/*
MIT License

Copyright (c) 2019 - 2024 Advanced Micro Devices, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

#include <chrono>
#include <cassert>
#include <cctype>
#include <cstdio>
#include <cstdlib>
#include <fstream>
#include <rpp/env.hpp>
#include <rpp/errors.hpp>
#include <rpp/gcn_asm_utils.hpp>
#include <rpp/manage_ptr.hpp>
#include <rpp/write_file.hpp>
#include <rpp/kernel.hpp>
#include <rpp/logger.hpp>
#include <sstream>

#ifdef __linux__
#include <rpp/temp_file.hpp>

#include <paths.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#endif // __linux__

RPP_DECLARE_ENV_VAR(RPP_EXPERIMENTAL_GCN_ASM_PATH)

static const char option_no_co_v3[] = "-mno-code-object-v3";

static bool GcnAssemblerSupportsCOv3();
static std::string CleanupPath(const char* p);

// Redirecting both input and output is not supported.
static int ExecuteGcnAssembler(const std::string& p, std::istream* in, std::ostream* out);

std::string GetGcnAssemblerPathImpl()
{
    const auto asm_path_env_p = rpp::GetStringEnv(RPP_EXPERIMENTAL_GCN_ASM_PATH{});
    if(asm_path_env_p != nullptr)
    {
        return CleanupPath(asm_path_env_p);
    }
#ifdef RPP_AMDGCN_ASSEMBLER // string literal generated by CMake
    return CleanupPath(RPP_AMDGCN_ASSEMBLER);
#else
    return "";
#endif
}

std::string GetGcnAssemblerPath()
{
    static const auto result = GetGcnAssemblerPathImpl();
    return result;
}

bool ValidateGcnAssemblerImpl()
{
#ifdef __linux__
    const auto path = GetGcnAssemblerPath();
    if(path.empty())
    {
        return false;
    }
    if(!std::ifstream(path).good())
    {
        return false;
    }

    std::stringstream clang_stdout;
    std::string clang_result_line;
    RPP_LOG_I2("Running: " << '\'' << path << " --version" << '\'');
    auto clang_rc = ExecuteGcnAssembler(path + " --version", nullptr, &clang_stdout);

    if(clang_rc != 0)
    {
        return false;
    }

    std::getline(clang_stdout, clang_result_line);
    RPP_LOG_I2(clang_result_line);
    if(clang_result_line.find("clang") != std::string::npos)
    {
        while(!clang_stdout.eof())
        {
            std::getline(clang_stdout, clang_result_line);
            RPP_LOG_I2(clang_result_line);
            if(clang_result_line.find("Target: ") != std::string::npos)
            {
                return clang_result_line.find("amdgcn") != std::string::npos;
            }
        }
    }
#endif // __linux__
    return false;
}

bool ValidateGcnAssembler()
{
    static bool result = ValidateGcnAssemblerImpl();
    return result;
}

static int ExecuteGcnAssembler(const std::string& p, std::istream* in, std::ostream* out)
{
#ifdef __linux__
    const auto redirect_stdin  = (in != nullptr);
    const auto redirect_stdout = (out != nullptr);

    assert(!(redirect_stdin && redirect_stdout));

    const auto file_mode = redirect_stdout ? "r" : "w";
    RPP_MANAGE_PTR(FILE*, pclose) pipe{popen(p.c_str(), file_mode)};

    if(!pipe)
        RPP_THROW("Error: X-AMDGCN-ASM: popen()");

    if(redirect_stdin || redirect_stdout)
    {
        std::array<char, 1024> buffer{};

        if(redirect_stdout)
        {
            while(feof(pipe.get()) == 0)
                if(fgets(buffer.data(), buffer.size(), pipe.get()) != nullptr)
                    *out << buffer.data();
        }
        else
        {
            while(!in->eof())
            {
                in->read(buffer.data(), buffer.size() - 1);
                buffer[in->gcount()] = 0;

                if(fputs(buffer.data(), pipe.get()) == EOF)
                    RPP_THROW("Error: X-AMDGCN-ASM: fputs()");
            }
        }
    }

    auto status = pclose(pipe.release());
    return WEXITSTATUS(status);
#else
    (void)p;
    (void)in;
    (void)out;
    return -1;
#endif // __linux__
}

static std::string CleanupPath(const char* p)
{
    std::string path(p);
    static const char bad[] = "!#$*;<>?@\\^`{|}";
    for(char* c = &path[0]; c < (&path[0] + path.length()); ++c)
    {
        if(std::iscntrl(*c) != 0)
        {
            *c = '_';
            continue;
        }
        for(const char* b = &bad[0]; b < (&bad[0] + sizeof(bad) - 1); ++b)
        {
            if(*b == *c)
            {
                *c = '_';
                break;
            }
        }
    }
    return path;
}

