#include <iostream>
#include <string>
#include <type_traits>
#include <memory>
#include <new>
#include <vector>
#include <unordered_map>
#include <functional>

#include "circ_elem_array.h"
#include "circ_queue.h"
#include "test.h"

namespace {

class Unit : public TestSuite {
    Q_OBJECT

    const char* name() const {
        return "test_circ";
    }

private slots:
    void initTestCase();
    void cleanupTestCase();

    void test_inst();
    void test_prod_cons_1v1();
    void test_prod_cons_1v3();
    void test_prod_cons_3v1();
    void test_prod_cons_performance();

    void test_queue();
} unit__;

#include "test_circ.moc"

using cq_t = ipc::circ::elem_array<12>;
cq_t* cq__;

constexpr int LoopCount = 1000000;

void Unit::initTestCase() {
    TestSuite::initTestCase();
    cq__ = new cq_t;
}

void Unit::cleanupTestCase() {
    delete cq__;
}

void Unit::test_inst() {
    std::cout << "cq_t::head_size  = " << cq_t::head_size  << std::endl;
    std::cout << "cq_t::data_size  = " << cq_t::data_size  << std::endl;
    std::cout << "cq_t::elem_size  = " << cq_t::elem_size  << std::endl;
    std::cout << "cq_t::block_size = " << cq_t::block_size << std::endl;

    QCOMPARE(static_cast<std::size_t>(cq_t::data_size) , static_cast<std::size_t>(12));
    QCOMPARE(sizeof(cq_t), static_cast<std::size_t>(cq_t::block_size + cq_t::head_size));

    std::cout << "sizeof(ipc::circ::elem_array<4096>) = " << sizeof(*cq__) << std::endl;

    auto a = cq__->take(1);
    auto b = cq__->take(2);
    QCOMPARE(static_cast<std::size_t>(static_cast<ipc::byte_t*>(b) -
                                      static_cast<ipc::byte_t*>(a)),
             static_cast<std::size_t>(cq_t::elem_size));
}

struct msg_t {
    int pid_;
    int dat_;
};

template <bool V>
struct test_verify {
    std::unordered_map<int, std::vector<int>>* list_;
    int lcount_;

    test_verify(int M) {
        list_ = new std::remove_reference_t<decltype(*list_)>[
                    static_cast<std::size_t>(lcount_ = M)
                ];
    }

    ~test_verify() {
        delete [] list_;
    }

    void prepare(void* pt) {
        std::cout << "start consumer: " << pt << std::endl;
    }

    void push_data(int cid, msg_t const & msg) {
        list_[cid][msg.pid_].push_back(msg.dat_);
    }

    void verify(int N, int Loops) {
        std::cout << "verifying..." << std::endl;
        for (int m = 0; m < lcount_; ++m) {
            auto& cons_vec = list_[m];
            for (int n = 0; n < N; ++n) {
                auto& vec = cons_vec[n];
                QCOMPARE(vec.size(), static_cast<std::size_t>(Loops));
                int i = 0;
                for (int d : vec) {
                    QCOMPARE(i, d);
                    ++i;
                }
            }
        }
    }
};

template <>
struct test_verify<false> {
    test_verify   (int)                {}
    void prepare  (void*)              {}
    void push_data(int, msg_t const &) {}
    void verify   (int, int)           {}
};

template <typename T>
struct test_cq;

template <std::size_t D>
struct test_cq<ipc::circ::elem_array<D>> {
    using ca_t = ipc::circ::elem_array<D>;
    using cn_t = typename ca_t::u2_t;

    ca_t* ca_;

    test_cq(ca_t* ca) : ca_(ca) {
        ::new (ca) ca_t;
    }

    cn_t connect() {
        auto cur = ca_->cursor();
        ca_->connect();
        return cur;
    }

    void disconnect(cn_t) {
        ca_->disconnect();
    }

    void wait_start(int M) {
        while (ca_->conn_count() != static_cast<std::size_t>(M)) {
            std::this_thread::yield();
        }
    }

    template <typename F>
    void recv(cn_t cur, F&& proc) {
        do {
            while (cur != ca_->cursor()) {
                msg_t* pmsg = static_cast<msg_t*>(ca_->take(cur)),
                        msg = *pmsg;
                ca_->put(pmsg);
                if (msg.pid_ < 0) return;
                ++cur;
                proc(msg);
            }
            std::this_thread::yield();
        } while(1);
    }

    void send(msg_t const & msg) {
        msg_t* pmsg = static_cast<msg_t*>(ca_->acquire());
        (*pmsg) = msg;
        ca_->commit(pmsg);
    }
};

template <typename T>
struct test_cq<ipc::circ::queue<T>> {
    using cn_t = ipc::circ::queue<T>;
    using ca_t = typename cn_t::array_t;

    ca_t* ca_;

    test_cq(void*) : ca_(reinterpret_cast<ca_t*>(cq__)) {
        ::new (ca_) ca_t;
    }

    cn_t connect() {
        cn_t queue;
        [&] {
            queue.attach(ca_);
            QVERIFY(queue.connect() != ipc::error_count);
        } ();
        return queue;
    }

