PROPERTY_MONITOR_USER_ID:
					$this->build_prop_monitor_by();
					break;
				case FILTER_PROPERTY_NOTE_USER_ID:
					$this->build_prop_note_by();
					break;
				case FILTER_PROPERTY_FILTER_BY_DATE_SUBMITTED:
					$this->build_prop_date_created();
					break;
				case FILTER_PROPERTY_FILTER_BY_LAST_UPDATED_DATE:
					$this->build_prop_date_updated();
					break;
				case FILTER_PROPERTY_BUILD:
					$this->build_prop_build();
					break;
				case FILTER_PROPERTY_VERSION:
					$this->build_prop_version();
					break;
				case FILTER_PROPERTY_FIXED_IN_VERSION:
					$this->build_prop_fixed_version();
					break;
				case FILTER_PROPERTY_TARGET_VERSION:
					$this->build_prop_target_version();
					break;
				case FILTER_PROPERTY_VIEW_STATE:
					$this->build_prop_view_state();
					break;
				case FILTER_PROPERTY_CATEGORY_ID:
					$this->build_prop_category();
					break;
				case FILTER_PROPERTY_SEVERITY:
					$this->build_prop_severity();
					break;
				case FILTER_PROPERTY_RESOLUTION:
					$this->build_prop_resolution();
					break;
				case FILTER_PROPERTY_PRIORITY:
					$this->build_prop_priority();
					break;
				case FILTER_PROPERTY_PROFILE_ID:
					$this->build_prop_profile();
					break;
				case FILTER_PROPERTY_PLATFORM:
					$this->build_prop_platform();
					break;
				case FILTER_PROPERTY_OS:
					$this->build_prop_os();
					break;
				case FILTER_PROPERTY_OS_BUILD:
					$this->build_prop_os_build();
					break;
				case FILTER_PROPERTY_SEARCH:
					$this->build_prop_search();
					break;
				case FILTER_PROPERTY_RELATIONSHIP_TYPE:
					$this->build_prop_relationship();
					break;
				case FILTER_PROPERTY_PROJECTION:
					$this->build_prop_projection();
					break;
			}
		}
		# these have several properties that must be built only once
		if( isset( $this->filter[FILTER_PROPERTY_TAG_STRING] )
				|| isset( $this->filter[FILTER_PROPERTY_TAG_SELECT] ) ) {
			$this->build_prop_tags();
		}
		if( isset( $this->filter['custom_fields'] ) ) {
			$this->build_prop_custom_fields();
		}

		if( isset( $this->filter[FILTER_PROPERTY_HIDE_STATUS] )
				|| isset( $this->filter[FILTER_PROPERTY_STATUS] )) {
			$this->build_prop_status();
		}

		$this->build_prop_plugin_filters();

		$this->unique_query_parts();
	}

	protected function unique_query_parts() {
		$this->parts_select = array_unique( $this->parts_select );
		$this->parts_from = array_unique( $this->parts_from );
		$this->parts_join = array_unique( $this->parts_join );
		$this->parts_order = array_unique( $this->parts_order );
	}

	/**
	 * Build the query parts for the filter projects
	 * @return void
	 */
	protected function build_projects() {
		$this->add_join( 'JOIN {project} ON {project}.id = {bug}.project_id' );
		$this->add_fixed_where( '{project}.enabled = ' . $this->param( true ) );

		$t_user_id = $this->user_id;
		$t_project_id = $this->project_id;

		$t_projects_query_required = true;
		$t_included_project_ids = filter_get_included_projects( $this->filter, $t_project_id, $t_user_id, true /* return ALL_PROJECTS */ );
		if( ALL_PROJECTS == $t_included_project_ids ) {
			# The list of expanded projects is needed later even if project_query is not required
			$t_included_project_ids = filter_get_included_projects( $this->filter, $t_project_id, $t_user_id, false /* return ALL_PROJECTS */ );
			# this special case can skip the projects query clause:
			if( user_is_administrator( $t_user_id ) ) {
				log_event( LOG_FILTERING, 'all projects + administrator, hence no project filter.' );
				$t_projects_query_required = false;
			}
		}
		$this->rt_included_projects = $t_included_project_ids;

		if( $t_projects_query_required ) {

			# if no projects are accessible, then stop here
			if( count( $t_included_project_ids ) == 0 ) {
				log_event( LOG_FILTERING, 'no accessible projects' );
				$this->add_fixed_where( '{project}.id = ' . $this->param( 0 ) );
				$this->rt_stop_build = true;
				return;
			}

			# Arrays for project visibility conditions. Each array will translate
			# to a set of conditions for visibility.
			# Based on the user access level, each project will be placed in one
			# or several of these arrays for later treatment.

			# this array is populated with projects that the current user
			# hasfull access to (public and private issues)
			$t_private_and_public_project_ids = array();
			# this array is populated with projects to search only public issues.
			$t_public_only_project_ids = array();
			# this array is populated with projects to search only accesible private
			# issues by being the reporter of those.
			$t_private_is_reporter_project_ids = array();

			# these arrays are populated with projects where the user has limited view,
			# with 'limit_view_unless_threshold' configuration

			# projects where the user has limited view, but can see any private issue
			$t_limited_public_and_private_project_ids = array();
			# projects where the user has limited view, and can't see private issues,
			# only public ones
			$t_limited_public_only_project_ids = array();

			# these arrays are populated with projects where the user has limited view,
			# with the old 'limit_reporters' configuration

			# projects where the user has limited view, but can see any private issue
			$t_old_limit_public_and_private_project_ids = array();
			# projects where the user has limited view, and can't see private issues,
			# only public ones
			$t_old_limit_public_only_project_ids = array();

			# make sure the project rows are cached, as they will be used to check access levels.
			project_cache_array_rows( $t_included_project_ids );

			# Old 'limit_reporters' option was previously only supported for ALL_PROJECTS,
			$t_old_limit_reporters = ( ON == config_get( 'limit_reporters', null, $t_user_id, ALL_PROJECTS ) );

			foreach( $t_included_project_ids as $t_pid ) {
				$t_access_required_to_view_private_bugs = config_get( 'private_bug_threshold', null, null, $t_pid );
				$t_can_see_private = access_has_project_level( $t_access_required_to_view_private_bugs, $t_pid, $t_user_id );

				if( access_has_limited_view( $t_pid, $t_user_id ) ) {
					if( $t_old_limit_reporters ) {
						# we have a reduced access (show only own reported issues)
						$t_old_limit_public_and_private_project_ids[] = $t_pid;
						if( !$t_can_see_private ) {
							$t_old_limit_public_only_project_ids[] = $t_pid;
						}
					} else{
						# we have a reduced access (show only own reported, handled, monitored issues)
						if( $t_can_see_private ) {
							$t_limited_public_and_private_project_ids[] = $t_pid;
						} else {
							$t_limited_public_only_project_ids[] = $t_pid;
							# private issues can be seen by the reporter, which is also a valid
							# case for the limited view configuration
							$t_private_is_reporter_project_ids[] = $t_pid;
						}
					}
				} else {
					# if there is no special limit, use the general project clauses
					if( $t_can_see_private ) {
						$t_private_and_public_project_ids[] = $t_pid;
					} else {
						$t_public_only_project_ids[] = $t_pid;
						$t_private_is_reporter_project_ids[] = $t_pid;
					}
				}
			}

