/*
 * =====================================================================================
 *
 *       Filename:  defs.cpp
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  2021年04月06日 19时23分14秒
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  Li Chao (), 
 *   Organization:  
 *
 * =====================================================================================
 */
#include "defs.h"
#include "msg.h"
#include "shm_msg_queue.h"
#include "shm_socket.h"
#include <boost/uuid/random_generator.hpp>
#include <boost/uuid/string_generator.hpp>
#include <boost/uuid/uuid.hpp>
#include <sys/file.h>

namespace
{

struct LastError {
	int ec_ = 0;
	std::string msg_;
};

LastError &LastErrorStore()
{
	thread_local LastError le;
	return le;
}

constexpr int64_t AllocSizeIndex[] = {
    16, 24, 32, 40, 48, 56, 64, 72,
    80, 88, 96, 104, 120, 136, 152, 168,
    184, 200, 224, 248, 272, 296, 328, 360,
    392, 432, 472, 520, 568, 624, 680, 744,
    816, 896, 984, 1080, 1184, 1296, 1416, 1544,
    1688, 1848, 2016, 2200, 2400, 2624, 2864, 3128,
    3416, 3728, 4072, 4448, 4856, 5304, 5792, 6320,
    6896, 7528, 8216, 8968, 9784, 10680, 11656, 12720,
    13880, 15144, 16520, 18024, 19664, 21456, 23408, 25536,
    27864, 30400, 33168, 36184, 39480, 43072, 46992, 51264,
    55928, 61016, 66568, 72624, 79232, 86440, 94304, 102880,
    112232, 122440, 133576, 145720, 158968, 173424, 189192, 206392,
    225160, 245632, 267968, 292328, 318904, 347896, 379528, 414032,
    451672, 492736, 537536, 586408, 639720, 697880, 761328, 830544,
    906048, 988416, 1078272, 1176296, 1283232, 1399896, 1527160, 1665992,
    1817448, 1982672, 2162920, 2359552, 2574056, 2808064, 3063344, 3341832,
    3645640, 3977064, 4338616, 4733040, 5163320, 5632712, 6144776, 6703392,
    7312792, 7977592, 8702832, 9494000, 10357096, 11298656, 12325808, 13446336,
    14668736, 16002264, 17457016, 19044024, 20775304, 22663968, 24724328, 26972000,
    29424000, 32098912, 35017000, 38200368, 41673128, 45461600, 49594472, 54103064,
    59021528, 64387128, 70240504, 76626008, 83592008, 91191288, 99481408, 108525176,
    118391104, 129153936, 140895208, 153703864, 167676944, 182920304, 199549424, 217690280,
    237480312, 259069432, 282621200, 308314040, 336342592, 366919192, 400275488, 436664168,
    476360912, 519666456, 566908864, 618446040, 674668408, 736001904, 802911168, 875903096,
    955530656, 1042397080, 1137160456, 1240538680, 1353314928, 1476343560, 1610556616, 1756970856,
    1916695480, 2090940528, 2281026032, 2488392040, 2714609504, 2961392192, 3230609664, 3524301456,
    3844692504, 4194210008, 4575501832, 4991456544, 5445225320, 5940245808, 6480268160, 7069383448,
    7712054672, 8413150552, 9177982424, 10012344464, 10922557600, 11915517384, 12998746240, 14180450448,
    15469582312, 16875907976, 18410081432, 20083725200, 21909518400, 23901292800, 26074137600, 28444513752,
    31030378640, 33851322152, 36928715080, 40285871000, 43948222912, 47943515904, 52302017352, 57056746208,
    62243723136, 67902243424, 74075174648, 80809281440, 88155579752, 96169723368, 104912425496, 114449918728,
    124854456800, 136204861968, 148587122152, 162095042352, 176830955296, 192906496688, 210443450936, 229574673752};

const int kAllocIndexLen = sizeof(AllocSizeIndex) / sizeof(AllocSizeIndex[0]);
static_assert(kAllocIndexLen == 256, "Make sure alloc 8 bit is enough.");
static_assert(AllocSizeIndex[255] > uint32_t(-1), "Make sure alloc size correct.");

