<?php

/*//////////////////////////////////////
// Set Excerpt Length for The Loop
//////////////////////////////////////*/

if ( ! class_exists( 'GTM_Excerpt' ) ) {
	class GTM_Excerpt {
		private static $instance;
		public $length;
		public $is_applied = false; // For checking adding of actions/filters
		public $is_alt     = false;
		public $alt_length;

		public static function getInstance() {
			if ( is_null( static::$instance ) ) {
				static::$instance = new self();
			}

			return static::$instance;
		}

		/* Set excerpt length */
		public static function set( $length ) {
			$instance         = static::getInstance();
			$instance->length = intval( $length );
			$instance->apply();
		}

		/* Set alternative length */
		public static function set_alt( $alt_length ) {
			$instance             = static::getInstance();
			$instance->is_alt     = true;
			$instance->alt_length = $alt_length;
		}

		/* Revert alternative length */
		public static function revert_alt() {
			$instance             = static::getInstance();
			$instance->is_alt     = false;
			$instance->alt_length = null;
		}

		/* Apply actions/filters for the loop */
		public function apply() {
			if ( ! $this->is_applied ) {
				add_filter( 'excerpt_length', [$this, 'excerpt_length'], 99 );
				add_action( 'loop_end', [$this, 'done'] );
				add_action( 'loop_no_results', [$this, 'done'] ); // WP 4.9+

				$this->is_applied = true;
			}
		}

		/* Override current excerpt length */
		public function excerpt_length( $length ) {
			if ( $this->is_alt ) {
				return $this->alt_length;
			} else {
				return $this->length;
			}
		}

		/* Remove custom excerpt length after loop */
		public function done( $wp_query = null ) {
			/* MY ADDED FILTER */ remove_filter( 'excerpt_length', [$this, 'excerpt_length'], 99 );
			remove_action( 'loop_end', [$this, 'done'] );
			remove_action( 'loop_no_results', [$this, 'done'] ); // WP 4.9+
			$this->is_applied = false;
		}
	}
}

// Get the custom excerpt only, return empty when NO custom excerpt inputted
function gtm_get_custom_excerpt( $post = null ) {
	if ( has_excerpt( $post ) ) {
		return get_the_excerpt( $post );
	}
}

// Get the automatic excerpt only, return empty when custom excerpt inputted
function gtm_get_automatic_excerpt_only( $post = null ) {
	if ( ! has_excerpt( $post ) ) {
		return get_the_excerpt( $post );
	}
}

// Always get an automatic excerpt
function gtm_get_automatic_excerpt( $post = null ) {
	$post = get_post( $post );
	if ( empty( $post ) ) {
		return '';
	}

	if ( post_password_required( $post ) ) {
		return esc_html__( 'There is no excerpt because this is a protected post.', 'gutenmate' );
	}

	return apply_filters( 'get_the_excerpt', '', $post );
}