#include "ehs/io/File_UNX.h"

#include <cstring>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
#include <cerrno>
#include <cstdio>

namespace ehs
{
	File::~File()
	{
		if (map != MAP_FAILED && munmap(map, mapSize) == -1)
			EHS_LOG_INT("Error", 0, "Failed to unmap with error #" + Str_8::FromNum(errno) + ".");

		if (hdl >= 0 && close(hdl) == -1)
			EHS_LOG_INT("Error", 0, "Failed to close file handle with error #" + Str_8::FromNum(errno) + ".");
	}

	File::File()
		: hdl(-1), map(MAP_FAILED), mapSize(0)
	{
	}

	File::File(const Str_8 &filePath, const Mode mode, const Disposition disposition)
		: BaseFile(filePath, mode, disposition), hdl(-1), map(MAP_FAILED), mapSize(0)
	{
		int linuxMode = 0;
		switch (mode)
		{
		case Mode::READ:
			linuxMode = O_RDONLY;
			break;
		case Mode::WRITE:
			linuxMode = O_WRONLY;
			break;
		case Mode::READ_WRITE:
			linuxMode = O_RDWR;
			break;
		}

		int linuxDisp = 0;
		switch (disposition)
		{
		case Disposition::CREATE_PERSISTENT:
			linuxDisp = O_CREAT;
			break;
		case Disposition::CREATE:
			linuxDisp = O_CREAT | O_EXCL;
			break;
		case Disposition::OPEN_PERSISTENT:
			linuxDisp = O_CREAT;
			break;
		case Disposition::OPEN:
			linuxDisp = 0;
			break;
		case Disposition::TRUNCATE:
			linuxDisp = O_TRUNC;
			break;
		}

		hdl = open64(path, linuxMode | linuxDisp, S_IRUSR | S_IWUSR);
		if (hdl == -1)
		{
			SInt_32 code = errno;
			if (code == EEXIST && (disposition == Disposition::CREATE_PERSISTENT || disposition == Disposition::OPEN_PERSISTENT))
			{
				hdl = open64(path, linuxMode, S_IRUSR | S_IWUSR);
				if (hdl == -1)
					EHS_LOG_INT("Error", 0, strerror(errno));
			}
			else
			{
				if (code == ENOENT)
					EHS_LOG_INT("Error", 0, "File at filepath, \"" + filePath + "\" not found.");
				else
					EHS_LOG_INT("Error", 0, strerror(code));
			}
		}
	}

	File::File(File&& file) noexcept
		: BaseFile(std::move(file)), hdl(file.hdl), map(file.map), mapSize(file.mapSize)
	{
		file.hdl = -1;
		file.map = MAP_FAILED;
		file.mapSize = 0;
	}

	File::File(const File &file)
		: BaseFile(file), hdl(-1), map(MAP_FAILED), mapSize(0)
	{
	}

	File& File::operator=(File&& file) noexcept
	{
		if (this == &file)
			return *this;

		BaseFile::operator=(std::move(file));

		hdl = file.hdl;
		map = file.map;
		mapSize = file.mapSize;

		file.hdl = -1;

		return *this;
	}

	File& File::operator=(const File &file)
	{
		if (this == &file)
			return *this;

		BaseFile::operator=(file);

		hdl = -1;
		map = MAP_FAILED;
		mapSize = 0;

		return *this;
	}

	File::operator const Byte*() const
	{
		return (const Byte*)map;
	}

	File::operator Byte*()
	{
		return (Byte*)map;
	}

	void File::Release()
	{
		if (IsMapped() && munmap(map, mapSize) == -1)
			EHS_LOG_INT("Error", 0, "Failed to unmap with error #" + Str_8::FromNum(errno) + ".");
		map = MAP_FAILED;
		mapSize = 0;

		if (IsValid() && close(hdl) == -1)
			EHS_LOG_INT("Error", 0, "Failed to close file handle with error #" + Str_8::FromNum(errno) + ".");
		hdl = -1;
	}