/*
 * Temporary function which emulates online assembly feature of OpenCL-on-ROCm being developed.
 * Not intended to be used in production code, so error handling is very straghtforward,
 * just catch whatever possible and throw an exception.
 */
void AmdgcnAssemble(std::string& source, const std::string& params)
{
#ifdef __linux__
    rpp::TempFile outfile("amdgcn-asm-out-XXXXXX");

    std::ostringstream options;
    options << " -x assembler -target amdgcn--amdhsa";
    if(GcnAssemblerSupportsCOv3())
    {
        options << ' ' << option_no_co_v3;
    }
    options << ' ' << params;
    if(GcnAssemblerHasBug34765())
    {
        GenerateClangDefsym(options, "WORKAROUND_BUG_34765", 1);
    }
    options << " - -o " << outfile.Path();

    std::istringstream clang_stdin(source);
    const auto clang_path = GetGcnAssemblerPath();
    const auto clang_rc =
        ExecuteGcnAssembler(clang_path + " " + options.str(), &clang_stdin, nullptr);
    if(clang_rc != 0)
    {
        RPP_LOG_W(options.str());
        RPP_THROW("Assembly error(" + std::to_string(clang_rc) + ")");
    }

    std::ifstream file(outfile, std::ios::binary | std::ios::ate);
    bool outfile_read_failed = false;
    do
    {
        const auto size = file.tellg();
        if(size == -1)
        {
            outfile_read_failed = true;
            break;
        }
        source.resize(size, '\0');
        file.seekg(std::ios::beg);
        if(file.fail())
        {
            outfile_read_failed = true;
            break;
        }
        if(file.rdbuf()->sgetn(&source[0], size) != size)
        {
            outfile_read_failed = true;
            break;
        }
    } while(false);
    file.close();
    if(outfile_read_failed)
    {
        RPP_THROW("Error: X-AMDGCN-ASM: outfile_read_failed");
    }
#else
    (void)source; // -warning
    (void)params; // -warning
    RPP_THROW("Error: X-AMDGCN-ASM: online assembly under Windows is not supported");
#endif //__linux__
}

static void AmdgcnAssembleQuiet(std::string& source, const std::string& params)
{
#ifdef __linux__
    std::stringstream clang_stdout_unused;
    const auto clang_path = GetGcnAssemblerPath();
    const auto args       = " -x assembler -target amdgcn--amdhsa " + params + " " + source +
                      " -o /dev/null" + // We do not need output file
                      " 2>&1";          // Keep console clean from error messages.
    RPP_LOG_I2(clang_path << " " << args);
    const int clang_rc =
        ExecuteGcnAssembler(clang_path + " " + args, nullptr, &clang_stdout_unused);
    if(clang_rc != 0)
        RPP_THROW("Assembly error(" + std::to_string(clang_rc) + ")");
#else
    (void)source; // -warning
    (void)params; // -warning
    RPP_THROW("Error: X-AMDGCN-ASM: online assembly under Windows is not supported");
#endif //__linux__
}

static bool GcnAssemblerHasBug34765Impl()
{
    auto p = fs::temp_directory_path() / std::to_string(std::chrono::system_clock::now().time_since_epoch().count());
    rpp::WriteFile(rpp::GetKernelSrc("bugzilla_34765_detect"), p);
    auto src = p.string();
    try
    {
        AmdgcnAssembleQuiet(src, "-mcpu=gfx900");
        return false;
    }
    catch(...)
    {
        RPP_LOG_I("Detected");
        return true;
    }
}

bool GcnAssemblerHasBug34765()
{
    const static bool b = GcnAssemblerHasBug34765Impl();
    return b;
}

static bool GcnAssemblerSupportsOption(const std::string& option)
{
    auto p = fs::temp_directory_path() / std::to_string(std::chrono::system_clock::now().time_since_epoch().count());
    rpp::WriteFile(rpp::GetKernelSrc("dummy_kernel"), p);
    auto src = p.string();
    try
    {
        AmdgcnAssembleQuiet(src, "-mcpu=gfx900 " + option);
        RPP_LOG_I("Supported: '" << option << '\'');
        return true;
    }
    catch(...)
    {
        RPP_LOG_I("Not supported: '" << option << '\'');
        return false;
    }
}

static bool GcnAssemblerSupportsCOv3()
{
    const static bool b = GcnAssemblerSupportsOption(option_no_co_v3);
    return b;
}

template <>
void GenerateClangDefsym<const std::string&>(std::ostream& stream,
                                             const std::string& name,
                                             const std::string& value)
{
    stream << " -Wa,-defsym," << name << "=" << value;
}

std::string MakeLutKey(
    int w, int h, int c, int n, int k, int conv_stride_h, int conv_stride_w, int dir, int CUs)
{
    std::ostringstream ss;
    ss << w << ";" << h << ";" << c << ";" << n << ";" << k << ";" << conv_stride_h << ";"
       << conv_stride_w << ";" << dir << ";" << CUs;
    return ss.str();
}

std::string MakeLutKey(int w, int h, int c, int n, int k, int dir, int CUs)
{
    return MakeLutKey(w, h, c, n, k, 1, 1, dir, CUs);
}
