<?php

namespace WP_Statistics\Service\Geolocation\Provider;

use WP_STATISTICS\Country;
use WP_STATISTICS\IP;
use WP_Statistics\Service\Geolocation\AbstractGeoIPProvider;
use Exception;

class CloudflareGeolocationProvider extends AbstractGeoIPProvider
{
    /**
     * Static method to check if Cloudflare geolocation headers are available
     *
     * @return bool 
     */
    public static function isAvailable()
    {
        if (empty(IP::getCloudflareIp())) {
            return false;
        }

        $headers = [
            'HTTP_CF_IPCOUNTRY',
            'HTTP_CF_IPCONTINENT',
            'HTTP_CF_REGION',
            'HTTP_CF_IPCITY',
            'HTTP_CF_IPLATITUDE',
            'HTTP_CF_IPLONGITUDE',
            'HTTP_CF_POSTAL_CODE'
        ];

        foreach ($headers as $header) {
            if (empty(filter_input(INPUT_SERVER, $header))) {
                return false;
            }
        }

        return true;
    }

    /**
     * Static method to check if the server is behind Cloudflare.
     *
     * @return bool
     */
    public static function isBehindCloudflare() {
        return isset($_SERVER['HTTP_CF_CONNECTING_IP']) || isset($_SERVER['HTTP_CF_IPCOUNTRY']);
    }

    /**
     * Fetch geolocation data.
     *
     * @param string $ipAddress
     * @return array
     * @throws Exception
     */
    public function fetchGeolocationData(string $ipAddress)
    {
        $rawData       = $this->getCloudflareHeaders();
        $sanitizedData = $this->sanitizeHeaderData($rawData);

        return [
            'country'      => Country::getName($sanitizedData['country_code']),
            'country_code' => $sanitizedData['country_code'],
            'continent'    => $this->getContinentName($sanitizedData['continent']),
            'region'       => $sanitizedData['region'],
            'city'         => $sanitizedData['city'],
            'latitude'     => $sanitizedData['latitude'],
            'longitude'    => $sanitizedData['longitude'],
            'postal_code'  => $sanitizedData['postal_code']
        ];
    }

    /**
     * Get all Cloudflare headers using filter_input.
     *
     * @return array Raw header data
     */
    private function getCloudflareHeaders()
    {
        return [
            'country_code' => filter_input(INPUT_SERVER, 'HTTP_CF_IPCOUNTRY', FILTER_DEFAULT),
            'continent'    => filter_input(INPUT_SERVER, 'HTTP_CF_IPCONTINENT', FILTER_DEFAULT),
            'region'       => filter_input(INPUT_SERVER, 'HTTP_CF_REGION', FILTER_DEFAULT),
            'city'         => filter_input(INPUT_SERVER, 'HTTP_CF_IPCITY', FILTER_DEFAULT),
            'latitude'     => filter_input(INPUT_SERVER, 'HTTP_CF_IPLATITUDE', FILTER_VALIDATE_FLOAT),
            'longitude'    => filter_input(INPUT_SERVER, 'HTTP_CF_IPLONGITUDE', FILTER_VALIDATE_FLOAT),
            'postal_code'  => filter_input(INPUT_SERVER, 'HTTP_CF_POSTAL_CODE', FILTER_DEFAULT)
        ];
    }

    /**
     * Sanitize header string data.
     *
     * @param array $data Raw header data
     * @return array Sanitized header data
     */
    private function sanitizeHeaderData(array $data)
    {
        $stringFields = ['country_code', 'continent', 'region', 'city', 'postal_code'];

        foreach ($stringFields as $field) {
            $data[$field] = $data[$field] ?
                htmlspecialchars($data[$field], ENT_QUOTES, 'UTF-8') :
                null;
        }

        return $data;
    }

    /**
     * Get continent full name from code.
     *
     * @param string|null $code Continent code.
     * 
     * @return string|null Continent name or null.
     */
    protected function getContinentName($code)
    {
        if (empty($code)) {
            return null;
        }

        $continents = [
            'AF' => 'Africa',
            'AN' => 'Antarctica',
            'AS' => 'Asia',
            'EU' => 'Europe',
            'NA' => 'North America',
            'OC' => 'Oceania',
            'SA' => 'South America'
        ];

        return $continents[$code] ?? null;
    }

    public function getDownloadUrl()
    {
        return '';
    }

    public function downloadDatabase()
    {
        return [];
    }

    public function getDatabaseType()
    {
        return '';
    }

    public function validateDatabaseFile() {}
}