/**
Lightweight profiler library for c++
Copyright(C) 2016  Sergey Yagovtsev, Victor Zarubkin


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.


GNU General Public License Usage
Alternatively, this file may be used under the terms of the GNU
General Public License as published by the Free Software Foundation,
either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.If not, see <http://www.gnu.org/licenses/>.
**/

#ifndef EASY_PROFILER____MANAGER____H______
#define EASY_PROFILER____MANAGER____H______

#include "easy/profiler.h"
#include "easy/easy_socket.h"
#include "spin_lock.h"
#include "outstream.h"
#include "hashed_cstr.h"
#include <map>
#include <vector>
#include <unordered_map>
#include <thread>
#include <atomic>
//#include <list>

//////////////////////////////////////////////////////////////////////////

#ifdef _WIN32
#include <Windows.h>
#else
#include <sys/types.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <chrono>
#include <time.h>
#endif

inline uint32_t getCurrentThreadId()
{
#ifdef _WIN32
    return (uint32_t)::GetCurrentThreadId();
#else
    EASY_THREAD_LOCAL static const pid_t x = syscall(__NR_gettid);
    EASY_THREAD_LOCAL static const uint32_t _id = (uint32_t)x;//std::hash<std::thread::id>()(std::this_thread::get_id());
    return _id;
#endif
}

namespace profiler {
    
    class SerializedBlock;

    struct do_not_calc_hash {
        template <class T> inline size_t operator()(T _value) const {
            return static_cast<size_t>(_value);
        }
    };

}

//////////////////////////////////////////////////////////////////////////

#ifndef EASY_ENABLE_BLOCK_STATUS
# define EASY_ENABLE_BLOCK_STATUS 1
#endif

#ifndef EASY_ENABLE_ALIGNMENT
# define EASY_ENABLE_ALIGNMENT 0
#endif

#if EASY_ENABLE_ALIGNMENT == 0
# define EASY_ALIGNED(TYPE, VAR, A) TYPE VAR
# define EASY_MALLOC(MEMSIZE, A) malloc(MEMSIZE)
# define EASY_FREE(MEMPTR) free(MEMPTR)
#else
# if defined(_WIN32)
#  define EASY_ALIGNED(TYPE, VAR, A) __declspec(align(A)) TYPE VAR
#  define EASY_MALLOC(MEMSIZE, A) _aligned_malloc(MEMSIZE, A)
#  define EASY_FREE(MEMPTR) _aligned_free(MEMPTR)
# elif defined(__GNUC__)
#  define EASY_ALIGNED(TYPE, VAR, A) TYPE VAR __attribute__(aligned(A))
# else
#  define EASY_ALIGNED(TYPE, VAR, A) TYPE VAR
# endif
#endif

template <const uint16_t N>
class chunk_allocator
{
    struct chunk { EASY_ALIGNED(int8_t, data[N], 64); chunk* prev = nullptr; };

    struct chunk_list
    {
        chunk* last = nullptr;

        ~chunk_list()
        {
            clear();
        }

        void clear()
        {
            do {
                auto p = last;
                last = last->prev;
                EASY_FREE(p);
            } while (last != nullptr);
        }

        chunk& back()
        {
            return *last;
        }

        void emplace_back()
        {
            auto prev = last;
            last = ::new (EASY_MALLOC(sizeof(chunk), 64)) chunk();
            last->prev = prev;
            *(uint16_t*)last->data = 0;
        }

        void invert()
        {
            chunk* next = nullptr;

            while (last->prev != nullptr) {
                auto p = last->prev;
                last->prev = next;
                next = last;
                last = p;
            }

            last->prev = next;
        }
    };

    //typedef std::list<chunk> chunk_list;

    chunk_list m_chunks;
    uint32_t     m_size;
    uint16_t    m_shift;

public:

    chunk_allocator() : m_size(0), m_shift(0)
    {
        m_chunks.emplace_back();
    }

    void* allocate(uint16_t n)
    {
        ++m_size;

        if (!need_expand(n))
        {
            int8_t* data = m_chunks.back().data + m_shift;
            m_shift += n + sizeof(uint16_t);