const int64_t kCenterInfoFixedAddress = 1024 * 4;
const int64_t kShmMetaInfoFixedAddress = 1024 * 16;

const boost::uuids::uuid kMetaInfoTag = boost::uuids::string_generator()("fc5007bd-0e62-4d91-95dc-948cf1f02e5a");

struct BHomeMetaInfo {
	boost::uuids::uuid tag_;
	std::atomic<uint64_t> shm_id_;
	std::atomic<uint64_t> ssn_id_;
};

struct CenterMetaInfo {
	boost::uuids::uuid tag_;
	CenterInfo info_;
};

int64_t Addr(void *ptr) { return reinterpret_cast<int64_t>(ptr); }
// void *Ptr(const int64_t offset) { return reinterpret_cast<void *>(offset); }
template <class T = void>
T *Ptr(const int64_t offset) { return reinterpret_cast<T *>(offset); }

class FileLock
{
public:
	FileLock(const std::string &path) :
	    fd_(Open(path))
	{
		if (fd_ == -1) { throw std::runtime_error("error open file:" + path); }
	}
	~FileLock() { Close(fd_); }
	bool try_lock() { return fd_ != -1 && (flock(fd_, LOCK_EX | LOCK_NB) == 0); }
	void unlock() { flock(fd_, LOCK_UN); }

private:
	static int Open(const std::string &path) { return open(path.c_str(), O_RDONLY, 0666); }
	static int Close(int fd) { return close(fd); }
	int fd_;
	std::mutex mtx_;
};

SharedMemory &BHomeMetaShm()
{
	static std::string name("bhshmq_meta_v0");
	static SharedMemory shm(name, 1024 * 128);
	return shm;
}

} // namespace

CenterInfo *GetCenterInfo(SharedMemory &shm)
{
	auto pmeta = Ptr<CenterMetaInfo>(kCenterInfoFixedAddress + Addr(shm.get_address()));
	if (pmeta->tag_ == kMetaInfoTag) {
		return &pmeta->info_;
	}
	return nullptr;
}

ShmSocket &DefaultSender(SharedMemory &shm)
{
	typedef std::pair<void *, std::shared_ptr<ShmSocket>> Pair;
	static std::vector<Pair> store;
	static std::mutex s_mtx;

	thread_local Pair local_cache;
	if (local_cache.first == &shm) {
		return *local_cache.second;
	}

	std::lock_guard<std::mutex> lk(s_mtx);
	for (auto &kv : store) {
		if (kv.first == &shm) {
			local_cache = kv;
			return *local_cache.second;
		}
	}
	auto &mq = GetCenterInfo(shm)->mq_sender_;
	store.emplace_back(&shm, new ShmSocket(mq.offset_, shm, mq.id_));
	local_cache = store.back();
	return *local_cache.second;
}

BHomeMetaInfo *GetBHomeMeta()
{
	auto p = Ptr<BHomeMetaInfo>(kShmMetaInfoFixedAddress + Addr(BHomeMetaShm().get_address()));
	return (p->tag_ == kMetaInfoTag) ? p : nullptr;
}

bool ShmMetaInit()
{
	SharedMemory &shm = BHomeMetaShm();

	static FileLock fl("/dev/shm/" + shm.name());
	if (!fl.try_lock()) { // single center instance only.
		return false;
	}

	auto pmeta = GetBHomeMeta();
	if (pmeta && pmeta->tag_ == kMetaInfoTag) {
		++pmeta->shm_id_; // inc shm id
		return true;      // already exist.
	} else {
		Mutex *mutex = shm.FindOrCreate<Mutex>("bhshmq_meta_lock");
		if (!mutex || !mutex->try_lock()) {
			return false;
		}
		DEFER1(mutex->unlock());

		auto base = Addr(shm.get_address());
		auto offset = kShmMetaInfoFixedAddress;
		void *p = shm.Alloc(offset * 2);
		if (Addr(p) - base <= offset) {
			pmeta = new (Ptr(offset + base)) BHomeMetaInfo;
			pmeta->tag_ = kMetaInfoTag;
			pmeta->shm_id_ = 100;
			pmeta->ssn_id_ = 10000;
			return true;
		}
	}
	return false;
}

