/*
    Copyright (c) 2005-2021 Intel Corporation

    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.
*/

#include "common/config.h"

#include "tbb/flow_graph.h"
#include "tbb/global_control.h"

#include "common/test.h"
#include "common/utils.h"
#include "common/graph_utils.h"
#include "common/test_follows_and_precedes_api.h"


//! \file test_buffer_node.cpp
//! \brief Test for [flow_graph.buffer_node] specification


#define N 1000
#define C 10

template< typename T >
void spin_try_get( tbb::flow::buffer_node<T> &b, T &value ) {
    while ( b.try_get(value) != true ) {}
}

template< typename T >
void check_item( T* count_value, T &value ) {
    count_value[value / N] += value % N;
}

template< typename T >
struct parallel_puts : utils::NoAssign {

    tbb::flow::buffer_node<T> &my_b;

    parallel_puts( tbb::flow::buffer_node<T> &b ) : my_b(b) {}

    void operator()(int i) const {
        for (int j = 0; j < N; ++j) {
            bool msg = my_b.try_put( T(N*i + j) );
            CHECK_MESSAGE( msg == true, "" );
        }
    }
};

template< typename T >
struct touches {

    bool **my_touches;
    int my_num_threads;

    touches( int num_threads ) : my_num_threads(num_threads) {
        my_touches = new bool* [my_num_threads];
        for ( int p = 0; p < my_num_threads; ++p) {
            my_touches[p] = new bool[N];
            for ( int n = 0; n < N; ++n)
                my_touches[p][n] = false;
        }
    }

    ~touches() {
        for ( int p = 0; p < my_num_threads; ++p) {
            delete [] my_touches[p];
        }
        delete [] my_touches;
    }

    bool check( T v ) {
        CHECK_MESSAGE( my_touches[v/N][v%N] == false, "" );
        my_touches[v/N][v%N] = true;
        return true;
    }

    bool validate_touches() {
        for ( int p = 0; p < my_num_threads; ++p) {
            for ( int n = 0; n < N; ++n) {
                CHECK_MESSAGE( my_touches[p][n] == true, "" );
            }
        }
        return true;
    }
};

template< typename T >
struct parallel_gets : utils::NoAssign {

    tbb::flow::buffer_node<T> &my_b;
    touches<T> &my_touches;

    parallel_gets( tbb::flow::buffer_node<T> &b, touches<T> &t) : my_b(b), my_touches(t) {}

    void operator()(int) const {
        for (int j = 0; j < N; ++j) {
            T v;
            spin_try_get( my_b, v );
            my_touches.check( v );
        }
    }

};

template< typename T >
struct parallel_put_get : utils::NoAssign {

    tbb::flow::buffer_node<T> &my_b;
    touches<T> &my_touches;

    parallel_put_get( tbb::flow::buffer_node<T> &b, touches<T> &t ) : my_b(b), my_touches(t) {}

    void operator()(int tid) const {

        for ( int i = 0; i < N; i+=C ) {
            int j_end = ( N < i + C ) ? N : i + C;
            // dump about C values into the buffer
            for ( int j = i; j < j_end; ++j ) {
                CHECK_MESSAGE( my_b.try_put( T (N*tid + j ) ) == true, "" );
            }
            // receiver about C values from the buffer
            for ( int j = i; j < j_end; ++j ) {
                T v;
                spin_try_get( my_b, v );
                my_touches.check( v );
            }
        }
    }

};

//
// Tests
//
// Item can be reserved, released, consumed ( single serial receiver )
//
template< typename T >
int test_reservation() {
    tbb::flow::graph g;
    T bogus_value(-1);

    // Simple tests
    tbb::flow::buffer_node<T> b(g);

    b.try_put(T(1));
    b.try_put(T(2));
    b.try_put(T(3));

    T v, vsum;
    CHECK_MESSAGE( b.try_reserve(v) == true, "" );
    CHECK_MESSAGE( b.try_release() == true, "" );
    v = bogus_value;
    g.wait_for_all();
    CHECK_MESSAGE( b.try_reserve(v) == true, "" );
    CHECK_MESSAGE( b.try_consume() == true, "" );
    vsum += v;
    v = bogus_value;
    g.wait_for_all();

