<?php

/**
 * The ics import engine to import feeds from API
 *
 * @author     Time.ly Network Inc.
 * @since      2.4
 *
 * @package    AI1EC
 * @subpackage AI1EC.Import-export
 */
class Ai1ec_Api_Ics_Import_Export_Engine
    extends Ai1ec_Base
    implements Ai1ec_Import_Export_Engine {

    /**
     * @var Ai1ec_Taxonomy
     */
    protected $_taxonomy_model = null;

    /**
     * Recurrence rule class. Contains filter method.
     *
     * @var Ai1ec_Recurrence_Rule
     */
    protected $_rule_filter = null;

    protected function is_valid( $cal ) {
        if ( is_null( $cal ) || ! is_array( $cal ) ) {
            return false;
        }
        return true;
    }

    /* (non-PHPdoc)
     * @see Ai1ec_Import_Export_Engine::import()
     */
    public function import( array $arguments ) {
        $cal = $arguments['source'];
        if ( $this->is_valid( $cal ) ) {
            try {
                $result = $this->add_vcalendar_events_to_db( $arguments );
            } catch ( Ai1ec_Parse_Exception $exception ) {
                throw new Ai1ec_Parse_Exception(
                    'Processing "' . $arguments['source'] .
                    '" triggered error: ' . $exception->getMessage()
                );
            }
            return $result;
        }
        throw new Ai1ec_Parse_Exception( 'The passed string is not a valid ics feed' );
    }

    public function events_order_comparator( $e1, $e2 ) {
        return strcmp( $e1->dtstart, $e2->dtstart );
    }

    /**
     * Process event instance - add events to database.
     *
     * @param array     $args Arbitrary arguments map.
     *
     * @throws Ai1ec_Parse_Exception
     *
     * @internal param array   $args           Array with events and configuration
     *
     * @return int Count of events added to database.
     */
    public function add_vcalendar_events_to_db( array $args ) {

        $cal             = $this->_normalize_google_uids( $args['source'] );

        $feed            = isset( $args['feed'] ) ? $args['feed'] : null;
        $comment_status  = isset( $args['comment_status'] ) ? $args['comment_status'] : 'open';
        $do_show_map     = isset( $args['do_show_map'] ) ? $args['do_show_map'] : 0;
        $count           = 0;
        $events_in_db    = isset( $args['events_in_db'] ) ? $args['events_in_db'] : 0;
        $feed_name       = $feed->feed_url;

        // Fetch default timezone in case individual properties don't define it
        $local_timezone  = $this->_registry->get( 'date.timezone' )->get_default_timezone();

        $messages        = array();

        // initialize empty custom exclusions structure
        $exclusions      = array();
        $api             = null;

        // go over each event
        foreach ( $cal as $e ) {

            // Event data array.
            $data = array();
            // =====================
            // = Start & end times =
            // =====================
            $start = (array)$e->dtstart;
            $end   = (array)$e->dtend;
            // For cases where a "VEVENT" calendar component
            // specifies a "DTSTART" property with a DATE value type but none
            // of "DTEND" nor "DURATION" property, the event duration is taken to
            // be one day.  For cases where a "VEVENT" calendar component
            // specifies a "DTSTART" property with a DATE-TIME value type but no
            // "DTEND" property, the event ends on the same calendar date and
            // time of day specified by the "DTSTART" property.
            if ( empty( $end ) )  {
                // #1 if duration is present, assign it to end time
                $end = $e->duration;
                if ( empty( $end ) ) {
                    // #2 if only DATE value is set for start, set duration to 1 day
                    if ( ! isset( $start['time']['hour'] ) ) {
                        $end = array(
                            'date' => array(
                                'year'   => $start['date']['year'],
                                'month'  => $start['date']['month'],
                                'day'    => $start['date']['day'] + 1,
                            ),
                            'time' => array(
                                'hour'   => 0,
                                'minute' => 0,
                                'second' => 0,
                            ),
                        );
                        // #3 set end date to start time
                        $end = $start;
                    }
                }
            }
            $categories = $e->categories;
            $imported_cat = array( Ai1ec_Event_Taxonomy::CATEGORIES => array() );
            // If the user chose to preserve taxonomies during import, add categories.
            if( $categories && $feed->keep_tags_categories ) {
                $imported_cat = $this->add_categories_and_tags(
                        $categories,
                        $imported_cat,
                        false,
                        true
                );
            }
            $feed_categories = $feed->feed_category;
            if( ! empty( $feed_categories ) ) {
                $imported_cat = $this->add_categories_and_tags(
                        $feed_categories,
                        $imported_cat,
                        false,
                        false
                );
            }
            $tags = $e->x_tags;
            $imported_tags = array( Ai1ec_Event_Taxonomy::TAGS => array() );
            // If the user chose to preserve taxonomies during import, add tags.
            if( $tags && $feed->keep_tags_categories ) {
                $imported_tags = $this->add_categories_and_tags(
                        $tags,
                        $imported_tags,
                        true,
                        true
                );
            }
            $feed_tags = $feed->feed_tags;
            if( ! empty( $feed_tags ) ) {
                $imported_tags = $this->add_categories_and_tags(
                        $feed_tags,
                        $imported_tags,
                        true,
                        true
                );
            }
            // Event is all-day if no time components are defined
            $allday = $this->_is_timeless( (array)$start['time'] ) &&
                      $this->_is_timeless( (array)$end['time'] );
            // Also check the proprietary MS all-day field.
            $ms_allday = $e->x_microsoft_cdo_alldayevent;
            if ( ! empty( $ms_allday ) && 'TRUE' == $ms_allday ) {
                $allday = true;
            }
            $event_timezone = $e->timezone;

