<?php

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

class ADCT_Visitor {

	public static function get_context_for_request() {
		$user_agent = isset( $_SERVER['HTTP_USER_AGENT'] )
			? sanitize_text_field( wp_unslash( $_SERVER['HTTP_USER_AGENT'] ) )
			: '';

		$parsed = self::parse_user_agent( $user_agent );
		$geo    = self::get_geo();

		return array(
			'device_type'     => $parsed['device_type'],
			'browser_name'    => $parsed['browser_name'],
			'visitor_country' => $geo['visitor_country'],
			'visitor_region'  => $geo['visitor_region'],
		);
	}

	public static function get_client_ip() {
		$candidates = array(
			'HTTP_CF_CONNECTING_IP',
			'HTTP_X_REAL_IP',
			'HTTP_X_FORWARDED_FOR',
			'REMOTE_ADDR',
		);

		foreach ( $candidates as $key ) {
			if ( empty( $_SERVER[ $key ] ) ) {
				continue;
			}

			$raw = sanitize_text_field( wp_unslash( $_SERVER[ $key ] ) );

			if ( 'HTTP_X_FORWARDED_FOR' === $key ) {
				$parts = array_map( 'trim', explode( ',', $raw ) );

				foreach ( $parts as $part ) {
					if ( self::is_public_ip( $part ) ) {
						return $part;
					}
				}

				continue;
			}

			if ( self::is_public_ip( $raw ) ) {
				return $raw;
			}
		}

		return '';
	}

	public static function parse_user_agent( $user_agent ) {
		$user_agent = (string) $user_agent;

		if ( '' === $user_agent ) {
			return array(
				'device_type'  => '',
				'browser_name' => '',
			);
		}

		$device = 'desktop';

		if ( preg_match( '/ipad|tablet|playbook|silk|(android(?!.*mobile))/i', $user_agent ) ) {
			$device = 'tablet';
		} elseif ( preg_match( '/mobile|iphone|ipod|android.*mobile|windows phone|blackberry/i', $user_agent ) ) {
			$device = 'mobile';
		}

		$browser = 'Unknown';

		if ( preg_match( '/EdgA|EdgiOS|Edg\//i', $user_agent ) ) {
			$browser = ( 'mobile' === $device ) ? 'Edge Mobile' : 'Edge';
		} elseif ( preg_match( '/OPR\/|Opera/i', $user_agent ) ) {
			$browser = ( 'mobile' === $device ) ? 'Opera Mobile' : 'Opera';
		} elseif ( preg_match( '/SamsungBrowser/i', $user_agent ) ) {
			$browser = 'Samsung Internet';
		} elseif ( preg_match( '/CriOS/i', $user_agent ) ) {
			$browser = 'Chrome Mobile';
		} elseif ( preg_match( '/Chrome/i', $user_agent ) ) {
			$browser = ( 'mobile' === $device || 'tablet' === $device ) ? 'Chrome Mobile' : 'Chrome';
		} elseif ( preg_match( '/FxiOS/i', $user_agent ) ) {
			$browser = 'Firefox Mobile';
		} elseif ( preg_match( '/Firefox/i', $user_agent ) ) {
			$browser = ( 'mobile' === $device ) ? 'Firefox Mobile' : 'Firefox';
		} elseif ( preg_match( '/iPhone|iPad|iPod/i', $user_agent ) && preg_match( '/Safari/i', $user_agent ) ) {
			$browser = ( 'desktop' === $device ) ? 'Safari' : 'Mobile Safari';
		} elseif ( preg_match( '/Safari/i', $user_agent ) ) {
			$browser = 'Safari';
		}

		return array(
			'device_type'  => $device,
			'browser_name' => $browser,
		);
	}

	/**
	 * Resolves the visitor's country from the Cloudflare geo header, when present.
	 *
	 * This reads the inbound HTTP_CF_IPCOUNTRY request header only -- it never sends
	 * the visitor's IP (or any data) to a third-party service. Region is not
	 * available from a request header, so it is always empty.
	 */
	public static function get_geo() {
		$country = '';

		if ( ! empty( $_SERVER['HTTP_CF_IPCOUNTRY'] ) ) {
			$country = self::country_code_to_name(
				sanitize_text_field( wp_unslash( $_SERVER['HTTP_CF_IPCOUNTRY'] ) )
			);
		}

		return array(
			'visitor_country' => $country,
			'visitor_region'  => '',
		);
	}

	private static function country_code_to_name( $code ) {
		$code = strtoupper( trim( (string) $code ) );

		if ( '' === $code || 'XX' === $code || 'T1' === $code ) {
			return '';
		}

		if ( function_exists( 'locale_get_display_region' ) ) {
			$name = locale_get_display_region( 'und_' . $code, 'en' );

			if ( $name && $name !== $code ) {
				return $name;
			}
		}

		$map = array(
			'AE' => 'United Arab Emirates',
			'SA' => 'Saudi Arabia',
			'OM' => 'Oman',
			'QA' => 'Qatar',
			'BH' => 'Bahrain',
			'KW' => 'Kuwait',
			'US' => 'United States',
			'GB' => 'United Kingdom',
			'IN' => 'India',
			'PK' => 'Pakistan',
		);

		return $map[ $code ] ?? $code;
	}

	private static function is_public_ip( $ip ) {
		return (bool) filter_var(
			$ip,
			FILTER_VALIDATE_IP,
			FILTER_FLAG_NO_PRIV_RANGE | FILTER_FLAG_NO_RES_RANGE
		);
	}
}