    CHECK_MESSAGE( b.try_get(v) == true, "" );
    vsum += v;
    v = bogus_value;
    g.wait_for_all();

    CHECK_MESSAGE( b.try_reserve(v) == true, "" );
    CHECK_MESSAGE( b.try_release() == true, "" );
    v = bogus_value;
    g.wait_for_all();
    CHECK_MESSAGE( b.try_reserve(v) == true, "" );
    CHECK_MESSAGE( b.try_consume() == true, "" );
    vsum += v;
    CHECK_MESSAGE( vsum == T(6), "");
    v = bogus_value;
    g.wait_for_all();

    return 0;
}

//
// Tests
//
// multiple parallel senders, items in arbitrary order
// multiple parallel senders, multiple parallel receivers, items in arbitrary order and all items received
//   * overlapped puts / gets
//   * all puts finished before any getS
//
template< typename T >
int test_parallel(int num_threads) {
    tbb::flow::graph g;
    tbb::flow::buffer_node<T> b(g);
    tbb::flow::buffer_node<T> b2(g);
    tbb::flow::buffer_node<T> b3(g);
    T bogus_value(-1);
    T j = bogus_value;

    NativeParallelFor( num_threads, parallel_puts<T>(b) );

    T *next_value = new T[num_threads];
    for (int tid = 0; tid < num_threads; ++tid) next_value[tid] = T(0);

    for (int i = 0; i < num_threads * N; ++i ) {
        spin_try_get( b, j );
        check_item( next_value, j );
        j = bogus_value;
    }
    for (int tid = 0; tid < num_threads; ++tid)  {
        CHECK_MESSAGE( next_value[tid] == T((N*(N-1))/2), "" );
    }

    j = bogus_value;
    g.wait_for_all();
    CHECK_MESSAGE( b.try_get( j ) == false, "" );
    CHECK_MESSAGE( j == bogus_value, "" );

    NativeParallelFor( num_threads, parallel_puts<T>(b) );

    {
        touches< T > t( num_threads );
        NativeParallelFor( num_threads, parallel_gets<T>(b, t) );
        g.wait_for_all();
        CHECK_MESSAGE( t.validate_touches(), "" );
    }
    j = bogus_value;
    CHECK_MESSAGE( b.try_get( j ) == false, "" );
    CHECK_MESSAGE( j == bogus_value, "" );

    g.wait_for_all();
    {
        touches< T > t( num_threads );
        NativeParallelFor( num_threads, parallel_put_get<T>(b, t) );
        g.wait_for_all();
        CHECK_MESSAGE( t.validate_touches(), "" );
    }
    j = bogus_value;
    CHECK_MESSAGE( b.try_get( j ) == false, "" );
    CHECK_MESSAGE( j == bogus_value, "" );

    tbb::flow::make_edge( b, b2 );
    tbb::flow::make_edge( b2, b3 );

    NativeParallelFor( num_threads, parallel_puts<T>(b) );
    {
        touches< T > t( num_threads );
        NativeParallelFor( num_threads, parallel_gets<T>(b3, t) );
        g.wait_for_all();
        CHECK_MESSAGE( t.validate_touches(), "" );
    }
    j = bogus_value;
    g.wait_for_all();
    CHECK_MESSAGE( b.try_get( j ) == false, "" );
    g.wait_for_all();
    CHECK_MESSAGE( b2.try_get( j ) == false, "" );
    g.wait_for_all();
    CHECK_MESSAGE( b3.try_get( j ) == false, "" );
    CHECK_MESSAGE( j == bogus_value, "" );

    // test copy constructor
    CHECK_MESSAGE( b.remove_successor( b2 ), "" );
    // fill up b:
    NativeParallelFor( num_threads, parallel_puts<T>(b) );
    // copy b:
    tbb::flow::buffer_node<T> b_copy(b);