			$t_query_projects_or = array();
			# for these projects, search all issues
			if( !empty( $t_private_and_public_project_ids ) ) {
				$t_query_projects_or[] = $this->sql_in( '{bug}.project_id', $t_private_and_public_project_ids );
			}

			# for these projects, search public issues
			if( !empty( $t_public_only_project_ids ) ) {
				$t_query_projects_or[] = $this->sql_in( '{bug}.project_id', $t_public_only_project_ids )
						. ' AND {bug}.view_state = ' . $this->param( VS_PUBLIC );
			}

			# for these projects, search private issues where the user is reporter
			if( !empty( $t_private_is_reporter_project_ids ) ) {
				$t_query_projects_or[] = $this->sql_in( '{bug}.project_id', $t_private_is_reporter_project_ids )
						. ' AND {bug}.view_state <> ' . $this->param( VS_PUBLIC )
						. ' AND {bug}.reporter_id = ' . $this->param( $t_user_id );
			}

			# for these projects, search any issue (public or private) valid for the old 'limit_reporters' configuration
			if( !empty( $t_old_limit_public_and_private_project_ids ) ) {
				$t_query_projects_or[] = $this->sql_in( '{bug}.project_id', $t_old_limit_public_and_private_project_ids )
						. ' AND {bug}.reporter_id = ' . $this->param( $t_user_id );
			}

			# for these projects, search public issues valid for the old 'limit_reporters' configuration
			if( !empty( $t_old_limit_public_only_project_ids ) ) {
				$t_query_projects_or[] = $this->sql_in( '{bug}.project_id', $t_old_limit_public_only_project_ids )
						. ' AND {bug}.view_state = ' . $this->param( VS_PUBLIC )
						. ' AND {bug}.reporter_id = ' . $this->param( $t_user_id );
			}

			# for these projects, search any issue (public or private) valid for limited view
			if( !empty( $t_limited_public_and_private_project_ids ) ) {
				$t_query_projects_or[] = $this->sql_in( '{bug}.project_id', $t_limited_public_and_private_project_ids )
						. ' AND ('
						. ' {bug}.reporter_id = ' . $this->param( $t_user_id )
						. ' OR {bug}.handler_id = ' . $this->param( $t_user_id )
						. ' OR EXISTS ( SELECT 1 FROM {bug_monitor} bm'
						. ' WHERE bm.user_id = ' . $this->param( $t_user_id )
						. ' AND bm.bug_id = {bug}.id )'
						. ' )';
			}

			# for these projects, search public issues valid for limited view
			if( !empty( $t_limited_public_only_project_ids ) ) {
				$t_query_projects_or[] = $this->sql_in( '{bug}.project_id', $t_limited_public_only_project_ids )
						. ' AND {bug}.view_state = ' . $this->param( VS_PUBLIC )
						. ' AND ('
						. ' {bug}.reporter_id = ' . $this->param( $t_user_id )
						. ' OR {bug}.handler_id = ' . $this->param( $t_user_id )
						. ' OR EXISTS ( SELECT 1 FROM {bug_monitor} bm'
						. ' WHERE bm.user_id = ' . $this->param( $t_user_id )
						. ' AND bm.bug_id = {bug}.id )'
						. ' )';
			}

			$t_project_query = '(' . implode( ' OR ', $t_query_projects_or ) . ')';

			$this->add_fixed_where( $t_project_query );
		}
	}

	/**
	 * Build the query parts for the filter properties related to "status"
	 * @return void
	 */
	protected function build_prop_status() {
		# take a list of all available statuses then remove the ones that we want hidden, then make sure
		# the ones we want shown are still available
		$t_desired_statuses = $this->filter[FILTER_PROPERTY_STATUS];

		# simple filtering: restrict by the hide status value if present
		if( FILTER_VIEW_TYPE_SIMPLE == $this->filter['_view_type'] ) {
			if( isset( $this->filter[FILTER_PROPERTY_HIDE_STATUS][0] ) && !filter_field_is_none( $this->filter[FILTER_PROPERTY_HIDE_STATUS][0] ) ) {
				$t_selected_status_array = $this->filter[FILTER_PROPERTY_STATUS];
				# if we have metavalue for "any", expand to all status, to filter them
				if( filter_field_is_any( $t_selected_status_array ) ) {
					$t_selected_status_array = MantisEnum::getValues( config_get( 'status_enum_string' ) );
				}
				$t_hide_status = $this->filter[FILTER_PROPERTY_HIDE_STATUS][0];
				# Filter out status that must be hidden
				$t_desired_statuses = array();
				foreach( $t_selected_status_array as $t_this_status ) {
					if( $t_hide_status > $t_this_status ) {
						$t_desired_statuses[] = $t_this_status;
					}
				}
			}
		}
		# advanced filtering: ignore hide_status, do nothing.

		# if show_status is "any", empty the array, to not include any condition on status.
		if( filter_field_is_any( $t_desired_statuses ) ) {
				$t_desired_statuses = array();
		}

		if( count( $t_desired_statuses ) > 0 ) {
			$t_clauses = $this->helper_array_map_int( $t_desired_statuses );
			$this->add_where( $this->sql_in( '{bug}.status', $t_clauses ) );
		}
	}

	/**
	 * Build the query parts for the filter property "creation date"
	 * @return void
	 */
	protected function build_prop_date_created() {
		if( ( gpc_string_to_bool( $this->filter[FILTER_PROPERTY_FILTER_BY_DATE_SUBMITTED] ) )
				&& is_numeric( $this->filter[FILTER_PROPERTY_DATE_SUBMITTED_START_MONTH] )
				&& is_numeric( $this->filter[FILTER_PROPERTY_DATE_SUBMITTED_START_DAY] )
				&& is_numeric( $this->filter[FILTER_PROPERTY_DATE_SUBMITTED_START_YEAR] )
				&& is_numeric( $this->filter[FILTER_PROPERTY_DATE_SUBMITTED_END_MONTH] )
				&& is_numeric( $this->filter[FILTER_PROPERTY_DATE_SUBMITTED_END_DAY] )
				&& is_numeric( $this->filter[FILTER_PROPERTY_DATE_SUBMITTED_END_YEAR] )
				) {
			$t_start_string = $this->filter[FILTER_PROPERTY_DATE_SUBMITTED_START_YEAR]
					. '-' . $this->filter[FILTER_PROPERTY_DATE_SUBMITTED_START_MONTH]
					. '-' . $this->filter[FILTER_PROPERTY_DATE_SUBMITTED_START_DAY]
					. ' 00:00:00';
			$t_end_string = $this->filter[FILTER_PROPERTY_DATE_SUBMITTED_END_YEAR]
					. '-' . $this->filter[FILTER_PROPERTY_DATE_SUBMITTED_END_MONTH]
					. '-' . $this->filter[FILTER_PROPERTY_DATE_SUBMITTED_END_DAY]
					. ' 23:59:59';

			$t_query_created_at = '{bug}.date_submitted BETWEEN '
					. $this->param( strtotime( $t_start_string ) ) . ' AND '
					. $this->param( strtotime( $t_end_string ) ) ;
			$this->add_fixed_where( $t_query_created_at );
		}
	}

