<?php
/**
 * qbirr — PHP client for the qbirr payment verification API.
 *
 *   $qb = new Qbirr\Qbirr('your_api_key');
 *   $r  = $qb->verify([
 *       'provider' => 'cbe',
 *       'ref' => 'FT23001234ABC',
 *       'amount' => 500,
 *       'receiver_name' => 'YOUR NAME',
 *       'receiver_account' => '1000017692643',
 *   ]);
 *   if ($r['verified']) echo "Paid by " . $r['payer'];
 */

declare(strict_types=1);

namespace Qbirr;

class QbirrException extends \RuntimeException {
    public ?int $status;
    public $body;
    public function __construct(string $msg, ?int $status = null, $body = null) {
        parent::__construct($msg);
        $this->status = $status;
        $this->body   = $body;
    }
}

class Qbirr {
    public const VERSION = '1.0.0';
    public const DEFAULT_BASE_URL = 'https://verify.qbirr.com';

    private string $apiKey;
    private string $baseUrl;
    private int    $timeoutSec;

    public function __construct(string $apiKey, string $baseUrl = self::DEFAULT_BASE_URL, int $timeoutSec = 30) {
        if ($apiKey === '') throw new QbirrException('apiKey is required');
        $this->apiKey     = $apiKey;
        $this->baseUrl    = rtrim($baseUrl, '/');
        $this->timeoutSec = $timeoutSec;
    }

    /**
     * Verify a transaction.
     *
     * @param array $req {
     *   provider:         cbe | telebirr | abyssinia | dashen | mpesa | awash | ebirr
     *   ref:              Transaction ref. For awash, SMS URL or token. For ebirr, "tenant/token" or URL.
     *   amount:           Expected payment in ETB.
     *   receiver_name:    Your receiving account name.
     *   receiver_account: Required for cbe and abyssinia.
     * }
     * @return array { verified: bool, payer: string, amount: float, error: string }
     */
    public function verify(array $req): array {
        $body = [
            'provider'      => $req['provider']      ?? '',
            'ref'           => $req['ref']           ?? '',
            'amount'        => $req['amount']        ?? 0,
            'receiver_name' => $req['receiver_name'] ?? '',
        ];
        if (!empty($req['receiver_account'])) $body['receiver_account'] = $req['receiver_account'];

        $data = $this->request('POST', '/api/v1/verify', $body);
        return [
            'verified' => (bool)   ($data['verified'] ?? false),
            'payer'    => (string) ($data['payer']    ?? ''),
            'amount'   => (float)  ($data['amount']   ?? 0),
            'error'    => (string) ($data['error']    ?? ''),
        ];
    }

    /**
     * @return array { used, limit, remaining, plan, period_start, period_end }
     */
    public function usage(): array {
        return $this->request('GET', '/api/v1/usage');
    }

    /**
     * Verify by uploading a receipt PDF or image.
     *
     * @param array $req { provider, amount, receiver_name, [receiver_account], filePath }
     *   OR { provider, ..., fileContent, fileName, mimeType }
     */
    public function verifyUpload(array $req): array {
        if (isset($req['filePath'])) {
            $fileContent = file_get_contents($req['filePath']);
            if ($fileContent === false) throw new QbirrException("Could not read file: " . $req['filePath']);
            $fileName = basename($req['filePath']);
            $mimeType = mime_content_type($req['filePath']) ?: 'application/octet-stream';
        } else {
            $fileContent = $req['fileContent'] ?? '';
            $fileName    = $req['fileName']    ?? 'upload.pdf';
            $mimeType    = $req['mimeType']    ?? 'application/octet-stream';
        }
        if ($fileContent === '') throw new QbirrException("Empty file content");

        $boundary = '----qbirrphp' . bin2hex(random_bytes(8));
        $body = '';
        foreach (['provider', 'amount', 'receiver_name', 'receiver_account'] as $k) {
            if (isset($req[$k]) && $req[$k] !== '') {
                $body .= "--{$boundary}\r\n"
                       . "Content-Disposition: form-data; name=\"{$k}\"\r\n\r\n"
                       . $req[$k] . "\r\n";
            }
        }
        $body .= "--{$boundary}\r\n"
               . "Content-Disposition: form-data; name=\"file\"; filename=\"{$fileName}\"\r\n"
               . "Content-Type: {$mimeType}\r\n\r\n"
               . $fileContent . "\r\n"
               . "--{$boundary}--\r\n";

        $ch = curl_init();
        curl_setopt_array($ch, [
            CURLOPT_URL            => $this->baseUrl . '/api/v1/verify/upload',
            CURLOPT_POST           => true,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => $this->timeoutSec + 30,
            CURLOPT_HTTPHEADER     => [
                'X-API-Key: ' . $this->apiKey,
                'Content-Type: multipart/form-data; boundary=' . $boundary,
                'Accept: application/json',
                'User-Agent: qbirr-php/' . self::VERSION,
            ],
            CURLOPT_POSTFIELDS => $body,
        ]);
        $raw  = curl_exec($ch);
        $err  = curl_error($ch);
        $code = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($raw === false) throw new QbirrException("Network error: $err");
        $data = json_decode((string) $raw, true);
        if (!is_array($data)) throw new QbirrException("Non-JSON response (HTTP $code)", $code, $raw);
        if ($code < 200 || $code >= 300) {
            throw new QbirrException((string)($data['error'] ?? "HTTP $code"), $code, $data);
        }
        return [
            'verified' => (bool)   ($data['verified'] ?? false),
            'payer'    => (string) ($data['payer']    ?? ''),
            'amount'   => (float)  ($data['amount']   ?? 0),
            'error'    => (string) ($data['error']    ?? ''),
        ];
    }

    private function request(string $method, string $path, ?array $body = null): array {
        $ch = curl_init();
        curl_setopt_array($ch, [
            CURLOPT_URL            => $this->baseUrl . $path,
            CURLOPT_CUSTOMREQUEST  => $method,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => $this->timeoutSec,
            CURLOPT_HTTPHEADER     => [
                'X-API-Key: ' . $this->apiKey,
                'Content-Type: application/json',
                'Accept: application/json',
                'User-Agent: qbirr-php/' . self::VERSION,
            ],
        ]);
        if ($body !== null) {
            curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($body));
        }

        $raw  = curl_exec($ch);
        $err  = curl_error($ch);
        $code = (int) curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($raw === false) throw new QbirrException("Network error: $err");

        $data = json_decode((string) $raw, true);
        if (!is_array($data)) {
            throw new QbirrException("Non-JSON response (HTTP $code)", $code, $raw);
        }
        if ($code < 200 || $code >= 300) {
            $msg = $data['error'] ?? "HTTP $code";
            throw new QbirrException((string) $msg, $code, $data);
        }
        return $data;
    }
}