            *(uint16_t*)data = n;
            data = data + sizeof(uint16_t);

            if (m_shift + 1 < N)
                *(uint16_t*)(data + n) = 0;

            return data;
        }

        m_shift = n + sizeof(uint16_t);
        m_chunks.emplace_back();
        auto data = m_chunks.back().data;

        *(uint16_t*)data = n;
        data = data + sizeof(uint16_t);

        *(uint16_t*)(data + n) = 0;
        return data;
    }

    inline bool need_expand(uint16_t n) const
    {
        return (m_shift + n + sizeof(uint16_t)) > N;
    }

    inline uint32_t size() const
    {
        return m_size;
    }

    inline bool empty() const
    {
        return m_size == 0;
    }

    void clear()
    {
        m_size = 0;
        m_shift = 0;
        m_chunks.clear();
        m_chunks.emplace_back();
    }

    /** Serialize data to stream.

    \warning Data will be cleared after serialization.
    */
    void serialize(profiler::OStream& _outputStream)
    {
        m_chunks.invert();

        auto current = m_chunks.last;
        do {
            const int8_t* data = current->data;
            uint16_t i = 0;
            while (i + 1 < N && *(uint16_t*)data != 0) {
                const uint16_t size = sizeof(uint16_t) + *(uint16_t*)data;
                _outputStream.write((const char*)data, size);
                data = data + size;
                i += size;
            }
            current = current->prev;
        } while (current != nullptr);

        clear();
    }
};

//////////////////////////////////////////////////////////////////////////

const uint16_t SIZEOF_CSWITCH = sizeof(profiler::BaseBlockData) + 1 + sizeof(uint16_t);

typedef std::vector<profiler::SerializedBlock*> serialized_list_t;

template <class T, const uint16_t N>
struct BlocksList
{
    BlocksList() = default;

    class Stack {
        //std::stack<T> m_stack;
        std::vector<T> m_stack;

    public:

        inline void clear() { m_stack.clear(); }
        inline bool empty() const { return m_stack.empty(); }

        inline void emplace(profiler::Block& _block) {
            //m_stack.emplace(_block);
            m_stack.emplace_back(_block);
        }

        inline void emplace(profiler::Block&& _block) {
            //m_stack.emplace(_block);
            m_stack.emplace_back(std::forward<profiler::Block&&>(_block));
        }

        template <class ... TArgs> inline void emplace(TArgs ... _args) {
            //m_stack.emplace(_args);
            m_stack.emplace_back(_args...);
        }

        inline T& top() {
            //return m_stack.top();
            return m_stack.back();
        }

        inline void pop() {
            //m_stack.pop();
            m_stack.pop_back();
        }
    };

    Stack                     openedList;
    chunk_allocator<N>        closedList;
    uint64_t          usedMemorySize = 0;

    void clearClosed() {
        //closedList.clear();
        usedMemorySize = 0;
    }
};


struct ThreadStorage
{
    BlocksList<std::reference_wrapper<profiler::Block>, SIZEOF_CSWITCH * (uint16_t)128U> blocks;
    BlocksList<profiler::Block, SIZEOF_CSWITCH * (uint16_t)128U>                           sync;
    std::string name;

#ifndef _WIN32
    const pthread_t pthread_id;
#endif

    const profiler::thread_id_t id;
    std::atomic_bool expired;
    bool allowChildren;
    bool named;

    void storeBlock(const profiler::Block& _block);
    void storeCSwitch(const profiler::Block& _block);
    void clearClosed();

    ThreadStorage();
};

//////////////////////////////////////////////////////////////////////////

class BlockDescriptor;

class ProfileManager
{
#ifndef EASY_MAGIC_STATIC_CPP11
    friend class ProfileManagerInstance;
#endif

