#include "log/LogUtils.h"

#include <mutex>
#include <array>
#include <deque>
#include <map>
#include <typeindex>

#define TRACK_OBJECT_ALLOCATION
#include "memtracker.h"

#define NO_IMPL //For fast disable (e.g. when you dont want to recompile the whole source)

#ifndef __GLIBC__
    #define _GLIBCXX_NOEXCEPT
#endif
#ifndef WIN32
    #include <cxxabi.h>
#endif
#ifdef WIN32
    typedef int64_t ssize_t;
#endif

//#define MEMTRACK_VERBOSE

inline bool should_track_mangled(const char* mangled) {
	if(strstr(mangled, "ViewEntry")) return true;
	if(strstr(mangled, "ViewEntry")) return true;
	if(strstr(mangled, "ClientChannelView")) return true;
	if(strstr(mangled, "LinkedTreeEntry")) return true;

	return false;
}

using namespace std;
namespace memtrack {
	struct TypeInfo {
		const char* name;
		std::string mangled;

		explicit TypeInfo(const char* name) : name(name) {}

		bool operator==(const TypeInfo& other) {
			return other.name == this->name || strcmp(other.name, this->name) == 0;
		}
		bool operator!=(const TypeInfo& other) {
			return ! this->operator==(other);
		}

		bool operator<(const TypeInfo& __rhs) const noexcept
		{ return this->before(__rhs); }

		bool operator<=(const TypeInfo& __rhs) const noexcept
		{ return !__rhs.before(*this); }

		bool operator>(const TypeInfo& __rhs) const noexcept
		{ return __rhs.before(*this); }

		bool operator>=(const TypeInfo& __rhs) const noexcept
		{ return !this->before(__rhs); }

		inline bool before(const TypeInfo& __arg) const _GLIBCXX_NOEXCEPT
		{ return (name[0] == '*' && __arg.name[0] == '*')
		         ? name < __arg.name
		         : strcmp (name, __arg.name) < 0; }

		inline std::string as_mangled() {
#ifndef WIN32
			int status;
			std::unique_ptr<char[], void (*)(void*)> result(abi::__cxa_demangle(name, 0, 0, &status), std::free);
			if(status != 0)
				return "error: " + to_string(status);

			this->mangled = result.get();
#else
            //FIXME Implement!
            this->mangled = this->name;
#endif
			return this->mangled;
		}
	};
	class entry {
		public:
			/* std::string name; */
			size_t type;
			void* address = nullptr;

			entry() {}
			entry(size_t type, void* address) : type(type), address(address) {}
			~entry() {}
	};

	template <int N>
	class brick {
		public:
			inline bool insert(size_t type, void* address) {
				auto slot = free_slot();
				if(slot == N) return false;
				entries[slot] = entry{type, address};
				findex = slot + 1;
				return true;
			}

			inline bool remove(size_t type, void* address) {
				for(int index = 0; index < N; index++) {
					auto& e = entries[index];
					if(e.address == address && e.type == type) {
						e = entry{};
						findex = index;
						return true;
					}
				}
				return false;
			}

			inline int capacity() { return N; }

			array<entry, N> entries;
		private:
			inline int free_slot() {
				while (findex < N && entries[findex].address) findex++;
				return findex;
			}
			int findex = 0;
	};
	typedef brick<1024> InfoBrick;

	template <typename T, T N>
	struct DefaultValued {
		T value = N;
	};


	map<TypeInfo, DefaultValued<ssize_t, -1>> type_indexes;
	vector<InfoBrick*> bricks;
	mutex bricks_lock;

	void allocated(const char* name, void* address) {
#ifdef NO_IMPL
		return;
#else
#ifdef MEMTRACK_VERBOSE
		logTrace(lstream << "[MEMORY] Allocated a new instance of '" << name << "' at " << address);
#endif
		if(!should_track_mangled(name)) return;

		lock_guard<mutex> lock(bricks_lock);
		TypeInfo local_info(name);
		auto& type_index = type_indexes[local_info];
		if(type_index.value == -1) {
			type_index.value = type_indexes.size() - 1;
		}

		auto _value = (size_t) type_index.value;
		for(auto it = bricks.begin(); it != bricks.end(); it++)
			if((*it)->insert(_value, address)) return;
		bricks.push_back(new InfoBrick{});
		auto success = bricks.back()->insert(type_index.value, address);
		assert(success);
#endif
	}

	void freed(const char* name, void* address) {
#ifdef NO_IMPL
		return;
#else
#ifdef MEMTRACK_VERBOSE
		logTrace(lstream << "[MEMORY] Deallocated a instance of '" << name << "' at " << address);
#endif
		if(!should_track_mangled(name)) return;

		lock_guard<mutex> lock(bricks_lock);
		TypeInfo local_info(name);
		auto& type_index = type_indexes[local_info];
		if(type_index.value == -1)
			type_index.value = type_indexes.size() - 1;

		auto _value = (size_t) type_index.value;
		for (auto &brick : bricks)
			if(brick->remove(_value, address)) return;
		logError(lstream << "[MEMORY] Got deallocated notify, but never the allocated! (Address: " << address << " Name: " << name << ")");
#endif
	}

	void statistics() {
#ifdef NO_IMPL
		logError("memtracker::statistics() does not work due compiler flags (NO_IMPL)");
		return;
#else
		map<size_t, deque<void*>> objects;
		map<size_t, std::string> mapping;

		{
			lock_guard<mutex> lock(bricks_lock);
			for(auto& brick : bricks)
				for(auto& entry : brick->entries)
					if(entry.address) {
						objects[entry.type].push_back(entry.address);
					}
			for(auto& type : type_indexes)
				mapping[type.second.value] = type.first.as_mangled();
		}

		logMessage("Allocated object types: " + to_string(objects.size()));
			for(const auto& entry : objects) {
				logMessage("  " + mapping[entry.first] + ": " + to_string(entry.second.size()));
				if (entry.second.size() < 50) {
					stringstream ss;
					for (int index = 0; index < entry.second.size(); index++) {
						if (index % 16 == 0) {
							if (index + 1 >= entry.second.size()) break;
							if (index != 0)
								logMessage(ss.str());
							ss = stringstream();
							ss << "    ";
						}
						ss << entry.second[index] << "  ";
					}
					if (!ss.str().empty())
						logMessage(ss.str());
				} else {
					logMessage("<snipped>");
				}
			}
#endif
	}
}