<?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/>.

/**
 * User Preferences API
 *
 * @package CoreAPI
 * @subpackage UserPreferencesAPI
 * @copyright Copyright 2000 - 2002  Kenzaburo Ito - kenito@300baud.org
 * @copyright Copyright 2002  MantisBT Team - mantisbt-dev@lists.sourceforge.net
 * @link http://www.mantisbt.org
 *
 * @uses authentication_api.php
 * @uses config_api.php
 * @uses constant_inc.php
 * @uses database_api.php
 * @uses error_api.php
 * @uses lang_api.php
 * @uses user_api.php
 * @uses utility_api.php
 */

require_api( 'authentication_api.php' );
require_api( 'config_api.php' );
require_api( 'constant_inc.php' );
require_api( 'database_api.php' );
require_api( 'error_api.php' );
require_api( 'lang_api.php' );
require_api( 'user_api.php' );
require_api( 'utility_api.php' );

/**
 * Preference Structure Definition
 */
class UserPreferences {
	/**
	 * Default Profile
	 */
	protected $default_profile = null;

	/**
	 * Default Project for user
	 */
	protected $default_project = null;

	/**
	 * Automatic Refresh delay
	 */
	protected $refresh_delay = null;

	/**
	 * Automatic Redirect delay
	 */
	protected $redirect_delay = null;

	/**
	 * Bugnote order - oldest/newest first
	 */
	protected $bugnote_order = null;

	/**
	 * Receive email on new bugs
	 */
	protected $email_on_new = null;

	/**
	 * Receive email on assigned bugs
	 */
	protected $email_on_assigned = null;

	/**
	 * Receive email on feedback
	 */
	protected $email_on_feedback = null;

	/**
	 * Receive email on resolved bugs
	 */
	protected $email_on_resolved = null;

	/**
	 * Receive email on closed bugs
	 */
	protected $email_on_closed = null;

	/**
	 * Receive email on reopened bugs
	 */
	protected $email_on_reopened = null;

	/**
	 * Receive email on new bugnote
	 */
	protected $email_on_bugnote = null;

	/**
	 * Receive email on bug status change
	 */
	protected $email_on_status = null;

	/**
	 * Receive email on bug priority change
	 */
	protected $email_on_priority = null;

	/**
	 * Minimum Severity on which to trigger email if set to receive
	 */
	protected $email_on_new_min_severity = null;

	/**
	 * Minimum Severity on which to trigger email if set to receive
	 */
	protected $email_on_assigned_min_severity = null;

	/**
	 * Minimum Severity on which to trigger email if set to receive
	 */
	protected $email_on_feedback_min_severity = null;

	/**
	 * Minimum Severity on which to trigger email if set to receive
	 */
	protected $email_on_resolved_min_severity = null;

	/**
	 * Minimum Severity on which to trigger email if set to receive
	 */
	protected $email_on_closed_min_severity = null;

	/**
	 * Minimum Severity on which to trigger email if set to receive
	 */
	protected $email_on_reopened_min_severity = null;

	/**
	 * Minimum Severity on which to trigger email if set to receive
	 */
	protected $email_on_bugnote_min_severity = null;

	/**
	 * Minimum Severity on which to trigger email if set to receive
	 */
	protected $email_on_status_min_severity = null;

	/**
	 * Minimum Severity on which to trigger email if set to receive
	 */
	protected $email_on_priority_min_severity = null;

	/**
	 * Number of bug notes to include in generated emails
	 */
	protected $email_bugnote_limit = null;

	/**
	 * Users language preference
	 */
	protected $language = null;

	/**
	 * User Timezone
	 */
	protected $timezone = null;

	/**
	 * User id
	 */
	private $pref_user_id;

	/**
	 * Project ID
	 */
	private $pref_project_id;

