<?php
class Archivist_Parser {
	
	public $post;
	public $template;
	
	public function __construct( $post, $template ) {
		$this->post = $post;
		$this->template = $template;
	}
	
	private function replace_tags( $matches ) {
		return get_the_tag_list( "", $matches[ 1 ], "" );
	}
	
	private function replace_categories( $matches ) {
		return get_the_category_list( $matches[ 1 ] );
    }

	private function replace_post_meta_with_separator( $matches ) {
		$list = get_post_meta( $this->post->ID, $matches[ 1 ], false );
		return implode( $matches[ 2 ], $list );
	}
	
	private function replace_post_meta( $matches ) {
		return get_post_meta( $this->post->ID, $matches[ 1 ], true );
	}

	private function replace_acf_field( $matches ) {
		
		if ( ! function_exists( 'get_field' ) ) {
			return;
		}

		return get_field( $matches[ 1 ], $this->post->ID );
	}
	
	private function replace_date( $matches ) {
		return get_the_date( $matches[ 1 ] );
	}
	
	private function replace_thumbnails( $matches ) {
		$thumb = get_the_post_thumbnail( $this->post->ID, array( $matches[ 1 ], $matches[ 2 ] ) );
			
		if ( ! $thumb ) {
			$default_thumb = archivist::$settings[ 'default_thumb' ];
			if ( $default_thumb ) {
				$thumb = "<img src=\"$default_thumb\" alt=\"Archive Thumb\" width=\"" 
				       . $matches[ 1 ] 
				       . "\" height=\"" . $matches[ 2 ] . "\">";
			}
		}

		return $thumb;
	}
	
	public function render() {
		$this->template = str_replace( '%DATE%', get_the_date(), $this->template );
		$this->template = str_replace( '%TITLE%', get_the_title(), $this->template );
		$this->template = str_replace( '%AUTHOR%', get_the_author(), $this->template );
		$this->template = str_replace( '%TAGS%', get_the_tag_list(), $this->template );			
		$this->template = str_replace( '%PERMALINK%', get_permalink(), $this->template );
		$this->template = str_replace( '%EXCERPT%', get_the_excerpt(), $this->template );
		$this->template = str_replace( '%COMMENTS%', get_comments_number(), $this->template );
		$this->template = str_replace( '%CATEGORIES%', get_the_category_list(), $this->template );

		// categories with custom separator
		$this->template = preg_replace_callback(
		    '/%TAGS\|(.*)%/',
		    array( $this, 'replace_tags' ),
		 	$this->template
		 );

		// categories with custom separator
		$this->template = preg_replace_callback(
		    '/%CATEGORIES\|(.*)%/',
		    array( $this, 'replace_categories' ),
		 	$this->template
		 );

		// custom post meta with separator
        $this->template = preg_replace_callback(
            '/%POST_META\|(.*?)\|(.*)%/',
            array( $this, 'replace_post_meta_with_separator' ),
            $this->template
         );

		// custom post meta
		$this->template = preg_replace_callback(
		    '/%POST_META\|(.*)%/',
		    array( $this, 'replace_post_meta' ),
		 	$this->template
		 );
		
		// custom date format
		$this->template = preg_replace_callback(
		    '/%DATE\|(.*)%/',
		    array( $this, 'replace_date' ),
		 	$this->template
		 );

		// custom post thumbnails
		$this->template = preg_replace_callback(
		    '/%POST_THUMBNAIL\|(\d+)x(\d+)%/',
		    array( $this, 'replace_thumbnails' ),
		 	$this->template
		 );

		// acf field
		$this->template = preg_replace_callback(
		    '/%ACF\|(.*)%/',
		    array( $this, 'replace_acf_field' ),
		 	$this->template
		 );

		$this->template = apply_filters( 'archivist_template_render', $this->template, $this->post );
		
		return do_shortcode( $this->template );
	}
	
}