<?php
/**
 * Plugin Name:       ReaderCount – Privacy-first stats
 * Plugin URI:        https://readercount.com/wordpress/
 * Description:       Cookie-free visitor stats from ReaderCount. Adds ReaderCount's small script to your site, leaves out your own visits, and shows your week's stats on the Dashboard.
 * Version:           1.0.0
 * Requires at least: 6.3
 * Requires PHP:      7.4
 * Author:            ReaderCount
 * Author URI:        https://readercount.com/
 * License:           GPL-2.0-or-later
 * License URI:       https://www.gnu.org/licenses/gpl-2.0.html
 * Text Domain:       readercount
 *
 * @package ReaderCount
 */

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

define( 'READERCOUNT_VERSION', '1.0.0' );
define( 'READERCOUNT_FILE', __FILE__ );
define( 'READERCOUNT_OPTION', 'readercount_settings' );
define( 'READERCOUNT_KEY_OPTION', 'readercount_api_key' );
define( 'READERCOUNT_SCRIPT', 'https://app.readercount.com/s.js' );
define( 'READERCOUNT_API', 'https://api.readercount.com/v1/' );
define( 'READERCOUNT_APP', 'https://app.readercount.com/' );

require_once __DIR__ . '/includes/settings.php';
require_once __DIR__ . '/includes/api.php';
require_once __DIR__ . '/includes/dashboard.php';

/**
 * The plugin's settings, with defaults filled in.
 *
 * @return array{enabled: bool, site: string, skip_editors: bool}
 */
function readercount_settings() {
	$saved = get_option( READERCOUNT_OPTION, array() );
	return wp_parse_args(
		is_array( $saved ) ? $saved : array(),
		array(
			'enabled'      => false,
			'site'         => '',
			'skip_editors' => true,
		)
	);
}

/**
 * "https://www.Example.com/blog" -> "example.com", the way ReaderCount names websites.
 *
 * @param string $value An address or a bare domain.
 * @return string The domain, or '' when it isn't one.
 */
function readercount_site_name( $value ) {
	$value = trim( (string) $value );
	if ( '' === $value ) {
		return '';
	}
	if ( false === strpos( $value, '://' ) ) {
		$value = 'https://' . $value;
	}
	$host = wp_parse_url( $value, PHP_URL_HOST );
	if ( ! is_string( $host ) || '' === $host ) {
		return '';
	}
	return preg_replace( '/^www\./', '', strtolower( $host ) );
}

/**
 * The website name ReaderCount counts this site as: the one set in Settings, otherwise this site's own address.
 *
 * @return string
 */
function readercount_site() {
	$settings = readercount_settings();
	$chosen   = readercount_site_name( $settings['site'] );
	return '' !== $chosen ? $chosen : readercount_site_name( home_url() );
}

/**
 * Whether this page view should be counted. Editors and admins reading their own site are left out by default.
 *
 * @return bool
 */
function readercount_should_count() {
	$settings = readercount_settings();
	if ( ! $settings['enabled'] || '' === readercount_site() ) {
		return false;
	}
	if ( is_preview() || is_customize_preview() ) {
		return false;
	}
	if ( $settings['skip_editors'] && current_user_can( 'edit_posts' ) ) {
		return false;
	}
	/**
	 * Filters whether ReaderCount counts the current page view.
	 *
	 * @param bool $count True to add ReaderCount's script to this page.
	 */
	return (bool) apply_filters( 'readercount_should_count', true );
}

/**
 * Adds ReaderCount's script to public pages.
 */
function readercount_enqueue() {
	if ( ! readercount_should_count() ) {
		return;
	}
	/**
	 * Filters the address of ReaderCount's script, for sites that serve it from their own address.
	 *
	 * @param string $src The script's address.
	 */
	$src = apply_filters( 'readercount_script_url', READERCOUNT_SCRIPT );
	// No version on the address: ReaderCount's script updates itself, and ?ver= would only split its cache.
	wp_enqueue_script(
		'readercount',
		esc_url_raw( $src ),
		array(),
		null, // phpcs:ignore WordPress.WP.EnqueuedResourceParameters.MissingVersion
		array(
			'strategy'  => 'defer',
			'in_footer' => false,
		)
	);
}
add_action( 'wp_enqueue_scripts', 'readercount_enqueue' );

/**
 * Tells the script which website it is counting.
 *
 * @param string $tag    The script tag WordPress is about to print.
 * @param string $handle The script's handle.
 * @return string
 */
function readercount_script_tag( $tag, $handle ) {
	if ( 'readercount' !== $handle ) {
		return $tag;
	}
	return str_replace( ' src=', ' data-site="' . esc_attr( readercount_site() ) . '" src=', $tag );
}
add_filter( 'script_loader_tag', 'readercount_script_tag', 10, 2 );

/**
 * Marks WordPress's "not found" page, so ReaderCount can list missing pages people are trying to reach.
 */
function readercount_not_found_meta() {
	if ( is_404() && readercount_should_count() ) {
		echo '<meta name="readercount" content="404">' . "\n";
	}
}
add_action( 'wp_head', 'readercount_not_found_meta', 1 );

/**
 * A Settings link on the Plugins screen.
 *
 * @param string[] $links The plugin's action links.
 * @return string[]
 */
function readercount_action_links( $links ) {
	array_unshift( $links, '<a href="' . esc_url( admin_url( 'options-general.php?page=readercount' ) ) . '">' . esc_html__( 'Settings', 'readercount' ) . '</a>' );
	return $links;
}
add_filter( 'plugin_action_links_' . plugin_basename( __FILE__ ), 'readercount_action_links' );