Changes out the Woocommerce Bookings date picker fields for a nice dropdown showing only available dates

Woocommerce Bookings Dropdown

<?php
/*
Plugin Name: Woocommerce Bookings Dropdown
Description: Swaps the date picker for a dropdown of dates
Version: 1.0.0
Author: Webby Scots
Author URI: http://webbyscots.com/
*/
$wswp_dates_built = false;
add_filter('booking_form_fields','wswp_booking_form_fields');

function wswp_booking_form_fields($fields) {

    global $wswp_dates_built;
    $i = 0;
    foreach($fields as $field) {
        $new_fields[$i] = $field;
        if ($field['type'] == "date-picker" && $wswp_dates_built === false)
        {
            $new_fields[$i]['class'] = array('picker-hidden');
            $i++;
            $new_fields[$i] = $field;
            $new_fields[$i]['type'] = "select";
            $new_fields[$i]['options'] = wswp_build_options($field['availability_rules'][0]);
            $new_fields[$i]['class'] = array('picker-chooser');
        }
        $i++;
    }
    return $new_fields;
}

function wswp_build_options($rules,$building = false) {
    global $wswp_dates_built;
    $dates = array();
    foreach($rules as $dateset) {
        if ($dateset[0] == "custom") {
            $year = reset(array_keys($dateset[1]));
            $month = reset(array_keys($dateset[1][$year]));
            $day = reset(array_keys($dateset[1][$year][$month]));
            $dtime = strtotime($year."-".$month."-".$day);
            $dates[$dtime] = date("d/m/Y",$dtime);
        }

    }
    ksort($dates);
    foreach($dates as $key => $date) {
        $dates[date("Y-m-d",$key)] = $date;
        unset($dates[$key]);
    }
    $wswp_dates_built = true;
    return $dates;
}

add_action('wp_footer','wswp_css_js');

function wswp_css_js() {
    //adding in footer as not enough to justify new stylesheet and js file
    ?><style type="text/css">
        .picker-hidden .picker,.picker-hidden legend {
            display:none;
        }
        </style>
        <script type='text/javascript'>
            jQuery(function($) {
                $(".picker-chooser").insertBefore('.wc-bookings-date-picker-date-fields');
                $("select#wc_bookings_field_start_date").on('change', function() {
				var selectedDate = $(this).val()
				var selectedDateBreakdown = selectedDate.split("-");

				$( "input[name*='wc_bookings_field_start_date_year']" ).val( selectedDateBreakdown[0] );
				$( "input[name*='wc_bookings_field_start_date_month']" ).val( selectedDateBreakdown[1] );
				$( "input[name*='wc_bookings_field_start_date_day']" ).val( selectedDateBreakdown[2] );
			});
            });

            </script>
            <?php
}

Thanks for the gist!

Note that this only populates the select box with Range Type: Date Range rules rather than Range Type: Range of Days/Weeks/Months rules. This doesn't throw errors but simply returns a blank array. Nevertheless, this is a great boost on how to extend WooCommerce Bookings when there's precious little information elsewhere.

doffs cap