    // b_copy should be empty
    j = bogus_value;
    g.wait_for_all();
    CHECK_MESSAGE( b_copy.try_get( j ) == false, "" );

    // hook them together:
    CHECK_MESSAGE( b.register_successor(b_copy) == true, "" );
    // try to get content from b_copy
    {
        touches< T > t( num_threads );
        NativeParallelFor( num_threads, parallel_gets<T>(b_copy, t) );
        g.wait_for_all();
        CHECK_MESSAGE( t.validate_touches(), "" );
    }
    // now both should be empty
    j = bogus_value;
    g.wait_for_all();
    CHECK_MESSAGE( b.try_get( j ) == false, "" );
    g.wait_for_all();
    CHECK_MESSAGE( b_copy.try_get( j ) == false, "" );
    CHECK_MESSAGE( j == bogus_value, "" );

    delete [] next_value;
    return 0;
}

//
// Tests
//
// Predecessors cannot be registered
// Empty buffer rejects item requests
// Single serial sender, items in arbitrary order
// Chained buffers ( 2 & 3 ), single sender, items at last buffer in arbitrary order
//

#define TBB_INTERNAL_NAMESPACE detail::d1
using tbb::TBB_INTERNAL_NAMESPACE::register_predecessor;
using tbb::TBB_INTERNAL_NAMESPACE::remove_predecessor;

template< typename T >
int test_serial() {
    tbb::flow::graph g;
    T bogus_value(-1);

    tbb::flow::buffer_node<T> b(g);
    tbb::flow::buffer_node<T> b2(g);
    T j = bogus_value;

    //
    // Rejects attempts to add / remove predecessor
    // Rejects request from empty buffer
    //
    CHECK_MESSAGE( register_predecessor<T>( b, b2 ) == false, "" );
    CHECK_MESSAGE( remove_predecessor<T>( b, b2 ) == false, "" );
    CHECK_MESSAGE( b.try_get( j ) == false, "" );
    CHECK_MESSAGE( j == bogus_value, "" );

    //
    // Simple puts and gets
    //

    for (int i = 0; i < N; ++i) {
        bool msg = b.try_put( T(i) );
        CHECK_MESSAGE( msg == true, "" );
    }

    T vsum = T(0);
    for (int i = 0; i < N; ++i) {
        j = bogus_value;
        spin_try_get( b, j );
        vsum += j;
    }
    CHECK_MESSAGE( vsum == (N*(N-1))/2, "");
    j = bogus_value;
    g.wait_for_all();
    CHECK_MESSAGE( b.try_get( j ) == false, "" );
    CHECK_MESSAGE( j == bogus_value, "" );

    tbb::flow::make_edge(b, b2);

    vsum = T(0);
    for (int i = 0; i < N; ++i) {
        bool msg = b.try_put( T(i) );
        CHECK_MESSAGE( msg == true, "" );
    }

    for (int i = 0; i < N; ++i) {
        j = bogus_value;
        spin_try_get( b2, j );
        vsum += j;
    }
    CHECK_MESSAGE( vsum == (N*(N-1))/2, "");
    j = bogus_value;
    g.wait_for_all();
    CHECK_MESSAGE( b.try_get( j ) == false, "" );
    g.wait_for_all();
    CHECK_MESSAGE( b2.try_get( j ) == false, "" );
    CHECK_MESSAGE( j == bogus_value, "" );

    tbb::flow::remove_edge(b, b2);
    CHECK_MESSAGE( b.try_put( 1 ) == true, "" );
    g.wait_for_all();
    CHECK_MESSAGE( b2.try_get( j ) == false, "" );
    CHECK_MESSAGE( j == bogus_value, "" );
    g.wait_for_all();
    CHECK_MESSAGE( b.try_get( j ) == true, "" );
    CHECK_MESSAGE( j == 1, "" );

    tbb::flow::buffer_node<T> b3(g);
    tbb::flow::make_edge( b, b2 );
    tbb::flow::make_edge( b2, b3 );