    void disconnect(cn_t& queue) {
        QVERIFY(queue.disconnect() != ipc::error_count);
        QVERIFY(queue.detach() != nullptr);
    }

    void wait_start(int M) {
        while (ca_->conn_count() != static_cast<std::size_t>(M)) {
            std::this_thread::yield();
        }
    }

    template <typename F>
    void recv(cn_t& queue, F&& proc) {
        do {
            auto msg = queue.pop();
            if (msg.pid_ < 0) return;
            proc(msg);
        } while(1);
    }

    void send(msg_t const & msg) {
        cn_t{ ca_ }.push(msg);
    }
};

template <int N, int M, bool V = true, int Loops = LoopCount, typename T>
void test_prod_cons(T* cq) {
    test_cq<T> tcq { cq };

    std::thread producers[N];
    std::thread consumers[M];
    std::atomic_int fini { 0 };

    test_stopwatch sw;
    test_verify<V> vf { M };

    int cid = 0;
    for (auto& t : consumers) {
        t = std::thread{[&, cid] {
            vf.prepare(&t);
            auto cn = tcq.connect();

            using namespace std::placeholders;
            tcq.recv(cn, std::bind(&test_verify<V>::push_data, &vf, cid, _1));

            tcq.disconnect(cn);
            if (++fini != std::extent<decltype(consumers)>::value) return;
            sw.print_elapsed(N, M, Loops);
            vf.verify(N, Loops);
        }};
        ++cid;
    }

    tcq.wait_start(M);

    std::cout << "start producers..." << std::endl;
    int pid = 0;
    for (auto& t : producers) {
        t = std::thread{[&, pid] {
            sw.start();
            for (int i = 0; i < Loops; ++i) {
                tcq.send({ pid, i });
            }
        }};
        ++pid;
    }
    for (auto& t : producers) t.join();
    // quit
    tcq.send({ -1, -1 });

    for (auto& t : consumers) t.join();
}

template <int N, int M, bool V = true, int Loops = LoopCount>
void test_prod_cons() {
    test_prod_cons<N, M, V, Loops>(cq__);
}

void Unit::test_prod_cons_1v1() {
    test_prod_cons<1, 1>();
}

void Unit::test_prod_cons_1v3() {
    test_prod_cons<1, 3>();
}

void Unit::test_prod_cons_3v1() {
    test_prod_cons<3, 1>();
}

template <int P, int C>
struct test_performance {
    static void start() {
        test_performance<P - 1, C - 1>::start();
        test_prod_cons<P, C, false>();
    }
};

template <int C>
struct test_performance<1, C> {
    static void start() {
        test_performance<1, C - 1>::start();
        test_prod_cons<1, C, false>();
    }
};

template <int P>
struct test_performance<P, 1> {
    static void start() {
        test_performance<P - 1, 1>::start();
        test_prod_cons<P, 1, false>();
    }
};

template <>
struct test_performance<1, 1> {
    static void start() {
        test_prod_cons<1, 1, false>();
    }
};

void Unit::test_prod_cons_performance() {
    test_performance<1 , 10>::start();
    test_performance<10, 1 >::start();
    test_performance<10, 10>::start();
    test_prod_cons  <3 , 3 >(); // test & verify
}

#ifndef QVERIFY_EXCEPTION_THROWN
#define QVERIFY_EXCEPTION_THROWN(expression, exceptiontype) \
do {\
    QT_TRY {\
        QT_TRY {\
            expression;\
            QTest::qFail("Expected exception of type " #exceptiontype " to be thrown" \
                         " but no exception caught", __FILE__, __LINE__);\
            return;\
        } QT_CATCH (const exceptiontype &) {\
        }\
    } QT_CATCH (const std::exception &e) {\
        QByteArray msg = QByteArray() + "Expected exception of type " #exceptiontype \
                         " to be thrown but std::exception caught with message: " + e.what(); \
        QTest::qFail(msg.constData(), __FILE__, __LINE__);\
        return;\
    } QT_CATCH (...) {\
        QTest::qFail("Expected exception of type " #exceptiontype " to be thrown" \
                     " but unknown exception caught", __FILE__, __LINE__);\
        return;\
    }\
} while (false)
#endif/*!QVERIFY_EXCEPTION_THROWN*/

void Unit::test_queue() {
    ipc::circ::queue<msg_t> queue;
    queue.push(1, 2);
    QVERIFY_EXCEPTION_THROWN(queue.pop(), std::exception);
    QVERIFY(sizeof(decltype(queue)::array_t) <= sizeof(*cq__));

    auto cq = ::new (cq__) decltype(queue)::array_t;
    queue.attach(cq);
    QVERIFY(queue.detach() != nullptr);

    test_prod_cons<1, 3>((ipc::circ::queue<msg_t>*)nullptr);
    test_prod_cons<3, 1>((ipc::circ::queue<msg_t>*)nullptr);
    test_prod_cons<3, 3>((ipc::circ::queue<msg_t>*)nullptr);
}

} // internal-linkage