<?php
/**
 * Small shared helpers. All prefixed sxanl_.
 */

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

/**
 * Best-effort real client IP.
 *
 * Only trusts proxy headers when the plugin is told the site sits behind a
 * known reverse proxy (Cloudflare / a load balancer). Default is REMOTE_ADDR
 * only — the safe choice, since proxy headers are attacker-controlled.
 *
 * The IP is used for GeoIP lookup and the daily visitor hash, then dropped.
 * It is never stored.
 *
 * @return string
 */
function sxanl_client_ip() {
	$remote = isset( $_SERVER['REMOTE_ADDR'] ) ? (string) $_SERVER['REMOTE_ADDR'] : '';

	$trust = SXANL_Settings::get( 'trust_proxy' ); // '', 'cloudflare', 'xff'
	if ( 'cloudflare' === $trust && ! empty( $_SERVER['HTTP_CF_CONNECTING_IP'] ) ) {
		$cand = trim( (string) $_SERVER['HTTP_CF_CONNECTING_IP'] );
		if ( filter_var( $cand, FILTER_VALIDATE_IP ) ) {
			return $cand;
		}
	}
	if ( 'xff' === $trust && ! empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
		$parts = explode( ',', (string) $_SERVER['HTTP_X_FORWARDED_FOR'] );
		$cand  = trim( $parts[0] );
		if ( filter_var( $cand, FILTER_VALIDATE_IP ) ) {
			return $cand;
		}
	}

	return filter_var( $remote, FILTER_VALIDATE_IP ) ? $remote : '';
}

/**
 * Truncate a UA string to something sane for classification.
 *
 * @param string $ua Raw UA.
 * @return string
 */
function sxanl_clean_ua( $ua ) {
	$ua = (string) $ua;
	$ua = preg_replace( '/[[:cntrl:]]/', '', $ua );
	return sxanl_str_limit( $ua, 400 );
}

/**
 * Multibyte-safe-ish substring limiter.
 *
 * @param string $str    Input.
 * @param int    $length Max length.
 * @return string
 */
function sxanl_str_limit( $str, $length ) {
	$str = (string) $str;
	if ( function_exists( 'mb_substr' ) ) {
		return mb_substr( $str, 0, $length );
	}
	return substr( $str, 0, $length );
}

/**
 * Normalise a request path: keep the path, drop the query string except a
 * short whitelist, collapse trailing slash, cap length.
 *
 * @param string $url_or_path A full URL or a path.
 * @return string
 */
function sxanl_normalise_path( $url_or_path ) {
	$url_or_path = (string) $url_or_path;
	$path        = wp_parse_url( $url_or_path, PHP_URL_PATH );
	if ( ! is_string( $path ) || '' === $path ) {
		$path = '/';
	}
	$path = '/' . ltrim( $path, '/' );
	if ( strlen( $path ) > 1 ) {
		$path = rtrim( $path, '/' );
	}
	$path = preg_replace( '#//+#', '/', $path );
	return sxanl_str_limit( $path, 512 );
}

/**
 * Extract the registrable-ish host from a referrer URL (lowercased, no www).
 *
 * @param string $referrer Referrer URL.
 * @return string Empty string if not parseable / not http(s).
 */
function sxanl_referrer_host( $referrer ) {
	$referrer = (string) $referrer;
	if ( '' === $referrer ) {
		return '';
	}
	$scheme = wp_parse_url( $referrer, PHP_URL_SCHEME );
	if ( ! in_array( strtolower( (string) $scheme ), array( 'http', 'https' ), true ) ) {
		return '';
	}
	$host = wp_parse_url( $referrer, PHP_URL_HOST );
	if ( ! is_string( $host ) || '' === $host ) {
		return '';
	}
	$host = strtolower( $host );
	if ( 0 === strpos( $host, 'www.' ) ) {
		$host = substr( $host, 4 );
	}
	return sxanl_str_limit( $host, 255 );
}

