<?php

declare(strict_types=1);

/**
 * Client PHP minimal pour l'API ClientZen v1 (aucune dépendance : cURL + json).
 * Usage :
 *   $cz = new ClientZenClient('czk_…');                 // jeton créé dans Paramètres › API et webhooks
 *   $clients = $cz->get('/customers', ['q' => 'Petit']);
 *   $client  = $cz->post('/customers', [...], idempotencyKey: 'commande-1234');
 * Erreurs : ClientZenApiException (statut HTTP + problème RFC 9457 dans ->problem).
 */
final class ClientZenClient
{
    public function __construct(private readonly string $token, private readonly string $baseUrl = 'https://clientzen.fr/api/v1', private readonly int $timeout = 15) {}

    /** @param array<string, scalar> $query @return array<string, mixed> */
    public function get(string $path, array $query = []): array
    {
        return $this->request('GET', $path.($query !== [] ? '?'.http_build_query($query) : ''));
    }

    /** @param array<string, mixed> $body @return array<string, mixed> */
    public function post(string $path, array $body, ?string $idempotencyKey = null): array
    {
        return $this->request('POST', $path, $body, $idempotencyKey);
    }

    /** @param array<string, mixed> $body @return array<string, mixed> */
    public function patch(string $path, array $body): array
    {
        return $this->request('PATCH', $path, $body);
    }

    /** Télécharge un binaire (ex. /invoices/{id}/pdf). */
    public function download(string $path): string
    {
        [$status, $raw] = $this->raw('GET', $path, null, null, 'application/pdf');
        if ($status >= 400) {
            throw ClientZenApiException::fromResponse($status, $raw);
        }

        return $raw;
    }

    /** Itère toutes les pages d'une liste. @param array<string, scalar> $query @return iterable<array<string, mixed>> */
    public function each(string $path, array $query = []): iterable
    {
        $page = 1;
        do {
            $res = $this->get($path, $query + ['page' => $page, 'per_page' => 100]);
            foreach ($res['data'] ?? [] as $row) {
                yield $row;
            }
            $page++;
        } while (($res['meta']['last_page'] ?? 1) >= $page);
    }

    /** @param array<string, mixed>|null $body @return array<string, mixed> */
    private function request(string $method, string $path, ?array $body = null, ?string $idempotencyKey = null): array
    {
        [$status, $raw] = $this->raw($method, $path, $body, $idempotencyKey, 'application/json');
        $json = json_decode($raw, true);
        if ($status >= 400) {
            throw ClientZenApiException::fromResponse($status, $raw);
        }

        return is_array($json) ? $json : [];
    }

    /** @param array<string, mixed>|null $body @return array{0: int, 1: string} */
    private function raw(string $method, string $path, ?array $body, ?string $idempotencyKey, string $accept): array
    {
        $headers = ['Authorization: Bearer '.$this->token, 'Accept: '.$accept, 'User-Agent: ClientZen-PHP-SDK/1'];
        $ch = curl_init($this->baseUrl.$path);
        if ($ch === false) {
            throw new RuntimeException('cURL indisponible.');
        }
        if ($body !== null) {
            $headers[] = 'Content-Type: application/json';
            curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($body, JSON_THROW_ON_ERROR));
        }
        if ($idempotencyKey !== null) {
            $headers[] = 'Idempotency-Key: '.$idempotencyKey;
        }
        curl_setopt_array($ch, [CURLOPT_CUSTOMREQUEST => $method, CURLOPT_HTTPHEADER => $headers, CURLOPT_RETURNTRANSFER => true, CURLOPT_TIMEOUT => $this->timeout, CURLOPT_FOLLOWLOCATION => false]);
        $raw = curl_exec($ch);
        $status = (int) curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
        $error = curl_error($ch);
        curl_close($ch);
        if ($raw === false) {
            throw new RuntimeException('Erreur réseau : '.$error);
        }

        return [$status, (string) $raw];
    }
}

final class ClientZenApiException extends RuntimeException
{
    /** @param array<string, mixed> $problem */
    public function __construct(public readonly int $status, public readonly array $problem)
    {
        parent::__construct(sprintf('ClientZen API %d : %s%s', $status, (string) ($problem['title'] ?? 'erreur'), isset($problem['detail']) ? ' — '.$problem['detail'] : ''));
    }

    public static function fromResponse(int $status, string $raw): self
    {
        $json = json_decode($raw, true);

        return new self($status, is_array($json) ? $json : ['title' => 'Réponse non JSON']);
    }
}