            // Check if the timezone is a recognized TZ in PHP
            // Note: the TZ may be perfectly valid, but it may not be an accepted value in the PHP version the plugin is running on
            try {
                $tz = @timezone_open( $event_timezone );
            } catch ( Exception $e ) {
                // Invalid timzeone
                $tz = null;
            }

            if ( ! $tz || $allday || preg_match( "/GMT[+|-][0-9]{4}.*/", $event_timezone ) ) {
                $event_timezone = $local_timezone;
            }
            $start = $this->_time_array_to_datetime(
                (array)$start['date'],
                (array)$start['time'],
                $event_timezone,
                $feed->import_timezone ? $local_timezone : null
            );
            $end   = $this->_time_array_to_datetime(
                (array)$end['date'],
                (array)$end['time'],
                $event_timezone,
                $feed->import_timezone ? $local_timezone : null
            );
            if ( false === $start || false === $end ) {
                throw new Ai1ec_Parse_Exception(
                    'Failed to parse one or more dates given timezone "' .
                    var_export( $event_timezone, true ) . '"'
                );
                continue;
            }

            // If all-day, and start and end times are equal, then this event has
            // invalid end time (happens sometimes with poorly implemented iCalendar
            // exports, such as in The Event Calendar), so set end time to 1 day
            // after start time.
            if ( $allday && $start->format() === $end->format() ) {
                $end->adjust_day( +1 );
            }

            $data += compact( 'start', 'end', 'allday' );

            // =======================================
            // = Recurrence rules & recurrence dates =
            // =======================================
            $rrule  = $e->rrule;
            $rdate  = $e->rdate;

            // =======================================
            // = Exclusion rules & exclusion dates   =
            // =======================================
            $exrule = $e->exrule;
            $exdate = $e->exdate;

            // Add custom exclusions if there any
            $recurrence_id = $e->recurrence_id;
            if (
                '' === $recurrence_id &&
                ! empty( $exclusions[$e->uid] )
            ) {
                if ( isset( $exdate{0} ) ) {
                    $exdate .= ',';
                }
                $exdate .= implode( ',', $exclusions[$e->uid] );
            }
            // ========================
            // = Latitude & longitude =
            // ========================
            $latitude = $longitude = NULL;
            $geo_tag  = isset( $e->geo ) ? $e->geo : null;
            if ( ! empty( $geo_tag ) && false !== strpos( $geo_tag, ',' ) ) {
                list( $latitude, $longitude ) = explode( ',', $geo_tag, 2 );
                $latitude  = (float)$latitude;
                $longitude = (float)$longitude;
            }
            unset( $geo_tag );
            if ( NULL !== $latitude ) {
                $data += compact( 'latitude', 'longitude' );
                // Check the input coordinates checkbox, otherwise lat/long data
                // is not present on the edit event page
                $data['show_coordinates'] = 1;
            }
            // ===================
            // = Venue & address =
            // ===================
            $data['country']     = '';
            $data['city']        = '';
            $data['province']    = '';
            $data['postal_code'] = '';

