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/**********************************************************************************************
	SCRIPT INFO:
	
	Description: Hierarchy-based random header images for the Graphene theme
	Author:      Francisco de Azevedo (a.k.a., Marventus)
                 (based on code by Syahir Hakim)
	License:     Share at will (with attribution)
	
	PLEASE DO NOT DELETE THIS INFO
***********************************************************************************************/


/***********************************************************************************************
	INSTRUCTIONS:
	
	A.  What It Does:
	This script allows you to display custom header images for specific category archive
	pages, single posts, and pages in the Graphene Theme based on your category and/or 
	page hierarchy. It supports up to 3 levels of depth.
	
	B.  How to Use It:
		In order for the script to work, you need to:
		1.  Create a folder called "custom-headers" inside the folder "graphene/images/";
		2.  Using the category and page slugs as folder names, create a directory tree inside
			that folder that mirrors the category and/or page hierarchy of the categories and
			pages for which you	wish to display custom images;
		3.  Upload images (.JPG only) to those folders; and
		4.  Insert all LEVEL 1 (i.e. main) category and page IDs you wish to target as a comma-
		 	separated list inside the $custom_image_ids array below. There is no need to
			include any LEVEL 2 or LEVEL 3 categories or pages (i.e., sub-categories or subpages)
			in the array: the script will retrieve custom images for all sub-categories and
			sub-pages under the targeted LEVEL 1 categories and pages.
	
	C.  How It Works:
		The script checks if the current category archive, post category, or page is targeted
		in the array, and if it is, it checks if a custom image folder exists for said cats or
		pages and if they contain any images. If they do, it wil fetch them and display a random
		one. If they do not, it will fetch the images from the LEVEL 1 category or page and
		display a random one.
		 
	D.  An Example:
		Let's suppose you have the following category structure. The cat ID of each
		category is shown in parenthesis. A star symbol (*) next to a main category means
		I am targeting that category (i.e., I have included it in the array). 
		An at symbol (@) next to any category means I would like to display custom images
		for that category:
		
		People (2) @ *
			- Family (12) @
				-- Close Family (41) @
				-- Extended Family (39)
			- Friends (15)
				-- School (30) @
				-- Work (32)
		Objects (5) @ *
			- Tools (10) @
				-- Utensils (25) @
				-- Computers (27)
		Places (7) *
		Hobbies (8)
					   
	  	Based on that, my $custom_image_ids array would be defined as such:
		$custom_image_ids = array(2,5,7);
		
		I would have to create the following directories inside
		"grapehne/images" and upload images to each one:
			/custom-headers/
			/custom-headers/people/
			/custom-headers/people/family/
			/custom-headers/people/family/close-family/
			/custom-headers/people/friends/
			/custom-headers/people/friends/school/
			/custom-headers/objects/
			/custom-headers/objects/tools/
			/custom-headers/objects/tools/utensils/
		
		Now, while navigating through the site, here's what I'll see inside
		each category:
		  - Inside People | Images from /people/;
		  - Inside People -> Family | Images from /people/family/;
		  - Inside People -> Family -> Close Family | Images from 
			 /people/family/close-family/;
		  - Inside People -> Family -> Extended Family | Images from /people/;
		  - Inside People -> Friends | Images from /people/;
		  - Inside People -> Friends -> School | Images from
		     /people/friends/school/;
		  - Inside People -> Friends -> Work | Images from /people/;	
		  - Inside Places (or its sub-cats) | Default images, because, even though
		  	the category is included in the $custom_image_ids array, there is no
		  	folder /custom-headers/places/;
		  - Inside Hobbies (or its sub-cats) | Default images.
		  
		The same logic would apply if we wanted to use pages for this, and the
		directory tree would be composed of folders named after the page slugs.

