/*
 * Distributed under the OSI-approved Apache License, Version 2.0.  See
 * accompanying file Copyright.txt for details.
 */
#include <cstdint>
#include <cstring>

#include <iostream>
#include <stdexcept>

#include <adios2.h>

#include <gtest/gtest.h>

#include "../SmallTestData.h"

std::string engineName; // comes from command line

class AppendTimeStepTest : public ::testing::Test
{
public:
    AppendTimeStepTest() = default;

    SmallTestData m_TestData;
};

//******************************************************************************
// 1D 1x8 test data
//******************************************************************************

// ADIOS2 HDF5 write, then append, then read back
TEST_F(AppendTimeStepTest, ADIOS2HDF5WriteAppendRead)
{
    // Each process would write a 1x8 array and all processes would
    // form a mpiSize * Nx 1D array
    std::string fname = "appendTest.h5";

    int mpiRank = 0, mpiSize = 1;
    // Number of rows
    const std::size_t Nx = 8;

    // Number of steps
    const std::size_t NSteps = 3;

#if ADIOS2_USE_MPI
    MPI_Comm_rank(MPI_COMM_WORLD, &mpiRank);
    MPI_Comm_size(MPI_COMM_WORLD, &mpiSize);
#endif

#if ADIOS2_USE_MPI
    adios2::ADIOS adios(MPI_COMM_WORLD);
#else
    adios2::ADIOS adios;
#endif

    // Write test data using HDF5 engine
    {
        adios2::IO io = adios.DeclareIO("TestIO");

        // Declare 1D variables (NumOfProcesses * Nx)
        // The local process' part (start, count) can be defined now or later
        // before Write().
        {
            adios2::Dims shape{static_cast<unsigned int>(Nx * mpiSize)};
            adios2::Dims start{static_cast<unsigned int>(Nx * mpiRank)};
            adios2::Dims count{static_cast<unsigned int>(Nx)};

            auto var_iString = io.DefineVariable<std::string>("iString");
            EXPECT_TRUE(var_iString);
            auto var_i8 = io.DefineVariable<int8_t>("i8", shape, start, count);
            EXPECT_TRUE(var_i8);
            auto var_i16 =
                io.DefineVariable<int16_t>("i16", shape, start, count);
            EXPECT_TRUE(var_i16);
            auto var_i32 =
                io.DefineVariable<int32_t>("i32", shape, start, count);
            EXPECT_TRUE(var_i32);
            auto var_i64 =
                io.DefineVariable<int64_t>("i64", shape, start, count);
            EXPECT_TRUE(var_i64);
            auto var_u8 = io.DefineVariable<uint8_t>("u8", shape, start, count);
            EXPECT_TRUE(var_u8);
            auto var_u16 =
                io.DefineVariable<uint16_t>("u16", shape, start, count);
            EXPECT_TRUE(var_u16);
            auto var_u32 =
                io.DefineVariable<uint32_t>("u32", shape, start, count);
            EXPECT_TRUE(var_u32);
            auto var_u64 =
                io.DefineVariable<uint64_t>("u64", shape, start, count);
            EXPECT_TRUE(var_u64);
            auto var_r32 = io.DefineVariable<float>("r32", shape, start, count);
            EXPECT_TRUE(var_r32);
            auto var_r64 =
                io.DefineVariable<double>("r64", shape, start, count);
            EXPECT_TRUE(var_r64);
        }

        if (!engineName.empty())
            io.SetEngine(engineName);
        else
            io.SetEngine("HDF5");

        io.AddTransport("file");

        adios2::Engine engine = io.Open(fname, adios2::Mode::Write);

        for (size_t step = 0; step < NSteps; ++step)
        {
            // Generate test data for each process uniquely
            SmallTestData currentTestData =
                generateNewSmallTestData(m_TestData, step, mpiRank, mpiSize);

            // Retrieve the variables that previously went out of scope
            auto var_iString = io.InquireVariable<std::string>("iString");
            auto var_i8 = io.InquireVariable<int8_t>("i8");
            auto var_i16 = io.InquireVariable<int16_t>("i16");
            auto var_i32 = io.InquireVariable<int32_t>("i32");
            auto var_i64 = io.InquireVariable<int64_t>("i64");
            auto var_u8 = io.InquireVariable<uint8_t>("u8");
            auto var_u16 = io.InquireVariable<uint16_t>("u16");
            auto var_u32 = io.InquireVariable<uint32_t>("u32");
            auto var_u64 = io.InquireVariable<uint64_t>("u64");
            auto var_r32 = io.InquireVariable<float>("r32");
            auto var_r64 = io.InquireVariable<double>("r64");

            // Make a 1D selection to describe the local dimensions of the
            // variable we write and its offsets in the global spaces
            adios2::Box<adios2::Dims> sel({mpiRank * Nx}, {Nx});

            var_i8.SetSelection(sel);
            var_i16.SetSelection(sel);
            var_i32.SetSelection(sel);
            var_i64.SetSelection(sel);
            var_u8.SetSelection(sel);
            var_u16.SetSelection(sel);
            var_u32.SetSelection(sel);
            var_u64.SetSelection(sel);
            var_r32.SetSelection(sel);
            var_r64.SetSelection(sel);