	/**
	 * Default Values - Config Field Mappings
	 */
	private static $_default_mapping = array(
	'default_profile' => array( 'default_profile', 'int' ),
	'default_project' => array( 'default_project', 'int' ),
	'refresh_delay' => array( 'default_refresh_delay', 'int' ),
	'redirect_delay' => array( 'default_redirect_delay', 'int' ),
	'bugnote_order' => array( 'default_bugnote_order', 'string' ),
	'email_on_new' => array( 'default_email_on_new', 'int' ),
	'email_on_assigned' => array(  'default_email_on_assigned', 'int' ),
	'email_on_feedback' => array(  'default_email_on_feedback', 'int' ),
	'email_on_resolved' => array(  'default_email_on_resolved', 'int' ),
	'email_on_closed' => array(  'default_email_on_closed', 'int' ),
	'email_on_reopened' => array(  'default_email_on_reopened', 'int' ),
	'email_on_bugnote' => array(  'default_email_on_bugnote', 'int' ),
	'email_on_status' => array(  'default_email_on_status', 'int' ),
	'email_on_priority' => array(  'default_email_on_priority', 'int' ),
	'email_on_new_min_severity' => array(  'default_email_on_new_minimum_severity', 'int' ),
	'email_on_assigned_min_severity' => array(  'default_email_on_assigned_minimum_severity', 'int' ),
	'email_on_feedback_min_severity' => array(  'default_email_on_feedback_minimum_severity', 'int' ),
	'email_on_resolved_min_severity' => array(  'default_email_on_resolved_minimum_severity', 'int' ),
	'email_on_closed_min_severity' => array(  'default_email_on_closed_minimum_severity', 'int' ),
	'email_on_reopened_min_severity' => array(  'default_email_on_reopened_minimum_severity', 'int' ),
	'email_on_bugnote_min_severity' => array(  'default_email_on_bugnote_minimum_severity', 'int' ),
	'email_on_status_min_severity' => array(  'default_email_on_status_minimum_severity', 'int' ),
	'email_on_priority_min_severity' => array(  'default_email_on_priority_minimum_severity', 'int' ),
	'email_bugnote_limit' => array(  'default_email_bugnote_limit', 'int' ),
	'language' => array(  'default_language', 'string' ),
	'timezone' => array( 'default_timezone', 'string' ),
	);

	/**
	 * Constructor
	 * @param integer $p_user_id    A valid user identifier.
	 * @param integer $p_project_id A valid project identifier.
	 */
	function __construct( $p_user_id, $p_project_id ) {
		$this->default_profile = 0;
		$this->default_project = ALL_PROJECTS;

		$this->pref_user_id = (int)$p_user_id;
		$this->pref_project_id = (int)$p_project_id;
	}

	/**
	 * Overloaded function
	 * @param string $p_name  The Property name to set.
	 * @param string $p_value A value to set the property to.
	 * @return void
	 * @access private
	 */
	public function __set( $p_name, $p_value ) {
		switch( $p_name ) {
			case 'timezone':
				if( $p_value == '' ) {
					$p_value = null;
				}
		}
		$this->$p_name = $p_value;
	}

	/**
	 * Overloaded function
	 * @param string $p_string Property name.
	 * @access private
	 * @return mixed
	 */
	public function __get( $p_string ) {
		if( is_null( $this->$p_string ) ) {
			$this->$p_string = config_get( self::$_default_mapping[$p_string][0], null, $this->pref_user_id, $this->pref_project_id );
		}
		switch( self::$_default_mapping[$p_string][1] ) {
			case 'int':
				return (int)($this->$p_string);
			default:
				return $this->$p_string;
		}
	}

	/**
	 * Public Get() function
	 * @param string $p_string Property to get.
	 * @return mixed
	 */
	function Get( $p_string ) {
		if( is_null( $this->$p_string ) ) {
			$this->$p_string = config_get( self::$_default_mapping[$p_string][0], null, $this->pref_user_id, $this->pref_project_id );
		}
		return $this->$p_string;
	}
}

$g_cache_user_pref = array();
$g_cache_current_user_pref = array();

/**
 * Cache a user preferences row if necessary and return the cached copy.
 * If preferences can't be found, will trigger an error if $p_trigger_errors is
 * true (default), or return false otherwise
 * @param integer $p_user_id        A valid user identifier.
 * @param integer $p_project_id     A valid project identifier.
 * @param boolean $p_trigger_errors Whether to trigger error on failure.
 * @return boolean|array
 */
function user_pref_cache_row( $p_user_id, $p_project_id = ALL_PROJECTS, $p_trigger_errors = true ) {
	global $g_cache_user_pref;

	if( !isset( $g_cache_user_pref[(int)$p_user_id][(int)$p_project_id] ) ) {
		user_pref_cache_array_rows( array( $p_user_id ), $p_project_id );
	}

