<?php

/**
 * Class MC4WP_Integration
 *
 * Base class for all integrations.
 *
 * Extend this class and implement the `add_hooks` method to get a settings page.
 *
 * @access public
 * @since 3.0
 * @abstract
 */
abstract class MC4WP_Integration
{
    /**
     * @var string Name of this integration.
     */
    public $name = '';

    /**
     * @var string Description
     */
    public $description = '';

    /**
     * @var string Slug, used as an unique identifier for this integration.
     */
    public $slug = '';

    /**
     * @var array Array of settings
     */
    public $options = array();

    /**
     * @var string Name attribute for the checkbox element. Will be created from slug if empty.
     */
    protected $checkbox_name = '';

    /**
     * @var string[]
     */
    public $checkbox_classes = array();

    /**
     * @var string[]
     */
    public $wrapper_classes = array();

    /**
     * Constructor
     *
     * @param string $slug
     * @param array $options
     */
    public function __construct($slug, array $options)
    {
        $this->slug    = $slug;
        $this->options = $this->parse_options($options);

        // if checkbox name is not set, set a good custom value
        if ($this->checkbox_name === '') {
            $this->checkbox_name = '_mc4wp_subscribe_' . $this->slug;
        }
    }

    /**
     * Return array of default options
     *
     * @return array
     */
    protected function get_default_options()
    {
        return array(
            'css'               => 0,
            'double_optin'      => 1,
            'enabled'           => 0,
            'implicit'          => 0,
            'label'             => __('Sign me up for the newsletter!', 'mailchimp-for-wp'),
            'lists'             => array(),
            'precheck'          => 0,
            'replace_interests' => 0,
            'update_existing'   => 0,
            'wrap_p'            => 1,
        );
    }

    /**
     * @param array $options
     *
     * @return array
     */
    protected function parse_options(array $options)
    {
        $slug = $this->slug;

        $default_options = $this->get_default_options();
        $options         = array_merge($default_options, $options);

        /**
         * Filters options for a specific integration
         *
         * The dynamic portion of the hook, `$slug`, refers to the slug of the ingration.
         *
         * @param array $integration_options
         */
        return (array) apply_filters('mc4wp_integration_' . $slug . '_options', $options);
    }

    /**
     * Initialize the integration
     */
    public function initialize()
    {
        $this->add_required_hooks();
        $this->add_hooks();
    }

    /**
     * Adds the required hooks for core functionality, like adding checkbox reset CSS.
     */
    protected function add_required_hooks()
    {
        if ($this->options['css'] && ! $this->options['implicit']) {
            add_action('wp_head', array( $this, 'print_css_reset' ));
        }
    }

    /**
     * Was integration triggered?
     *
     * Will always return true when integration is implicit. Otherwise, will check value of checkbox.
     *
     * @param int $object_id Useful when overriding method. (optional)
     * @return bool
     */
    public function triggered($object_id = null)
    {
        return $this->options['implicit'] || $this->checkbox_was_checked();
    }

    /**
     * Adds the hooks which are specific to this integration
     */
    abstract protected function add_hooks();

    /**
     * Print CSS reset
     *
     * @hooked `wp_head`
     */
    public function print_css_reset()
    {
        $css = file_get_contents(MC4WP_PLUGIN_DIR . '/assets/css/checkbox-reset.css');

        // replace selector by integration specific selector so the css affects just this checkbox
        $css = str_ireplace('__INTEGRATION_SLUG__', $this->slug, $css);

        printf('<style>%s</style>', $css);
    }

    /**
     * Get the text for the label element
     *
     * @return string
     */
    public function get_label_text()
    {
        $integration = $this;
        $label       = $this->options['label'];

        if (empty($label)) {
            $default_options = $this->get_default_options();
            $label           = $default_options['label'];
        }

        /**
         * Filters the checkbox label
         *
         * @since 3.0
         *
         * @param string $label
         * @param MC4WP_Integration $integration
         * @ignore
         */
        $label = (string) apply_filters('mc4wp_integration_checkbox_label', $label, $integration);
        return $label;
    }

    /**
     * Was the integration checkbox checked?
     *
     * @return bool
     */
    public function checkbox_was_checked()
    {
        $data = $this->get_data();
        return isset($data[ $this->checkbox_name ]) && (int) $data[ $this->checkbox_name ] === 1;
    }

    /**
     * Get a string of attributes for the HTML element wrapping the checkbox + label
     *
     * @return string
     */
    protected function get_wrapper_attributes()
    {
        $html_attrs = array(
            'class' => sprintf('mc4wp-checkbox mc4wp-checkbox-%s %s', $this->slug, join(' ', $this->wrapper_classes)),
        );
        return $this->array_to_attr_string($html_attrs);
    }

    /**
     * Get a string of attributes for the checkbox element.
     *
     * @return string
     */
    protected function get_checkbox_attributes()
    {
        $integration = $this;
        $slug        = $this->slug;

        $attributes = array();

        if ($this->options['precheck']) {
            $attributes['checked'] = 'checked';
        }

        if (! empty($this->checkbox_classes)) {
            $attributes['class'] = join(' ', $this->checkbox_classes);
        }

