// MIT License
//
// Copyright (c) 2022 Advanced Micro Devices, Inc. All Rights Reserved.
//
// 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 "library/cpu_freq.hpp"
#include "library/common.hpp"
#include "library/components/pthread_create_gotcha.hpp"
#include "library/config.hpp"
#include "library/debug.hpp"
#include "library/defines.hpp"
#include "library/perfetto.hpp"
#include "library/timemory.hpp"

#include <timemory/components/rusage/backends.hpp>
#include <timemory/mpl/types.hpp>
#include <timemory/units.hpp>
#include <timemory/utility/procfs/cpuinfo.hpp>
#include <timemory/utility/type_list.hpp>

#include <cstdlib>
#include <string>
#include <sys/resource.h>
#include <tuple>
#include <utility>
#include <vector>

namespace cpuinfo = tim::procfs::cpuinfo;

namespace omnitrace
{
namespace cpu_freq
{
template <typename... Tp>
using type_list = tim::type_list<Tp...>;

namespace
{
struct cpu_freq
{};
struct cpu_page
{};
struct cpu_virt
{};
struct cpu_context_switch
{};
struct cpu_page_fault
{};
struct cpu_user_mode_time
{};
struct cpu_kernel_mode_time
{};
using cpu_data_tuple_t = std::tuple<size_t, int64_t, int64_t, int64_t, int64_t, int64_t,
                                    int64_t, std::vector<double>>;

std::set<size_t>             enabled_cpu_freqs = {};
std::deque<cpu_data_tuple_t> cpu_data          = {};
int64_t                      ncpu              = threading::affinity::hw_concurrency();

template <typename... Types>
void init_perfetto_counter_tracks(type_list<Types...>)
{
    (perfetto_counter_track<Types>::init(), ...);
}
}  // namespace
}  // namespace cpu_freq
}  // namespace omnitrace

TIMEMORY_DEFINE_NAME_TRAIT("cpu_freq", omnitrace::cpu_freq::cpu_freq);
TIMEMORY_DEFINE_NAME_TRAIT("process_page_fault", omnitrace::cpu_freq::cpu_page);
TIMEMORY_DEFINE_NAME_TRAIT("process_virtual_memory", omnitrace::cpu_freq::cpu_virt);
TIMEMORY_DEFINE_NAME_TRAIT("process_context_switch",
                           omnitrace::cpu_freq::cpu_context_switch);
TIMEMORY_DEFINE_NAME_TRAIT("process_page_fault", omnitrace::cpu_freq::cpu_page_fault);
TIMEMORY_DEFINE_NAME_TRAIT("process_user_cpu_time",
                           omnitrace::cpu_freq::cpu_user_mode_time);
TIMEMORY_DEFINE_NAME_TRAIT("process_kernel_cpu_time",
                           omnitrace::cpu_freq::cpu_kernel_mode_time);

namespace omnitrace
{
namespace cpu_freq
{
void
setup()
{
    init_perfetto_counter_tracks(
        type_list<cpu_freq, cpu_page, cpu_virt, cpu_context_switch, cpu_page_fault,
                  cpu_user_mode_time, cpu_kernel_mode_time>{});
}

void
config()
{
    auto _ncpu          = cpuinfo::freq::size();
    auto _enabled_freqs = std::set<size_t>{};