	$t_row = $g_cache_user_pref[(int)$p_user_id][(int)$p_project_id];
	if( false === $t_row && $p_trigger_errors ) {
		trigger_error( ERROR_USER_PREFS_NOT_FOUND, ERROR );
	}
	return $t_row;
}

/**
 * Cache user preferences for a set of users
 * @param array   $p_user_id_array An array of valid user identifiers.
 * @param integer $p_project_id    A valid project identifier.
 * @return void
 */
function user_pref_cache_array_rows( array $p_user_id_array, $p_project_id = ALL_PROJECTS ) {
	global $g_cache_user_pref;
	$c_user_id_array = array();

	# identify the user ids that are not cached already.
	foreach( $p_user_id_array as $t_user_id ) {
		if( !isset( $g_cache_user_pref[(int)$t_user_id][(int)$p_project_id] ) ) {
			$c_user_id_array[(int)$t_user_id] = (int)$t_user_id;
		}
	}

	# if all users are already cached, then return
	if( empty( $c_user_id_array ) ) {
		return;
	}

	$t_query = new DbQuery( 'SELECT * FROM {user_pref} WHERE user_id IN :user_array AND project_id = :project_id' );
	$t_query->bind( 'user_array', $c_user_id_array );
	$t_query->bind( 'project_id', (int)$p_project_id );

	$t_result = $t_query->fetch_all();
	if( $t_result ) {
		foreach( $t_result as $t_row ) {
			$t_user_id = (int)$t_row['user_id'];
			if( !isset( $g_cache_user_pref[$t_user_id] ) ) {
				$g_cache_user_pref[$t_user_id] = array();
			}
			$g_cache_user_pref[$t_user_id][(int)$p_project_id] = $t_row;

			# remove found users from required set.
			unset( $c_user_id_array[$t_user_id] );
		}
	}

	# cache users that are not found as false (i.e. negative cache)
	foreach( $c_user_id_array as $t_user_id ) {
		$g_cache_user_pref[(int)$t_user_id][(int)$p_project_id] = false;
	}
}

/**
 * Clear the user preferences cache (or just the given id if specified)
 * @param integer $p_user_id    A valid user identifier.
 * @param integer $p_project_id A valid project identifier.
 * @return boolean
 */
function user_pref_clear_cache( $p_user_id = null, $p_project_id = null ) {
	global $g_cache_user_pref;

	if( null === $p_user_id ) {
		$g_cache_user_pref = array();
	} else if( null === $p_project_id ) {
		unset( $g_cache_user_pref[(int)$p_user_id] );
	} else {
		unset( $g_cache_user_pref[(int)$p_user_id][(int)$p_project_id] );
	}

	return true;
}

/**
 * return true if the user has preferences assigned for the given project,
 * false otherwise
 * @param integer $p_user_id    A valid user identifier.
 * @param integer $p_project_id A valid project identifier.
 * @return boolean
 */
function user_pref_exists( $p_user_id, $p_project_id = ALL_PROJECTS ) {
	if( false === user_pref_cache_row( $p_user_id, $p_project_id, false ) ) {
		return false;
	} else {
		return true;
	}
}

/**
 * Backwards compatibility wrapper for user_pref_db_insert()
 * @deprecated	Use user_pref_db_insert()
 */
function user_pref_insert( $p_user_id, $p_project_id, UserPreferences $p_prefs ) {
	user_ensure_unprotected( $p_user_id );
	user_pref_db_insert( $p_user_id, $p_project_id, $p_prefs );
}

/**
 * perform an insert of a preference object into the DB
 * @param integer         $p_user_id    A valid user identifier.
 * @param integer         $p_project_id A valid project identifier.
 * @param UserPreferences $p_prefs      A UserPrefences Object.
 * @return boolean
 */
function user_pref_db_insert( $p_user_id, $p_project_id, UserPreferences $p_prefs ) {
	static $s_vars;
	$c_user_id = (int)$p_user_id;
	$c_project_id = (int)$p_project_id;

	if( $s_vars == null ) {
		$s_vars = getClassProperties( 'UserPreferences', 'protected' );
	}

	$t_values = array();
	$t_values[] = $c_user_id;
	$t_values[] = $c_project_id;
	foreach( $s_vars as $t_var => $t_val ) {
		array_push( $t_values, $p_prefs->Get( $t_var ) );
	}