	/**
	 * Build the query parts for the filter property "last updated date"
	 * @return void
	 */
	protected function build_prop_date_updated() {
		if( ( gpc_string_to_bool( $this->filter[FILTER_PROPERTY_FILTER_BY_LAST_UPDATED_DATE] ) )
				&& is_numeric( $this->filter[FILTER_PROPERTY_LAST_UPDATED_START_MONTH] )
				&& is_numeric( $this->filter[FILTER_PROPERTY_LAST_UPDATED_START_DAY] )
				&& is_numeric( $this->filter[FILTER_PROPERTY_LAST_UPDATED_START_YEAR] )
				&& is_numeric( $this->filter[FILTER_PROPERTY_LAST_UPDATED_END_MONTH] )
				&& is_numeric( $this->filter[FILTER_PROPERTY_LAST_UPDATED_END_DAY] )
				&& is_numeric( $this->filter[FILTER_PROPERTY_LAST_UPDATED_END_YEAR] )
				) {
			$t_start_string = $this->filter[FILTER_PROPERTY_LAST_UPDATED_START_YEAR]
					. '-' . $this->filter[FILTER_PROPERTY_LAST_UPDATED_START_MONTH]
					. '-' . $this->filter[FILTER_PROPERTY_LAST_UPDATED_START_DAY]
					. ' 00:00:00';
			$t_end_string = $this->filter[FILTER_PROPERTY_LAST_UPDATED_END_YEAR]
					. '-' . $this->filter[FILTER_PROPERTY_LAST_UPDATED_END_MONTH]
					. '-' . $this->filter[FILTER_PROPERTY_LAST_UPDATED_END_DAY]
					. ' 23:59:59';

			$t_query_updated_at = '{bug}.last_updated BETWEEN '
					. $this->param( strtotime( $t_start_string ) ) . ' AND '
					. $this->param( strtotime( $t_end_string ) ) ;
			$this->add_fixed_where( $t_query_updated_at );
		}
	}

	/**
	 * Build the query parts for the filter property "view state"
	 * @return void
	 */
	protected function build_prop_view_state() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_VIEW_STATE] ) ) {
			return;
		}
		$t_view_state = (int)$this->filter[FILTER_PROPERTY_VIEW_STATE];
		$t_view_state_query = '{bug}.view_state = ' . $this->param( $t_view_state ) ;
		log_event( LOG_FILTERING, 'view_state query = ' . $t_view_state_query );
		$this->add_where( $t_view_state_query );
	}

	/**
	 * Utility function to process the values for a filter property that is related
	 * to a database id number, used to represent users.
	 * Manages special case meta-value-none, which is translated to id "0", to be able
	 * to match database values where "0" is the default for empty/none
	 * Manages special case meta-value-myself, by replacing with the actual current user id.
	 *
	 * @param array $p_users_array	Input array with user ids
	 * @return array	Converted array
	 */
	protected function helper_process_users_property( array $p_users_array ) {
		$t_new_array = array();
		foreach( $p_users_array as $t_user ) {
			if( filter_field_is_none( $t_user ) ) {
				$t_new_array[] = 0;
			} else {
				$c_user_id = (int)$t_user;
				if( filter_field_is_myself( $c_user_id ) ) {
					$t_new_array[] = $this->user_id;
				} else {
					$t_new_array[] = $c_user_id;
				}
			}
		}
		return $t_new_array;
	}

	/**
	 * Build the query parts for the filter property "reporter"
	 * @return void
	 */
	protected function build_prop_reporter() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_REPORTER_ID] ) ) {
			return;
		}
		$t_user_ids = $this->helper_process_users_property( $this->filter[FILTER_PROPERTY_REPORTER_ID] );
		$t_users_query = $this->sql_in( '{bug}.reporter_id', $t_user_ids );
		log_event( LOG_FILTERING, 'reporter query = ' . $t_users_query );
		$this->add_where( $t_users_query );
	}

	/**
	 * Build the query parts for the filter property "handler"
	 * @return void
	 */
	protected function build_prop_handler() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_HANDLER_ID] ) ) {
			return;
		}

		# the user can view handler if he meets access level for
		# 'view_handler_threshold' or if he is the handler
		$t_projects_can_view = $this->helper_filter_projects_using_access( 'view_handler_threshold' );
		if( ALL_PROJECTS == $t_projects_can_view ) {
			$t_view_condition = null;
		} else {
			$t_view_condition = '{bug}.handler_id = ' . $this->param( $this->user_id );
			if( !empty( $t_projects_can_view ) ) {
				$t_view_condition = '(' . $t_view_condition . ' OR '
						. $this->sql_in( '{bug}.project_id', $t_projects_can_view ) . ')';
			}
		}
		if( $t_view_condition ) {
			$t_view_condition = ' AND ' . $t_view_condition;
		}

		$t_user_ids = $this->helper_process_users_property( $this->filter[FILTER_PROPERTY_HANDLER_ID] );
		$t_query = $this->sql_in( '{bug}.handler_id', $t_user_ids ) . $t_view_condition;
		log_event( LOG_FILTERING, 'handler query = ' . $t_query );
		$this->add_where( $t_query );
	}

	/**
	 * Build the query parts for the filter property "category"
	 * @return void
	 */
	protected function build_prop_category() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_CATEGORY_ID] ) ) {
			return;
		}
		$t_names = array();
		$t_use_none = false;
		foreach( $this->filter[FILTER_PROPERTY_CATEGORY_ID] as $t_filter_member ) {
			if( filter_field_is_none( $t_filter_member ) ) {
				$t_use_none = true;
			} else {
				$t_names[] = $t_filter_member;
			}
		}

		$t_join = 'LEFT JOIN {category} ON {bug}.category_id = {category}.id';
		$t_query_or = array();
		if( !empty( $t_names ) ) {
			$t_query_or[] = $this->sql_in( '{category}.name', $t_names );
		}
		if( $t_use_none ) {
			$t_query_or[] = '{category}.name IS NULL';
		}
		$t_where = '(' . implode( ' OR ', $t_query_or ) . ')';
		log_event( LOG_FILTERING, 'category query = ' . $t_where );
		$this->add_join( $t_join );
		$this->add_where( $t_where );
	}

	/**
	 * Build the query parts for the filter property "severity"
	 * @return void
	 */
	protected function build_prop_severity() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_SEVERITY] ) ) {
			return;
		}
		$t_query = $this->sql_in( '{bug}.severity', $this->filter[FILTER_PROPERTY_SEVERITY] );
		$this->add_where( $t_query );
	}

	/**
	 * Build the query parts for the filter property "resolution"
	 * @return void
	 */
	protected function build_prop_resolution() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_RESOLUTION] ) ) {
			return;
		}
		$t_query = $this->sql_in( '{bug}.resolution', $this->filter[FILTER_PROPERTY_RESOLUTION] );
		$this->add_where( $t_query );
	}

	/**
	 * Build the query parts for the filter property "priority"
	 * @return void
	 */
	protected function build_prop_priority() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_PRIORITY] ) ) {
			return;
		}
		$t_query = $this->sql_in( '{bug}.priority', $this->filter[FILTER_PROPERTY_PRIORITY] );
		$this->add_where( $t_query );
	}

	/**
	 * Build the query parts for the filter property "projection"
	 * @return void
	 */
	protected function build_prop_projection() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_PROJECTION] ) ) {
			return;
		}
		$t_query = $this->sql_in( '{bug}.projection', $this->filter[FILTER_PROPERTY_PROJECTION] );
		$this->add_where( $t_query );
	}

	/**
	 * Utility function to process the values for a filter property that is related
	 * to a database string field.
	 * Manages special case meta-value-none, which is translated to "", to be able
	 * to match database values where "" is the default for empty/null
	 *
	 * @param array $p_array	Input array with strings
	 * @return array	Converted array
	 */
	protected function helper_process_string_property( $p_array ) {
		$t_new_array = array();
		foreach( $p_array as $t_elem ) {
			if( filter_field_is_none( $t_elem ) ) {
				$t_new_array[] = '';
			} else {
				$t_new_array[] = $t_elem;
			}
		}
		return $t_new_array;
	}