// put center info at fixed memory position.
// as boost shm find object (find socket/mq by id, etc...) also locks inside,
// which node might crash inside and cause deadlock.
bool CenterInit()
{
	if (!ShmMetaInit()) { return false; }

	SharedMemory &shm = BHomeShm();
	Mutex *mutex = shm.FindOrCreate<Mutex>("shm_center_lock");
	if (!mutex || !mutex->try_lock()) {
		return false;
	}
	DEFER1(mutex->unlock());

	auto pmeta = Ptr<CenterMetaInfo>(kCenterInfoFixedAddress + Addr(shm.get_address()));
	if (pmeta->tag_ == kMetaInfoTag) {
		return true;
	} else {
		auto base = Addr(shm.get_address());
		auto offset = kCenterInfoFixedAddress;
		void *p = shm.Alloc(offset * 2);
		if (Addr(p) - base <= offset) {
			pmeta = new (Ptr(offset + base)) CenterMetaInfo;
			auto &info = pmeta->info_;

			auto InitMQ = [&](auto &mq, auto &&id) {
				mq.id_ = id;
				ShmSocket tmp(shm, id, eOpenOrCreate);
				mq.offset_ = tmp.AbsAddr();
			};

			int id = 100;
			auto NextId = [&]() { return ++id; };
			InitMQ(info.mq_sender_, NextId());
			InitMQ(info.mq_center_, NextId());
			InitMQ(info.mq_bus_, NextId());

			pmeta->tag_ = kMetaInfoTag;
			return true;
		}
	}
	return false;
}

const MQInfo &BHTopicCenterAddress(SharedMemory &shm) { return GetCenterInfo(shm)->mq_center_; }
const MQInfo &BHTopicBusAddress(SharedMemory &shm) { return GetCenterInfo(shm)->mq_bus_; }
bool BHNodeInit(SharedMemory &shm, const int64_t request, int64_t &reply)
{
	return GetCenterInfo(shm)->init_rr_.ClientRequest(request, reply);
}
void BHCenterHandleInit(SharedMemory &shm, std::function<int64_t(const int64_t)> const &onReq)
{
	GetCenterInfo(shm)->init_rr_.ServerProcess(onReq);
}

int64_t CalcAllocIndex(int64_t size)
{
	auto pos = std::lower_bound(AllocSizeIndex, AllocSizeIndex + kAllocIndexLen, size);
	return (pos == AllocSizeIndex + kAllocIndexLen) ? -1 : pos - AllocSizeIndex;
}

int64_t GetAllocSize(int index) { return index < kAllocIndexLen ? AllocSizeIndex[index] : 0; }

std::string BHomeShmName()
{
	auto bhome_meta = Ptr<BHomeMetaInfo>(kShmMetaInfoFixedAddress + Addr(BHomeMetaShm().get_address()));
	return "bhome_shmq_id_" + std::to_string(bhome_meta->shm_id_.load());
}

SharedMemory &BHomeShm()
{
	static SharedMemory shm(BHomeShmName(), 1024 * 1024 * 512);
	return shm;
}

bool GlobalInit(SharedMemory &shm) { return GetCenterInfo(shm); }

MQId NewSession() { return 10 * (++GetBHomeMeta()->ssn_id_); }

void SetLastError(const int ec, const std::string &msg)
{
	LastErrorStore().ec_ = ec;
	LastErrorStore().msg_ = msg;
}

void GetLastError(int &ec, std::string &msg)
{
	ec = LastErrorStore().ec_;
	msg = LastErrorStore().msg_;
}

int NodeTimeoutSec() { return 60; }

std::string BHLogDir() { return "/opt/vasystem/valog/"; }