<?php
declare(strict_types=1);

require_once __DIR__ . '/../../modules/shared/db.php';
require_once __DIR__ . '/../../modules/market_management/mcp.php';

final class MarketManagementMcpJsonRpcException extends RuntimeException
{
    public function __construct(private int $rpcCode, string $message, ?Throwable $previous = null)
    {
        parent::__construct($message, 0, $previous);
    }

    public function rpcCode(): int
    {
        return $this->rpcCode;
    }
}

header('Content-Type: application/json; charset=utf-8');
header('Cache-Control: no-store');

$env = expand_env_values(parse_env_file(__DIR__ . '/../../.env'));

try {
    $userSubject = market_management_mcp_authorize($env);
    $pdo = connect_database($env);
    $body = file_get_contents('php://input');
    $request = json_decode($body === false ? '' : $body, true, 512, JSON_THROW_ON_ERROR);
    if (!is_array($request) || ($request['jsonrpc'] ?? '') !== '2.0') {
        throw new InvalidArgumentException('Ungültige JSON-RPC-Anfrage.');
    }

    if (array_key_exists('params', $request) && !is_array($request['params'])) {
        throw new MarketManagementMcpJsonRpcException(-32602, 'Parameter müssen als Objekt oder Array übergeben werden.');
    }

    $id = $request['id'] ?? null;
    $method = (string) ($request['method'] ?? '');
    $params = is_array($request['params'] ?? null) ? $request['params'] : [];

    if ($method === 'initialize') {
        $result = [
            'protocolVersion' => (string) ($params['protocolVersion'] ?? '2025-03-26'),
            'capabilities' => ['tools' => ['listChanged' => false]],
            'serverInfo' => ['name' => 'naurua-market-management', 'version' => '1.0.0'],
        ];
    } elseif ($method === 'notifications/initialized') {
        http_response_code(202);
        exit;
    } elseif ($method === 'tools/list') {
        $result = ['tools' => market_management_mcp_tools()];
    } elseif ($method === 'tools/call') {
        $tool = (string) ($params['name'] ?? '');
        $arguments = is_array($params['arguments'] ?? null) ? $params['arguments'] : [];
        if (array_key_exists('arguments', $params) && !is_array($params['arguments'])) {
            throw new MarketManagementMcpJsonRpcException(-32602, 'Tool-Argumente müssen als Objekt übergeben werden.');
        }
        try {
            $result = [
                'content' => [[
                    'type' => 'text',
                    'text' => json_encode(market_management_mcp_call_idempotent($pdo, $userSubject, $tool, $arguments), JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_THROW_ON_ERROR),
                ]],
                'isError' => false,
            ];
        } catch (InvalidArgumentException $e) {
            throw new MarketManagementMcpJsonRpcException(-32602, $e->getMessage(), $e);
        }
    } else {
        throw new MarketManagementMcpJsonRpcException(-32601, 'Unbekannte JSON-RPC-Methode: ' . $method);
    }

    echo json_encode(['jsonrpc' => '2.0', 'id' => $id, 'result' => $result], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_THROW_ON_ERROR);
} catch (Throwable $e) {
    $isAuthError = $e instanceof RuntimeException && str_contains($e->getMessage(), 'Token');
    $isJsonRpcError = $e instanceof MarketManagementMcpJsonRpcException;
    http_response_code($isJsonRpcError ? 200 : ($isAuthError ? 401 : 400));
    echo json_encode([
        'jsonrpc' => '2.0',
        'id' => $request['id'] ?? null,
        'error' => [
            'code' => $isJsonRpcError ? $e->rpcCode() : -32600,
            'message' => $e->getMessage(),
        ],
    ], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
}