// This software is in the public domain. Where that dedication is not
// recognized, you are granted a perpetual, irrevocable license to copy,
// distribute, and modify this file as you see fit.
// Authored in 2015 by Dimitri Diakopoulos (http://www.dimitridiakopoulos.com)
// https://github.com/ddiakopoulos/tinyply

#ifndef tinyply_h
#define tinyply_h

#include <vector>
#include <algorithm>
#include <string>
#include <stdint.h>
#include <map>
#include <iostream>
#include <sstream>
#include <type_traits>
#include <memory>
#include <functional>
#include <cstring>

namespace tinyply
{

	template<typename T> T endian_swap(const T & v) { return v; }
	template<> inline uint16_t endian_swap(const uint16_t & v) { return (v << 8) | (v >> 8); }
	template<> inline uint32_t endian_swap(const uint32_t & v) { return (v << 24) | ((v << 8) & 0x00ff0000) | ((v >> 8) & 0x0000ff00) | (v >> 24); }
	template<> inline uint64_t endian_swap(const uint64_t & v)
	{
		return (((v & 0x00000000000000ffLL) << 56) |
			((v & 0x000000000000ff00LL) << 40) |
			((v & 0x0000000000ff0000LL) << 24) |
			((v & 0x00000000ff000000LL) << 8) |
			((v & 0x000000ff00000000LL) >> 8) |
			((v & 0x0000ff0000000000LL) >> 24) |
			((v & 0x00ff000000000000LL) >> 40) |
			((v & 0xff00000000000000LL) >> 56));
	}
	template<> inline int16_t endian_swap(const int16_t & v) { uint16_t r = endian_swap(*(uint16_t*)&v); return *(int16_t*)&r; }
	template<> inline int32_t endian_swap(const int32_t & v) { uint32_t r = endian_swap(*(uint32_t*)&v); return *(int32_t*)&r; }
	template<> inline int64_t endian_swap(const int64_t & v) { uint64_t r = endian_swap(*(uint64_t*)&v); return *(int64_t*)&r; }
	inline float endian_swap_float(const uint32_t & v) { uint32_t r = endian_swap(v); return *(float*)&r; }
	inline double endian_swap_double(const uint64_t & v) { uint64_t r = endian_swap(v); return *(double*)&r; }

	struct DataCursor
	{
		void * vector;
		uint8_t * data;
		size_t offset;
		bool realloc = false;
	};

	class PlyProperty
	{
		void parse_internal(std::istream & is);
	public:

		enum class Type : uint8_t
		{
			INVALID,
			INT8,
			UINT8,
			INT16,
			UINT16,
			INT32,
			UINT32,
			FLOAT32,
			FLOAT64
		};

		PlyProperty(std::istream & is);
		PlyProperty(Type type, const std::string & name) : propertyType(type), isList(false), name(name) {}
		PlyProperty(Type list_type, Type prop_type, const std::string & name, int listCount) : listType(list_type), propertyType(prop_type), isList(true), name(name), listCount(listCount) {}

		Type listType, propertyType;
		bool isList;
		int listCount = 0;
		std::string name;
	};

	inline std::string make_key(const std::string & a, const std::string & b)
	{
		return (a + "-" + b);
	}

	template<typename T>
	void ply_cast(void * dest, const char * src, bool be)
	{
		*(static_cast<T *>(dest)) = (be) ? endian_swap(*(reinterpret_cast<const T *>(src))) : *(reinterpret_cast<const T *>(src));
	}

	template<typename T>
	void ply_cast_float(void * dest, const char * src, bool be)
	{
		*(static_cast<T *>(dest)) = (be) ? endian_swap_float(*(reinterpret_cast<const uint32_t *>(src))) : *(reinterpret_cast<const T *>(src));
	}

	template<typename T>
	void ply_cast_double(void * dest, const char * src, bool be)
	{
		*(static_cast<T *>(dest)) = (be) ? endian_swap_double(*(reinterpret_cast<const uint64_t *>(src))) : *(reinterpret_cast<const T *>(src));
	}

	template<typename T>
	T ply_read_ascii(std::istream & is)
	{
		T data;
		is >> data;
		return data;
	}

	template<typename T>
	void ply_cast_ascii(void * dest, std::istream & is)
	{
		*(static_cast<T *>(dest)) = ply_read_ascii<T>(is);
	}

	struct PropertyInfo { int stride; std::string str; };
	static std::map<PlyProperty::Type, PropertyInfo> PropertyTable
	{
		{ PlyProperty::Type::INT8,{ 1, "char" } },
		{ PlyProperty::Type::UINT8,{ 1, "uchar" } },
		{ PlyProperty::Type::INT16,{ 2, "short" } },
		{ PlyProperty::Type::UINT16,{ 2, "ushort" } },
		{ PlyProperty::Type::INT32,{ 4, "int" } },
		{ PlyProperty::Type::UINT32,{ 4, "uint" } },
		{ PlyProperty::Type::FLOAT32,{ 4, "float" } },
		{ PlyProperty::Type::FLOAT64,{ 8, "double" } },
		{ PlyProperty::Type::INVALID,{ 0, "INVALID" } }
	};