        /**
         * Filters the attributes array.
         *
         * @param array $attributes
         * @param MC4WP_Integration $integration
         * @ignore
         */
        $attributes = (array) apply_filters('mc4wp_integration_checkbox_attributes', $attributes, $integration);

        /**
         * Filters the attributes array.
         *
         * The dynamic portion of the hook, `$slug`, refers to the slug for this integration.
         *
         * @param array $attributes
         * @param MC4WP_Integration $integration
         * @ignore
         */
        $attributes = (array) apply_filters('mc4wp_integration_' . $slug . '_checkbox_attributes', $attributes, $integration);

        return $this->array_to_attr_string($attributes);
    }

    /**
     * Outputs a checkbox
     */
    public function output_checkbox()
    {
        echo $this->get_checkbox_html();
    }

    /**
     * Get HTML string for the checkbox row (incl. wrapper, label, etc.)
     *
     * @return string
     */
    public function get_checkbox_html()
    {
        $show_checkbox    = empty($this->options['implicit']);
        $integration_slug = $this->slug;

        /**
         * Filters whether to show the sign-up checkbox for this integration.
         *
         * @param bool $show_checkbox
         * @param string $integration_slug
         */
        $show_checkbox = (bool) apply_filters('mc4wp_integration_show_checkbox', $show_checkbox, $integration_slug);
        if (! $show_checkbox) {
            return '';
        }

        ob_start();

        echo sprintf('<!-- Mailchimp for WordPress v%s - https://www.mc4wp.com/ -->', MC4WP_VERSION);

        /** @ignore */
        do_action('mc4wp_integration_before_checkbox_wrapper', $this);

        /** @ignore */
        do_action('mc4wp_integration_' . $this->slug . '_before_checkbox_wrapper', $this);

        $wrapper_tag   = $this->options['wrap_p'] ? 'p' : 'span';
        $wrapper_attrs = $this->get_wrapper_attributes();

        // Hidden field to make sure "0" is sent to server
        echo sprintf('<input type="hidden" name="%s" value="0" />', esc_attr($this->checkbox_name));
        echo sprintf('<%s %s>', $wrapper_tag, $wrapper_attrs);
        echo '<label>';
        echo sprintf('<input type="checkbox" name="%s" value="1" %s />', esc_attr($this->checkbox_name), $this->get_checkbox_attributes());
        echo sprintf('<span>%s</span>', $this->get_label_text());
        echo '</label>';
        echo sprintf('</%s>', $wrapper_tag);

        /** @ignore */
        do_action('mc4wp_integration_after_checkbox_wrapper', $this);

        /** @ignore */
        do_action('mc4wp_integration_' . $this->slug . '_after_checkbox_wrapper', $this);
        echo '<!-- / Mailchimp for WordPress -->';

        $html = ob_get_clean();
        return $html;
    }

    /**
     * Get the selected Mailchimp lists
     *
     * @return array Array of List ID's
     */
    public function get_lists()
    {
        $data        = $this->get_data();
        $integration = $this;
        $slug        = $this->slug;

        // get checkbox lists options
        $lists = $this->options['lists'];

        // get lists from request, if set.
        if (! empty($data['_mc4wp_lists'])) {
            $lists = $data['_mc4wp_lists'];

            // ensure lists is an array
            if (! is_array($lists)) {
                $lists = explode(',', $lists);
                $lists = array_map('trim', $lists);
            }
        }

        /**
         * Allow plugins to filter final lists value. This filter is documented elsewhere.
         *
         * @since 2.0
         * @see MC4WP_Form::get_lists
         * @ignore
         */
        $lists = (array) apply_filters('mc4wp_lists', $lists);

        /**
         * Filters the Mailchimp lists this integration should subscribe to
         *
         * @since 3.0
         *
         * @param array $lists
         * @param MC4WP_Integration $integration
         */
        $lists = (array) apply_filters('mc4wp_integration_lists', $lists, $integration);

        /**
         * Filters the Mailchimp lists a specific integration should subscribe to
         *
         * The dynamic portion of the hook, `$slug`, refers to the slug of the integration.
         *
         * @since 3.0
         *
         * @param array $lists
         * @param MC4WP_Integration $integration
         */
        $lists = (array) apply_filters('mc4wp_integration_' . $slug . '_lists', $lists, $integration);

        return $lists;
    }

    /**
     * Makes a subscription request
     *
     * @param array $data
     * @param int $related_object_id
     *
     * @return boolean
     */
    protected function subscribe(array $data, $related_object_id = 0)
    {
        $integration = $this;
        $slug        = $this->slug;
        $mailchimp   = new MC4WP_MailChimp();
        $log         = $this->get_log();
        $list_ids    = $this->get_lists();

        /** @var MC4WP_MailChimp_Subscriber $subscriber */
        $subscriber = null;
        $result     = false;

        // validate lists
        if (empty($list_ids)) {
            $log->warning(sprintf('%s > No Mailchimp lists were selected', $this->name));
            return false;
        }