		  
YOI CAN DELETE THESE INSTRUCTIONS OR SAVE THEM TO A TEXT FILE IF DESIRED
***********************************************************************************************/


/***********************************************************************************************
	SCRIPT START
***********************************************************************************************/

function custom_header_image($random_image) {

/* CATEGORY AND PAGE IDS FOR CUSTOM IMAGES */	  
	   $custom_image_ids = array(4,6,8,9); // modify at will
		
/* GET CURRENT CAT OR PAGE INFO */
	// Test if we are inside a cat archive, a post, or a page
	if ( is_category() || is_single() || is_page() ){
		// If we are, test if we are inside a cat archive or a post
		if ( is_category() || is_single() ) {
		// If we are, test if we are inside a cat archive
			if (is_category() ) {
				// If we are, get cat and cat info
				$current_id = get_query_var( 'cat' );
				$current_array = get_category($current_id);
				$current_slug = $current_array->slug;
				$parent_id = $current_array->parent;
			// If we are not, we are inside a single post
			} else {
				// Get cat and cat info
        		global $post;
				$current_array = get_the_category( $post->ID );
				$current_id = $current_array[0]->cat_ID;
				$current_slug = $current_array[0]->slug;
				$parent_id = $current_array[0]->parent;
			}
			// Get the rest of the cat info
			$parent_array = get_category($parent_id);
			$parent_slug = $parent_array->slug;
			$ancestor_id = $parent_array->parent;
			$ancestor_array = get_category($ancestor_id);
			$ancestor_slug = $ancestor_array->slug;
		// If it's neither a cat archive or a post, it's a page
		} else {
			// Get page and page info
			global $post;
			$current_array = get_page( $post->ID );
			$current_id = $post->ID;
			$current_slug = $post->post_name;
			$current_ancestors = get_ancestors ($current_id, 'page');
			$parent_id = $current_ancestors[0];
			// Test if current page has a parent
			if ( $parent_id ) {
			$parent_array = get_page( $parent_id );
			$parent_slug = $parent_array->post_name;
			}
			$ancestor_id = $current_ancestors[1];
			// Test if current page has an ancestor
			if ( $ancestor_id ) {
			$ancestor_array = get_page( $ancestor_id );
			$ancestor_slug = $ancestor_array->post_name;
			}
		}


/* GET CUSTOM IMAGES FOR CATS */
		// Check if we are dealing with one of the selected categories
		if ( in_array( $current_id, $custom_image_ids ) || in_array( $parent_id, $custom_image_ids )|| in_array( $ancestor_id, $custom_image_ids ) ) {
		// If we are, put together the absolute path
			$current_slug_slash = $current_slug . '/';
			$parent_slug_slash = $parent_slug . '/';
			$ancestor_slug_slash = $ancestor_slug . '/';
			$image_start_path = get_stylesheet_directory() . '/images/custom-headers/';
			$image_start_dir = get_stylesheet_directory_uri() . '/images/custom-headers/';
			$custom_images = '';
			// Check which directory to retrieve the custom images from and save them in a variable
			if ( $ancestor_slug ) {
				$image_abs_path = $image_start_path . $ancestor_slug_slash . $parent_slug_slash . $current_slug_slash;
				if ( is_dir( $image_abs_path ) && $custom_images = glob( $image_abs_path . "/*.jpg" ) ) {
					$image_dir = $image_start_dir . $ancestor_slug_slash . $parent_slug_slash . $current_slug_slash;
				} else {
					$image_abs_path = $image_start_path . $ancestor_slug_slash;
					$image_dir = $image_start_dir . $ancestor_slug_slash;					
					$custom_images = glob( $image_abs_path . "/*.jpg" );
				}
			}
			elseif ( !$ancestor_slug && $parent_slug ) {
				$image_abs_path = $image_start_path . $parent_slug_slash . $current_slug_slash;
				if ( is_dir( $image_abs_path ) && $custom_images = glob( $image_abs_path . "/*.jpg" ) ) {
					$image_dir = $image_start_dir . $parent_slug_slash . $current_slug_slash;
				} else {
					$image_abs_path = $image_start_path . $parent_slug_slash;
					$image_dir = $image_start_dir . $parent_slug_slash;
					$custom_images = glob( $image_abs_path . "/*.jpg" );
				}
			}
			elseif ( $current_slug && !$parent_slug ) {
				$image_abs_path = $image_start_path . $current_slug_slash;
				if ( is_dir( $image_abs_path ) && $custom_images = glob( $image_abs_path . "/*.jpg" ) ) {
					$image_dir = $image_start_dir . $current_slug_slash;
				}
			}
			// Retrieve random images from custom image  obtained
			if ( $custom_images ) {
				$key = array_rand( $custom_images );
				$random_image = $image_dir . basename( $custom_images[$key] );
			}
		}
	}
	// Return the random image obtained
	return $random_image;
}
add_filter( 'graphene_header_image', 'custom_header_image' );

/***********************************************************************************************
	SCRIPT END
***********************************************************************************************/