<?php

/**

 * WordPress Taxonomy Administration API.

 *

 * @package WordPress

 * @subpackage Administration

 */

//

// Category.

//

/**

 * Checks whether a category exists.

 *

 * @since 2.0.0

 *

 * @see term_exists()

 *

 * @param int|string $cat_name        Category name.

 * @param int        $category_parent Optional. ID of parent category.

 * @return string|null Returns the category ID as a numeric string if the pairing exists, null if not.

 */

function category_exists( $cat_name, $category_parent = null ) {

	$id = term_exists( $cat_name, 'category', $category_parent );

	if ( is_array( $id ) ) {

		$id = $id['term_id'];

	}

	return $id;

}

/**

 * Gets category object for given ID and 'edit' filter context.

 *

 * @since 2.0.0

 *

 * @param int $id

 * @return object

 */

function get_category_to_edit( $id ) {

	$category = get_term( $id, 'category', OBJECT, 'edit' );

	_make_cat_compat( $category );

	return $category;

}

/**

 * Adds a new category to the database if it does not already exist.

 *

 * @since 2.0.0

 *

 * @param int|string $cat_name        Category name.

 * @param int        $category_parent Optional. ID of parent category.

 * @return int|WP_Error

 */

function wp_create_category( $cat_name, $category_parent = 0 ) {

	$id = category_exists( $cat_name, $category_parent );

	if ( $id ) {

		return $id;

	}

	return wp_insert_category(

		array(

			'cat_name'        => $cat_name,

			'category_parent' => $category_parent,

		)

	);

}

/**

 * Creates categories for the given post.

 *

 * @since 2.0.0

 *

 * @param string[] $categories Array of category names to create.

 * @param int      $post_id    Optional. The post ID. Default empty.

 * @return int[] Array of IDs of categories assigned to the given post.

 */

function wp_create_categories( $categories, $post_id = '' ) {

	$cat_ids = array();

	foreach ( $categories as $category ) {

		$id = category_exists( $category );

		if ( $id ) {

			$cat_ids[] = $id;

		} else {

			$id = wp_create_category( $category );

			if ( $id ) {

				$cat_ids[] = $id;

			}

		}

	}

	if ( $post_id ) {

		wp_set_post_categories( $post_id, $cat_ids );

	}

	return $cat_ids;

}

/**

 * Updates an existing Category or creates a new Category.

 *

 * @since 2.0.0

 * @since 2.5.0 $wp_error parameter was added.

 * @since 3.0.0 The 'taxonomy' argument was added.

 *

 * @param array $catarr {

 *     Array of arguments for inserting a new category.

 *

 *     @type int        $cat_ID               Category ID. A non-zero value updates an existing category.

 *                                            Default 0.

 *     @type string     $taxonomy             Taxonomy slug. Default 'category'.

 *     @type string     $cat_name             Category name. Default empty.

 *     @type string     $category_description Category description. Default empty.

 *     @type string     $category_nicename    Category nice (display) name. Default empty.

 *     @type int|string $category_parent      Category parent ID. Default empty.

 * }

 * @param bool  $wp_error Optional. Default false.

 * @return int|WP_Error The ID number of the new or updated Category on success. Zero or a WP_Error on failure,

 *                      depending on param `$wp_error`.

 */

function wp_insert_category( $catarr, $wp_error = false ) {

	$cat_defaults = array(

		'cat_ID'               => 0,

		'taxonomy'             => 'category',

		'cat_name'             => '',

		'category_description' => '',

		'category_nicename'    => '',

		'category_parent'      => '',

	);

	$catarr       = wp_parse_args( $catarr, $cat_defaults );

	if ( '' === trim( $catarr['cat_name'] ) ) {

		if ( ! $wp_error ) {

			return 0;

		} else {

			return new WP_Error( 'cat_name', __( 'You did not enter a category name.' ) );

		}

	}

	$catarr['cat_ID'] = (int) $catarr['cat_ID'];

	// Are we updating or creating?

	$update = ! empty( $catarr['cat_ID'] );

	$name        = $catarr['cat_name'];

	$description = $catarr['category_description'];

	$slug        = $catarr['category_nicename'];

	$parent      = (int) $catarr['category_parent'];

	if ( $parent < 0 ) {

		$parent = 0;

	}

	if ( empty( $parent )

		|| ! term_exists( $parent, $catarr['taxonomy'] )

		|| ( $catarr['cat_ID'] && term_is_ancestor_of( $catarr['cat_ID'], $parent, $catarr['taxonomy'] ) ) ) {

		$parent = 0;

	}

	$args = compact( 'name', 'slug', 'parent', 'description' );

	if ( $update ) {

		$catarr['cat_ID'] = wp_update_term( $catarr['cat_ID'], $catarr['taxonomy'], $args );

	} else {

		$catarr['cat_ID'] = wp_insert_term( $catarr['cat_name'], $catarr['taxonomy'], $args );

	}

	if ( is_wp_error( $catarr['cat_ID'] ) ) {

		if ( $wp_error ) {

			return $catarr['cat_ID'];

		} else {

			return 0;

		}

	}

	return $catarr['cat_ID']['term_id'];

}

/**

 * Aliases wp_insert_category() with minimal args.