            // Write each one
            // fill in the variable with values from starting index to
            // starting index + count
            engine.BeginStep();
            engine.Put(var_iString, currentTestData.S1);
            engine.Put(var_i8, currentTestData.I8.data());
            engine.Put(var_i16, currentTestData.I16.data());
            engine.Put(var_i32, currentTestData.I32.data());
            engine.Put(var_i64, currentTestData.I64.data());
            engine.Put(var_u8, currentTestData.U8.data());
            engine.Put(var_u16, currentTestData.U16.data());
            engine.Put(var_u32, currentTestData.U32.data());
            engine.Put(var_u64, currentTestData.U64.data());
            engine.Put(var_r32, currentTestData.R32.data());
            engine.Put(var_r64, currentTestData.R64.data());
            engine.EndStep();
        }

        // Close the file
        engine.Close();
    }

    size_t ExtraSteps = 2;

    {
        // Append
        adios2::IO io = adios.DeclareIO("ioAppend");

        if (!engineName.empty())
            io.SetEngine(engineName);
        else
            io.SetEngine("HDF5");

        adios2::Engine appender = io.Open(fname, adios2::Mode::Append);

        for (size_t step = NSteps; step < NSteps + ExtraSteps; ++step)
        {
            // Generate test data for each process uniquely
            SmallTestData currentTestData =
                generateNewSmallTestData(m_TestData, step, mpiRank, mpiSize);

            // Retrieve the variables that previously went out of scope
            auto var_iString = io.InquireVariable<std::string>("iString");
            EXPECT_TRUE(var_iString);
            auto var_i8 = io.InquireVariable<int8_t>("i8");
            EXPECT_TRUE(var_i8);
            auto var_i16 = io.InquireVariable<int16_t>("i16");
            auto var_i32 = io.InquireVariable<int32_t>("i32");
            auto var_i64 = io.InquireVariable<int64_t>("i64");
            auto var_u8 = io.InquireVariable<uint8_t>("u8");
            auto var_u16 = io.InquireVariable<uint16_t>("u16");
            auto var_u32 = io.InquireVariable<uint32_t>("u32");
            auto var_u64 = io.InquireVariable<uint64_t>("u64");
            auto var_r32 = io.InquireVariable<float>("r32");
            auto var_r64 = io.InquireVariable<double>("r64");

            // Make a 1D selection to describe the local dimensions of the
            // variable we write and its offsets in the global spaces
            adios2::Box<adios2::Dims> sel({mpiRank * Nx}, {Nx});

            EXPECT_THROW(var_iString.SetSelection(sel), std::invalid_argument);
            var_i8.SetSelection(sel);
            var_i16.SetSelection(sel);
            var_i32.SetSelection(sel);
            var_i64.SetSelection(sel);
            var_u8.SetSelection(sel);
            var_u16.SetSelection(sel);
            var_u32.SetSelection(sel);
            var_u64.SetSelection(sel);
            var_r32.SetSelection(sel);
            var_r64.SetSelection(sel);

            // Write each one
            // fill in the variable with values from starting index to
            // starting index + count
            appender.BeginStep();
            appender.Put(var_iString, currentTestData.S1);
            appender.Put(var_i8, currentTestData.I8.data());
            appender.Put(var_i16, currentTestData.I16.data());
            appender.Put(var_i32, currentTestData.I32.data());
            appender.Put(var_i64, currentTestData.I64.data());
            appender.Put(var_u8, currentTestData.U8.data());
            appender.Put(var_u16, currentTestData.U16.data());
            appender.Put(var_u32, currentTestData.U32.data());
            appender.Put(var_u64, currentTestData.U64.data());
            appender.Put(var_r32, currentTestData.R32.data());
            appender.Put(var_r64, currentTestData.R64.data());
            appender.EndStep();
        }
        appender.Close();
    }

    {
        // Read back
        adios2::IO io = adios.DeclareIO("ioRead");
        if (!engineName.empty())
            io.SetEngine(engineName);
        else
            io.SetEngine("HDF5");

        adios2::Engine reader = io.Open(fname, adios2::Mode::Read);
        EXPECT_EQ(reader.Steps(), NSteps + ExtraSteps);

        std::string IString;
        std::array<int8_t, Nx> I8;
        std::array<int16_t, Nx> I16;
        std::array<int32_t, Nx> I32;
        std::array<int64_t, Nx> I64;
        std::array<uint8_t, Nx> U8;
        std::array<uint16_t, Nx> U16;
        std::array<uint32_t, Nx> U32;
        std::array<uint64_t, Nx> U64;
        std::array<float, Nx> R32;
        std::array<double, Nx> R64;

        auto var_iString = io.InquireVariable<std::string>("iString");
        EXPECT_TRUE(var_iString);
        EXPECT_EQ(var_iString.Steps(), NSteps + ExtraSteps);

        auto var_i8 = io.InquireVariable<int8_t>("i8");
        EXPECT_TRUE(var_i8);
        EXPECT_EQ(var_i8.Steps(), NSteps + ExtraSteps);