	/**
	 * Build the query parts for the filter property "build"
	 * @return void
	 */
	protected function build_prop_build() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_BUILD] ) ) {
			return;
		}
		$t_array = $this->helper_process_string_property( $this->filter[FILTER_PROPERTY_BUILD] );
		$t_query = $this->sql_in( '{bug}.build', $t_array );
		$this->add_where( $t_query );
	}

	/**
	 * Build the query parts for the filter property "version"
	 * @return void
	 */
	protected function build_prop_version() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_VERSION] ) ) {
			return;
		}
		$t_array = $this->helper_process_string_property( $this->filter[FILTER_PROPERTY_VERSION] );
		$t_query = $this->sql_in( '{bug}.version', $t_array );
		$this->add_where( $t_query );
	}

	/**
	 * Utility function to process the values for a filter property that is related
	 * to a database id number.
	 * Manages special cases like meta-value-none, which is translated to id "0", to be able
	 * to match database values where "0" is the default for empty/none
	 * @param array $p_array	Input array with ids
	 * @return array	Converted array
	 */
	protected function helper_process_id_property( $p_array ) {
		$t_new_array = array();
		foreach( $p_array as $t_elem ) {
			if( filter_field_is_none( $t_elem ) ) {
				$t_new_array[] = 0;
			} else {
				$t_new_array[] = $t_elem;
			}
		}
		return $t_new_array;
	}

	/**
	 * Build the query parts for the filter property "profile"
	 * @return void
	 */
	protected function build_prop_profile() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_PROFILE_ID] ) ) {
			return;
		}
		$t_array = $this->helper_process_id_property( $this->filter[FILTER_PROPERTY_PROFILE_ID] );
		$t_query = $this->sql_in( '{bug}.profile_id', $t_array );
		$this->add_where( $t_query );
	}

	/**
	 * Build the query parts for the filter property "platform"
	 * @return void
	 */
	protected function build_prop_platform() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_PLATFORM] ) ) {
			return;
		}
		$t_array = $this->helper_process_string_property( $this->filter[FILTER_PROPERTY_PLATFORM] );
		$t_query = $this->sql_in( '{bug}.platform', $t_array );
		$this->add_where( $t_query );
	}

	/**
	 * Build the query parts for the filter property "OS"
	 * @return void
	 */
	protected function build_prop_os() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_OS] ) ) {
			return;
		}
		$t_array = $this->helper_process_string_property( $this->filter[FILTER_PROPERTY_OS] );
		$t_query = $this->sql_in( '{bug}.os', $t_array );
		$this->add_where( $t_query );
	}

	/**
	 * Build the query parts for the filter property "OS build"
	 * @return void
	 */
	protected function build_prop_os_build() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_OS_BUILD] ) ) {
			return;
		}
		$t_array = $this->helper_process_string_property( $this->filter[FILTER_PROPERTY_OS_BUILD] );
		$t_query = $this->sql_in( '{bug}.os_build', $t_array );
		$this->add_where( $t_query );
	}

	/**
	 * Build the query parts for the filter property "fixed in version"
	 * @return void
	 */
	protected function build_prop_fixed_version() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_FIXED_IN_VERSION] ) ) {
			return;
		}
		$t_array = $this->helper_process_string_property( $this->filter[FILTER_PROPERTY_FIXED_IN_VERSION] );
		$t_query = $this->sql_in( '{bug}.fixed_in_version', $t_array );
		$this->add_where( $t_query );
	}

	/**
	 * Build the query parts for the filter property "target version"
	 * @return void
	 */
	protected function build_prop_target_version() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_TARGET_VERSION] ) ) {
			return;
		}
		$t_array = $this->helper_process_string_property( $this->filter[FILTER_PROPERTY_TARGET_VERSION] );
		$t_query = $this->sql_in( '{bug}.target_version', $t_array );
		$this->add_where( $t_query );
	}

	/**
	 * Build the query parts for the filter property "monitor by"
	 * @return void
	 */
	protected function build_prop_monitor_by() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_MONITOR_USER_ID] ) ) {
			return;
		}
		$t_user_ids = $this->helper_process_users_property( $this->filter[FILTER_PROPERTY_MONITOR_USER_ID] );
		$t_use_none = ( in_array( 0, $t_user_ids ) );

		# Build a condition for determining monitoring visibility, the user can view:
		# - his own monitored issues
		# - other users monitoring if he meets access level for 'show_monitor_list_threshold'
		$t_projects_can_view = $this->helper_filter_projects_using_access( 'show_monitor_list_threshold' );
		if( ALL_PROJECTS == $t_projects_can_view ) {
			$t_view_condition = null;
		} else {
			$t_view_condition = '{bug_monitor}.user_id = ' . $this->param( $this->user_id );
			if( !empty( $t_projects_can_view ) ) {
				$t_view_condition = '(' . $t_view_condition . ' OR '
						. $this->sql_in( '{bug}.project_id', $t_projects_can_view ) . ')';
			}
		}
		if( $t_view_condition ) {
			$t_view_condition = ' AND ' . $t_view_condition;
		}

		$this->add_join( 'LEFT JOIN {bug_monitor} ON {bug}.id = {bug_monitor}.bug_id' . $t_view_condition );
		if( $t_use_none ) {
			$t_expr = 'COALESCE( {bug_monitor}.user_id, 0 )';
		} else {
			$t_expr = '{bug_monitor}.user_id';
		}

		$t_where = $this->sql_in( $t_expr, $t_user_ids );
		$this->add_where( $t_where );
	}

	/**
	 * Creates a JOIN clause for the bugnote table and returns the table alias used
	 * for this join, to be used in sql expressions.
	 * This JOIN is built with restrictions to meet user permissions to view private notes.
	 *
	 * The JOIN is created only once for this class, If it's already created, this function
	 * returns the alias to be reused.
	 *
	 * @return string	A table alias for this join clause
	 */
	protected function helper_table_alias_for_bugnote() {
		if( $this->rt_table_alias_bugnote ) {
			return $this->rt_table_alias_bugnote;
		}
		# Build a condition for determining note visibility, the user can view:
		# - public notes
		# - his own private notes
		# - private notes if meets access level for 'private_bugnote_threshold'
		$t_projects_can_view_private = $this->helper_filter_projects_using_access( 'private_bugnote_threshold' );
		$t_table_alias = 'visible_bugnote';
		if( ALL_PROJECTS == $t_projects_can_view_private ) {
			$t_view_condition = null;
		} else {
			$t_view_condition = $t_table_alias . '.view_state = ' . $this->param( VS_PUBLIC )
					. ' OR ' . $t_table_alias . '.reporter_id = ' . $this->param( $this->user_id );
			if( !empty( $t_projects_can_view_private ) ) {
				$t_view_condition .= ' OR ' . $this->sql_in( '{bug}.project_id', $t_projects_can_view_private );
			}
		}
		if( $t_view_condition ) {
			$t_view_condition = ' AND (' . $t_view_condition . ')';
		}
		$t_join = 'LEFT JOIN {bugnote} ' . $t_table_alias
				. ' ON {bug}.id = ' . $t_table_alias . '.bug_id'
				. $t_view_condition;