    ProfileManager();
    ProfileManager(const ProfileManager& p) = delete;
    ProfileManager& operator=(const ProfileManager&) = delete;

    typedef profiler::guard_lock<profiler::spin_lock> guard_lock_t;
    typedef std::map<profiler::thread_id_t, ThreadStorage> map_of_threads_stacks;
    typedef std::vector<BlockDescriptor*> block_descriptors_t;

#ifdef _WIN32
    typedef std::unordered_map<profiler::hashed_cstr, profiler::block_id_t> descriptors_map_t;
#else
    typedef std::unordered_map<profiler::hashed_stdstring, profiler::block_id_t> descriptors_map_t;
#endif

    map_of_threads_stacks             m_threads;
    block_descriptors_t           m_descriptors;
    descriptors_map_t          m_descriptorsMap;
    uint64_t               m_usedMemorySize = 0;
    profiler::timestamp_t       m_beginTime = 0;
    profiler::timestamp_t         m_endTime = 0;
    profiler::spin_lock                  m_spin;
    profiler::spin_lock            m_storedSpin;
    std::atomic_bool                m_isEnabled;
    std::atomic_bool    m_isEventTracingEnabled;
    std::atomic_bool        m_isAlreadyListening;

    std::string m_csInfoFilename = "/tmp/cs_profiling_info.log";

    uint32_t dumpBlocksToStream(profiler::OStream& _outputStream);
    void setBlockStatus(profiler::block_id_t _id, profiler::EasyBlockStatus _status);

    std::thread m_listenThread;
    void listen(uint16_t _port);

    int m_socket = 0;//TODO crossplatform

    std::atomic_bool m_stopListen;

public:

    static ProfileManager& instance();
    ~ProfileManager();

    const profiler::BaseBlockDescriptor* addBlockDescriptor(profiler::EasyBlockStatus _defaultStatus,
                                                            const char* _autogenUniqueId,
                                                            const char* _name,
                                                            const char* _filename,
                                                            int _line,
                                                            profiler::block_type_t _block_type,
                                                            profiler::color_t _color);

    void storeBlock(const profiler::BaseBlockDescriptor* _desc, const char* _runtimeName);
    void beginBlock(profiler::Block& _block);
    void endBlock();
    void setEnabled(bool isEnable, bool _setTime = true);
    void setEventTracingEnabled(bool _isEnable);
    uint32_t dumpBlocksToFile(const char* filename);
    const char* registerThread(const char* name, profiler::ThreadGuard& threadGuard);
    const char* registerThread(const char* name);

    void setContextSwitchLogFilename(const char* name)
    {
        m_csInfoFilename = name;
    }

    const char* getContextSwitchLogFilename() const
    {
        return m_csInfoFilename.c_str();
    }

    void beginContextSwitch(profiler::thread_id_t _thread_id, profiler::timestamp_t _time, profiler::thread_id_t _target_thread_id, const char* _target_process, bool _lockSpin = true);
    void storeContextSwitch(profiler::thread_id_t _thread_id, profiler::timestamp_t _time, profiler::thread_id_t _target_thread_id, bool _lockSpin = true);
    void endContextSwitch(profiler::thread_id_t _thread_id, profiler::timestamp_t _endtime, bool _lockSpin = true);
    void startListen(uint16_t _port);
    void stopListen();

private:

    bool checkThreadExpired(ThreadStorage& _registeredThread);

    void storeBlockForce(const profiler::BaseBlockDescriptor* _desc, const char* _runtimeName, ::profiler::timestamp_t& _timestamp);
    void storeBlockForce2(const profiler::BaseBlockDescriptor* _desc, const char* _runtimeName, ::profiler::timestamp_t _timestamp);

    ThreadStorage& threadStorage(profiler::thread_id_t _thread_id);
    ThreadStorage* _findThreadStorage(profiler::thread_id_t _thread_id);

    ThreadStorage* findThreadStorage(profiler::thread_id_t _thread_id)
    {
        guard_lock_t lock(m_spin);
        return _findThreadStorage(_thread_id);
    }
};

#endif // EASY_PROFILER____MANAGER____H______