            $address             = '';
            $venue               = '';
            $location            = $e->location;
            $matches             = array();
            // This regexp matches a venue / address in the format
            // "venue @ address" or "venue - address".
            preg_match( '/\s*(.*\S)\s+[\-@]\s+(.*)\s*/', $location, $matches );
            // if there is no match, it's not a combined venue + address
            if ( empty( $matches ) ) {
                // temporary fix for Mac ICS import. Se AIOEC-2187
                // and https://github.com/iCalcreator/iCalcreator/issues/13
                $location = str_replace( '\n', "\n", $location );
                // if there is a comma, probably it's an address
                if ( false === strpos( $location, ',' ) ) {
                    $venue = $location;
                } else {
                    $address = $location;
                }
            } else {
                $venue = isset( $matches[1] ) ? $matches[1] : '';
                $address = isset( $matches[2] ) ? $matches[2] : '';
            }

            // =====================================================
            // = Set show map status based on presence of location =
            // =====================================================
            $event_do_show_map = $do_show_map;
            if (
                1 === $do_show_map &&
                NULL === $latitude &&
                empty( $address )
            ) {
                $event_do_show_map = 0;
            }

            // ==================
            // = Cost & tickets =
            // ==================
            $cost       = $e->x_cost;
            $ticket_url = $e->x_tickets_url;

            // ===============================
            // = Contact name, phone, e-mail =
            // ===============================
            // Initialize default values
            $data['contact_email'] = '';
            $data['contact_url']   = '';
            $data['contact_phone'] = '';
            $data['contact_name']  = '';

            $organizer             = $e->organizer;
            if (
                'MAILTO:' === substr( $organizer, 0, 7 ) &&
                false === strpos( $organizer, '@' )
            ) {
                $organizer = substr( $organizer, 7 );
            }
            $contact = $e->contact;
            $elements = explode( ';', $contact, 4 );

            foreach ( $elements as $el ) {
                $el = trim( $el );
                // Detect e-mail address.
                if ( false !== strpos( $el, '@' ) ) {
                    $data['contact_email'] = $el;
                }
                // Detect URL.
                elseif ( false !== strpos( $el, '://' ) ) {
                    $data['contact_url']   = $el;
                }
                // Detect phone number.
                elseif ( preg_match( '/^[\+0-9\-\(\)\s]*$/', $el ) && strlen( $el ) <= 32 ) {
                    $data['contact_phone'] = $el;
                }
                // Default to name.
                else {
                    $data['contact_name']  = $el;
                }
            }
            if ( ! isset( $data['contact_name'] ) || ! $data['contact_name'] ) {
                // If no contact name, default to organizer property.
                $data['contact_name']    = $organizer;
            }

            $description = stripslashes(
                            str_replace(
                                '\n',
                                "\n",
                                $e->description
                            ));

            $description = $this->_remove_ticket_url( $description );

            // Store yet-unsaved values to the $data array.
            $data += array(
                'recurrence_rules'  => $rrule,
                'exception_rules'   => $exrule,
                'recurrence_dates'  => $rdate,
                'exception_dates'   => $exdate,
                'venue'             => $venue,
                'address'           => $address,
                'cost'              => $cost,
                'ticket_url'        => $ticket_url,
                'show_map'          => $event_do_show_map,
                'ical_feed_url'     => $feed->feed_url,
                'ical_source_url'   => $e->url,
                'ical_organizer'    => $organizer,
                'ical_contact'      => $contact,
                'ical_uid'          => $this->_get_ical_uid( $e ),
                'categories'        => array_keys( $imported_cat[Ai1ec_Event_Taxonomy::CATEGORIES] ),
                'tags'              => array_keys( $imported_tags[Ai1ec_Event_Taxonomy::TAGS] ),
                'feed'              => $feed,
                'post'              => array(
                    'post_status'       => 'publish',
                    'comment_status'    => $comment_status,
                    'post_type'         => AI1EC_POST_TYPE,
                    'post_author'       => 1,
                    'post_title'        => $e->summary,
                    'post_content'      => $description
                )
            );
            // register any custom exclusions for given event
            $exclusions = $this->_add_recurring_events_exclusions(
                $e,
                $exclusions,
                $start
            );

