<?php
/*
 *  $Id: NestedSet.php 5901 2009-06-22 15:44:45Z jwage $
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.phpdoctrine.org>.
 */

/**
 * Doctrine_Tree_NestedSet
 *
 * @package     Doctrine
 * @subpackage  Tree
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link        www.phpdoctrine.org
 * @since       1.0
 * @version     $Revision: 5901 $
 * @author      Joe Simms <joe.simms@websites4.com>
 * @author      Roman Borschel <roman@code-factory.org>
 */
class Doctrine_Tree_NestedSet extends Doctrine_Tree implements Doctrine_Tree_Interface
{
    private $_baseQuery;
    private $_baseAlias = "base";

    /**
     * constructor, creates tree with reference to table and sets default root options
     *
     * @param object $table                     instance of Doctrine_Table
     * @param array $options                    options
     */
    public function __construct(Doctrine_Table $table, $options)
    {
        // set default many root attributes
        $options['hasManyRoots'] = isset($options['hasManyRoots']) ? $options['hasManyRoots'] : false;
        if ($options['hasManyRoots']) {
            $options['rootColumnName'] = isset($options['rootColumnName']) ? $options['rootColumnName'] : 'root_id';
        }

        parent::__construct($table, $options);
    }

    /**
     * used to define table attributes required for the NestetSet implementation
     * adds lft and rgt columns for corresponding left and right values
     *
     */
    public function setTableDefinition()
    {
        if (($root = $this->getAttribute('rootColumnName')) && (!$this->table->hasColumn($root))) {
            $this->table->setColumn($root, 'integer');
        }

        $this->table->setColumn('lft', 'integer', 4);
        $this->table->setColumn('rgt', 'integer', 4);
        $this->table->setColumn('level', 'integer', 2);
    }

    /**
     * Creates root node from given record or from a new record.
     *
     * Note: When using a tree with multiple root nodes (hasManyRoots), you MUST pass in a
     * record to use as the root. This can either be a new/transient record that already has
     * the root id column set to some numeric value OR a persistent record. In the latter case
     * the records id will be assigned to the root id. You must use numeric columns for the id
     * and root id columns.
     *
     * @param object $record        instance of Doctrine_Record
     */
    public function createRoot(Doctrine_Record $record = null)
    {
        if ($this->getAttribute('hasManyRoots')) {
            if ( ! $record || ( ! $record->exists() && $record->getNode()->getRootValue() <= 0)
                    || $record->getTable()->isIdentifierComposite()) {
                throw new Doctrine_Tree_Exception("Node must have a root id set or must "
                        . " be persistent and have a single-valued numeric primary key in order to"
                        . " be created as a root node. Automatic assignment of a root id on"
                        . " transient/new records is no longer supported.");
            }
            
            if ($record->exists() && $record->getNode()->getRootValue() <= 0) {
                // Default: root_id = id
                $identifier = $record->getTable()->getIdentifier();
                $record->getNode()->setRootValue($record->get($identifier));
            }
        }
        
        if ( ! $record) {
            $record = $this->table->create();
        }

        $record->set('lft', '1');
        $record->set('rgt', '2');
        $record->set('level', 0);

        $record->save();

        return $record;
    }

    /**
     * Fetches a/the root node.
     *
     * @param integer $rootId
     * @todo Better $rootid = null and exception if $rootId == null && hasManyRoots?
     *       Fetching with id = 1 is too magical and cant work reliably anyway.
     */
    public function fetchRoot($rootId = 1)
    {
        $q = $this->getBaseQuery();
        $q = $q->addWhere($this->_baseAlias . '.lft = ?', 1);

        // if tree has many roots, then specify root id
        $q = $this->returnQueryWithRootId($q, $rootId);
        $data = $q->execute();

        if (count($data) <= 0) {
            return false;
        }

        if ($data instanceof Doctrine_Collection) {
            $root = $data->getFirst();
            $root['level'] = 0;
        } else if (is_array($data)) {
            $root = array_shift($data);
            $root['level'] = 0;
        } else {
            throw new Doctrine_Tree_Exception("Unexpected data structure returned.");
        }

        return $root;
    }

    /**
     * Fetches a tree.
     *
     * @param array $options  Options
     * @param integer $fetchmode  One of the Doctrine::HYDRATE_* constants.
     * @return mixed          The tree or FALSE if the tree could not be found.
     */
    public function fetchTree($options = array(), $hydrationMode = null)
    {
        // fetch tree
        $q = $this->getBaseQuery();

        $depth = isset($options['depth']) ? $options['depth'] : null;

        $q->addWhere($this->_baseAlias . ".lft >= ?", 1);

