<?php

require_once( AMP__DIR__ . '/includes/utils/class-amp-dom-utils.php' );
require_once( AMP__DIR__ . '/includes/utils/class-amp-html-utils.php' );
require_once( AMP__DIR__ . '/includes/utils/class-amp-string-utils.php' );

require_once( AMP__DIR__ . '/includes/class-amp-content.php' );

require_once( AMP__DIR__ . '/includes/sanitizers/class-amp-blacklist-sanitizer.php' );
require_once( AMP__DIR__ . '/includes/sanitizers/class-amp-img-sanitizer.php' );
require_once( AMP__DIR__ . '/includes/sanitizers/class-amp-video-sanitizer.php' );
require_once( AMP__DIR__ . '/includes/sanitizers/class-amp-iframe-sanitizer.php' );
require_once( AMP__DIR__ . '/includes/sanitizers/class-amp-audio-sanitizer.php' );

require_once( AMP__DIR__ . '/includes/embeds/class-amp-twitter-embed.php' );
require_once( AMP__DIR__ . '/includes/embeds/class-amp-youtube-embed.php' );
require_once( AMP__DIR__ . '/includes/embeds/class-amp-gallery-embed.php' );
require_once( AMP__DIR__ . '/includes/embeds/class-amp-instagram-embed.php' );
require_once( AMP__DIR__ . '/includes/embeds/class-amp-vine-embed.php' );
require_once( AMP__DIR__ . '/includes/embeds/class-amp-facebook-embed.php' );

class AMP_Post_Template {
	const SITE_ICON_SIZE = 32;
	const CONTENT_MAX_WIDTH = 600;

	private $template_dir;
	private $data;

	public function __construct( $post_id ) {
		$this->template_dir = apply_filters( 'amp_post_template_dir', AMP__DIR__ . '/templates' );

		$this->ID = $post_id;
		$this->post = get_post( $post_id );

		$content_max_width = self::CONTENT_MAX_WIDTH;
		if ( isset( $GLOBALS['content_width'] ) && $GLOBALS['content_width'] > 0 ) {
			$content_max_width = $GLOBALS['content_width'];
		}
		$content_max_width = apply_filters( 'amp_content_max_width', $content_max_width );

		$this->data = array(
			'content_max_width' => $content_max_width,

			'document_title' => function_exists( 'wp_get_document_title' ) ? wp_get_document_title() : wp_title( '', false ), // back-compat with 4.3
			'canonical_url' => get_permalink( $post_id ),
			'home_url' => home_url(),
			'blog_name' => get_bloginfo( 'name' ),

			'site_icon_url' => apply_filters( 'amp_site_icon_url', function_exists( 'get_site_icon_url' ) ? get_site_icon_url( self::SITE_ICON_SIZE ) : '' ),
			'placeholder_image_url' => amp_get_asset_url( 'images/placeholder-icon.png' ),

			'amp_runtime_script' => 'https://cdn.ampproject.org/v0.js',
			'amp_component_scripts' => array(),

			/**
			 * Add amp-analytics tags.
			 *
			 * This filter allows you to easily insert any amp-analytics tags without needing much heavy lifting.
			 *
			 * @since 0.4
			 *.
			 * @param	array	$analytics	An associative array of the analytics entries we want to output. Each array entry must have a unique key, and the value should be an array with the following keys: `type`, `attributes`, `script_data`. See readme for more details.
			 * @param	object	$post	The current post.
			 */
			'amp_analytics' => apply_filters( 'amp_post_template_analytics', array(), $this->post ),
		);

		$this->build_post_content();
		$this->build_post_data();

		$this->data = apply_filters( 'amp_post_template_data', $this->data, $this->post );
	}

	public function get( $property, $default = null ) {
		if ( isset( $this->data[ $property ] ) ) {
			return $this->data[ $property ];
		} else {
			_doing_it_wrong( __METHOD__, sprintf( __( 'Called for non-existant key ("%s").', 'amp' ), esc_html( $property ) ), '0.1' );
		}

		return $default;
	}

	public function load() {
		$this->load_parts( array( 'single' ) );
	}

	public function load_parts( $templates ) {
		foreach ( $templates as $template ) {
			$file = $this->get_template_path( $template );
			$this->verify_and_include( $file, $template );
		}
	}

	private function get_template_path( $template ) {
		return sprintf( '%s/%s.php', $this->template_dir, $template );
	}

	private function add_data( $data ) {
		$this->data = array_merge( $this->data, $data );
	}

	private function add_data_by_key( $key, $value ) {
		$this->data[ $key ] = $value;
	}

	private function merge_data_for_key( $key, $value ) {
		if ( is_array( $this->data[ $key ] ) ) {
			$this->data[ $key ] = array_merge( $this->data[ $key ], $value );
		} else {
			$this->add_data_by_key( $key, $value );
		}
	}

	private function build_post_data() {
		$post_title = get_the_title( $this->ID );
		$post_publish_timestamp = get_the_date( 'U', $this->ID );
		$post_modified_timestamp = get_post_modified_time( 'U', false, $this->post );
		$post_author = get_userdata( $this->post->post_author );

