/*
 * This file is open source software, licensed to you under the terms
 * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
 * distributed with this work for additional information regarding copyright
 * ownership.  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.
 */
/*
 * Copyright (C) 2019 Red Hat, Inc.
 */ 

#include <seastar/testing/test_case.hh>
#include <seastar/core/seastar.hh>
#include <seastar/net/api.hh>
#include <seastar/net/inet_address.hh>
#include <seastar/core/print.hh>
#include <seastar/core/reactor.hh>
#include <seastar/core/thread.hh>
#include <seastar/util/log.hh>
#include <seastar/util/std-compat.hh>

using namespace seastar;
using std::string;
using namespace std::string_literals;
using namespace std::chrono_literals;

static logger iplog("unix_domain");

class ud_server_client {
public:
    ud_server_client(string server_path, std::optional<string> client_path, int rounds) :
        ud_server_client(server_path, client_path, rounds, 0) {};

    ud_server_client(string server_path, std::optional<string> client_path, int rounds,
                     int abort_run) :
        server_addr{unix_domain_addr{server_path}}, client_path{client_path},
                    rounds{rounds},
                    rounds_left{rounds}, abort_after{abort_run} {}

    future<> run();
    ud_server_client(ud_server_client&&) = default;
    ud_server_client(const ud_server_client&) = delete;

private:
    const string test_message{"are you still the same?"s};
    future<> init_server();
    future<> client_round();
    const socket_address server_addr;

    const std::optional<string> client_path;
    server_socket server;
    const int rounds;
    int rounds_left;
    server_socket* lstn_sock;
    seastar::thread th;
    int abort_after; // if set - force the listening socket down after that number of rounds
    bool planned_abort{false}; // set when abort_accept() is called
};

future<> ud_server_client::init_server() {
    return do_with(seastar::listen(server_addr), [this](server_socket& lstn) mutable {

        lstn_sock = &lstn; // required when aborting (on some tests)

        //  start the clients here, where we know the server is listening

        th = seastar::thread([this]{
            for (int i=0; i<rounds; ++i) {
                if (abort_after) {
                    if (--abort_after == 0) {
                        planned_abort = true;
                        lstn_sock->abort_accept();
                        break;
                    }
                }
                (void)client_round().get0();
            } 
        });

        return do_until([this](){return rounds_left<=0;}, [&lstn,this]() {
            return lstn.accept().then([this](accept_result from_accept) {
                connected_socket cn    = std::move(from_accept.connection);
                socket_address cn_addr = std::move(from_accept.remote_address);
                --rounds_left;
                //  verify the client address
                if (client_path) {
                    socket_address tmmp{unix_domain_addr{*client_path}};
                    BOOST_REQUIRE_EQUAL(cn_addr, socket_address{unix_domain_addr{*client_path}});
                }

                return do_with(cn.input(), cn.output(), [](auto& inp, auto& out) {

                    return inp.read().then([&out](auto bb) {
                        string ans = "-"s;
                        if (bb && bb.size()) {
                            ans = "+"s + string{bb.get(), bb.size()};
                        }
                        return out.write(ans).then([&out](){return out.flush();}).
                        then([&out](){return out.close();});
                    }).then([&inp]() { return inp.close(); }).
                    then([]() { return make_ready_future<>(); });

                }).then([]{ return make_ready_future<>();});
            });
        }).handle_exception([this](auto e) {
            // OK to get here only if the test was a "planned abort" one
            if (!planned_abort) {
                std::rethrow_exception(e);
            }
        }).finally([this]{
            return th.join();
        });
    });
}

/// Send a message to the server, and expect (almost) the same string back.
/// If 'client_path' is set, the client binds to the named path.
future<> ud_server_client::client_round() {
    auto cc = client_path ? 
        engine().net().connect(server_addr, socket_address{unix_domain_addr{*client_path}}).get0() :
        engine().net().connect(server_addr).get0();

    return do_with(cc.input(), cc.output(), [this](auto& inp, auto& out) {

        return out.write(test_message).then(
            [&out](){ return out.flush(); }).then(
            [&inp](){ return inp.read(); }).then(
            [this,&inp](auto bb){
                BOOST_REQUIRE_EQUAL(std::string_view(bb.begin(), bb.size()), "+"s+test_message);
                return inp.close();
            }).then([&out](){return out.close();}).then(
            []{ return make_ready_future<>(); });
    });

}

future<> ud_server_client::run() {
    return async([this] {
        auto serverfut = init_server();
        (void)serverfut.get();
    });

}

//  testing the various address types, both on the server and on the
//  client side

SEASTAR_TEST_CASE(unixdomain_server) {
    system("rm -f /tmp/ry");
    ud_server_client uds("/tmp/ry", std::nullopt, 3);
    return do_with(std::move(uds), [](auto& uds){
        return uds.run();
    });
    return make_ready_future<>();
}

SEASTAR_TEST_CASE(unixdomain_abs) {
    char sv_name[]{'\0', '1', '1', '1'};
    //ud_server_client uds(string{"\0111",4}, string{"\0112",4}, 1);
    ud_server_client uds(string{sv_name,4}, std::nullopt, 4);
    return do_with(std::move(uds), [](auto& uds){
        return uds.run();
    });
    //return make_ready_future<>();
}

SEASTAR_TEST_CASE(unixdomain_abs_bind) {
    char sv_name[]{'\0', '1', '1', '1'};
    char cl_name[]{'\0', '1', '1', '2'};
    ud_server_client uds(string{sv_name,4}, string{cl_name,4}, 1);
    return do_with(std::move(uds), [](auto& uds){
        return uds.run();
    });
}

SEASTAR_TEST_CASE(unixdomain_abs_bind_2) {
    char sv_name[]{'\0', '1', '\0', '\12', '1'};
    char cl_name[]{'\0', '1', '\0', '\12', '2'};
    ud_server_client uds(string{sv_name,5}, string{cl_name,5}, 2);
    return do_with(std::move(uds), [](auto& uds){
        return uds.run();
    });
}

SEASTAR_TEST_CASE(unixdomain_text) {
    socket_address addr1{unix_domain_addr{"abc"}};
    BOOST_REQUIRE_EQUAL(format("{}", addr1), "abc");
    socket_address addr2{unix_domain_addr{""}};
    BOOST_REQUIRE_EQUAL(format("{}", addr2), "{unnamed}");
    socket_address addr3{unix_domain_addr{std::string("\0abc", 5)}};
    BOOST_REQUIRE_EQUAL(format("{}", addr3), "@abc_");
    return make_ready_future<>();
}

SEASTAR_TEST_CASE(unixdomain_bind) {
    system("rm -f 111 112");
    ud_server_client uds("111"s, "112"s, 1);
    return do_with(std::move(uds), [](auto& uds){
        return uds.run();
    });
}

SEASTAR_TEST_CASE(unixdomain_short) {
    system("rm -f 3");
    ud_server_client uds("3"s, std::nullopt, 10);
    return do_with(std::move(uds), [](auto& uds){
        return uds.run();
    });
}

//  test our ability to abort the accept()'ing on a socket.
//  The test covers a specific bug in the handling of abort_accept()
SEASTAR_TEST_CASE(unixdomain_abort) {
    std::string sockname{"7"s}; // note: no portable & warnings-free option
    std::ignore = ::unlink(sockname.c_str());
    ud_server_client uds(sockname, std::nullopt, 10, 4);
    return do_with(std::move(uds), [sockname](auto& uds){
        return uds.run().finally([sockname](){
            std::ignore = ::unlink(sockname.c_str());
            return seastar::make_ready_future<>();
        });
    });
}