		$this->add_join( $t_join );
		$this->rt_table_alias_bugnote = $t_table_alias;
		return $this->rt_table_alias_bugnote;
	}

	/**
	 * Build the query parts for the filter property "note by"
	 * @return void
	 */
	protected function build_prop_note_by() {
		if( filter_field_is_any( $this->filter[FILTER_PROPERTY_NOTE_USER_ID] ) ) {
			return;
		}
		$t_user_ids = $this->helper_process_users_property( $this->filter[FILTER_PROPERTY_NOTE_USER_ID] );
		$t_use_none = ( in_array( 0, $t_user_ids ) );

		$t_table_alias = $this->helper_table_alias_for_bugnote();

		if( $t_use_none ) {
			$t_alias = 'COALESCE( ' . $t_table_alias . '.reporter_id, 0 )';
		} else {
			$t_alias = $t_table_alias . '.reporter_id';
		}

		$t_where = $this->sql_in( $t_alias, $t_user_ids );
		$this->add_where( $t_where );
	}

	/**
	 * Build the query parts for the filter property "relationship"
	 * @return void
	 */
	protected function build_prop_relationship() {
		$c_rel_type = (int)$this->filter[FILTER_PROPERTY_RELATIONSHIP_TYPE];
		$c_rel_bug = (int)$this->filter[FILTER_PROPERTY_RELATIONSHIP_BUG];
		if( BUG_REL_ANY == $c_rel_type && META_FILTER_ANY == $c_rel_bug ) {
			return;
		}
		# use the complementary type
		if( $c_rel_type >= 0 ) {
			$t_comp_type = relationship_get_complementary_type( $c_rel_type );
		}
		$t_table_dst = 'rel_dst';
		$t_table_src = 'rel_src';
		$t_use_join = true;

		# build conditions for relation type and bug match
		if( BUG_REL_NONE == $c_rel_type ) {
			if( META_FILTER_NONE == $c_rel_bug
				|| META_FILTER_ANY == $c_rel_bug ) {
				# rel NONE, bug ANY/NONE, those bugs that are not related in any way to another
				$t_where = $t_table_dst . '.relationship_type IS NULL AND ' . $t_table_src . '.relationship_type IS NULL';
			} else {
				# rel NONE, bug ID, those bugs that are not related in any way to bug ID
				# also, exclude target id from results
				$t_where = 'NOT EXISTS ( SELECT 1 FROM {bug_relationship} WHERE source_bug_id = ' . $this->param( $c_rel_bug )
						. ' AND destination_bug_id = {bug}.id'
						. ' OR destination_bug_id = ' . $this->param( $c_rel_bug )
						. ' AND source_bug_id = {bug}.id )'
						. ' AND NOT {bug}.id = ' . $this->param( $c_rel_bug );
				$t_use_join = false;
			}
		} elseif( BUG_REL_ANY == $c_rel_type ) {
			if( META_FILTER_NONE == $c_rel_bug ) {
				# rel ANY, bug NONE, bugs that are not related in any way to another
				$t_where = $t_table_dst . '.relationship_type IS NULL AND ' . $t_table_src . '.relationship_type IS NULL';
			} elseif ( META_FILTER_ANY == $c_rel_bug ) {
				# rel ANY, bug ANY, do nothing
				return;
			} else {
				# rel ANY, bug ID, those bugs that have any relation to bug ID
				$t_where = '(' . $t_table_dst . '.source_bug_id = ' . $this->param( $c_rel_bug )
						. ' OR ' . $t_table_src . '.destination_bug_id = ' . $this->param( $c_rel_bug ) . ')';
			}
		} else {
			# relation is specified
			if( META_FILTER_NONE == $c_rel_bug ) {
				# rel REL, bug NONE, those bugs that don't have any REL relation (may have other types)
				# map to a non-existent relation type -1 to include nulls
				$t_where = 'COALESCE(' . $t_table_dst . '.relationship_type, -1) <> ' . $this->param( $t_comp_type )
						. ' AND COALESCE(' . $t_table_src . '.relationship_type, -1) <> ' . $this->param( $c_rel_type );
			} elseif( META_FILTER_ANY == $c_rel_bug ) {
				# rel REL, bug ANY, those bugs that are related by REL to any bug
				$t_where = '(' . $t_table_dst . '.relationship_type=' . $this->param( $t_comp_type )
						. ' OR ' . $t_table_src . '.relationship_type=' . $this->param( $c_rel_type ) . ')';
			} else {
				# rel REL, bug ID, those bugs that are related by REL to bug ID
				$t_where = '('
						. $t_table_dst . '.relationship_type=' . $this->param( $t_comp_type )
						. ' AND ' . $t_table_dst . '.source_bug_id=' . $this->param( $c_rel_bug )
						. ' OR '
						. $t_table_src . '.relationship_type=' . $this->param( $c_rel_type )
						. ' AND ' . $t_table_src . '.destination_bug_id=' . $this->param( $c_rel_bug )
						. ')';
			}
		}

		if( $t_use_join ) {
			$this->add_join( 'LEFT JOIN {bug_relationship} ' . $t_table_dst . ' ON ' . $t_table_dst . '.destination_bug_id = {bug}.id' );
			$this->add_join( 'LEFT JOIN {bug_relationship} ' . $t_table_src . ' ON ' . $t_table_src . '.source_bug_id = {bug}.id' );
		}
		$this->add_where( $t_where );
	}

	/**
	 * Utility function to return the projects, from the current filter scope, that meets some
	 * access level threshold. The specified access can be either a int/array threshold, or
	 * a configuration option to be evaluated at each project
	 * (see documentation for access_project_array_filter() )
	 *
	 * The returned value can be:
	 * - All_PROJECTS constant: meaning that all projects reached by the current filter meets the requested access.
	 * - Empty array: meaning that none of the filter projects meets the required access
	 * - Array of project ids: containing those projects which meets the requested access
	 *   Note that if all projects meet the access, then ALL_PROJECTS will be returned.
	 *
	 * @param integer|array|string $p_access	An access level threshold or configuration option
	 * @return array|integer
	 */
	protected function helper_filter_projects_using_access( $p_access ) {
		$t_filtered_projects = access_project_array_filter( $p_access, $this->rt_included_projects, $this->user_id );
		$t_diff = array_diff( $this->rt_included_projects, $t_filtered_projects );
		if( empty( $t_diff ) ) {
			return ALL_PROJECTS;
		} else {
			return $t_filtered_projects;
		}
	}

	/**
	 * Utility function to cast all array element to int type
	 * @param array $p_array	Input array
	 * @return array	Converted array
	 */
	protected function helper_array_map_int( $p_array ) {
		$t_new_array = array();
		foreach( $p_array as $t_elem ) {
			$t_new_array[] = (int)$t_elem;
		}
		return $t_new_array;
	}

	/**
	 * Build the query parts for the filter property "tags"
	 * @return void
	 */
	protected function build_prop_tags() {
		$c_tag_string = trim( $this->filter[FILTER_PROPERTY_TAG_STRING] );
		$c_tag_select = (int)$this->filter[FILTER_PROPERTY_TAG_SELECT];
		if( is_blank( $c_tag_string ) && $c_tag_select == 0 ) {
			# shortcut exit
			return;
		}

		$t_tags = tag_parse_filters( $c_tag_string );
		if( empty( $t_tags ) && $c_tag_select == 0 ) {
			# shortcut exit
			return;
		}

