<?php

namespace Glovario\Frontend;

use Glovario\Domain\BuiltinVariables;
use Glovario\Domain\Renderer;
use Glovario\Domain\VariableResolver;

defined( 'ABSPATH' ) || exit;

final class Shortcode {
	private $resolver;
	private $renderer;
	private $building_excerpt = false;

	public function __construct( VariableResolver $resolver, Renderer $renderer ) {
		$this->resolver = $resolver;
		$this->renderer = $renderer;
	}

	public function register() {
		add_shortcode( 'glvr', array( $this, 'render' ) );
		// WordPress strips every shortcode before trimming an automatic excerpt,
		// which left sentences like "Call us at ." Keep ours only while an
		// excerpt is built; it is then resolved with the rest of the content.
		add_filter( 'get_the_excerpt', array( $this, 'begin_excerpt' ), 9 );
		add_filter( 'get_the_excerpt', array( $this, 'end_excerpt' ), 11 );
		add_filter( 'strip_shortcodes_tagnames', array( $this, 'keep_in_excerpt' ) );
	}

	public function begin_excerpt( $excerpt ) {
		$this->building_excerpt = true;
		return $excerpt;
	}

	public function end_excerpt( $excerpt ) {
		$this->building_excerpt = false;
		return $excerpt;
	}

	public function keep_in_excerpt( $tags ) {
		return $this->building_excerpt ? array_values( array_diff( (array) $tags, array( 'glvr' ) ) ) : $tags;
	}

	public function render( $attributes ) {
		$attributes = shortcode_atts(
			array(
				'key'      => '',
				'fallback' => '',
				'format'   => BuiltinVariables::DEFAULT_DATE_FORMAT,
				'size'     => '',
			),
			is_array( $attributes ) ? $attributes : array(),
			'glvr'
		);
		$key     = sanitize_key( $attributes['key'] );
		$context = array(
			'source'     => 'shortcode',
			'image_size' => sanitize_key( $attributes['size'] ),
		);
		if ( BuiltinVariables::CURRENT_DATE_KEY === $key ) {
			$context['date_format'] = BuiltinVariables::sanitize_date_format( $attributes['format'] );
		}
		$resolved = $key ? $this->resolver->resolve( $key, $context ) : null;
		if ( ! $resolved ) {
			return esc_html( $attributes['fallback'] );
		}
		return $this->renderer->render( $resolved['value'], $resolved['variable']['type'], $resolved['context'] );
	}
}