<?php

/**
 * Gets WP-Cron schedules.
 *
 * ## EXAMPLES
 *
 *     # List available cron schedules
 *     $ wp cron schedule list
 *     +------------+-------------+----------+
 *     | name       | display     | interval |
 *     +------------+-------------+----------+
 *     | hourly     | Once Hourly | 3600     |
 *     | twicedaily | Twice Daily | 43200    |
 *     | daily      | Once Daily  | 86400    |
 *     +------------+-------------+----------+
 */
class Cron_Schedule_Command extends WP_CLI_Command {

    private $fields = array(
        'name',
        'display',
        'interval',
    );

    /**
     * List available cron schedules.
     *
     * ## OPTIONS
     *
     * [--fields=<fields>]
     * : Limit the output to specific object fields.
     *
     * [--field=<field>]
     * : Prints the value of a single field for each schedule.
     *
     * [--format=<format>]
     * : Render output in a particular format.
     * ---
     * default: table
     * options:
     *   - table
     *   - csv
     *   - ids
     *   - json
     *   - yaml
     * ---
     *
     * ## AVAILABLE FIELDS
     *
     * These fields will be displayed by default for each cron schedule:
     *
     * * name
     * * display
     * * interval
     *
     * There are no additional fields.
     *
     * ## EXAMPLES
     *
     *     # List available cron schedules
     *     $ wp cron schedule list
     *     +------------+-------------+----------+
     *     | name       | display     | interval |
     *     +------------+-------------+----------+
     *     | hourly     | Once Hourly | 3600     |
     *     | twicedaily | Twice Daily | 43200    |
     *     | daily      | Once Daily  | 86400    |
     *     +------------+-------------+----------+
     *
     *     # List id of available cron schedule
     *     $ wp cron schedule list --fields=name --format=ids
     *     hourly twicedaily daily
     *
     * @subcommand list
     */
    public function list_( $args, $assoc_args ) {
        $formatter = $this->get_formatter( $assoc_args );

        $schedules = self::get_schedules();

        if ( 'ids' === $formatter->format ) {
            echo implode( ' ', wp_list_pluck( $schedules, 'name' ) );
        } else {
            $formatter->display_items( $schedules );
        }
    }

    /**
     * Callback function to format a cron schedule.
     *
     * @param array $schedule The schedule.
     * @param string $name The schedule name.
     * @return array The formatted schedule.
     */
    protected static function format_schedule( array $schedule, $name ) {
        $schedule['name'] = $name;
        return $schedule;
    }

    /**
    * Return a list of the cron schedules sorted according to interval.
    *
    * @return array The array of cron schedules. Each schedule is itself an array.
    */
    protected static function get_schedules() {
        $schedules = wp_get_schedules();
        if ( ! empty( $schedules ) ) {
            uasort( $schedules, 'Cron_Schedule_Command::sort' );
            $schedules = array_map( 'Cron_Schedule_Command::format_schedule', $schedules, array_keys( $schedules ) );
        }
        return $schedules;
    }

    /**
     * Callback function to sort the cron schedule array by interval.
     *
     */
    protected static function sort( array $a, array $b ) {
        return $a['interval'] - $b['interval'];
    }

    private function get_formatter( &$assoc_args ) {
        return new \WP_CLI\Formatter( $assoc_args, $this->fields, 'schedule' );
    }
}