		$t_projects_can_view_tags = $this->helper_filter_projects_using_access( 'tag_view_threshold' );
		if( ALL_PROJECTS == $t_projects_can_view_tags ) {
			$t_tag_projects_clause = '';
		} else {
			if( empty( $t_projects_can_view_tags ) ) {
				# if can't view tags in any project, exit
				log_event( LOG_FILTERING, 'tags query, no accessible projects ' );
				return;
			} else {
				$t_tag_projects_clause = ' AND ' . $this->sql_in( '{bug}.project_id', $t_projects_can_view_tags );
				log_event( LOG_FILTERING, 'tags query, accessible projects =  @P' . implode( ', @P', $t_projects_can_view_tags ) );
			}
		}

		$t_tags_always = array();
		$t_tags_any = array();
		$t_tags_never = array();

		# @TODO, use constants for tag modifiers
		foreach( $t_tags as $t_tag_row ) {
			switch( $t_tag_row['filter'] ) {
				case 1:
					# A matched issue must always have this tag
					$t_tags_always[] = $t_tag_row;
					break;
				case 0:
					# A matched issue may have this tag
					$t_tags_any[] = $t_tag_row;
					break;
				case -1:
					# A matched must never have this tag
					$t_tags_never[] = $t_tag_row;
					break;
			}
		}

		# Consider those tags that must always match, to also be part of those that can be
		# optionally matched. This solves the scenario for an issue that matches one tag
		# from the "always" group, and none from the "any" group.
		if( !empty( $t_tags_always ) && !empty( $t_tags_any ) ) {
			$t_tags_any = array_merge( $t_tags_any, $t_tags_always );
		}

		# Add the tag id to the array, from filter field "tag_select"
		if( 0 < $c_tag_select && tag_exists( $c_tag_select ) ) {
			$t_tags_any[] = tag_get( $c_tag_select );
		}

		$t_where = array();

		if( count( $t_tags_always ) ) {
			foreach( $t_tags_always as $t_tag_row ) {
				$t_tag_alias = 'bug_tag_alias_alw_' . $t_tag_row['id'];
				$t_join_inc = 'LEFT JOIN {bug_tag} ' . $t_tag_alias . ' ON ' . $t_tag_alias . '.bug_id = {bug}.id'
					. ' AND ' . $t_tag_alias . '.tag_id = ' . $this->param( (int)$t_tag_row['id'] )
					. $t_tag_projects_clause;
				$this->add_join( $t_join_inc );
				$t_where[] = $t_tag_alias . '.tag_id IS NOT NULL';
			}
		}

		if( count( $t_tags_any ) ) {
			$t_tag_alias = 'bug_tag_alias_any';
			$t_tag_ids = $this->helper_array_map_int( array_column( $t_tags_any, 'id' ) );
			$t_join_any = 'LEFT JOIN {bug_tag} ' . $t_tag_alias . ' ON ' . $t_tag_alias . '.bug_id = {bug}.id'
				. ' AND ' . $this->sql_in( $t_tag_alias . '.tag_id', $t_tag_ids )
				. $t_tag_projects_clause;
			$this->add_join( $t_join_any );
			$t_where[] = $t_tag_alias . '.tag_id IS NOT NULL';
		}

		if( count( $t_tags_never ) ) {
			$t_tag_alias = 'bug_tag_alias_nev';
			$t_tag_ids = $this->helper_array_map_int( array_column( $t_tags_never, 'id' ) );
			$t_join_exc = 'LEFT JOIN {bug_tag} ' . $t_tag_alias . ' ON ' . $t_tag_alias . '.bug_id = {bug}.id'
				. ' AND ' . $this->sql_in(  $t_tag_alias . '.tag_id', $t_tag_ids )
				. $t_tag_projects_clause;
			$this->add_join( $t_join_exc );
			$t_where[] = $t_tag_alias . '.tag_id IS NULL';
		}

		if( !empty( $t_where ) ) {
			$this->add_where( implode( ' AND ', $t_where ) );
		}
	}

	/**
	 * Creates a JOIN clause for the custom field table and returns the table
	 * alias used for this join.
	 * May return false if the join was not created. This may happen, if no
	 * values are viewable.
	 * @param array $p_cfdef	Custom field definition array
	 * @return string	A table alias for this join clause
	 */
	protected function helper_table_alias_for_cf( $p_cfdef ) {
		$t_id = (int)$p_cfdef['id'];
		if( isset( $this->rt_table_alias_cf[$t_id] ) ) {
			return $this->rt_table_alias_cf[$t_id];
		}
		$t_table_name = 'cf_alias_' . $t_id;
		$t_cf_join_clause = 'LEFT OUTER JOIN {custom_field_string} ' . $t_table_name . ' ON {bug}.id = ' . $t_table_name . '.bug_id AND ' . $t_table_name . '.field_id = ' . $this->param( $t_id );

		# get which projects are valid for this custom field
		$t_searchable_projects = array_intersect( $this->rt_included_projects, custom_field_get_project_ids( $t_id ) );
		# and for which of those projects the user have read access to this field
		$t_projects_can_view_field = access_project_array_filter( (int)$p_cfdef['access_level_r'], $t_searchable_projects, $this->user_id );
		if( empty( $t_projects_can_view_field ) ) {
			$this->rt_table_alias_cf[$t_id] = false;
		} else {
			# This diff will contain those included projects that can't view this custom field
			$t_diff = array_diff( $this->rt_included_projects, $t_projects_can_view_field );
			# If not empty, it means there are some projects that can't view the field values,
			# so a project filter must be used to not include values from those projects
			if( !empty( $t_diff ) ) {
				$t_cf_join_clause .= ' AND ' . $this->sql_in( '{bug}.project_id', $t_projects_can_view_field );
			}
			$this->rt_table_alias_cf[$t_id] = $t_table_name;
			$this->add_join( $t_cf_join_clause );
		}
		return $this->rt_table_alias_cf[$t_id];
	}

	/**
	 * Build the query parts for the filter properties related to custom fields
	 * @return void
	 */
	protected function build_prop_custom_fields() {
		if( ON != config_get( 'filter_by_custom_fields' ) ) {
			log_event( LOG_FILTERING, 'filter custom fields is globally disabled, skip' );
			return;
		}

		$t_custom_fields = custom_field_get_linked_ids( $this->rt_included_projects );

		foreach( $t_custom_fields as $t_cfid ) {
			$t_field_info = custom_field_cache_row( $t_cfid, true );
			if( !$t_field_info['filter_by'] ) {
				# skip this custom field if it shouldn't be filterable
				log_event( LOG_FILTERING, 'filter custom fields, field_id=' . $t_cfid . ' is not valid for filtering');
				continue;
			}

			$t_field = $this->filter['custom_fields'][$t_cfid];

			$t_custom_where_clause = '';
			$t_def = custom_field_get_definition( $t_cfid );

			# Skip date custom fields with value of "any", these have a special array format
			if( $t_def['type'] == CUSTOM_FIELD_TYPE_DATE && $t_field[0] == CUSTOM_FIELD_DATE_ANY ) {
				continue;
			}
			# Ignore custom fields that are not set, or that are set to '' or "any"
			if( filter_field_is_any( $t_field ) ) {
				continue;
			}