	inline PlyProperty::Type property_type_from_string(const std::string & t)
	{
		if (t == "int8" || t == "char")             return PlyProperty::Type::INT8;
		else if (t == "uint8" || t == "uchar")      return PlyProperty::Type::UINT8;
		else if (t == "int16" || t == "short")      return PlyProperty::Type::INT16;
		else if (t == "uint16" || t == "ushort")    return PlyProperty::Type::UINT16;
		else if (t == "int32" || t == "int")        return PlyProperty::Type::INT32;
		else if (t == "uint32" || t == "uint")      return PlyProperty::Type::UINT32;
		else if (t == "float32" || t == "float")    return PlyProperty::Type::FLOAT32;
		else if (t == "float64" || t == "double")   return PlyProperty::Type::FLOAT64;
		return PlyProperty::Type::INVALID;
	}

	template<typename T>
	inline uint8_t * resize(void * v, size_t newSize)
	{
		auto vec = static_cast<std::vector<T> *>(v);
		vec->resize(newSize);
		return reinterpret_cast<uint8_t *>(vec->data());
	}

	inline void resize_vector(const PlyProperty::Type t, void * v, size_t newSize, uint8_t *& ptr)
	{
		switch (t)
		{
		case PlyProperty::Type::INT8:       ptr = resize<int8_t>(v, newSize);   break;
		case PlyProperty::Type::UINT8:      ptr = resize<uint8_t>(v, newSize);  break;
		case PlyProperty::Type::INT16:      ptr = resize<int16_t>(v, newSize);  break;
		case PlyProperty::Type::UINT16:     ptr = resize<uint16_t>(v, newSize); break;
		case PlyProperty::Type::INT32:      ptr = resize<int32_t>(v, newSize);  break;
		case PlyProperty::Type::UINT32:     ptr = resize<uint32_t>(v, newSize); break;
		case PlyProperty::Type::FLOAT32:    ptr = resize<float>(v, newSize);    break;
		case PlyProperty::Type::FLOAT64:    ptr = resize<double>(v, newSize);   break;
		case PlyProperty::Type::INVALID:    throw std::invalid_argument("invalid ply property");
		}
	}

	template <typename T>
	inline PlyProperty::Type property_type_for_type(std::vector<T> & theType)
	{
		if (std::is_same<T, int8_t>::value)          return PlyProperty::Type::INT8;
		else if (std::is_same<T, uint8_t>::value)    return PlyProperty::Type::UINT8;
		else if (std::is_same<T, int16_t>::value)    return PlyProperty::Type::INT16;
		else if (std::is_same<T, uint16_t>::value)   return PlyProperty::Type::UINT16;
		else if (std::is_same<T, int32_t>::value)    return PlyProperty::Type::INT32;
		else if (std::is_same<T, uint32_t>::value)   return PlyProperty::Type::UINT32;
		else if (std::is_same<T, float>::value)      return PlyProperty::Type::FLOAT32;
		else if (std::is_same<T, double>::value)     return PlyProperty::Type::FLOAT64;
		else return PlyProperty::Type::INVALID;
	}

	class PlyElement
	{
		void parse_internal(std::istream & is);
	public:
		PlyElement(std::istream & istream);
		PlyElement(const std::string & name, size_t count) : name(name), size(count) {}
		std::string name;
		size_t size;
		std::vector<PlyProperty> properties;
	};

	inline int find_element(const std::string key, std::vector<PlyElement> & list)
	{
		for (size_t i = 0; i < list.size(); ++i)
		{
			if (list[i].name == key)
			{
				return i;
			}
		}
		return -1;
	}

	class PlyFile
	{

	public:

		PlyFile() {}
		PlyFile(std::istream & is);

		void read(std::istream & is);
		void write(std::ostream & os, bool isBinary);

		std::vector<PlyElement> & get_elements() { return elements; }

		std::vector<std::string> comments;
		std::vector<std::string> objInfo;

		template<typename T>
		size_t request_properties_from_element(const std::string & elementKey, std::vector<std::string> propertyKeys, std::vector<T> & source, const int listCount = 1)
		{
			if (get_elements().size() == 0)
				return 0;

			if (find_element(elementKey, get_elements()) >= 0)
			{
				if (std::find(requestedElements.begin(), requestedElements.end(), elementKey) == requestedElements.end())
					requestedElements.push_back(elementKey);
			}
			else return 0;

			// count and verify large enough
			auto instance_counter = [&](const std::string & elementKey, const std::string & propertyKey)
			{
				for (auto e : get_elements())
				{
					if (e.name != elementKey) continue;
					for (auto p : e.properties)
					{
						if (p.name == propertyKey)
						{
							if (PropertyTable[property_type_for_type(source)].stride != PropertyTable[p.propertyType].stride)
								throw std::runtime_error("destination vector is wrongly typed to hold this property");
							return e.size;

