<?php if ( ! defined( 'ABSPATH' ) ) exit;

/**
 * Class NF_Abstracts_ActionNewsletter
 */
abstract class NF_Abstracts_ActionNewsletter extends NF_Abstracts_Action
{
    /**
     * @var array
     */
    protected $_tags = array( 'newsletter' );

    /**
     * @var string
     */
    protected $_timing = 'normal';

    /**
     * @var int
     */
    protected $_priority = '10';

    protected $_settings = array();

    protected $_transient = '';

    protected $_transient_expiration = '';

    protected $_setting_labels = array(
        'list'   => 'List',
        'fields' => 'List Field Mapping',
        'groups' => 'Interest Groups',
    );

    /**
     * Constructor
     */
    public function __construct()
    {
        parent::__construct();

        if( ! $this->_transient ){
            $this->_transient = $this->get_name() . '_newsletter_lists';
        }

        /**
         * Ajax call handled in '_get_lists', but bulk of work could be done in
         * the NewsLetter class that extends this class
         */
        add_action( 'wp_ajax_nf_' . $this->_name . '_get_lists', array( $this, '_get_lists' ) );

        $this->get_list_settings();
    }

    /*
    * PUBLIC METHODS
    */

    public function save( $action_settings )
    {

    }

    public function process( $action_settings, $form_id, $data )
    {

    }

    public function _get_lists()
    {
        check_ajax_referer( 'ninja_forms_builder_nonce', 'security' );

        $lists = $this->get_lists();

        if( $this->is_failed_lookup( $lists ) ){

            /*
             * The lookup did not produce a usable list of lists. Report that
             * rather than answering with an empty list, which the builder
             * cannot tell apart from a real answer.
             */
            echo wp_json_encode( array( 'lists' => array(), 'error' => $this->get_list_lookup_message() ) );

            wp_die();
        }

        array_unshift( $lists, array( 'value' => 0, 'label' => '-', 'fields' => array(), 'groups' => array() ) );

        $this->cache_lists( $lists );

        echo wp_json_encode( array( 'lists' => $lists, 'error' => '' ) );

        wp_die(); // this is required to terminate immediately and return a proper response
    }

    /*
     * PROTECTED METHODS
     */

    abstract protected function get_lists();

    /**
     * Did this lookup fail to produce a usable list of lists?
     *
     * An empty result, or a result holding nothing but the placeholder entry,
     * means the provider could not be reached or refused the request. It is
     * never a real answer, and must not be cached or shown as one.
     *
     * @param mixed $lists
     * @return bool
     */
    protected function is_failed_lookup( $lists )
    {
        if( ! is_array( $lists ) || empty( $lists ) ) return TRUE;

        if( 1 === count( $lists ) ){

            $only = reset( $lists );

            if( isset( $only[ 'value' ] ) && 0 == $only[ 'value' ] ) return TRUE;
        }

        return FALSE;
    }

    /**
     * Explain to the person why their lists could not be loaded.
     *
     * Add-ons override this to name their own service and, where they can,
     * the actual reason.
     *
     * @return string
     */
    protected function get_list_lookup_message()
    {
        return esc_html__( 'Your lists could not be loaded. The connection to this service may need to be refreshed.', 'ninja-forms' );
    }

    /*
     * PRIVATE METHODS
     */

    private function get_list_settings()
    {
        $label_defaults = array(
            'list'   => 'List',
            'fields' => 'List Field Mapping',
            'groups' => 'Interest Groups',
        );
        $labels = array_merge( $label_defaults, $this->_setting_labels );

        $prefix = $this->get_name();

        $lists = get_transient( $this->_transient );

        /*
         * A cached failure is not an answer. Sites that cached a blank list
         * before this was fixed ask the provider again instead of serving that
         * blank result forever.
         */
        if( $this->is_failed_lookup( $lists ) ) {
            $lists = $this->get_lists();
            $this->cache_lists( $lists );
        }

        $lookup_failed = $this->is_failed_lookup( $lists );

        if( $lookup_failed ) $lists = array();

        $label = $labels[ 'list' ] . ' <a class="js-newsletter-list-update extra"><span class="dashicons dashicons-update"></span></a>';

        /*
         * The field is always offered, even when the lists could not be
         * loaded, so the person sees a control and a reason rather than a
         * settings panel with the list silently missing from it.
         */
        if( $lookup_failed ){
            $label .= '<span class="nf-setting-error nf-newsletter-list-error">' . $this->get_list_lookup_message() . '</span>';
        }

        $this->_settings[ $prefix . 'newsletter_list' ] = array(
            'name' => 'newsletter_list',
            'type' => 'select',
            'label' => $label,
            'width' => 'full',
            'group' => 'primary',
            'value' => '0',
            'options' => array(),
        );

        $fields = array();
        foreach( $lists as $list ) {
            $this->_settings[ $prefix . 'newsletter_list' ][ 'options' ][] = $list;

            //Check to see if list has fields array set.
            if ( isset( $list[ 'fields' ] ) ) {

                foreach ( $list[ 'fields' ] as $field ) {
                    $name = $list[ 'value' ] . '_' . $field[ 'value' ];
                    $fields[] = array(
                        'name' => $name,
                        'type' => 'textbox',
                        'label' => $field[ 'label' ],
                        'width' => 'full',
                        'use_merge_tags' => array(
                            'exclude' => array(
                                'user', 'post', 'system', 'querystrings'
                            )
                        )
                    );
                }
            }
        }

        $this->_settings[ $prefix . 'newsletter_list_fields' ] = array(
            'name' => 'newsletter_list_fields',
            'label' => esc_html__( 'List Field Mapping', 'ninja-forms' ),
            'type' => 'fieldset',
            'group' => 'primary',
            'settings' => array()
        );

        $this->_settings[ $prefix . 'newsletter_list_groups' ] = array(
            'name' => 'newsletter_list_groups',
            'label' => esc_html__( 'Interest Groups', 'ninja-forms' ),
            'type' => 'fieldset',
            'group' => 'primary',
            'settings' => array()
        );
    }

    private function cache_lists( $lists )
    {
        // A failed lookup is never remembered; the next attempt asks again.
        if( $this->is_failed_lookup( $lists ) ) return;

        set_transient( $this->_transient, $lists, $this->_transient_expiration );
    }
}