			$t_table_name = $this->helper_table_alias_for_cf( $t_def );
			if( !$t_table_name ) {
				continue;
			}

			if( $t_def['type'] == CUSTOM_FIELD_TYPE_DATE ) {
				# Define the value field with type cast to integer
				$t_value_field = 'CAST(COALESCE(NULLIF(' . $t_table_name . '.value, \'\'), \'0\') AS DECIMAL)';
				switch( $t_field[0] ) {
					# Closing parenthesis intentionally omitted, will be added later on
					# CUSTOM_FIELD_DATE_ANY can't appear here, it was previously skipped
					case CUSTOM_FIELD_DATE_NONE:
						$t_custom_where_clause = '( ' . $t_table_name . '.bug_id IS NULL OR ' . $t_value_field . ' = 0 ';
						break;
					case CUSTOM_FIELD_DATE_BEFORE:
						$t_custom_where_clause = '( ' . $t_value_field . ' != 0 AND ' . $t_value_field . ' < ' . $this->param( $t_field[2] );
						break;
					case CUSTOM_FIELD_DATE_AFTER:
						$t_custom_where_clause = '( ' . $t_value_field . ' > ' . $this->param( $t_field[1] + 1 );
						break;
					default:
						$t_custom_where_clause = '( ' . $t_value_field . ' BETWEEN ' . $this->param( $t_field[1] ) . ' AND ' . $this->param( $t_field[2] );
						break;
				}
			} else {
				$t_filter_array = array();
				foreach( $t_field as $t_filter_member ) {
					$t_filter_member = stripslashes( $t_filter_member );
					if( filter_field_is_none( $t_filter_member ) ) {
						# but also add those _not_ present in the custom field string table
						$t_filter_array[] = $t_table_name . '.value IS NULL';

						switch( $t_def['type'] ) {
							case CUSTOM_FIELD_TYPE_TEXTAREA:
								$t_filter_array[] = $t_table_name . '.text = ' . $this->param( '' );
								break;
							default:
								$t_filter_array[] = $t_table_name . '.value = ' . $this->param( '' );
						}
					} else {
						switch( $t_def['type'] ) {
							case CUSTOM_FIELD_TYPE_CHECKBOX:
							case CUSTOM_FIELD_TYPE_MULTILIST:
								$t_filter_array[] = $this->sql_like( $t_table_name . '.value', '%|' . $t_filter_member . '|%' );
								break;
							case CUSTOM_FIELD_TYPE_TEXTAREA:
								$t_filter_array[] = $this->sql_like( $t_table_name . '.text', '%' . $t_filter_member . '%' );
								break;
							default:
								$t_filter_array[] = $t_table_name . '.value = ' . $this->param( $t_filter_member );
						}
					}
				}
				$t_custom_where_clause .= '(' . implode( ' OR ', $t_filter_array );
			}
			if( !is_blank( $t_custom_where_clause ) ) {
				$this->add_where( $t_custom_where_clause . ')' );
			}
		} # foreach cf
	}

	/**
	 * Build the query parts for the filter property "text search"
	 * @return void
	 */
	protected function build_prop_search() {
		if( is_blank( $this->filter[FILTER_PROPERTY_SEARCH] ) ) {
			return;
		}

		# break up search terms by spacing or quoting
		preg_match_all( "/-?([^'\"\s]+|\"[^\"]+\"|'[^']+')/", $this->filter[FILTER_PROPERTY_SEARCH], $t_matches, PREG_SET_ORDER );

		# organize terms without quoting, paying attention to negation
		$t_search_terms = array();
		foreach( $t_matches as $t_match ) {
			$t_search_terms[trim( $t_match[1], "\'\"" )] = ( $t_match[0][0] == '-' );
		}

		$t_bugnote_table = $this->helper_table_alias_for_bugnote();

		# build a big where-clause and param list for all search terms, including negations
		$t_first = true;
		$t_textsearch_where_clause = '( ';
		foreach( $t_search_terms as $t_search_term => $t_negate ) {
			if( !$t_first ) {
				$t_textsearch_where_clause .= ' AND ';
			}

			if( $t_negate ) {
				$t_textsearch_where_clause .= 'NOT ';
			}

			$c_search = '%' . $t_search_term . '%';
			$t_textsearch_where_clause .= '( ' . $this->sql_like( '{bug}.summary', $c_search )
					. ' OR ' . $this->sql_like( '{bug_text}.description', $c_search )
					. ' OR ' . $this->sql_like( '{bug_text}.steps_to_reproduce', $c_search )
					. ' OR ' . $this->sql_like( '{bug_text}.additional_information', $c_search )
					. ' OR ' . $this->sql_like( '{bugnote_text}.note', $c_search );

			if( is_numeric( $t_search_term ) ) {
				# Note: no need to test negative values, '-' sign has been removed
				if( $t_search_term <= DB_MAX_INT ) {
					$c_search_int = (int)$t_search_term;
					$t_textsearch_where_clause .= ' OR {bug}.id = ' . $this->param( $c_search_int );
					$t_textsearch_where_clause .= ' OR ' . $t_bugnote_table . '.id = ' . $this->param( $c_search_int );
				}
			}

			$t_textsearch_where_clause .= ' )';
			$t_first = false;
		}
		$t_textsearch_where_clause .= ' )';

		# add text query elements to arrays
		if( !$t_first ) {
			# join with bugnote table has already been created or reused
			$this->add_join( 'JOIN {bug_text} ON {bug}.bug_text_id = {bug_text}.id' );
			# Outer join required otherwise we don't retrieve issues without notes
			$this->add_join( 'LEFT JOIN {bugnote_text} ON ' . $t_bugnote_table . '.bugnote_text_id = {bugnote_text}.id' );
			$this->add_where( $t_textsearch_where_clause );
		}

	}

	/**
	 * Translates a sql string created with legacy db_param() syntax, into
	 * a string with valid parameters and values binded to current query object.
	 *
	 * @param string $p_string	Sql string
	 * @param array $p_params	Array of parameter values
	 *
	 * @return string
	 */
	protected function helper_convert_legacy_clause( $p_string, array $p_params = [] ) {
		if( empty( $p_params ) ) {
			# shortcut, if there are no parameters, there's no need to translate
			return $p_string;
		}
		$t_params = array_values( $p_params );
		$t_param_index = 0;
		$cb_add_param = function ( $t_matches ) use ( $t_params, &$t_param_index ) {
			return $this->param( $t_params[$t_param_index++] );
		};

		$t_new_string = preg_replace_callback( '/(?<token>\?|\$|:)(?<index>[0-9]*)/', $cb_add_param, $p_string );
		return $t_new_string;
	}

	/**
	 * Build the query parts for the filter properties related to plugin filter fields
	 * @return void
	 */
	protected function build_prop_plugin_filters() {
		$t_plugin_filters = filter_get_plugin_filters();
		foreach( $t_plugin_filters as $t_field_name => $t_filter_object ) {
			if( !filter_field_is_any( $this->filter[$t_field_name] ) || $t_filter_object->type == FILTER_TYPE_BOOLEAN ) {
				$t_filter_query = $t_filter_object->query( $this->filter[$t_field_name] );
				if( is_array( $t_filter_query ) ) {
					if( isset( $t_filter_query['join'] ) ) {
						$this->add_join( $t_filter_query['join'] );
					}
					$t_params = [];
					if( isset( $t_filter_query['params'] ) && is_array( $t_filter_query['params'] ) ) {
						$t_params = $t_filter_query['params'];
					}
					if( isset( $t_filter_query['where'] ) ) {
						$t_where = $this->helper_convert_legacy_clause( $t_filter_query['where'], $t_params );
						$this->add_where( $t_where );
					}
				}
			}
		}
	}