	$t_columns = 'user_id, project_id, ' . implode( ', ', array_keys( $s_vars ) );
	$t_query = new DBQuery( 'INSERT INTO {user_pref} (' . $t_columns . ') VALUES :values' );
	$t_query->bind( 'values', $t_values );
	$t_query->execute();

	return true;
}

/**
 * Backwards compatibility wrapper for user_pref_db_update()
 * @deprecated	Use user_pref_db_update()
 */
function user_pref_update( $p_user_id, $p_project_id, UserPreferences $p_prefs ) {
	user_ensure_unprotected( $p_user_id );
	user_pref_db_update($p_user_id, $p_project_id, $p_prefs );
	user_pref_clear_cache( $p_user_id, $p_project_id );
}

/**
 * perform an update of a preference object into the DB
 * @param integer         $p_user_id    A valid user identifier.
 * @param integer         $p_project_id A valid project identifier.
 * @param UserPreferences $p_prefs      A UserPrefences Object.
 * @return void
 */
function user_pref_db_update( $p_user_id, $p_project_id, UserPreferences $p_prefs ) {
	static $s_vars;

	if( $s_vars == null ) {
		$s_vars = getClassProperties( 'UserPreferences', 'protected' );
	}

	$t_pairs = array();
	foreach( $s_vars as $t_var => $t_val ) {
		$t_pairs[] = "$t_var = :$t_var";
		$t_param[$t_var] = $p_prefs->$t_var;
	}

	$t_query = new DbQuery( 'UPDATE {user_pref}
		SET ' . implode( ', ', $t_pairs ) . '
		WHERE user_id = :user_id AND project_id = :project_id' );
	$t_query->bind( $t_param );
	$t_query->bind( 'user_id', $p_user_id );
	$t_query->bind( 'project_id', $p_project_id );
	$t_query->execute();
}

/**
 * Backwards compatibility wrapper for user_pref_db_delete()
 * @deprecated	Use user_pref_db_delete()
 */
function user_pref_delete( $p_user_id, $p_project_id = ALL_PROJECTS ) {
	user_ensure_unprotected( $p_user_id );
	user_pref_db_delete( $p_user_id, $p_project_id );
	user_pref_clear_cache( $p_user_id, $p_project_id );
}

/**
 * delete a preferences row
 * returns true if the preferences were successfully deleted
 * @param integer $p_user_id    A valid user identifier.
 * @param integer $p_project_id A valid project identifier.
 * @return void
 */
function user_pref_db_delete( $p_user_id, $p_project_id ) {
	$t_query = new DbQuery( 'DELETE FROM {user_pref}'
		. ' WHERE user_id=:user_id AND project_id=:project_id'
	);
	$t_query->bind( 'user_id', (int)$p_user_id );
	$t_query->bind( 'project_id', (int)$p_project_id );
	$t_query->execute();
}

/**
 * Backwards compatibility wrapper for user_pref_db_delete_user()
 * @deprecated	Use user_pref_db_delete_user()
 */
function user_pref_delete_all( $p_user_id ) {
	user_ensure_unprotected( $p_user_id );
	user_pref_db_delete_user( $p_user_id );
	user_pref_clear_cache( $p_user_id );
}

/**
 * delete all preferences for a user in all projects
 * returns true if the prefs were successfully deleted
 *
 * It is far more efficient to delete them all in one query than to
 *  call user_pref_delete() for each one and the code is short so that's
 *  what we do
 * @param integer $p_user_id A valid user identifier.
 * @return void
 */
function user_pref_db_delete_user( $p_user_id ) {
	$t_query = new DbQuery( 'DELETE FROM {user_pref} WHERE user_id=:user_id' );
	$t_query->bind( 'user_id', (int)$p_user_id );
	$t_query->execute();
}

/**
 * Sets project default to ALL_PROJECTS.
 *
 * @param integer $p_project_id A valid project identifier.
 * @param array   $p_users      A list of users (empty = all users).
 *
 * @return void
 */
function user_pref_clear_project_default( $p_project_id, array $p_users = array() ) {
	$t_query = new DbQuery( 'UPDATE {user_pref}'
		. ' SET default_project = ' . ALL_PROJECTS
		. ' WHERE default_project = :default'
	);
	$t_query->bind( 'default', (int)$p_project_id );
	if( $p_users ) {
		$t_query->append_sql( ' AND ' . $t_query->sql_in( 'user_id', 'users' ) );
		$t_query->bind( 'users', $p_users );
	}
	$t_query->execute();
}

