<?php

namespace ADQS_Directory;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class CookiesHandler {

	private static $instance = null;
	private $cookie_name     = 'adqs_visitor_data';
	private $cookie_lifetime = 3600;
	private $default_data    = [ 'visitor' => 'guest' ];

	private $cookie_options = [
		'path'     => '/',
		'domain'   => '',
		'secure'   => false,
		'httponly' => false,
		'samesite' => 'Lax',
	];

	private $pending_cookies = [];
	private $runtime_data    = null;

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

	public function __construct() {
		$this->cookie_options['domain'] = $_SERVER['HTTP_HOST'] ?? '';
		add_action( 'init', [ $this, 'applyCookies' ], 1 );
	}

	public function set( $key, $value, $cookie_lifetime = null ) {
		if ( $cookie_lifetime === null ) {
			$cookie_lifetime = $this->cookie_lifetime;
		}

		$data = $this->get();

		if ( ! is_array( $data ) ) {
			$data = $this->default_data;
		}

		if ( $value === null ) {
			unset( $data[ $key ] );
		} else {
			$data[ $key ] = $value;
		}

		$this->runtime_data = $data;

		$json_data = json_encode( $data, JSON_UNESCAPED_UNICODE );
		if ( $json_data === false ) {
			return $this;
		}

		$this->pending_cookies[] = [
			'name'    => $this->cookie_name,
			'value'   => $json_data,
			'expires' => time() + $cookie_lifetime,
		];

		if ( ! headers_sent() ) {
			$this->applyCookies();
		}

		return $this;
	}

	public function get( $key = null, $default = null ) {
		if ( $this->runtime_data !== null ) {
			$data = $this->runtime_data;
		} elseif ( isset( $_COOKIE[ $this->cookie_name ] ) ) {
			$cookie_value = wp_unslash( $_COOKIE[ $this->cookie_name ] );
			$data         = json_decode( $cookie_value, true );
			if ( ! is_array( $data ) ) {
				$data = $this->default_data;
			}
			$this->runtime_data = $data;
		} else {
			$data               = $this->default_data;
			$this->runtime_data = $data;
		}

		return $key !== null ? ( $data[ $key ] ?? $default ) : $data;
	}

	public function has( $key ) {
		$data = $this->get();
		return isset( $data[ $key ] );
	}

	public function remove( $key ) {
		$data = $this->get();
		if ( isset( $data[ $key ] ) ) {
			unset( $data[ $key ] );
			$this->runtime_data = $data;

			$json_data = json_encode( $data, JSON_UNESCAPED_UNICODE );
			if ( $json_data === false ) {
				return $this;
			}

			$this->pending_cookies[] = [
				'name'    => $this->cookie_name,
				'value'   => $json_data,
				'expires' => time() + $this->cookie_lifetime,
			];

			if ( ! headers_sent() ) {
				$this->applyCookies();
			}
		}
		return $this;
	}

	public function clear() {
		$this->runtime_data      = null;
		$this->pending_cookies[] = [
			'name'    => $this->cookie_name,
			'value'   => '',
			'expires' => time() - 3600,
		];

		if ( ! headers_sent() ) {
			$this->applyCookies();
		}

		return $this;
	}

	public function applyCookies() {
		foreach ( $this->pending_cookies as $cookie ) {
			setcookie(
				$cookie['name'],
				$cookie['value'],
				[
					'expires'  => $cookie['expires'],
					'path'     => $this->cookie_options['path'],
					'domain'   => $this->cookie_options['domain'],
					'secure'   => $this->cookie_options['secure'],
					'httponly' => $this->cookie_options['httponly'],
					'samesite' => $this->cookie_options['samesite'],
				]
			);
		}
		$this->pending_cookies = [];
	}
}