						}
					}
				}
				return size_t(0);
			};

			// Check if requested key is in the parsed header
			std::vector<std::string> unusedKeys;
			for (auto key : propertyKeys)
			{
				for (auto e : get_elements())
				{
					if (e.name != elementKey) continue;
					std::vector<std::string> headerKeys;
					for (auto p : e.properties)
					{
						headerKeys.push_back(p.name);
					}

					if (std::find(headerKeys.begin(), headerKeys.end(), key) == headerKeys.end())
					{
						unusedKeys.push_back(key);
					}

				}
			}

			// Not using them? Don't let them affect the propertyKeys count used for calculating array sizes
			for (auto k : unusedKeys)
			{
				propertyKeys.erase(std::remove(propertyKeys.begin(), propertyKeys.end(), k), propertyKeys.end());
			}
			if (!propertyKeys.size()) return 0;

			// All requested properties in the userDataTable share the same cursor (thrown into the same flat array)
			auto cursor = std::make_shared<DataCursor>();

			std::vector<size_t> instanceCounts;

			for (auto key : propertyKeys)
			{
				if (int instanceCount = instance_counter(elementKey, key))
				{
					instanceCounts.push_back(instanceCount);
					auto result = userDataTable.insert(std::pair<std::string, std::shared_ptr<DataCursor>>(make_key(elementKey, key), cursor));
					if (result.second == false)
						throw std::invalid_argument("property has already been requested: " + key);
				}
				else continue;
			}

			size_t totalInstanceSize = [&]() { size_t t = 0; for (auto c : instanceCounts) { t += c; } return t; }() * listCount;
			source.resize(totalInstanceSize); // this satisfies regular properties; `cursor->realloc` is for list types since tinyply uses single-pass parsing
			cursor->offset = 0;
			cursor->vector = &source;
			cursor->data = reinterpret_cast<uint8_t *>(source.data());

			if (listCount > 1)
			{
				cursor->realloc = true;
				return (totalInstanceSize / propertyKeys.size()) / listCount;
			}

			return totalInstanceSize / propertyKeys.size();
		}

		template<typename T>
		void add_properties_to_element(const std::string & elementKey, const std::vector<std::string> & propertyKeys, std::vector<T> & source, const int listCount = 1, const PlyProperty::Type listType = PlyProperty::Type::INVALID)
		{
			auto cursor = std::make_shared<DataCursor>();
			cursor->offset = 0;
			cursor->vector = &source;
			cursor->data = reinterpret_cast<uint8_t *>(source.data());

			auto create_property_on_element = [&](PlyElement & e)
			{
				for (auto key : propertyKeys)
				{
					PlyProperty::Type t = property_type_for_type(source);
					PlyProperty newProp = (listType == PlyProperty::Type::INVALID) ? PlyProperty(t, key) : PlyProperty(listType, t, key, listCount);
					userDataTable.insert(std::pair<std::string, std::shared_ptr<DataCursor>>(make_key(e.name, key), cursor));
					e.properties.push_back(newProp);
				}
			};

			int idx = find_element(elementKey, elements);
			if (idx >= 0)
			{
				PlyElement & e = elements[idx];
				create_property_on_element(e);
			}
			else
			{
				PlyElement newElement = (listCount == 1) ? PlyElement(elementKey, source.size() / propertyKeys.size()) : PlyElement(elementKey, source.size() / listCount);
				create_property_on_element(newElement);
				elements.push_back(newElement);
			}
		}

	private:

		size_t skip_property_binary(const PlyProperty & property, std::istream & is);
		void skip_property_ascii(const PlyProperty & property, std::istream & is);

		void read_property_binary(PlyProperty::Type t, void * dest, size_t & destOffset, std::istream & is);
		void read_property_ascii(PlyProperty::Type t, void * dest, size_t & destOffset, std::istream & is);
		void write_property_ascii(PlyProperty::Type t, std::ostream & os, uint8_t * src, size_t & srcOffset);
		void write_property_binary(PlyProperty::Type t, std::ostream & os, uint8_t * src, size_t & srcOffset);

		bool parse_header(std::istream & is);
		void write_header(std::ostream & os);

		void read_header_format(std::istream & is);
		void read_header_element(std::istream & is);
		void read_header_property(std::istream & is);
		void read_header_text(std::string line, std::istream & is, std::vector<std::string> & place, int erase = 0);

		void read_internal(std::istream & is);

		void write_ascii_internal(std::ostream & os);
		void write_binary_internal(std::ostream & os);

		bool isBinary = false;
		bool isBigEndian = false;

		std::map<std::string, std::shared_ptr<DataCursor>> userDataTable;

		std::vector<PlyElement> elements;
		std::vector<std::string> requestedElements;
	};

} // namesapce tinyply

#endif // tinyply_h