        auto var_i16 = io.InquireVariable<int16_t>("i16");
        EXPECT_TRUE(var_i16);
        EXPECT_EQ(var_i16.Steps(), NSteps + ExtraSteps);

        auto var_i32 = io.InquireVariable<int32_t>("i32");
        EXPECT_TRUE(var_i32);
        EXPECT_EQ(var_i32.Steps(), NSteps + ExtraSteps);

        auto var_i64 = io.InquireVariable<int64_t>("i64");
        EXPECT_TRUE(var_i64);
        EXPECT_EQ(var_i64.Steps(), NSteps + ExtraSteps);

        auto var_u8 = io.InquireVariable<uint8_t>("u8");
        EXPECT_TRUE(var_u8);
        EXPECT_EQ(var_u8.Steps(), NSteps + ExtraSteps);

        auto var_u16 = io.InquireVariable<uint16_t>("u16");
        EXPECT_TRUE(var_u16);
        EXPECT_EQ(var_u16.Steps(), NSteps + ExtraSteps);

        auto var_u32 = io.InquireVariable<uint32_t>("u32");
        EXPECT_TRUE(var_u32);
        EXPECT_EQ(var_u32.Steps(), NSteps + ExtraSteps);

        auto var_u64 = io.InquireVariable<uint64_t>("u64");
        EXPECT_TRUE(var_u64);
        EXPECT_EQ(var_u64.Steps(), NSteps + ExtraSteps);

        auto var_r32 = io.InquireVariable<float>("r32");
        EXPECT_TRUE(var_r32);
        EXPECT_EQ(var_r32.Steps(), NSteps + ExtraSteps);

        auto var_r64 = io.InquireVariable<double>("r64");
        EXPECT_TRUE(var_r64);
        EXPECT_EQ(var_r64.Steps(), NSteps + ExtraSteps);

        adios2::Box<adios2::Dims> sel({mpiRank * Nx}, {Nx});

        for (size_t step = 0; step < NSteps + ExtraSteps; ++step)
        {
            SmallTestData currentTestData =
                generateNewSmallTestData(m_TestData, step, mpiRank, mpiSize);

            var_i8.SetStepSelection({step, 1});
            var_i8.SetSelection(sel);
            reader.Get(var_i8, I8.data());

            var_i16.SetStepSelection({step, 1});
            var_i16.SetSelection(sel);
            reader.Get(var_i16, I16.data());

            var_i32.SetStepSelection({step, 1});
            var_i32.SetSelection(sel);
            reader.Get(var_i32, I32.data());

            var_i64.SetStepSelection({step, 1});
            var_i64.SetSelection(sel);
            reader.Get(var_i64, I64.data());

            var_u8.SetStepSelection({step, 1});
            var_u8.SetSelection(sel);
            reader.Get(var_u8, U8.data());

            var_u16.SetStepSelection({step, 1});
            var_u16.SetSelection(sel);
            reader.Get(var_u16, U16.data());

            var_u32.SetStepSelection({step, 1});
            var_u32.SetSelection(sel);
            reader.Get(var_u32, U32.data());

            var_u64.SetStepSelection({step, 1});
            var_u64.SetSelection(sel);
            reader.Get(var_u64, U64.data());

            var_r32.SetStepSelection({step, 1});
            var_r32.SetSelection(sel);
            reader.Get(var_r32, R32.data());

            var_r64.SetStepSelection({step, 1});
            var_r64.SetSelection(sel);
            reader.Get(var_r64, R64.data());

            reader.Get(var_iString, IString);
            reader.PerformGets();

            EXPECT_EQ(IString, currentTestData.S1);

            for (size_t i = 0; i < Nx; ++i)
            {
                std::stringstream ss;
                ss << "step=" << step << " i=" << i << " rank=" << mpiRank;
                std::string msg = ss.str();

                EXPECT_EQ(I8[i], currentTestData.I8[i]) << msg;
                EXPECT_EQ(I16[i], currentTestData.I16[i]) << msg;
                EXPECT_EQ(I32[i], currentTestData.I32[i]) << msg;
                EXPECT_EQ(I64[i], currentTestData.I64[i]) << msg;

                EXPECT_EQ(U8[i], currentTestData.U8[i]) << msg;
                EXPECT_EQ(U16[i], currentTestData.U16[i]) << msg;
                EXPECT_EQ(U32[i], currentTestData.U32[i]) << msg;
                EXPECT_EQ(U64[i], currentTestData.U64[i]) << msg;

                EXPECT_EQ(R32[i], currentTestData.R32[i]) << msg;
                EXPECT_EQ(R64[i], currentTestData.R64[i]) << msg;
            }
        }

        reader.Close();
    }
}

//******************************************************************************
// main
//******************************************************************************

int main(int argc, char **argv)
{
#if ADIOS2_USE_MPI
    MPI_Init(nullptr, nullptr);
#endif

    int result;
    ::testing::InitGoogleTest(&argc, argv);

    if (argc > 1)
    {
        engineName = std::string(argv[1]);
    }
    result = RUN_ALL_TESTS();

#if ADIOS2_USE_MPI
    MPI_Finalize();
#endif

    return result;
}
