<?php

/*
 *
 * Copyright 2020 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
namespace DeliciousBrains\WP_Offload_Media\Gcp\Grpc;

/**
 * This is an experimental and incomplete implementation of gRPC server
 * for PHP. APIs are _definitely_ going to be changed.
 *
 * DO NOT USE in production.
 */
/**
 * Class RpcServer
 * @package Grpc
 */
class RpcServer extends Server
{
    // [ <String method_full_path> => MethodDescriptor ]
    private $paths_map = [];
    private function waitForNextEvent()
    {
        return $this->requestCall();
    }
    /**
     * Add a service to this server
     *
     * @param Object   $service      The service to be added
     */
    public function handle($service)
    {
        $methodDescriptors = $service->getMethodDescriptors();
        $exist_methods = \array_intersect_key($this->paths_map, $methodDescriptors);
        if (!empty($exist_methods)) {
            \fwrite(\STDERR, "WARNING: " . 'override already registered methods: ' . \implode(', ', \array_keys($exist_methods)) . \PHP_EOL);
        }
        $this->paths_map = \array_merge($this->paths_map, $methodDescriptors);
        return $this->paths_map;
    }
    public function run()
    {
        $this->start();
        while (\true) {
            try {
                // This blocks until the server receives a request
                $event = $this->waitForNextEvent();
                $full_path = $event->method;
                $context = new ServerContext($event);
                $server_writer = new ServerCallWriter($event->call, $context);
                if (!\array_key_exists($full_path, $this->paths_map)) {
                    $context->setStatus(Status::unimplemented());
                    $server_writer->finish();
                    continue;
                }
                $method_desc = $this->paths_map[$full_path];
                $server_reader = new ServerCallReader($event->call, $method_desc->request_type);
                try {
                    $this->processCall($method_desc, $server_reader, $server_writer, $context);
                } catch (\Exception $e) {
                    $context->setStatus(Status::status(STATUS_INTERNAL, $e->getMessage()));
                    $server_writer->finish();
                }
            } catch (\Exception $e) {
                \fwrite(\STDERR, "ERROR: " . $e->getMessage() . \PHP_EOL);
                exit(1);
            }
        }
    }
    private function processCall(MethodDescriptor $method_desc, ServerCallReader $server_reader, ServerCallWriter $server_writer, ServerContext $context)
    {
        // Dispatch to actual server logic
        switch ($method_desc->call_type) {
            case MethodDescriptor::UNARY_CALL:
                $request = $server_reader->read();
                $response = \call_user_func(array($method_desc->service, $method_desc->method_name), $request ?? new $method_desc->request_type(), $context);
                $server_writer->finish($response);
                break;
            case MethodDescriptor::SERVER_STREAMING_CALL:
                $request = $server_reader->read();
                \call_user_func(array($method_desc->service, $method_desc->method_name), $request ?? new $method_desc->request_type(), $server_writer, $context);
                break;
            case MethodDescriptor::CLIENT_STREAMING_CALL:
                $response = \call_user_func(array($method_desc->service, $method_desc->method_name), $server_reader, $context);
                $server_writer->finish($response);
                break;
            case MethodDescriptor::BIDI_STREAMING_CALL:
                \call_user_func(array($method_desc->service, $method_desc->method_name), $server_reader, $server_writer, $context);
                break;
            default:
                throw new \Exception();
        }
    }
}