        // if tree has many roots, then specify root id
        $rootId = isset($options['root_id']) ? $options['root_id'] : '1';
        if (is_array($rootId)) {
            $q->addOrderBy($this->_baseAlias . "." . $this->getAttribute('rootColumnName') .
                    ", " . $this->_baseAlias . ".lft ASC");
        } else {
            $q->addOrderBy($this->_baseAlias . ".lft ASC");
        }

        if ( ! is_null($depth)) { 
            $q->addWhere($this->_baseAlias . ".level BETWEEN ? AND ?", array(0, $depth)); 
        }

        $q = $this->returnQueryWithRootId($q, $rootId);

        $tree = $q->execute(array(), $hydrationMode);

        if (count($tree) <= 0) {
            return false;
        }

        return $tree;
    }

    /**
     * Fetches a branch of a tree.
     *
     * @param mixed $pk              primary key as used by table::find() to locate node to traverse tree from
     * @param array $options         Options.
     * @param integer $fetchmode  One of the Doctrine::HYDRATE_* constants.
     * @return mixed                 The branch or FALSE if the branch could not be found.
     * @todo Only fetch the lft and rgt values of the initial record. more is not needed.
     */
    public function fetchBranch($pk, $options = array(), $hydrationMode = null)
    {
        $record = $this->table->find($pk);
        if ( ! ($record instanceof Doctrine_Record) || !$record->exists()) {
            // TODO: if record doesn't exist, throw exception or similar?
            return false;
        }

        $depth = isset($options['depth']) ? $options['depth'] : null;

        $q = $this->getBaseQuery();
        $params = array($record->get('lft'), $record->get('rgt'));
        $q->addWhere($this->_baseAlias . ".lft >= ? AND " . $this->_baseAlias . ".rgt <= ?", $params)
                ->addOrderBy($this->_baseAlias . ".lft asc");

        if ( ! is_null($depth)) { 
            $q->addWhere($this->_baseAlias . ".level BETWEEN ? AND ?", array($record->get('level'), $record->get('level')+$depth)); 
        }

        $q = $this->returnQueryWithRootId($q, $record->getNode()->getRootValue());

        return $q->execute(array(), $hydrationMode);
    }

    /**
     * Fetches all root nodes. If the tree has only one root this is the same as
     * fetchRoot().
     *
     * @return mixed  The root nodes.
     */
    public function fetchRoots()
    {
        $q = $this->getBaseQuery();
        $q = $q->addWhere($this->_baseAlias . '.lft = ?', 1);
        return $q->execute();
    }

    /**
     * returns parsed query with root id where clause added if applicable
     *
     * @param object    $query    Doctrine_Query
     * @param integer   $root_id  id of destination root
     * @return Doctrine_Query
     */
    public function returnQueryWithRootId($query, $rootId = 1)
    {
        if ($root = $this->getAttribute('rootColumnName')) {
            if (is_array($rootId)) {
               $query->addWhere($root . ' IN (' . implode(',', array_fill(0, count($rootId), '?')) . ')',
                       $rootId);
            } else {
               $query->addWhere($root . ' = ?', $rootId);
            }
        }

        return $query;
    }

    /**
     * Enter description here...
     *
     * @param array $options
     * @return unknown
     */
    public function getBaseQuery()
    {
        if ( ! isset($this->_baseQuery)) {
            $this->_baseQuery = $this->_createBaseQuery();
        }
        return $this->_baseQuery->copy();
    }

    /**
     * Enter description here...
     *
     */
    public function getBaseAlias()
    {
        return $this->_baseAlias;
    }

    /**
     * Enter description here...
     *
     */
    private function _createBaseQuery()
    {
        $this->_baseAlias = "base";
        $q = new Doctrine_Query();
        $q->select($this->_baseAlias . ".*")->from($this->getBaseComponent() . " " . $this->_baseAlias);
        return $q;
    }

    /**
     * Enter description here...
     *
     * @param Doctrine_Query $query
     */
    public function setBaseQuery(Doctrine_Query $query)
    {
        $this->_baseAlias = $query->getRootAlias();
        $query->addSelect($this->_baseAlias . ".lft, " . $this->_baseAlias . ".rgt, ". $this->_baseAlias . ".level");
        if ($this->getAttribute('rootColumnName')) {
            $query->addSelect($this->_baseAlias . "." . $this->getAttribute('rootColumnName'));
        }
        $this->_baseQuery = $query;
    }

    /**
     * Enter description here...
     *
     */
    public function resetBaseQuery()
    {
        $this->_baseQuery = $this->_createBaseQuery();
    }
}
