<?php
/**
 * Render the request as html.
 *
 * @author     Time.ly Network Inc.
 * @since      2.0
 *
 * @package    AI1EC
 * @subpackage AI1EC.Http.Response.Render.Strategy
 */
class Ai1ec_Render_Strategy_Html extends Ai1ec_Http_Response_Render_Strategy {

    /**
     * Twig page content placeholder.
     */
    const CALENDAR_PLACEHOLDER = '<!-- AI1EC_PAGE_CONTENT_PLACEHOLDER -->';

    /**
     * @var string the event html.
     */
    protected $_html;

    /**
     * @var string The html for the footer of the event.
     */
    protected $_html_footer = '';

    /**
     * Caller identifier. Just for paranoid check in append_content method.
     * Expected 'calendar' or none.
     *
     * @var string
     */
    protected $_caller     = '';

    /**
     * Registers proper filters for content modifications.
     *
     * @param array $params Function params.
     *
     * @return void Method does not return.
     */
    public function render( array $params ) {
        $this->_html = $params['data'];
        if ( isset( $params['caller'] ) ) {
            $this->_caller = $params['caller'];
        }
        if ( isset( $params['footer'] ) ) {
            $this->_html_footer = $params['footer'];
        }
        if ( isset( $params['is_event'] ) ) {
            // Filter event post content, in single- and multi-post views
            add_filter( 'the_content', array( $this, 'event_content' ), PHP_INT_MAX - 1 );
            return;
        }
        // Replace page content - make sure it happens at (almost) the very end of
        add_filter( 'the_content', array( $this, 'append_content' ), PHP_INT_MAX - 1 );
    }

    /**
     * Append locally generated content to normal page content. By default,
     * first checks if we are in The Loop before outputting to prevent multiple
     * calendar display - unless setting is turned on to skip this check.
     * We should not append full calendar body to single event content as it
     * leads to "calendar" nesting if default calendar page contains calendar
     * shortcode.
     *
     * @param  string $content Post/Page content
     * @return string          Modified Post/Page content
     */
    public function append_content( $content ) {
        if (
            'calendar' === $this->_caller &&
            ! $this->_registry->get( 'calendar.state' )->append_content()
        ) {
            return $content;
        }
        $settings = $this->_registry->get( 'model.settings' );

        // Include any admin-provided page content in the placeholder specified in
        // the calendar theme template.
        if ( $settings->get( 'skip_in_the_loop_check' ) || in_the_loop() ) {
            $content = str_replace(
                self::CALENDAR_PLACEHOLDER,
                $content,
                $this->_html
            );
            $content .= $this->_html_footer;
        }
        return $content;
    }

    /**
     * event_content function
     *
     * Filter event post content by inserting relevant details of the event
     * alongside the regular post content.
     *
     * @param string $content Post/Page content
     *
     * @return string         Post/Page content
     **/
    public function event_content( $content ) {
        if ( ! $this->_registry->get( 'calendar.state' )->append_content() ) {
            $content = '';
        }
        $to_return = $this->_html . $content;
        if ( isset( $this->_html_footer ) ) {
            $to_return .= $this->_html_footer;
        }
        // Pass the orginal content to the filter so that it can be modified
        return apply_filters(
            'ai1ec_event_content',
            $to_return,
            $content
        );
    }

}