<?php

namespace Sabre\CalDAV;

use Sabre\VObject;

/**
 * Parses the calendar-query report request body.
 *
 * Whoever designed this format, and the CalDAV equivalent even more so,
 * has no feel for design.
 *
 * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
 * @author Evert Pot (http://evertpot.com/)
 * @license http://sabre.io/license/ Modified BSD License
 */
class CalendarQueryParser {

    /**
     * List of requested properties the client wanted
     *
     * @var array
     */
    public $requestedProperties;

    /**
     * List of property/component filters.
     *
     * @var array
     */
    public $filters;

    /**
     * This property will contain null if CALDAV:expand was not specified,
     * otherwise it will contain an array with 2 elements (start, end). Each
     * contain a DateTime object.
     *
     * If expand is specified, recurring calendar objects are to be expanded
     * into their individual components, and only the components that fall
     * within the specified time-range are to be returned.
     *
     * For more details, see rfc4791, section 9.6.5.
     *
     * @var null|array
     */
    public $expand;

    /**
     * DOM Document
     *
     * @var DOMDocument
     */
    protected $dom;

    /**
     * DOM XPath object
     *
     * @var DOMXPath
     */
    protected $xpath;

    /**
     * Creates the parser
     *
     * @param \DOMDocument $dom
     */
    public function __construct(\DOMDocument $dom) {

        $this->dom = $dom;
        $this->xpath = new \DOMXPath($dom);
        $this->xpath->registerNameSpace('cal',Plugin::NS_CALDAV);
        $this->xpath->registerNameSpace('dav','urn:DAV');

    }

    /**
     * Parses the request.
     *
     * @return void
     */
    public function parse() {

        $filterNode = null;

        $filter = $this->xpath->query('/cal:calendar-query/cal:filter');
        if ($filter->length !== 1) {
            throw new \Sabre\DAV\Exception\BadRequest('Only one filter element is allowed');
        }

        $compFilters = $this->parseCompFilters($filter->item(0));
        if (count($compFilters)!==1) {
            throw new \Sabre\DAV\Exception\BadRequest('There must be exactly 1 top-level comp-filter.');
        }

        $this->filters = $compFilters[0];
        $this->requestedProperties = array_keys(\Sabre\DAV\XMLUtil::parseProperties($this->dom->firstChild));

        $expand = $this->xpath->query('/cal:calendar-query/dav:prop/cal:calendar-data/cal:expand');
        if ($expand->length>0) {
            $this->expand = $this->parseExpand($expand->item(0));
        }


    }

    /**
     * Parses all the 'comp-filter' elements from a node
     *
     * @param \DOMElement $parentNode
     * @return array
     */
    protected function parseCompFilters(\DOMElement $parentNode) {

        $compFilterNodes = $this->xpath->query('cal:comp-filter', $parentNode);
        $result = array();

        for($ii=0; $ii < $compFilterNodes->length; $ii++) {

            $compFilterNode = $compFilterNodes->item($ii);

            $compFilter = array();
            $compFilter['name'] = $compFilterNode->getAttribute('name');
            $compFilter['is-not-defined'] = $this->xpath->query('cal:is-not-defined', $compFilterNode)->length>0;
            $compFilter['comp-filters'] = $this->parseCompFilters($compFilterNode);
            $compFilter['prop-filters'] = $this->parsePropFilters($compFilterNode);
            $compFilter['time-range'] = $this->parseTimeRange($compFilterNode);

            if ($compFilter['time-range'] && !in_array($compFilter['name'],array(
                'VEVENT',
                'VTODO',
                'VJOURNAL',
                'VFREEBUSY',
                'VALARM',
            ))) {
                throw new \Sabre\DAV\Exception\BadRequest('The time-range filter is not defined for the ' . $compFilter['name'] . ' component');
            };

            $result[] = $compFilter;

        }

        return $result;

    }

    /**
     * Parses all the prop-filter elements from a node
     *
     * @param \DOMElement $parentNode
     * @return array
     */
    protected function parsePropFilters(\DOMElement $parentNode) {

