<?php
/*
 * Gallery - a web based photo album viewer and editor
 * Copyright (C) 2000-2007 Bharat Mediratta
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA.
 */

/**
 * This controller will handle changing the order of items in an album.
 * @package GalleryCore
 * @subpackage UserInterface
 * @author Bharat Mediratta <bharat@menalto.com>
 * @version $Revision: 15513 $
 */
class ItemReorderController extends GalleryController {

    /**
     * @see GalleryController::handleRequest
     */
    function handleRequest($form) {
	global $gallery;

	$itemId = GalleryUtilities::getRequestVariables('itemId');

	/* Check permissions */
	$ret = GalleryCoreApi::assertHasItemPermission($itemId, 'core.edit');
	if ($ret) {
	    return array($ret, null);
	}

	$status = $error = array();
	if (isset($form['action']['reorder'])) {

	    /* Verify that we've got what we need */
	    if (empty($form['selectedId'])) {
		$error[] = 'form[error][selectedId][missing]';
	    }

	    if (empty($form['targetId'])) {
		$error[] = 'form[error][targetId][missing]';
	    }

	    $before = 0;
	    if (empty($form['placement']) || $form['placement'] == 'before') {
		$before = 1;
	    }

	    /*
	     * Make sure that the selectedId and targetId are children of the album
	     */
	    if (empty($error)) {
		$selectedId = $form['selectedId'];
		$targetId = $form['targetId'];
		list ($ret, $entities) =
		    GalleryCoreApi::loadEntitiesById(array($selectedId, $targetId));
		if ($ret) {
		    return array($ret, null);
		}

		if ($entities[0]->getParentId() != $itemId ||
		    $entities[1]->getParentId() != $itemId) {
		    return array(GalleryCoreApi::error(ERROR_PERMISSION_DENIED), null);
		}
	    }

	    if (empty($error)) {
		$loopCount = 0;
		while (true) {
		    /*
		     * Get the current and target order weights (have to do
		     * this after every rebalance, too)
		     */
		    list ($ret, $orderWeights) =
			GalleryCoreApi::fetchItemOrderWeights(array($selectedId, $targetId));
		    if ($ret) {
			return array($ret, null);
		    }

		    list ($ret, $next) = GalleryCoreApi::fetchNextItemWeight($targetId,
			$before ? LOWER_WEIGHT : HIGHER_WEIGHT);
		    if ($ret) {
			return array($ret, null);
		    }

		    if (isset($next)) {
			/* Floor rounds down, so separate the sign and the magnitude */
			$delta = (int)(($next - $orderWeights[$targetId]) / 2);
		    } else {
			/*
			 * We couldn't get a weight, which means that the
			 * target is at the edge.  So go beyond the edge
			 */
			$delta = $before ? -1000 : 1000;
		    }

		    if (abs($delta) > 0) {
			break;
		    }

		    if ($loopCount++ > 0) {
			/*
			 * If we have to rebalance more than once then something went wrong!
			 */
			return array(GalleryCoreApi::error(ERROR_UNKNOWN), null);
		    }

		    /* A delta of 0 means that we don't have room, so rebalance */
		    $ret = GalleryCoreApi::rebalanceChildOrderWeights($itemId);
		    if ($ret) {
			return array($ret, null);
		    }
		}
		$newWeight = $orderWeights[$targetId] + $delta;

		$ret = GalleryCoreApi::setItemOrderWeight($selectedId, $newWeight);
		if ($ret) {
		    return array($ret, null);
		}

		$event = GalleryCoreApi::newEvent('Gallery::ItemOrder');
		$event->setData($itemId);
		list ($ret) = GalleryCoreApi::postEvent($event);
		if ($ret) {
		    return array($ret, null);
		}

		/* Redirect back to the same page so that we can do more reordering */
		$redirect['view'] = 'core.ItemAdmin';
		$redirect['subView'] = 'core.ItemReorder';
		$redirect['itemId'] = $itemId;
		$status['saved'] = 1;
	    }
	} else if (isset($form['action']['cancel'])) {
	    $redirect['return'] = true;
	}

	if (!empty($redirect)) {
	    $results['redirect'] = $redirect;
	} else {
	    $results['delegate']['view'] = 'core.ItemAdmin';
	    $results['delegate']['subView'] = 'core.ItemReorder';
	}
	$results['status'] = $status;
	$results['error'] = $error;

	return array(null, $results);
    }
}

/**
 * This view will prompt for how to change the order of items in the album
 */
class ItemReorderView extends GalleryView {

    /**
     * @see GalleryView::loadTemplate
     */
    function loadTemplate(&$template, &$form) {
	global $gallery;

	/* itemId is the album where we want to move items from */
	$itemId = GalleryUtilities::getRequestVariables('itemId');

	if ($form['formName'] == 'ItemReorder') {
	    /* No validation at the moment */
	} else {
	    /* First time around, load the form with item data */
	    $form['formName'] = 'ItemReorder';
	}

	list ($ret, $item) = GalleryCoreApi::loadEntitiesById($itemId);
	if ($ret) {
	    return array($ret, null);
	}

	$show = array();
	$ItemReorder = array();
	$orderBy = $item->getOrderBy();
	if (empty($orderBy)) {
	    list ($ret, $orderBy) =
		GalleryCoreApi::getPluginParameter('module', 'core', 'default.orderBy');
	    if ($ret) {
		return array($ret, null);
	    }
	}
	if ($orderBy != 'orderWeight') {
	    $show['automaticOrderMessage'] = 1;
	} else {

	    /* Get all peers that we can see */
	    list ($ret, $peerIds) = GalleryCoreApi::fetchChildItemIds($item);
	    if ($ret) {
		return array($ret, null);
	    }

	    /* Load all the peers */
	    list ($ret, $peerItems) = GalleryCoreApi::loadEntitiesById($peerIds);
	    if ($ret) {
		return array($ret, null);
	    }

	    /* Build our peers table */
	    $peers = array();
	    foreach ($peerItems as $peerItem) {
		$peers[$peerItem->getId()] = (array)$peerItem;
		if (GalleryUtilities::isA($peerItem, 'GalleryAlbumItem')) {
		    $peerTypes['album'][$peerItem->getId()] = 1;
		} else {
		    $peerTypes['data'][$peerItem->getId()] = 1;
		}
		$peers[$peerItem->getId()]['selected'] =
		    isset($form['selectedIds'][$peerItem->getId()]);
	    }
	    $ItemReorder['peers'] = $peers;
	    $ItemReorder['peerTypes'] = $peerTypes;
	}

	$ItemReorder['show'] = $show;

	$template->setVariable('ItemReorder', $ItemReorder);
	$template->setVariable('controller', 'core.ItemReorder');
	return array(null, array('body' => 'modules/core/templates/ItemReorder.tpl'));
    }

    /**
     * @see GalleryView::getViewDescription
     */
    function getViewDescription() {
	list ($ret, $core) = GalleryCoreApi::loadPlugin('module', 'core');
	if ($ret) {
	    return array($ret, null);
	}

	return array(null, $core->translate('reorder items'));
    }
}
?>