    vsum = T(0);
    for (int i = 0; i < N; ++i) {
        bool msg = b.try_put( T(i) );
        CHECK_MESSAGE( msg == true, "" );
    }

    for (int i = 0; i < N; ++i) {
        j = bogus_value;
        spin_try_get( b3, j );
        vsum += j;
    }
    CHECK_MESSAGE( vsum == (N*(N-1))/2, "");
    j = bogus_value;
    g.wait_for_all();
    CHECK_MESSAGE( b.try_get( j ) == false, "" );
    g.wait_for_all();
    CHECK_MESSAGE( b2.try_get( j ) == false, "" );
    g.wait_for_all();
    CHECK_MESSAGE( b3.try_get( j ) == false, "" );
    CHECK_MESSAGE( j == bogus_value, "" );

    tbb::flow::remove_edge(b, b2);
    CHECK_MESSAGE( b.try_put( 1 ) == true, "" );
    g.wait_for_all();
    CHECK_MESSAGE( b2.try_get( j ) == false, "" );
    CHECK_MESSAGE( j == bogus_value, "" );
    g.wait_for_all();
    CHECK_MESSAGE( b3.try_get( j ) == false, "" );
    CHECK_MESSAGE( j == bogus_value, "" );
    g.wait_for_all();
    CHECK_MESSAGE( b.try_get( j ) == true, "" );
    CHECK_MESSAGE( j == 1, "" );

    return 0;
}

#if __TBB_PREVIEW_FLOW_GRAPH_NODE_SET
#include <array>
#include <vector>
void test_follows_and_precedes_api() {
    using msg_t = tbb::flow::continue_msg;

    std::array<msg_t, 3> messages_for_follows = { {msg_t(), msg_t(), msg_t()} };
    std::vector<msg_t> messages_for_precedes = {msg_t(), msg_t(), msg_t()};

    follows_and_precedes_testing::test_follows<msg_t, tbb::flow::buffer_node<msg_t>>(messages_for_follows);
    follows_and_precedes_testing::test_precedes<msg_t, tbb::flow::buffer_node<msg_t>>(messages_for_precedes);
}
#endif

#if __TBB_CPP17_DEDUCTION_GUIDES_PRESENT
void test_deduction_guides() {
    using namespace tbb::flow;
    graph g;
    broadcast_node<int> br(g);
    buffer_node<int> b0(g);

#if __TBB_PREVIEW_FLOW_GRAPH_NODE_SET
    buffer_node b1(follows(br));
    static_assert(std::is_same_v<decltype(b1), buffer_node<int>>);

    buffer_node b2(precedes(br));
    static_assert(std::is_same_v<decltype(b2), buffer_node<int>>);
#endif

    buffer_node b3(b0);
    static_assert(std::is_same_v<decltype(b3), buffer_node<int>>);
    g.wait_for_all();
}
#endif

#include <iomanip>

//! Test buffer_node with parallel and serial neighbours
//! \brief \ref requirement \ref error_guessing
TEST_CASE("Serial and parallel test"){
    for (int p = 2; p <= 4; ++p) {
        tbb::global_control thread_limit(tbb::global_control::max_allowed_parallelism, p);
        tbb::task_arena arena(p);
        arena.execute(
            [&]() {
                test_serial<int>();
                test_parallel<int>(p);
            }
        );
    }
}

//! Test reset and cancellation behavior
//! \brief \ref error_guessing
TEST_CASE("Resets"){
    test_resets<int,tbb::flow::buffer_node<int> >();
    test_resets<float,tbb::flow::buffer_node<float> >();
}

#if __TBB_PREVIEW_FLOW_GRAPH_NODE_SET
//! Test deprecated follows and preceedes API
//! \brief \ref error_guessing
TEST_CASE("Follows and precedes API"){
    test_follows_and_precedes_api();
}
#endif

#if __TBB_CPP17_DEDUCTION_GUIDES_PRESENT
//! Test deduction guides
//! \brief requirement
TEST_CASE("Deduction guides"){
    test_deduction_guides();
}
#endif