            // Create event object.
            $data  = apply_filters(
                'ai1ec_pre_init_event_from_feed',
                $data,
                $e,
                $feed
            );

            $event = $this->_registry->get( 'model.event', $data );

            // Instant Event
            $is_instant = $e->x_instant_event;
            if ( $is_instant ) {
                $event->set_no_end_time();
            }

            $recurrence = $event->get( 'recurrence_rules' );
            $search = $this->_registry->get( 'model.search' );
            // first let's check by UID
            $matching_event_id = $search
                ->get_matching_event_by_uid_and_url(
                    $event->get( 'ical_uid' ),
                    $event->get( 'ical_feed_url' )
                );
            // if no result, perform the legacy check.
            if ( null === $matching_event_id ) {
                $matching_event_id = $search
                    ->get_matching_event_id(
                        $event->get( 'ical_uid' ),
                        $event->get( 'ical_feed_url' ),
                        $event->get( 'start' ),
                        ! empty( $recurrence )
                    );
            }
            if ( null === $matching_event_id ) {

                // =================================================
                // = Event was not found, so store it and the post =
                // =================================================
                $event->save();
                $count++;
            } else {
                // ======================================================
                // = Event was found, let's store the new event details =
                // ======================================================
                $uid_cal = $e->uid;
                if ( ! ai1ec_is_blank( $uid_cal ) ) {
                    $uid_cal_original = sprintf( $event->get_uid_pattern(), $matching_event_id );
                    if ( $uid_cal_original === $uid_cal ) {
                        //avoiding cycle import
                        //ignore the event, it belongs to site
                        unset( $events_in_db[$matching_event_id] );
                        continue;
                    }
                }

                // Update the post
                $post               = get_post( $matching_event_id );

                if ( null !== $post ) {
                    $post->post_title   = $event->get( 'post' )->post_title;
                    $post->post_content = $event->get( 'post' )->post_content;
                    wp_update_post( $post );

                    // Update the event
                    $event->set( 'post_id', $matching_event_id );
                    $event->set( 'post',    $post );
                    $event->save( true );
                    $count++;
                }
            }
            do_action( 'ai1ec_ics_event_saved', $event, $feed );

            // import not standard taxonomies.
            unset( $imported_cat[Ai1ec_Event_Taxonomy::CATEGORIES] );
            foreach ( $imported_cat as $tax_name => $ids ) {
                wp_set_post_terms( $event->get( 'post_id' ), array_keys( $ids ), $tax_name );
            }

            unset( $imported_tags[Ai1ec_Event_Taxonomy::TAGS] );
            foreach ( $imported_tags as $tax_name => $ids ) {
                wp_set_post_terms( $event->get( 'post_id' ), array_keys( $ids ), $tax_name );
            }

            // import the metadata used by ticket events

            $cost_type    = $e->x_cost_type;
            if ( $cost_type && false === ai1ec_is_blank( $cost_type ) ) {
                update_post_meta( $event->get( 'post_id' ), '_ai1ec_cost_type', $cost_type );
            }

            $api_event_id = $e->x_api_event_id;
            if ( $api_event_id && false === ai1ec_is_blank( $api_event_id ) ) {
                $api_event_id = $api_event_id;
            } else {
                $api_event_id = null;
            }

            $api_url = $e->x_api_url;
            if ( $api_url && false === ai1ec_is_blank( $api_url ) ) {
                $api_url = $api_url;
            } else {
                $api_url = null;
            }

            $checkout_url = $e->x_checkout_url;
            if ( $checkout_url && false === ai1ec_is_blank( $checkout_url ) ) {
                $checkout_url = $checkout_url;
            } else {
                $checkout_url = null;
            }

            $currency = $e->x_api_event_currency;
            if ( ! $currency || ai1ec_is_blank( $currency ) ) {
                $currency = null;
            }
            if ( $api_event_id || $api_url || $checkout_url || $currency ) {
                if ( ! isset( $api ) ) {
                    $api = $this->_registry->get( 'model.api.api-ticketing' );
                }
                $api->save_api_event_data( $event->get( 'post_id' ), $api_event_id, $api_url, $checkout_url, $currency );
            }

