<?php
namespace Footloom;

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

// Country lookup from the visitor's IP. The IP is only used in memory and never stored.
class Geo {

	public static function register() {
		add_action( 'footloom_geo_update', array( self::class, 'update' ) );
	}

	// True when the site owner has turned on country lookup in Settings.
	public static function enabled() {
		return (bool) get_option( 'footloom_geo', 0 );
	}

	public static function file() {
		$uploads = wp_upload_dir( null, false );
		return $uploads['basedir'] . '/footloom/dbip-country-lite.mmdb';
	}

	// Download the free DB-IP Lite country database. Tries this month, then last month.
	public static function update() {
		global $wp_filesystem;
		require_once ABSPATH . 'wp-admin/includes/file.php';
		if ( ! WP_Filesystem() ) {
			return false;
		}

		$file = self::file();
		wp_mkdir_p( dirname( $file ) );

		foreach ( array( 'now', 'first day of last month' ) as $when ) {
			$month    = gmdate( 'Y-m', strtotime( $when ) );
			$response = wp_remote_get(
				"https://download.db-ip.com/free/dbip-country-lite-$month.mmdb.gz",
				array( 'timeout' => 60 )
			);

			if ( is_wp_error( $response ) || 200 !== wp_remote_retrieve_response_code( $response ) ) {
				continue;
			}

			$data = gzdecode( wp_remote_retrieve_body( $response ) );
			if ( $data && $wp_filesystem->put_contents( $file . '.tmp', $data ) && $wp_filesystem->move( $file . '.tmp', $file, true ) ) {
				return true;
			}
		}

		return false;
	}

	public static function client_ip() {
		// Behind a proxy the first forwarded address is the visitor. Only used for country, never stored.
		if ( ! empty( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
			$ip = trim( explode( ',', sanitize_text_field( wp_unslash( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) )[0] );
			if ( filter_var( $ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE ) ) {
				return $ip;
			}
		}
		return isset( $_SERVER['REMOTE_ADDR'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REMOTE_ADDR'] ) ) : '';
	}

	// Returns a two letter country code or null.
	public static function country() {
		if ( ! empty( $_SERVER['HTTP_CF_IPCOUNTRY'] ) ) {
			$code = strtoupper( substr( sanitize_text_field( wp_unslash( $_SERVER['HTTP_CF_IPCOUNTRY'] ) ), 0, 2 ) );
			// Cloudflare uses XX for unknown and T1 for Tor.
			return preg_match( '/^[A-Z]{2}$/', $code ) && 'XX' !== $code && 'T1' !== $code ? $code : null;
		}

		if ( ! self::enabled() ) {
			return null;
		}

		$ip   = self::client_ip();
		$file = self::file();
		if ( ! $ip || ! file_exists( $file ) ) {
			return null;
		}

		try {
			$reader = new \MaxMind\Db\Reader( $file );
			$record = $reader->get( $ip );
			$reader->close();
		} catch ( \Exception $e ) {
			return null;
		}

		return isset( $record['country']['iso_code'] ) ? $record['country']['iso_code'] : null;
	}
}