/**
 * Sets project default to ALL_PROJECTS if current default is not valid.
 *
 * When users are removed from a project, the ones having that project as
 * default but who are no longer authorized to access it, need to have their
 * now-invalid preference updated.
 *
 * @param integer $p_project_id A valid project identifier.
 * @param array   $p_users      A list of users (empty = all users).
 *
 * @return void
 */
function user_pref_clear_invalid_project_default( $p_project_id, array $p_users = array() ) {
	# Get all users having the project as default
	$t_query = new DbQuery( 'SELECT user_id FROM {user_pref} WHERE default_project = :default' );
	$t_query->bind( 'default', (int)$p_project_id );
	if( $p_users ) {
		$t_query->append_sql( ' AND ' . $t_query->sql_in( 'user_id', 'users' ) );
		$t_query->bind( 'users', $p_users );
	}
	$t_query->execute();

	$t_users_having_project_as_default = array_column( $t_query->fetch_all(), 'user_id' );

	# Users who can't access the project anymore must have the default cleared
	$t_users_to_clear = array();
	foreach( $t_users_having_project_as_default as $t_id ) {
		if( access_get_project_level( $p_project_id, $t_id ) == ANYBODY ) {
			$t_users_to_clear[] = $t_id;
		}
	}

	if( !empty( $t_users_to_clear ) ) {
		user_pref_clear_project_default( $p_project_id, $t_users_to_clear );
	}
}

/**
 * delete all preferences for a project for all users (part of deleting the project)
 * returns true if the prefs were successfully deleted
 *
 * It is far more efficient to delete them all in one query than to
 * call user_pref_delete() for each one and the code is short so that's what we do
 * @param integer $p_project_id A valid project identifier.
 * @return void
 */
function user_pref_db_delete_project( $p_project_id ) {
	$t_query = new DbQuery( 'DELETE FROM {user_pref} WHERE project_id=:project_id' );
	$t_query->bind( 'project_id', (int)$p_project_id );
	$t_query->execute();
}

/**
 * return the user's preferences in a UserPreferences object
 * @param integer $p_user_id    A valid user identifier.
 * @param integer $p_project_id A valid project identifier.
 * @return UserPreferences
 */
function user_pref_get( $p_user_id, $p_project_id = ALL_PROJECTS ) {
	static $s_vars;
	global $g_cache_current_user_pref;

	if( isset( $g_cache_current_user_pref[(int)$p_project_id] ) &&
		auth_is_user_authenticated() &&
		auth_get_current_user_id() == $p_user_id ) {
		return $g_cache_current_user_pref[(int)$p_project_id];
	}

	$t_prefs = new UserPreferences( $p_user_id, $p_project_id );

	$t_row = user_pref_cache_row( $p_user_id, $p_project_id, false );

	# If the user has no preferences for the given project
	if( false === $t_row ) {
		if( ALL_PROJECTS != $p_project_id ) {
			# Try to get the prefs for ALL_PROJECTS (the defaults)
			$t_row = user_pref_cache_row( $p_user_id, ALL_PROJECTS, false );
		}

		# If $t_row is still false (the user doesn't have default preferences)
		if( false === $t_row ) {
			# We use an empty array
			$t_row = array();
		}
	}

	if( $s_vars == null ) {
		$s_vars = getClassProperties( 'UserPreferences', 'protected' );
	}

	$t_row_keys = array_keys( $t_row );

	# Check each variable in the class
	foreach( $s_vars as $t_var => $t_val ) {
		# If we got a field from the DB with the same name
		if( in_array( $t_var, $t_row_keys, true ) ) {
			# Store that value in the object
			$t_prefs->$t_var = $t_row[$t_var];
		}
	}
	if( auth_is_user_authenticated() && auth_get_current_user_id() == $p_user_id ) {
		$g_cache_current_user_pref[(int)$p_project_id] = $t_prefs;
	}
	return $t_prefs;
}