            $wp_images_url  = $e->x_wp_image_url;
            if ( $wp_images_url && false === ai1ec_is_blank( $wp_images_url ) ) {
                $images_arr = explode( ',', $wp_images_url );
                foreach ( $images_arr as $key => $value ) {
                    $images_arr[ $key ] = explode( ';', $value );
                }
                if ( count( $images_arr ) > 0 ) {
                    update_post_meta( $event->get( 'post_id' ), '_featured_image', $images_arr );
                }
            }

            unset( $events_in_db[$event->get( 'post_id' )] );
        } //close while iteration

        return array(
            'count'            => $count,
            'events_to_delete' => $events_in_db,
            'messages'         => $messages,
            'name'             => $feed_name,
        );

    }

    /**
     * Returns modified ical uid for google recurring edited events.
     *
     * @param array $e Vevent object.
     *
     * @return string ICAL uid.
     */
    protected function _get_ical_uid( $e ) {
        $ical_uid      = $e->uid;
        $recurrence_id = $e->recurrence_id;
        if ( '' !== $recurrence_id ) {
            $ical_uid = $recurrence_id . '-' . $ical_uid;
        }

        return $ical_uid;
    }

    /**
     * time_array_to_timestamp function
     *
     * Converts time array to time string.
     * Passed array: Array( 'year', 'month', 'day', ['hour', 'minute', 'second', ['tz']] )
     * Return int: UNIX timestamp in GMT
     *
     * @param array       $time            iCalcreator time property array
     *                                     (*full* format expected)
     * @param string      $def_timezone    Default time zone in case not defined
     *                                     in $time
     * @param null|string $forced_timezone Timezone to use instead of UTC.
     *
     * @return int UNIX timestamp
     **/
    protected function _time_array_to_datetime(
        array $date,
        array $time,
        $def_timezone,
        $forced_timezone = null
    ) {
        $timezone = $def_timezone;

        $date_time = $this->_registry->get( 'date.time' );

        if ( ! empty( $timezone ) ) {
            $parser = $this->_registry->get( 'date.timezone' );
            $timezone = $parser->get_name( $timezone );
            if ( false === $timezone ) {
                return false;
            }
        }

        // Set default timezone
        $date_time->set_timezone( $timezone );

        if ( ! isset( $time['hour'] ) ) {
            $time['hour'] = $time['minute'] = $time['second'] = 0;
        }

        $date_time
            ->set_date(
                $date['year'],
                $date['month'],
                $date['day']
            )
            ->set_time(
                $time['hour'],
                $time['minute'],
                $time['second']
            );

        // Set choosen timezone
        if ( null !== $forced_timezone) {
            $date_time->set_timezone( $forced_timezone );
        }

        return $date_time;
    }

    /**
     * Check if date-time specification has no (empty) time component.
     *
     * @param array $datetime Datetime array returned by iCalcreator.
     *
     * @return bool Timelessness.
     */
    protected function _is_timeless( array $datetime ) {
        $timeless = true;
        foreach ( array( 'hour', 'minute', 'second' ) as $field ) {
            $timeless &= (
                isset( $datetime[$field] ) &&
                0 != $datetime[$field]
                )
                ? false
                : true;
        }
        return $timeless;
    }

    /**
     * Parse importable feed timezone to sensible value.
     *
     * @param string $def_timezone Timezone value from feed.
     *
     * @return string Valid timezone name to use.
     */
    protected function _get_import_timezone( $def_timezone ) {
        $parser   = $this->_registry->get( 'date.timezone' );
        $timezone = $parser->get_name( $def_timezone );
        if ( false === $timezone ) {
            return 'sys.default';
        }
        return $timezone;
    }

    /**
     * _string_to_datetime function
     *
     * Converts time string "Y-m-d H:i:s" to DateTime object.
     * Passed array: Array( 'year', 'month', 'day', ['hour', 'minute', 'second', ['tz']] )
     * Return int: UNIX timestamp in GMT
     *
     * @param array       $time            iCalcreator time property array
     *                                     (*full* format expected)
     * @param string      $def_timezone    Default time zone in case not defined
     *                                     in $time
     * @param null|string $forced_timezone Timezone to use instead of UTC.
     *
     * @return int UNIX timestamp
     **/
    protected function _string_to_datetime(
        $time,
        $def_timezone,
        $forced_timezone = null
    ) {
        $date_time = null;
        if ( 0 === strcasecmp( $def_timezone, 'utc' ) &&
            null !== $forced_timezone ) {
            $date_time = $this->_registry->get( 'date.time',  $time, $forced_timezone );
        } else {
            $date_time = $this->_registry->get( 'date.time',  $time, $def_timezone );
        }
        return $date_time;
    }


