<?php
/**
 * Postcode Service - Handles postcode lookup via postcode.tech API
 * with fallback to openpostcode.nl API
 */

class PostcodeService
{
    /**
     * Lookup address by postcode and house number
     * Uses postcode.tech as primary, falls back to openpostcode.nl
     *
     * @param string $postcode
     * @param string $number
     * @return array
     */
    public static function lookup(string $postcode, string $number): array
    {
        $postcode = strtoupper(str_replace(' ', '', $postcode));
        
        if (empty($postcode) || empty($number)) {
            return [
                'success' => false,
                'error' => 'Postcode en huisnummer zijn verplicht',
                'http_code' => 400
            ];
        }
        
        // Try primary service (postcode.tech)
        $result = self::lookupPostcodeTech($postcode, $number);
        
        // If primary service fails (server error or timeout), try fallback
        if (!$result['success'] && $result['http_code'] >= 500) {
            $result = self::lookupOpenPostcode($postcode, $number);
        }
        
        return $result;
    }
    
    /**
     * Lookup via postcode.tech API (primary)
     *
     * @param string $postcode
     * @param string $number
     * @return array
     */
    private static function lookupPostcodeTech(string $postcode, string $number): array
    {
        $url = "https://postcode.tech/api/v1/postcode?postcode={$postcode}&number={$number}";
        
        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HTTPHEADER, [
            "Authorization: Bearer " . $_ENV['POSTCODE_TECH_KEY']
        ]);
        curl_setopt($ch, CURLOPT_TIMEOUT, 10);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 5);
        
        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $curlError = curl_error($ch);
        curl_close($ch);
        
        if ($curlError || $httpCode >= 500) {
            return [
                'success' => false,
                'error' => 'Postcode.tech service niet bereikbaar',
                'details' => $curlError,
                'http_code' => 503
            ];
        }
        
        if ($httpCode >= 400) {
            return [
                'success' => false,
                'error' => self::translateErrorMessage($response, $httpCode),
                'http_code' => $httpCode
            ];
        }
        
        $data = json_decode($response, true);
        
        return [
            'success' => true,
            'data' => $data,
            'http_code' => 200
        ];
    }
    
    /**
     * Lookup via openpostcode.nl API (fallback)
     * No authentication required
     *
     * @param string $postcode
     * @param string $number
     * @return array
     */
    private static function lookupOpenPostcode(string $postcode, string $number): array
    {
        $url = "https://openpostcode.nl/api/address?postcode={$postcode}&huisnummer={$number}";
        
        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_TIMEOUT, 10);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 5);
        
        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $curlError = curl_error($ch);
        curl_close($ch);
        
        if ($curlError || $httpCode >= 500) {
            return [
                'success' => false,
                'error' => 'Postcode service niet bereikbaar, vul straat en woonplaats zelf in',
                'details' => $curlError,
                'http_code' => 503
            ];
        }
        
        if ($httpCode >= 400) {
            return [
                'success' => false,
                'error' => self::translateErrorMessage($response, $httpCode),
                'http_code' => $httpCode
            ];
        }
        
        $data = json_decode($response, true);
        
        // Transform openpostcode.nl response to match postcode.tech format
        $transformedData = self::transformOpenPostcodeResponse($data);
        
        return [
            'success' => true,
            'data' => $transformedData,
            'http_code' => 200
        ];
    }
    
    /**
     * Transform openpostcode.nl response to match postcode.tech format
     *
     * openpostcode.nl returns:
     * - postcode, huisnummer, straat, buurt, wijk, woonplaats, gemeente, provincie, latitude, longitude
     *
     * postcode.tech returns:
     * - postcode, number, street, city, municipality, province, geo (lat, lng)
     *
     * @param array $data
     * @return array
     */
    private static function transformOpenPostcodeResponse(array $data): array
    {
        return [
            'postcode' => $data['postcode'] ?? '',
            'number' => $data['huisnummer'] ?? '',
            'street' => $data['straat'] ?? '',
            'city' => $data['woonplaats'] ?? '',
            'municipality' => $data['gemeente'] ?? '',
            'province' => $data['provincie'] ?? '',
            'geo' => [
                'lat' => $data['latitude'] ?? null,
                'lng' => $data['longitude'] ?? null
            ]
        ];
    }
    
    /**
     * Translate API error messages to user-friendly Dutch messages
     *
     * @param string $response Raw API response
     * @param int $httpCode HTTP status code
     * @return string User-friendly error message in Dutch
     */
    private static function translateErrorMessage(string $response, int $httpCode): string
    {
        $decoded = json_decode($response, true);
        $apiError = ($decoded && isset($decoded['error'])) ? strtolower($decoded['error']) : '';
        
        // Map common API error messages to Dutch user-friendly messages
        if (strpos($apiError, 'huisnummer not found') !== false ||
            strpos($apiError, 'house number not found') !== false ||
            strpos($apiError, 'number not found') !== false) {
            return 'Dit huisnummer is niet gevonden bij deze postcode. Controleer het huisnummer of vul het adres handmatig in.';
        }
        
        if (strpos($apiError, 'postcode not found') !== false ||
            strpos($apiError, 'invalid postcode') !== false) {
            return 'Deze postcode is niet gevonden. Controleer de postcode of vul het adres handmatig in.';
        }
        
        if (strpos($apiError, 'invalid') !== false) {
            return 'Ongeldige invoer. Controleer de postcode en het huisnummer.';
        }
        
        if ($httpCode === 404) {
            return 'Adres niet gevonden. Controleer de postcode en het huisnummer of vul het adres handmatig in.';
        }
        
        if ($httpCode === 429) {
            return 'Te veel verzoeken. Probeer het later opnieuw of vul het adres handmatig in.';
        }
        
        // Default message
        return 'Adres niet gevonden. Vul straat en woonplaats handmatig in.';
    }
}