        $propFilterNodes = $this->xpath->query('cal:prop-filter', $parentNode);
        $result = array();

        for ($ii=0; $ii < $propFilterNodes->length; $ii++) {

            $propFilterNode = $propFilterNodes->item($ii);
            $propFilter = array();
            $propFilter['name'] = $propFilterNode->getAttribute('name');
            $propFilter['is-not-defined'] = $this->xpath->query('cal:is-not-defined', $propFilterNode)->length>0;
            $propFilter['param-filters'] = $this->parseParamFilters($propFilterNode);
            $propFilter['text-match'] = $this->parseTextMatch($propFilterNode);
            $propFilter['time-range'] = $this->parseTimeRange($propFilterNode);

            $result[] = $propFilter;

        }

        return $result;

    }

    /**
     * Parses the param-filter element
     *
     * @param \DOMElement $parentNode
     * @return array
     */
    protected function parseParamFilters(\DOMElement $parentNode) {

        $paramFilterNodes = $this->xpath->query('cal:param-filter', $parentNode);
        $result = array();

        for($ii=0;$ii<$paramFilterNodes->length;$ii++) {

            $paramFilterNode = $paramFilterNodes->item($ii);
            $paramFilter = array();
            $paramFilter['name'] = $paramFilterNode->getAttribute('name');
            $paramFilter['is-not-defined'] = $this->xpath->query('cal:is-not-defined', $paramFilterNode)->length>0;
            $paramFilter['text-match'] = $this->parseTextMatch($paramFilterNode);

            $result[] = $paramFilter;

        }

        return $result;

    }

    /**
     * Parses the text-match element
     *
     * @param \DOMElement $parentNode
     * @return array|null
     */
    protected function parseTextMatch(\DOMElement $parentNode) {

        $textMatchNodes = $this->xpath->query('cal:text-match', $parentNode);

        if ($textMatchNodes->length === 0)
            return null;

        $textMatchNode = $textMatchNodes->item(0);
        $negateCondition = $textMatchNode->getAttribute('negate-condition');
        $negateCondition = $negateCondition==='yes';
        $collation = $textMatchNode->getAttribute('collation');
        if (!$collation) $collation = 'i;ascii-casemap';

        return array(
            'negate-condition' => $negateCondition,
            'collation' => $collation,
            'value' => $textMatchNode->nodeValue
        );

    }

    /**
     * Parses the time-range element
     *
     * @param \DOMElement $parentNode
     * @return array|null
     */
    protected function parseTimeRange(\DOMElement $parentNode) {

        $timeRangeNodes = $this->xpath->query('cal:time-range', $parentNode);
        if ($timeRangeNodes->length === 0) {
            return null;
        }

        $timeRangeNode = $timeRangeNodes->item(0);

        if ($start = $timeRangeNode->getAttribute('start')) {
            $start = VObject\DateTimeParser::parseDateTime($start);
        } else {
            $start = null;
        }
        if ($end = $timeRangeNode->getAttribute('end')) {
            $end = VObject\DateTimeParser::parseDateTime($end);
        } else {
            $end = null;
        }

        if (!is_null($start) && !is_null($end) && $end <= $start) {
            throw new \Sabre\DAV\Exception\BadRequest('The end-date must be larger than the start-date in the time-range filter');
        }

        return array(
            'start' => $start,
            'end' => $end,
        );

    }

    /**
     * Parses the CALDAV:expand element
     *
     * @param \DOMElement $parentNode
     * @return void
     */
    protected function parseExpand(\DOMElement $parentNode) {

        $start = $parentNode->getAttribute('start');
        if(!$start) {
            throw new \Sabre\DAV\Exception\BadRequest('The "start" attribute is required for the CALDAV:expand element');
        }
        $start = VObject\DateTimeParser::parseDateTime($start);

        $end = $parentNode->getAttribute('end');
        if(!$end) {
            throw new \Sabre\DAV\Exception\BadRequest('The "end" attribute is required for the CALDAV:expand element');
        }

        $end = VObject\DateTimeParser::parseDateTime($end);

        if ($end <= $start) {
            throw new \Sabre\DAV\Exception\BadRequest('The end-date must be larger than the start-date in the expand element.');
        }

        return array(
            'start' => $start,
            'end' => $end,
        );

    }

}
