<?php
/**
 * Class PageTemplater
 * https://www.wpexplorer.com/wordpress-page-templates-plugin/
 */

class NinetyPageTemplater {

	/**
	 * A reference to an instance of this class.
	 */
	private static $instance;

	/**
	 * The array of templates that this plugin tracks.
	 */
	protected $templates;

	/**
	 * Is this a Genesis theme?
	 */
	protected $genesis;

	/**
	 * Path to custom page templates
	 */
	protected $tempate_path;

	/**
	 * Returns an instance of this class.
	 */
	public static function get_instance() {

		if ( null == self::$instance ) {
			self::$instance = new NinetyPageTemplater();
		}

		return self::$instance;
	}

	/**
	 * Initializes the plugin by setting filters and administration functions.
	 */
	private function __construct() {

		// Set custom page template path to plugin root.
		$this->tempate_path = NINETY_NINETY_PATH . 'templates/';

		// Get theme to see if it's Genesis.
		$theme = wp_get_theme();

		// Is a Genesis theme active?
		$this->genesis = 'genesis' === $theme->get_template() ? true : false;

		// Initialize as empty array.
		$this->templates = array();

		// Add a filter to the attributes metabox to inject template into the cache.
		if ( version_compare( floatval( get_bloginfo( 'version' ) ), '4.7', '<' ) ) {

			// 4.6 and older
			add_filter(
				'page_attributes_dropdown_pages_args',
				array(
					$this,
					'register_project_templates',
				)
			);

		} else {

			// Add a filter to the wp 4.7 version attributes metabox.
			add_filter(
				'theme_page_templates',
				array(
					$this,
					'add_new_template',
				), 10, 4 );

		}

		// Add a filter to the save post to inject out template into the page cache.
		add_filter( 'wp_insert_post_data', array( $this, 'register_project_templates' ) );

		// Add a filter to the template include to determine if the page has our
		// template assigned and return it's path.
		add_filter( 'template_include', array( $this, 'view_project_template' ) );

		// Add page templates to this array - different templates for Genesis.
		$gen = $this->genesis ? 'genesis-' : '';

		$template_name = "template-{$gen}90-map.php";

		$template = $this->tempate_path . $template_name;

		if (  file_exists( $template ) ) {
			$this->templates = array(
				$template_name => '90/90 Map',
			);
		}

	}

	/**
	 * Adds our templates to the page dropdown for v4.7+
	 */
	public function add_new_template( $post_templates, $theme, $post, $post_type ) {

		$post_templates = array_merge( $post_templates, $this->templates );

		return $post_templates;
	}

	/**
	 * Adds our templates to the pages cache in order to trick WordPress
	 * into thinking the template file exists where it doens't really exist.
	 */
	public function register_project_templates( $atts ) {

		// Create the key used for the themes cache
		$cache_key = 'page_templates-' . md5( get_theme_root() . '/' . get_stylesheet() );

		// Retrieve the cache list.
		// If it doesn't exist, or it's empty prepare an array
		$templates = wp_get_theme()->get_page_templates();

		if ( empty( $templates ) ) {
			$templates = array();
		}

		// New cache, therefore remove the old one
		wp_cache_delete( $cache_key, 'themes' );

		// Now add our template to the list of templates by merging our templates
		// with the existing templates array from the cache.
		$templates = array_merge( $templates, $this->templates );

		// Add the modified cache to allow WordPress to pick it up for listing
		// available templates.
		wp_cache_add( $cache_key, $templates, 'themes', 1800 );

		return $atts;
	}

	/**
	 * Checks if the template is assigned to the page
	 */
	public function view_project_template( $template ) {

		// Return the search template if we're searching (instead of the template for the first result).
		if ( is_search() || is_archive() ) {
			return $template;
		}
		// Get global post.
		global $post;

		// Return template if post is empty.
		if ( ! $post ) {
			return $template;
		}

		// Return default template if we don't have a custom one defined.
		if ( ! isset( $this->templates[ get_post_meta( $post->ID, '_wp_page_template', true ) ] ) ) {
			return $template;
		}

		// Allows filtering of file path.
		$filepath = apply_filters( 'page_templater_plugin_dir_path', $this->tempate_path );
		$name     = get_post_meta( $post->ID, '_wp_page_template', true );
		$file     = $filepath . $name;

		// Just to be safe, we check if the file exist first.
		if ( file_exists( $file ) ) {
			return $file;
		} else {
			echo 'Template ' . $file . ' <strong>not found</strong>';
		}

		// Return template.
		return $template;
	}
}

add_action( 'plugins_loaded', array( 'NinetyPageTemplater', 'get_instance' ) );