	/**
	 * Return a column name for the specified property to sort on.
	 * Valid only for standard bug table fields
	 * Manages joining with other tables to allow sorting by display names instead
	 * of its numerical ids.
	 * @param string $p_prop	Filter property for sorting
	 * @return string	A column alias to be used in the sql order part
	 */
	protected function helper_sort_column_alias( $p_prop ) {

		switch( $p_prop ) {

			case 'category_id':
				# This join will be reduced as unique, if category search is active
				$this->add_join( 'LEFT JOIN {category} ON {bug}.category_id = {category}.id' );
				$this->add_select( '{category}.name' );
				return '{category}.name';
				break;

			case 'project_id':
				# project table is already joined by default
				$this->add_select( '{project}.name' );
				return '{project}.name';
				break;

			case 'handler_id':
			case 'reporter_id':
				$t_table_alias = $p_prop . '_sort_table';
				$t_join = 'LEFT JOIN {user} ' . $t_table_alias
						. ' ON {bug}.' . $p_prop . ' = ' . $t_table_alias . '.id';
				$this->add_join( $t_join );
				$t_col_alias = $p_prop . '_sort_alias';

				# sorting by username: coalesce( username, $prefix_for_deleted || id )
				# sorting by realname: coalesce( nullif(realname,''), username, $prefix_for_deleted || id )
				$t_select = 'COALESCE(';
				# Note: show_realname should only be set at global or all_projects
				# Note: sort_by_last_name is not supported here
				if( user_show_realname() ) {
					$t_select .= 'NULLIF(' . $t_table_alias . '.realname, \'\'), ';
				}
				$t_select .= $t_table_alias . '.username, ';
				$t_select .= 'CONCAT(\'' . lang_get( 'prefix_for_deleted_users' ) . '\', {bug}.' . $p_prop . ')';
				$t_select .= ') AS ' . $t_col_alias;

				$this->add_select( $t_select );
				return $t_col_alias;
				break;

			default:
				return '{bug}.' . $p_prop;
		}
	}

	/**
	 * Build the query parts for the filter related to sorting
	 * @return void
	 */
	protected function build_order_by() {

		# Get only the visible, and sortable, column properties
		# @TODO cproensa: this defaults to COLUMNS_TARGET_VIEW_PAGE
		# are we sure that filters are only used with the column set for view page?
		$t_sort_properties = filter_get_visible_sort_properties_array( $this->filter );
		$t_sort_fields = $t_sort_properties[FILTER_PROPERTY_SORT_FIELD_NAME];
		$t_dir_fields = $t_sort_properties[FILTER_PROPERTY_SORT_DIRECTION];

		if( gpc_string_to_bool( $this->filter[FILTER_PROPERTY_STICKY] ) && ( $this->use_sticky ) ) {
			$this->add_order( '{bug}.sticky DESC' );
		}

		$t_count = count( $t_sort_fields );
		for( $i = 0; $i < $t_count; $i++ ) {
			$c_sort = $t_sort_fields[$i];
			$c_dir = 'DESC' == $t_dir_fields[$i] ? 'DESC' : 'ASC';

			# if sorting by a custom field
			if( column_is_custom_field( $c_sort ) ) {
				$t_custom_field = column_get_custom_field_name( $c_sort );
				$t_custom_field_id = custom_field_get_id_from_name( $t_custom_field );
				$t_def = custom_field_get_definition( $t_custom_field_id );
				$t_value_field = ( $t_def['type'] == CUSTOM_FIELD_TYPE_TEXTAREA ? 'text' : 'value' );

				$t_table_name = $this->helper_table_alias_for_cf( $t_def );
				if( !$t_table_name ) {
					continue;
				}

				# if no join can be used (eg, no view access), skip this field from the order clause
				if( empty( $t_table_name ) ) {
					continue;
				}

				$t_field_alias = 'cf_sortfield_' . $t_custom_field_id;
				$t_sort_col = $t_table_name . '.' . $t_value_field;

				# which types need special type cast
				switch( $t_def['type'] ) {
						case CUSTOM_FIELD_TYPE_FLOAT:
							# mysql can't cast to float, use alternative syntax
							$t_sort_expr = db_is_mysql() ? $t_sort_col . '+0.0' : 'CAST(NULLIF(' . $t_sort_col . ',\'\') AS FLOAT)';
							break;
						case CUSTOM_FIELD_TYPE_DATE:
						case CUSTOM_FIELD_TYPE_NUMERIC:
							$t_sort_expr = 'CAST(NULLIF(' . $t_sort_col . ',\'\') AS DECIMAL)';
							break;
						default: # no cast needed
							$t_sort_expr = $t_sort_col;
				}

				# which types need special treatment for null sorting
				switch( $t_def['type'] ) {
					case CUSTOM_FIELD_TYPE_DATE:
					case CUSTOM_FIELD_TYPE_NUMERIC:
					case CUSTOM_FIELD_TYPE_FLOAT:
						$t_null_last = true;
						break;
					default:
						$t_null_last = false;
				}

				if( $t_null_last ) {
					$t_null_expr = 'CASE WHEN NULLIF(' . $t_sort_col . ', \'\') IS NULL THEN 1 ELSE 0 END';
					$t_clause_for_select = $t_null_expr . ' AS ' . $t_field_alias . '_null';
					$t_clause_for_select .= ', ' . $t_sort_expr . ' AS ' . $t_field_alias;
					$t_clause_for_order = $t_field_alias . '_null ASC, ' . $t_field_alias . ' ' . $c_dir;
				} else {
					$t_clause_for_select = $t_sort_expr . ' AS ' . $t_field_alias;
					$t_clause_for_order = $t_field_alias . ' ' . $c_dir;
				}

				# Note: pgsql needs the sort expression to appear as member of the "select distinct"
				$this->add_select( $t_clause_for_select );
				$this->add_order( $t_clause_for_order );

			# if sorting by plugin columns
			} else if( column_is_plugin_column( $c_sort ) ) {
				$t_plugin_columns = columns_get_plugin_columns();
				$t_column_object = $t_plugin_columns[$c_sort];

				$t_clauses = $t_column_object->sortquery( $c_dir );
				if( is_array( $t_clauses ) ) {
					if( isset( $t_clauses['select'] ) ) {
						$this->add_select( $t_clauses['select'] );
					}
					if( isset( $t_clauses['join'] ) ) {
						$this->add_join( $t_clauses['join'] );
					}
					if( isset( $t_clauses['order'] ) ) {
						$this->add_order( $t_clauses['order'] );
					}
				}

			# standard column
			} else {
				$t_sort_col = $this->helper_sort_column_alias( $c_sort );

				# When sorting by due_date, always display undefined dates last.
				# Undefined date is defaulted as "1" in database, so add a special
				# sort clause to group and sort by this.
				if( 'due_date' == $c_sort && 'ASC' == $c_dir ) {
					$t_null_expr = 'CASE ' . $t_sort_col . ' WHEN 1 THEN 1 ELSE 0 END';
					$this->add_select( $t_null_expr . ' AS due_date_sort_null' );
					$this->add_order( 'due_date_sort_null ASC' );
				}
				# main sort clause for due date
				$this->add_order( $t_sort_col . ' ' .$c_dir );
			}
		}

		# add basic sorting if necessary
		if( !in_array( 'last_updated', $t_sort_fields ) ) {
			$this->add_order( '{bug}.last_updated DESC' );
		}
		if( !in_array( 'date_submitted', $t_sort_fields ) ) {
			$this->add_order( '{bug}.date_submitted DESC' );
		}
	}
}