/**
 * Return the specified preference field for the user id
 * If the preference can't be found try to return a defined default
 * If that fails, trigger a WARNING and return ''
 * @param integer $p_user_id    A valid user identifier.
 * @param string  $p_pref_name  A valid user preference name.
 * @param integer $p_project_id A valid project identifier.
 * @return string
 */
function user_pref_get_pref( $p_user_id, $p_pref_name, $p_project_id = ALL_PROJECTS ) {
	static $s_vars;

	$t_prefs = user_pref_get( $p_user_id, $p_project_id );

	if( $s_vars == null ) {
		$t_reflection = new ReflectionClass( 'UserPreferences' );
		$s_vars = $t_reflection->getDefaultProperties();
	}

	if( in_array( $p_pref_name, array_keys( $s_vars ), true ) ) {
		return $t_prefs->Get( $p_pref_name );
	} else {
		error_parameters( $p_pref_name );
		trigger_error( ERROR_DB_FIELD_NOT_FOUND, WARNING );
		return '';
	}
}

/**
 * returns user language
 * @param integer $p_user_id    A valid user identifier.
 * @param integer $p_project_id A valid project identifier.
 * @return string language name or null if invalid language specified
 */
function user_pref_get_language( $p_user_id, $p_project_id = ALL_PROJECTS ) {
	$t_prefs = user_pref_get( $p_user_id, $p_project_id );

	# ensure the language is a valid one
	$t_lang = $t_prefs->language;
	if( !lang_language_exists( $t_lang ) ) {
		$t_lang = null;
	}
	return $t_lang;
}

/**
 * Set a user preference
 *
 * By getting the preferences for the project first we deal fairly well with defaults. If there are currently no
 * preferences for that project, the ALL_PROJECTS preferences will be returned so we end up storing a new set of
 * preferences for the given project based on the preferences for ALL_PROJECTS.  If there isn't even an entry for
 * ALL_PROJECTS, we'd get returned a default UserPreferences object to modify.
 * @param integer $p_user_id    A valid user identifier.
 * @param string  $p_pref_name  The name of the preference value to set.
 * @param string  $p_pref_value A preference value to set.
 * @param integer $p_project_id A valid project identifier.
 * @param boolean $p_check_protected	Whether to perform a check to not allow modify protected users
 * @return boolean
 */
function user_pref_set_pref( $p_user_id, $p_pref_name, $p_pref_value, $p_project_id = ALL_PROJECTS, $p_check_protected = true ) {
	$t_prefs = user_pref_get( $p_user_id, $p_project_id );

	if( $t_prefs->$p_pref_name != $p_pref_value ) {
		$t_prefs->$p_pref_name = $p_pref_value;
		user_pref_set( $p_user_id, $t_prefs, $p_project_id, $p_check_protected );
	}

	return true;
}

/**
 * Set the user's preferences for the project from the given preferences object
 * Do the work by calling update or insert as appropriate
 * @param integer         $p_user_id    A valid user identifier.
 * @param UserPreferences $p_prefs      A UserPreferences object containing settings to set.
 * @param integer         $p_project_id A valid project identifier.
 * @param boolean         $p_check_protected	Whether to perform a check to not allow modify protected users
 * @return void
 */
function user_pref_set( $p_user_id, UserPreferences $p_prefs, $p_project_id = ALL_PROJECTS, $p_check_protected = true ) {
	if( $p_check_protected ) {
		user_ensure_unprotected( $p_user_id );
	}
	if( user_pref_exists( $p_user_id, $p_project_id ) ) {
		user_pref_db_update( $p_user_id, $p_project_id, $p_prefs );
	} else {
		user_pref_db_insert( $p_user_id, $p_project_id, $p_prefs );
	}
	user_pref_clear_cache( $p_user_id, $p_project_id );
}

/**
 * Delete the user's preferences row for the given project
 * @param integer         $p_user_id    A valid user identifier.
 * @param integer         $p_project_id A valid project identifier.
 * @param boolean         $p_check_protected	Whether to perform a check to not allow modify protected users
 * @return void
 */
function user_pref_reset( $p_user_id, $p_project_id = ALL_PROJECTS, $p_check_protected = true ) {
	if( $p_check_protected ) {
		user_ensure_unprotected( $p_user_id );
	}
	if( user_pref_exists( $p_user_id, $p_project_id ) ) {
		user_pref_db_delete( $p_user_id, $p_project_id );
	}
	user_pref_clear_cache( $p_user_id, $p_project_id );
}