		$this->add_data( array(
			'post' => $this->post,
			'post_id' => $this->ID,
			'post_title' => $post_title,
			'post_publish_timestamp' => $post_publish_timestamp,
			'post_modified_timestamp' => $post_modified_timestamp,
			'post_author' => $post_author,
		) );

		$metadata = array(
			'@context' => 'http://schema.org',
			'@type' => 'BlogPosting',
			'mainEntityOfPage' => $this->get( 'canonical_url' ),
			'publisher' => array(
				'@type' => 'Organization',
				'name' => $this->get( 'blog_name' ),
			),
			'headline' => $post_title,
			'datePublished' => date( 'c', $post_publish_timestamp ),
			'dateModified' => date( 'c', $post_modified_timestamp ),
			'author' => array(
				'@type' => 'Person',
				'name' => $post_author->display_name,
			),
		);

		$site_icon_url = $this->get( 'site_icon_url' );
		if ( $site_icon_url ) {
			$metadata['publisher']['logo'] = array(
				'@type' => 'ImageObject',
				'url' => $site_icon_url,
				'height' => self::SITE_ICON_SIZE,
				'width' => self::SITE_ICON_SIZE,
			);
		}

		$image_metadata = $this->get_post_image_metadata();
		if ( $image_metadata ) {
			$metadata['image'] = $image_metadata;
		}

		$this->add_data_by_key( 'metadata', apply_filters( 'amp_post_template_metadata', $metadata, $this->post ) );
	}

	private function build_post_content() {
		$amp_content = new AMP_Content( $this->post->post_content,
			apply_filters( 'amp_content_embed_handlers', array(
				'AMP_Twitter_Embed_Handler' => array(),
				'AMP_YouTube_Embed_Handler' => array(),
				'AMP_Instagram_Embed_Handler' => array(),
				'AMP_Vine_Embed_Handler' => array(),
				'AMP_Facebook_Embed_Handler' => array(),
				'AMP_Gallery_Embed_Handler' => array(),
			), $this->post ),
			apply_filters( 'amp_content_sanitizers', array(
				 'AMP_Blacklist_Sanitizer' => array(),
				 'AMP_Img_Sanitizer' => array(),
				 'AMP_Video_Sanitizer' => array(),
				 'AMP_Audio_Sanitizer' => array(),
				 'AMP_Iframe_Sanitizer' => array(
					 'add_placeholder' => true,
				 ),
			), $this->post ),
			array(
				'content_max_width' => $this->get( 'content_max_width' ),
			)
		);

		$this->add_data_by_key( 'post_amp_content', $amp_content->get_amp_content() );
		$this->merge_data_for_key( 'amp_component_scripts', $amp_content->get_amp_scripts() );
	}

	/**
	 * Grabs featured image or the first attached image for the post
	 *
	 * TODO: move to a utils class?
	 */
	private function get_post_image_metadata() {
		$post_image_meta = null;
		$post_image_id = false;

		if ( has_post_thumbnail( $this->ID ) ) {
			$post_image_id = get_post_thumbnail_id( $this->ID );
		} else {
			$attached_image_ids = get_posts( array(
				'post_parent' => $this->ID,
				'post_type' => 'attachment',
				'post_mime_type' => 'image',
				'posts_per_page' => 1,
				'orderby' => 'menu_order',
				'order' => 'ASC',
				'fields' => 'ids',
				'suppress_filters' => false,
			) );

			if ( ! empty( $attached_image_ids ) ) {
				$post_image_id = array_shift( $attached_image_ids );
			}
		}

		if ( ! $post_image_id ) {
			return false;
		}

		$post_image_src = wp_get_attachment_image_src( $post_image_id, 'full' );

		if ( is_array( $post_image_src ) ) {
			$post_image_meta = array(
				'@type' => 'ImageObject',
				'url' => $post_image_src[0],
				'width' => $post_image_src[1],
				'height' => $post_image_src[2],
			);
		}

		return $post_image_meta;
	}

	private function verify_and_include( $file, $template_type ) {
		$located_file = $this->locate_template( $file );
		if ( $located_file ) {
			$file = $located_file;
		}

		$file = apply_filters( 'amp_post_template_file', $file, $template_type, $this->post );
		if ( ! $this->is_valid_template( $file ) ) {
			_doing_it_wrong( __METHOD__, sprintf( __( 'Path validation for template (%s) failed. Path cannot traverse and must be located in `%s`.', 'amp' ), esc_html( $file ), 'WP_CONTENT_DIR' ), '0.1' );
			return;
		}

		include( $file );
	}


	private function locate_template( $file ) {
		$search_file = sprintf( 'amp/%s', basename( $file ) );
		return locate_template( array( $search_file ), false );
	}

	private function is_valid_template( $template ) {
		if ( false !== strpos( $template, '..' ) ) {
			return false;
		}

		if ( false !== strpos( $template, './' ) ) {
			return false;
		}

		if ( ! file_exists( $template ) ) {
			return false;
		}

		return true;
	}
}