/**
 * The site's own host (for "internal referrer" detection).
 *
 * @return string
 */
function sxanl_site_host() {
	static $host = null;
	if ( null === $host ) {
		$host = strtolower( (string) wp_parse_url( home_url(), PHP_URL_HOST ) );
		if ( 0 === strpos( $host, 'www.' ) ) {
			$host = substr( $host, 4 );
		}
	}
	return $host;
}

/**
 * A device-class bucket from a UA string: 'mobile' | 'tablet' | 'desktop'.
 *
 * Deliberately crude — we are not building a device database.
 *
 * @param string $ua UA string.
 * @return string
 */
function sxanl_device_type( $ua ) {
	$ua = strtolower( (string) $ua );
	if ( '' === $ua ) {
		return 'unknown';
	}
	if ( false !== strpos( $ua, 'ipad' ) || ( false !== strpos( $ua, 'android' ) && false === strpos( $ua, 'mobile' ) ) || false !== strpos( $ua, 'tablet' ) ) {
		return 'tablet';
	}
	if ( false !== strpos( $ua, 'mobi' ) || false !== strpos( $ua, 'iphone' ) || false !== strpos( $ua, 'ipod' ) || false !== strpos( $ua, 'windows phone' ) ) {
		return 'mobile';
	}
	return 'desktop';
}

/**
 * A coarse browser family from a UA string.
 *
 * @param string $ua UA string.
 * @return string
 */
function sxanl_browser_family( $ua ) {
	$ua = (string) $ua;
	$map = array(
		'Edg/'       => 'Edge',
		'OPR/'       => 'Opera',
		'SamsungBrowser' => 'Samsung Internet',
		'Firefox/'   => 'Firefox',
		'Chrome/'    => 'Chrome',
		'CriOS/'     => 'Chrome',
		'Version/'   => 'Safari',
		'MSIE '      => 'Internet Explorer',
		'Trident/'   => 'Internet Explorer',
	);
	foreach ( $map as $needle => $name ) {
		if ( false !== strpos( $ua, $needle ) ) {
			return $name;
		}
	}
	return 'Other';
}

/**
 * A coarse OS family from a UA string.
 *
 * @param string $ua UA string.
 * @return string
 */
function sxanl_os_family( $ua ) {
	$ua = (string) $ua;
	$map = array(
		'Windows NT 10' => 'Windows',
		'Windows NT'    => 'Windows',
		'iPhone OS'     => 'iOS',
		'iPad; CPU OS'  => 'iPadOS',
		'Mac OS X'      => 'macOS',
		'Android'       => 'Android',
		'CrOS'          => 'ChromeOS',
		'Linux'         => 'Linux',
	);
	foreach ( $map as $needle => $name ) {
		if ( false !== strpos( $ua, $needle ) ) {
			return $name;
		}
	}
	return 'Other';
}

/**
 * Screen-width bucket label.
 *
 * @param int $width Reported CSS pixel width.
 * @return string
 */
function sxanl_screen_bucket( $width ) {
	$width = (int) $width;
	if ( $width <= 0 ) {
		return 'unknown';
	}
	if ( $width < 576 ) {
		return 'xs';
	}
	if ( $width < 768 ) {
		return 'sm';
	}
	if ( $width < 992 ) {
		return 'md';
	}
	if ( $width < 1400 ) {
		return 'lg';
	}
	return 'xl';
}

/**
 * ISO 3166-1 alpha-2 -> English country name map (bundled).
 *
 * @return array<string,string>
 */
function sxanl_country_names() {
	static $names = null;
	if ( null === $names ) {
		$names = array();
		$file  = SXANL_DIR . 'data/country-names.json';
		if ( is_readable( $file ) ) {
			$decoded = json_decode( (string) file_get_contents( $file ), true ); // phpcs:ignore WordPress.WP.AlternativeFunctions
			if ( is_array( $decoded ) ) {
				$names = $decoded;
			}
		}
	}
	return $names;
}

/**
 * ISO date (Y-m-d) for a unix timestamp in the site's timezone.
 *
 * @param int $ts Unix timestamp. Defaults to now.
 * @return string
 */
function sxanl_site_date( $ts = null ) {
	$ts = null === $ts ? time() : (int) $ts;
	return wp_date( 'Y-m-d', $ts );
}