<?php
declare(strict_types=1);

final class Calco2latoApiClient
{
    private string $baseUrl;
    private string $apiKey;
    private int $timeout;

    public function __construct(string $baseUrl, string $apiKey, int $timeoutSeconds = 10)
    {
        $this->baseUrl = rtrim($baseUrl, '/');
        $this->apiKey  = $apiKey;
        $this->timeout = $timeoutSeconds;
    }

    /**
     * Low-level request wrapper (GET/POST/DELETE/PUT/PATCH).
     * $query is appended to URL; $body (if provided) is JSON-encoded.
     */
    private function request(string $method, string $path, array $query = [], ?array $body = null): array
    {
        $url = $this->baseUrl . '/' . ltrim($path, '/');
        if (!empty($query)) {
            $url .= (str_contains($url, '?') ? '&' : '?') . http_build_query($query);
        }

        $ch = curl_init($url);
        $headers = [
            'Accept: application/json',
            'Authorization: Bearer ' . $this->apiKey,
        ];
        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_CUSTOMREQUEST  => strtoupper($method),
            CURLOPT_HTTPHEADER     => $headers,
            CURLOPT_TIMEOUT        => $this->timeout,
        ]);

        if ($body !== null) {
            $json = json_encode($body, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
            $headers[] = 'Content-Type: application/json';
            curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $json);
        }

        $responseBody = curl_exec($ch);
        $status       = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $err          = curl_error($ch);
        curl_close($ch);

        if ($responseBody === false) {
            throw new RuntimeException('cURL error: ' . $err);
        }

        $decoded = json_decode($responseBody, true);
        if ($decoded === null && json_last_error() !== JSON_ERROR_NONE) {
            throw new RuntimeException('Invalid JSON from API (HTTP ' . $status . '): ' . $responseBody);
        }

        if ($status < 200 || $status >= 300) {
            $msg = $decoded['error'] ?? $decoded['message'] ?? 'Upstream API error';
            throw new RuntimeException('API error (HTTP ' . $status . '): ' . $msg);
        }

        return $decoded;
    }

    // ---------- Airports ----------

    /** Search airports by free-text (IATA/ICAO/name/city/country) */
    public function searchAirports(string $q, int $per_page = 20, int $page = 0): array
    {
        return $this->request('GET', '/api/latest/airports', [
            'iata' => $q,
            'per_page' => $per_page,
            'page' => $page,
        ]);
    }

    /** Get a single airport by IATA or ICAO code */
    public function getAirport(string $code): array
    {
        return $this->request('GET', '/api/latest/airports/' . urlencode($code));
    }

    // ---------- Flights ----------

    /**
     * Get flight estimate / emissions (example – adjust to your API)
     * $params might include origin, destination, date, pax, class, etc.
     */
    public function flightEstimate(array $params): array
    {
        return $this->request('POST', '/api/latest/flights/estimate', [], $params);
    }

    /** Optional: resolve a route or fetch a published flight record */
    public function getFlightById(string $id): array
    {
        return $this->request('GET', '/api/latest/flights/' . urlencode($id));
    }
}