    auto _enabled_val = get_sampling_cpus();
    for(auto& itr : _enabled_val)
        itr = tolower(itr);
    if(_enabled_val == "off")
        _enabled_val = "none";
    else if(_enabled_val == "on")
        _enabled_val = "all";
    if(_enabled_val != "none" && _enabled_val != "all")
    {
        auto _enabled = tim::delimit(_enabled_val, ",; \t");
        if(_enabled.empty())
        {
            for(size_t i = 0; i < _ncpu; ++i)
                _enabled_freqs.emplace(i);
        }
        for(auto&& _v : _enabled)
        {
            if(_v.find_first_not_of("0123456789-") != std::string::npos)
            {
                OMNITRACE_VERBOSE_F(
                    0,
                    "Invalid CPU specification. Only numerical values (e.g., 0) or "
                    "ranges (e.g., 0-7) are permitted. Ignoring %s...",
                    _v.c_str());
                continue;
            }
            if(_v.find('-') != std::string::npos)
            {
                auto _vv = tim::delimit(_v, "-");
                OMNITRACE_CONDITIONAL_THROW(
                    _vv.size() != 2,
                    "Invalid CPU range specification: %s. Required format N-M, e.g. 0-4",
                    _v.c_str());
                for(size_t i = std::stoull(_vv.at(0)); i <= std::stoull(_vv.at(1)); ++i)
                    _enabled_freqs.emplace(i);
            }
            else
            {
                _enabled_freqs.emplace(std::stoull(_v));
            }
        }
    }
    else if(_enabled_val == "all")
    {
        for(size_t i = 0; i < _ncpu; ++i)
            _enabled_freqs.emplace(i);
    }
    else if(_enabled_val == "none")
    {
        _enabled_freqs.clear();
    }

    for(auto itr : _enabled_freqs)
    {
        if(itr < cpuinfo::freq::size())
            _enabled_freqs.emplace(itr);
        else
        {
            OMNITRACE_VERBOSE(
                0, "[cpu_freq::config] Warning! Removing invalid cpu %zu...\n", itr);
            OMNITRACE_CI_FAIL(true, "[cpu_freq::config] CPU frequencies are disabled "
                                    ":: unable to open /proc/cpuinfo");
        }
    }

    if(!cpuinfo::freq{})
    {
        OMNITRACE_VERBOSE(0, "[cpu_freq::config] Warning! CPU frequencies are disabled "
                             ":: unable to open /proc/cpuinfo");
        _enabled_freqs.clear();
    }

    OMNITRACE_CI_FAIL(!cpuinfo::freq{}, "[cpu_freq::config] CPU frequencies are disabled "
                                        ":: unable to open /proc/cpuinfo");

    enabled_cpu_freqs = _enabled_freqs;
}

void
sample()
{
    std::vector<double> _freqs{};
    if(!enabled_cpu_freqs.empty())
    {
        _freqs.reserve(enabled_cpu_freqs.size());
        auto&& _freq = cpuinfo::freq{};
        for(const auto& itr : enabled_cpu_freqs)
        {
            _freqs.emplace_back(_freq(itr));
        }
    }

    auto _ts = tim::get_clock_real_now<size_t, std::nano>();

    tim::rusage_cache _rcache{ RUSAGE_SELF };
    // user and kernel mode times are in microseconds
    cpu_data.emplace_back(_ts, tim::get_page_rss(), tim::get_virt_mem(),
                          _rcache.get_num_priority_context_switch() +
                              _rcache.get_num_voluntary_context_switch(),
                          _rcache.get_num_major_page_faults() +
                              _rcache.get_num_minor_page_faults(),
                          _rcache.get_user_mode_time() * 1000,
                          _rcache.get_kernel_mode_time() * 1000, std::move(_freqs));
}

void
shutdown()
{}

namespace
{
template <typename... Types, size_t N = sizeof...(Types)>
void
config_perfetto_counter_tracks(type_list<Types...>, std::array<const char*, N> _labels,
                               std::array<const char*, N> _units)
{
    auto _config = [&](auto _t) {
        using type          = std::decay_t<decltype(_t)>;
        using track         = perfetto_counter_track<type>;
        constexpr auto _idx = tim::index_of<type, type_list<Types...>>::value;
        if(!track::exists(0))
        {
            auto addendum = [&](const char* _v) { return JOIN(" ", "CPU", _v, "(S)"); };
            track::emplace(0, addendum(_labels.at(_idx)), _units.at(_idx));
        }
    };