 *

 * If you want to update only some fields of an existing category, call this

 * function with only the new values set inside $catarr.

 *

 * @since 2.0.0

 *

 * @param array $catarr The 'cat_ID' value is required. All other keys are optional.

 * @return int|false The ID number of the new or updated Category on success. Zero or FALSE on failure.

 */

function wp_update_category( $catarr ) {

	$cat_id = (int) $catarr['cat_ID'];

	if ( isset( $catarr['category_parent'] ) && ( $cat_id === (int) $catarr['category_parent'] ) ) {

		return false;

	}

	// First, get all of the original fields.

	$category = get_term( $cat_id, 'category', ARRAY_A );

	_make_cat_compat( $category );

	// Escape data pulled from DB.

	$category = wp_slash( $category );

	// Merge old and new fields with new fields overwriting old ones.

	$catarr = array_merge( $category, $catarr );

	return wp_insert_category( $catarr );

}

//

// Tags.

//

/**

 * Checks whether a post tag with a given name exists.

 *

 * @since 2.3.0

 *

 * @param int|string $tag_name

 * @return mixed Returns null if the term does not exist.

 *               Returns an array of the term ID and the term taxonomy ID if the pairing exists.

 *               Returns 0 if term ID 0 is passed to the function.

 */

function tag_exists( $tag_name ) {

	return term_exists( $tag_name, 'post_tag' );

}

/**

 * Adds a new tag to the database if it does not already exist.

 *

 * @since 2.3.0

 *

 * @param int|string $tag_name

 * @return array|WP_Error

 */

function wp_create_tag( $tag_name ) {

	return wp_create_term( $tag_name, 'post_tag' );

}

/**

 * Gets comma-separated list of tags available to edit.

 *

 * @since 2.3.0

 *

 * @param int    $post_id

 * @param string $taxonomy Optional. The taxonomy for which to retrieve terms. Default 'post_tag'.

 * @return string|false|WP_Error

 */

function get_tags_to_edit( $post_id, $taxonomy = 'post_tag' ) {

	return get_terms_to_edit( $post_id, $taxonomy );

}

/**

 * Gets comma-separated list of terms available to edit for the given post ID.

 *

 * @since 2.8.0

 *

 * @param int    $post_id

 * @param string $taxonomy Optional. The taxonomy for which to retrieve terms. Default 'post_tag'.

 * @return string|false|WP_Error

 */

function get_terms_to_edit( $post_id, $taxonomy = 'post_tag' ) {

	$post_id = (int) $post_id;

	if ( ! $post_id ) {

		return false;

	}

	$terms = get_object_term_cache( $post_id, $taxonomy );

	if ( false === $terms ) {

		$terms = wp_get_object_terms( $post_id, $taxonomy );

		wp_cache_add( $post_id, wp_list_pluck( $terms, 'term_id' ), $taxonomy . '_relationships' );

	}

	if ( ! $terms ) {

		return false;

	}

	if ( is_wp_error( $terms ) ) {

		return $terms;

	}

	$term_names = array();

	foreach ( $terms as $term ) {

		$term_names[] = $term->name;

	}

	$terms_to_edit = esc_attr( implode( ',', $term_names ) );

	/**

	 * Filters the comma-separated list of terms available to edit.

	 *

	 * @since 2.8.0

	 *

	 * @see get_terms_to_edit()

	 *

	 * @param string $terms_to_edit A comma-separated list of term names.

	 * @param string $taxonomy      The taxonomy name for which to retrieve terms.

	 */

	$terms_to_edit = apply_filters( 'terms_to_edit', $terms_to_edit, $taxonomy );

	return $terms_to_edit;

}

/**

 * Adds a new term to the database if it does not already exist.

 *

 * @since 2.8.0

 *

 * @param string $tag_name The term name.

 * @param string $taxonomy Optional. The taxonomy within which to create the term. Default 'post_tag'.

 * @return array|WP_Error

 */

function wp_create_term( $tag_name, $taxonomy = 'post_tag' ) {

	$id = term_exists( $tag_name, $taxonomy );

	if ( $id ) {

		return $id;

	}

	return wp_insert_term( $tag_name, $taxonomy );

}