<?php
/**
 * Geocoder class for address lookup
 *
 * Uses Nominatim (OpenStreetMap) for free geocoding.
 * Results are cached in transients to minimize API calls.
 */

if (!defined('ABSPATH')) {
    exit;
}

class MLS_Geocoder {

    /**
     * Cache expiration in seconds (30 days)
     */
    const CACHE_EXPIRATION = 2592000;

    /**
     * Nominatim API endpoint
     */
    const API_URL = 'https://nominatim.openstreetmap.org/search';

    /**
     * Geocode an address string
     *
     * @param string $address Full address string
     * @return array|null Geocoding result or null on failure
     */
    public function geocode($address) {
        if (empty($address)) {
            return null;
        }

        // Normalize address for cache key
        $cache_key = 'mls_geo_' . md5(strtolower(trim($address)));

        // Check cache
        $cached = get_transient($cache_key);
        if ($cached !== false) {
            return $cached;
        }

        // Make API request
        $result = $this->fetch_geocode($address);

        if ($result) {
            // Cache the result
            set_transient($cache_key, $result, self::CACHE_EXPIRATION);
        }

        return $result;
    }

    /**
     * Fetch geocoding data from Nominatim
     *
     * @param string $address
     * @return array|null
     */
    private function fetch_geocode($address) {
        // Build request URL
        $url = add_query_arg(array(
            'q' => $address,
            'format' => 'json',
            'addressdetails' => 1,
            'limit' => 1,
            'countrycodes' => 'us',
        ), self::API_URL);

        // Make request with proper User-Agent (required by Nominatim)
        $response = wp_remote_get($url, array(
            'timeout' => 10,
            'headers' => array(
                'User-Agent' => 'HomeProz WordPress MLS Plugin/1.0 (contact@homeproz.com)',
            ),
        ));

        if (is_wp_error($response)) {
            return null;
        }

        $body = wp_remote_retrieve_body($response);
        $data = json_decode($body, true);

        if (empty($data) || !is_array($data) || empty($data[0])) {
            return null;
        }

        $result = $data[0];
        $addr = $result['address'] ?? array();

        // Extract components
        return array(
            'latitude' => isset($result['lat']) ? (float) $result['lat'] : null,
            'longitude' => isset($result['lon']) ? (float) $result['lon'] : null,
            'city' => $this->extract_city($addr),
            'state' => $addr['state'] ?? null,
            'state_code' => $this->get_state_code($addr['state'] ?? ''),
            'postal_code' => $addr['postcode'] ?? null,
            'county' => isset($addr['county']) ? str_replace(' County', '', $addr['county']) : null,
            'country' => $addr['country'] ?? null,
            'display_name' => $result['display_name'] ?? null,
        );
    }

    /**
     * Extract city from address components
     *
     * Nominatim may return city in different fields depending on location type
     *
     * @param array $addr Address components
     * @return string|null
     */
    private function extract_city($addr) {
        // Try different fields where city might be
        $city_fields = array('city', 'town', 'village', 'municipality', 'hamlet');

        foreach ($city_fields as $field) {
            if (!empty($addr[$field])) {
                return $addr[$field];
            }
        }

        return null;
    }

    /**
     * Get state code from state name
     *
     * @param string $state_name Full state name
     * @return string|null Two-letter state code
     */
    private function get_state_code($state_name) {
        $states = array(
            'Alabama' => 'AL',
            'Alaska' => 'AK',
            'Arizona' => 'AZ',
            'Arkansas' => 'AR',
            'California' => 'CA',
            'Colorado' => 'CO',
            'Connecticut' => 'CT',
            'Delaware' => 'DE',
            'Florida' => 'FL',
            'Georgia' => 'GA',
            'Hawaii' => 'HI',
            'Idaho' => 'ID',
            'Illinois' => 'IL',
            'Indiana' => 'IN',
            'Iowa' => 'IA',
            'Kansas' => 'KS',
            'Kentucky' => 'KY',
            'Louisiana' => 'LA',
            'Maine' => 'ME',
            'Maryland' => 'MD',
            'Massachusetts' => 'MA',
            'Michigan' => 'MI',
            'Minnesota' => 'MN',
            'Mississippi' => 'MS',
            'Missouri' => 'MO',
            'Montana' => 'MT',
            'Nebraska' => 'NE',
            'Nevada' => 'NV',
            'New Hampshire' => 'NH',
            'New Jersey' => 'NJ',
            'New Mexico' => 'NM',
            'New York' => 'NY',
            'North Carolina' => 'NC',
            'North Dakota' => 'ND',
            'Ohio' => 'OH',
            'Oklahoma' => 'OK',
            'Oregon' => 'OR',
            'Pennsylvania' => 'PA',
            'Rhode Island' => 'RI',
            'South Carolina' => 'SC',
            'South Dakota' => 'SD',
            'Tennessee' => 'TN',
            'Texas' => 'TX',
            'Utah' => 'UT',
            'Vermont' => 'VT',
            'Virginia' => 'VA',
            'Washington' => 'WA',
            'West Virginia' => 'WV',
            'Wisconsin' => 'WI',
            'Wyoming' => 'WY',
        );

        // If already a code, return as-is
        if (strlen($state_name) === 2) {
            return strtoupper($state_name);
        }

        return $states[$state_name] ?? null;
    }

    /**
     * Reverse geocode coordinates to address
     *
     * @param float $lat Latitude
     * @param float $lng Longitude
     * @return array|null Address components or null on failure
     */
    public function reverse_geocode($lat, $lng) {
        $cache_key = 'mls_rgeo_' . md5($lat . '_' . $lng);

        $cached = get_transient($cache_key);
        if ($cached !== false) {
            return $cached;
        }

        $url = add_query_arg(array(
            'lat' => $lat,
            'lon' => $lng,
            'format' => 'json',
            'addressdetails' => 1,
        ), 'https://nominatim.openstreetmap.org/reverse');

        $response = wp_remote_get($url, array(
            'timeout' => 10,
            'headers' => array(
                'User-Agent' => 'HomeProz WordPress MLS Plugin/1.0 (contact@homeproz.com)',
            ),
        ));

        if (is_wp_error($response)) {
            return null;
        }

        $body = wp_remote_retrieve_body($response);
        $data = json_decode($body, true);

        if (empty($data) || !isset($data['address'])) {
            return null;
        }

        $addr = $data['address'];

        $result = array(
            'latitude' => (float) $lat,
            'longitude' => (float) $lng,
            'city' => $this->extract_city($addr),
            'state' => $addr['state'] ?? null,
            'state_code' => $this->get_state_code($addr['state'] ?? ''),
            'postal_code' => $addr['postcode'] ?? null,
            'county' => isset($addr['county']) ? str_replace(' County', '', $addr['county']) : null,
            'display_name' => $data['display_name'] ?? null,
        );

        set_transient($cache_key, $result, self::CACHE_EXPIRATION);

        return $result;
    }

    /**
     * Clear geocoding cache for an address
     *
     * @param string $address
     */
    public function clear_cache($address) {
        $cache_key = 'mls_geo_' . md5(strtolower(trim($address)));
        delete_transient($cache_key);
    }
}