    (_config(Types{}), ...);
}

template <typename Tp, typename... Args>
void
write_perfetto_counter_track(Args... _args)
{
    using track = perfetto_counter_track<Tp>;
    TRACE_COUNTER(trait::name<Tp>::value, track::at(0, 0), _args...);
}
}  // namespace

void
post_process()
{
    OMNITRACE_PRINT("Post-processing %zu cpu frequency and memory usage entries...\n",
                    cpu_data.size());
    auto _process_frequencies = [](size_t _idx, size_t _offset) {
        using freq_track = perfetto_counter_track<cpu_freq>;
        if(!freq_track::exists(_idx))
        {
            auto addendum = [&](const char* _v) {
                return JOIN(" ", "CPU", _v, JOIN("", '[', _idx, ']'), "(S)");
            };
            freq_track::emplace(_idx, addendum("Frequency"), "MHz");
        }

        for(auto& itr : cpu_data)
        {
            uint64_t _ts   = std::get<0>(itr);
            double   _freq = std::get<7>(itr).at(_offset);
            if(!pthread_create_gotcha::is_valid_execution_time(0, _ts)) continue;
            TRACE_COUNTER("cpu_freq", freq_track::at(_idx, 0), _ts, _freq);
        }

        auto _end_ts = pthread_create_gotcha::get_execution_time(0)->second;
        TRACE_COUNTER("cpu_freq", freq_track::at(_idx, 0), _end_ts, 0);
    };

    auto _process_cpu_rusage = []() {
        config_perfetto_counter_tracks(
            type_list<cpu_page, cpu_virt, cpu_context_switch, cpu_page_fault,
                      cpu_user_mode_time, cpu_kernel_mode_time>{},
            { "Memory Usage", "Virtual Memory Usage", "Context Switches", "Page Faults",
              "User Time", "Kernel Time" },
            { "MB", "MB", "", "", "sec", "sec" });

        for(auto& itr : cpu_data)
        {
            uint64_t _ts = std::get<0>(itr);
            if(!pthread_create_gotcha::is_valid_execution_time(0, _ts)) continue;

            double   _page = std::get<1>(itr);
            double   _virt = std::get<2>(itr);
            uint64_t _cntx = std::get<3>(itr);
            uint64_t _flts = std::get<4>(itr);
            double   _user = std::get<5>(itr);
            double   _kern = std::get<6>(itr);
            write_perfetto_counter_track<cpu_page>(_ts, _page / units::megabyte);
            write_perfetto_counter_track<cpu_virt>(_ts, _virt / units::megabyte);
            write_perfetto_counter_track<cpu_context_switch>(_ts, _cntx);
            write_perfetto_counter_track<cpu_page_fault>(_ts, _flts);
            write_perfetto_counter_track<cpu_user_mode_time>(_ts, _user / units::sec);
            write_perfetto_counter_track<cpu_kernel_mode_time>(_ts, _kern / units::sec);
        }

        auto _end_ts = pthread_create_gotcha::get_execution_time(0)->second;
        write_perfetto_counter_track<cpu_page>(_end_ts, 0);
        write_perfetto_counter_track<cpu_virt>(_end_ts, 0);
        write_perfetto_counter_track<cpu_context_switch>(_end_ts, 0);
        write_perfetto_counter_track<cpu_page_fault>(_end_ts, 0);
        write_perfetto_counter_track<cpu_user_mode_time>(_end_ts, 0);
        write_perfetto_counter_track<cpu_kernel_mode_time>(_end_ts, 0);
    };

    _process_cpu_rusage();
    for(auto itr = enabled_cpu_freqs.begin(); itr != enabled_cpu_freqs.end(); ++itr)
    {
        auto _idx    = *itr;
        auto _offset = std::distance(enabled_cpu_freqs.begin(), itr);
        _process_frequencies(_idx, _offset);
    }

    enabled_cpu_freqs.clear();
}
}  // namespace cpu_freq
}  // namespace omnitrace