        /**
         * Filters data for integration requests.
         *
         * @param array $data
         */
        $data = apply_filters('mc4wp_integration_data', $data);

        /**
         * Filters data for a specific integration request.
         *
         * The dynamic portion of the hook, `$slug`, refers to the integration slug.
         *
         * @param array $data
         * @param int $related_object_id
         */
        $data = apply_filters("mc4wp_integration_{$slug}_data", $data, $related_object_id);

        $email_type = mc4wp_get_email_type();

        $mapper = new MC4WP_List_Data_Mapper($data, $list_ids);

        /** @var MC4WP_MailChimp_Subscriber[] $map */
        $map = $mapper->map();

        foreach ($map as $list_id => $subscriber) {
            $subscriber->status     = $this->options['double_optin'] ? 'pending' : 'subscribed';
            $subscriber->email_type = $email_type;
            $subscriber->ip_signup  = mc4wp_get_request_ip_address();

            /** @ignore (documented elsewhere) */
            $subscriber = apply_filters('mc4wp_subscriber_data', $subscriber);
            if (! $subscriber instanceof MC4WP_MailChimp_Subscriber) {
                continue;
            }

            /**
             * Filters subscriber data before it is sent to Mailchimp. Only fires for integration requests.
             *
             * @param MC4WP_MailChimp_Subscriber $subscriber
             */
            $subscriber = apply_filters('mc4wp_integration_subscriber_data', $subscriber);
            if (! $subscriber instanceof MC4WP_MailChimp_Subscriber) {
                continue;
            }

            /**
             * Filters subscriber data before it is sent to Mailchimp. Only fires for integration requests.
             *
             * The dynamic portion of the hook, `$slug`, refers to the integration slug.
             *
             * @param MC4WP_MailChimp_Subscriber $subscriber
             * @param int $related_object_id
             */
            $subscriber = apply_filters("mc4wp_integration_{$slug}_subscriber_data", $subscriber, $related_object_id);
            if (! $subscriber instanceof MC4WP_MailChimp_Subscriber) {
                continue;
            }

            $result = $mailchimp->list_subscribe($list_id, $subscriber->email_address, $subscriber->to_array(), $this->options['update_existing'], $this->options['replace_interests']);
        }

        // if result failed, show error message
        if (! $result) {
            // log error
            if ((int) $mailchimp->get_error_code() === 214) {
                $log->warning(sprintf('%s > %s is already subscribed to the selected list(s)', $this->name, $subscriber->email_address));
            } else {
                $log->error(sprintf('%s > Mailchimp API Error: %s', $this->name, $mailchimp->get_error_message()));
            }

            // bail
            return false;
        }

        $log->info(sprintf('%s > Successfully subscribed %s', $this->name, $subscriber->email_address));

        /**
         * Runs right after someone is subscribed using an integration
         *
         * @since 3.0
         *
         * @param MC4WP_Integration $integration
         * @param string $email_address
         * @param array $merge_vars
         * @param MC4WP_MailChimp_Subscriber[] $subscriber_data
         * @param int $related_object_id
         */
        do_action('mc4wp_integration_subscribed', $integration, $subscriber->email_address, $subscriber->merge_fields, $map, $related_object_id);

        return true;
    }

    /**
     * Are the required dependencies for this integration installed?
     *
     * @return bool
     */
    public function is_installed()
    {
        return false;
    }

    /**
     * Which UI elements should we show on the settings page for this integration?
     *
     * @return array
     */
    public function get_ui_elements()
    {
        return array_keys($this->options);
    }

    /**
     * Does integration have the given UI element?
     *
     * @param string $element
     * @return bool
     */
    public function has_ui_element($element)
    {
        $elements = $this->get_ui_elements();
        return in_array($element, $elements, true);
    }

    /**
     * Return a string to the admin settings page for this object (if any)
     *
     * @param int $object_id
     * @return string
     */
    public function get_object_link($object_id)
    {
        return '';
    }

    /**
     * Get the data for this integration request
     *
     * By default, this will return a combination of all $_GET and $_POST parameters.
     * Override this method if you need data from somewhere else.
     *
     * This data should contain the value of the checkbox (required)
     * and the lists to which should be subscribed (optional)
     *
     * @see MC4WP_Integration::$checkbox_name
     * @see MC4WP_Integration::get_lists
     * @see MC4WP_Integration::checkbox_was_checked
     *
     * @return array
     */
    public function get_data()
    {
        return array_merge((array) $_GET, (array) $_POST);
    }

    /**
     * Converts an array to an attribute string (foo="bar" bar="foo") with escaped values.
     *
     * @param array $attrs
     * @return string
     */
    protected function array_to_attr_string(array $attrs)
    {
        $str = '';
        foreach ($attrs as $key => $value) {
            $str .= sprintf('%s="%s" ', $key, esc_attr($value));
        }
        return $str;
    }

    /**
     * @return MC4WP_Debug_Log
     */
    protected function get_log()
    {
        return mc4wp('log');
    }

    /**
     * @return MC4WP_API_V3
     */
    protected function get_api()
    {
        return mc4wp('api');
    }
}