/*
 * Copyright 2015 ScyllaDB
 */

/*
 * This file is part of Scylla.
 *
 * Scylla is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Scylla is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Scylla.  If not, see <http://www.gnu.org/licenses/>.
 */

#define BOOST_TEST_DYN_LINK

#include <random>
#include <bitset>
#include <boost/test/unit_test.hpp>
#include <boost/range/irange.hpp>
#include <seastar/core/semaphore.hh>

#include "tests/test-utils.hh"
#include "utils/flush_queue.hh"

#include <iostream>

std::random_device rd;
std::default_random_engine e1(rd());

SEASTAR_TEST_CASE(test_queue_ordering_random_ops) {
    struct env {
        env(size_t n) : promises(n) {}

        utils::flush_queue<int> queue;
        std::vector<promise<>> promises;
        std::vector<int> result;
        promise<> end;
    };

    auto r = boost::irange(0, 20);

    return do_for_each(r, [](int) {
        constexpr size_t num_ops = 1000;

        auto e = make_lw_shared<env>(num_ops);

        int i = 0;
        for (auto& p : e->promises) {
            e->queue.run_with_ordered_post_op(i, [&p] {
                return p.get_future();
            }, [i, e] {
                //std::cout << "POST " << i << "(" << e->result.size() << ")" << std::endl;
                e->result.emplace_back(i);
                if (e->result.size() == e->promises.size()) {
                    e->end.set_value();
                }
            });
            ++i;
        }

        std::uniform_int_distribution<size_t> dist(0, num_ops - 1);
        std::bitset<num_ops> set;

        while (!set.all()) {
            size_t i = dist(e1);
            if (!set.test(i)) {
                //std::cout << "SET " << i << "(" << e->result.size() << ")" << std::endl;
                set[i] = true;
                e->promises[i].set_value();
            }
        }

        return e->end.get_future().then([e] {
            BOOST_CHECK_EQUAL(e->result.size(), e->promises.size());
            BOOST_REQUIRE(std::is_sorted(e->result.begin(), e->result.end()));
        }).finally([e] {
            //std::cout <<  "Bulle" << std::endl;
        });
    });
}