    /**
     * Takes a comma-separated list of tags or categories.
     * If they exist, reuses
     * the existing ones. If not, creates them.
     *
     * The $imported_terms array uses keys to store values rather than values to
     * speed up lookups (using isset() insted of in_array()).
     *
     * @param string  $terms
     * @param array   $imported_terms
     * @param boolean $is_tag
     * @param boolean $use_name
     *
     * @return array
     */
    public function add_categories_and_tags(
        $terms,
        array $imported_terms,
        $is_tag,
        $use_name
    ) {
        $taxonomy       = $is_tag ? 'events_tags' : 'events_categories';
        $categories     = explode( ',', $terms );
        $event_taxonomy = $this->_registry->get( 'model.event.taxonomy' );

        foreach ( $categories as $cat_name ) {
            $cat_name = trim( $cat_name );
            if ( empty( $cat_name ) ) {
                continue;
            }
            $term = $event_taxonomy->initiate_term( $cat_name, $taxonomy, ! $use_name );
            if ( false !== $term ) {
                if ( ! isset( $imported_terms[$term['taxonomy']] ) ) {
                    $imported_terms[$term['taxonomy']] = array();
                }
                $imported_terms[$term['taxonomy']][$term['term_id']] = true;
            }
        }
        return $imported_terms;
    }

    /**
     * Remove the Ticket URL that maybe exists inside the field Description of the Event
     */
    protected function _remove_ticket_url( $description ) {
        return preg_replace( '/<p>[^<>]+<a[^<>]+class=[\'"]?ai1ec-ticket-url-exported[\'"]?[^<>]+>.[^<>]+<\/a>[\.\s]*<\/p>/'
                , ''
                , $description );
    }

/* (non-PHPdoc)
     * @see Ai1ec_Import_Export_Engine::export()
     */
    public function export( array $arguments, array $params = array() ) {
        throw new Exception( 'Export not supported' );
    }

    /**
     * Returns modified exclusions structure for given event.
     *
     * @param array           $e          Event object.
     * @param array           $exclusions Exclusions.
     * @param Ai1ec_Date_Time $start Date time object.
     *
     * @return array Modified exclusions structure.
     */
    protected function _add_recurring_events_exclusions( $e, $exclusions, $start ) {
        $recurrence_id = $e->recurrence_id;

        if ( '' === $recurrence_id ||
            ! preg_match('/^[0-9]{4}[0-1][0-9][0-3][0-9]/', $recurrence_id)) {
            return $exclusions;
        }

        $exclusions[$e->uid][] = $recurrence_id;
        return $exclusions;
    }

    /**
     * Strips Google duplicated events created when editing recurrent ones
     *
     * Code contributed by cmezzett (https://wordpress.org/support/profile/cmezzett)
     */
    protected function _normalize_google_uids ( array $calendar ) {

        foreach ( $calendar as $event ) {
            if ( strpos( $event->uid, '@google.com' ) !== false && strpos( $event->uid, '_R' ) !== false ) {
                preg_match( "/^(.*)_R.*@google.com$/i", $event->uid, $matches );
                $tmp_uid = $matches[1] . '@google.com';
                if ( ( $e = $this->_search_for_id( $tmp_uid, $calendar ) ) !== null ) {
                    $suspect = $calendar[$e];
                    if ( empty( $suspect->recurrence_id ) ) {
                        //error_log( 'Discarded UID without recurrence-id: ' . $suspect->uid . '; Object: ' . serialize( $suspect ) );
                        unset( $calendar[$e] );
                    }
                }
            }
        }

        return $calendar;
    }

    protected function _search_for_id( $id, $array ) {

        foreach ( $array as $key => $val ) {
            if ( $val->uid === $id ) {
                return $key;
            }
        }

        return null;
    }

}