	bool File::IsMapped() const
	{
		return map != MAP_FAILED;
	}

	UInt_64 File::MapSize() const
	{
		return mapSize;
	}

	void File::Map(const UInt_64 offset, const UInt_64 size)
	{
		if (!IsValid() || IsMapped())
			return;

		int linuxMode = 0;
		switch (mode)
		{
			case Mode::READ:
				linuxMode = PROT_READ;
				break;
			case Mode::WRITE:
				linuxMode = PROT_WRITE;
				break;
			case Mode::READ_WRITE:
				linuxMode = PROT_READ | PROT_WRITE;
				break;
		}

		map = mmap64(nullptr, size, linuxMode, MAP_SHARED, hdl, (off64_t)offset);
		if (map == MAP_FAILED)
		{
			EHS_LOG_INT("Error", 0, "Failed to map with error #" + Str_8::FromNum(errno) + ".");
			return;
		}

		mapSize = size;
	}

	void File::Unmap()
	{
		if (!IsValid() || !IsMapped())
			return;

		if (munmap(map, mapSize) == -1)
			EHS_LOG_INT("Error", 0, "Failed to unmap with error #" + Str_8::FromNum(errno) + ".");

		map = MAP_FAILED;
		mapSize = 0;
	}

	void File::FlushMap()
	{
		if (!IsValid() || !IsMapped())
			return;

		if (msync((void*)map, mapSize, MS_SYNC) == -1)
			EHS_LOG_INT("Error", 0, "Failed to flush view with error #" + Str_8::FromNum(errno) + ".");
	}

	UInt_64 File::Write(const Byte *const data, const UInt_64 size)
	{
		if (!IsValid() || IsMapped())
			return 0;

		SInt_64 written = 0;
		written = write(hdl, data, size);
		if (written == -1)
			EHS_LOG_INT("Error", 0, "Failed to write to file, \"" + path + "\", with error #" + Str_8::FromNum(errno) + ".");

		return (UInt_64)written;
	}

	UInt_64 File::Read(Byte *const data, const UInt_64 size)
	{
		if (!IsValid() || IsMapped())
			return 0;

		SInt_64 read = 0;
		read = ::read(hdl, data, (size_t)size);
		if (read == -1)
			EHS_LOG_INT("Error", 0, "Failed to read from file, \"" + path + "\", with error #" + Str_8::FromNum(errno) + ".");

		return (UInt_64)read;
	}

	void File::Seek(UInt_64 index)
	{
		if (!IsValid() || IsMapped())
			return;

		if (lseek64(hdl, (off64_t)index, SEEK_SET) == -1)
			EHS_LOG_INT("Error", 0, "Failed to seek with error #" + Str_8::FromNum(errno) + ".");
	}

	void File::SeekBeginning()
	{
		if (!IsValid() || IsMapped())
			return;

		if (lseek64(hdl, 0, SEEK_SET) == -1)
			EHS_LOG_INT("Error", 0, "Failed to seek with error #" + Str_8::FromNum(errno) + ".");
	}

	void File::SeekEnd()
	{
		if (!IsValid() || IsMapped())
			return;

		if (lseek64(hdl, 0, SEEK_END) == -1)
			EHS_LOG_INT("Error", 0, "Failed to seek with error #" + Str_8::FromNum(errno) + ".");
	}

	void File::Truncate(const UInt_64 size)
	{
		if (!IsValid() || IsMapped())
			return;

		if (ftruncate64(hdl, (off64_t)size) == -1)
			EHS_LOG_INT("Error", 0, "Failed to truncate with error #" + Str_8::FromNum(errno) + ".");
	}

	UInt_64 File::Size() const
	{
		struct stat64 info = {};

		if (fstat64(hdl, &info) == -1)
			EHS_LOG_INT("Error", 0, "Failed to retrieve file size with error #" + Str_8::FromNum(errno) + ".");

		return info.st_size;
	}

	bool File::IsValid() const
	{
		return hdl >= 0;
	}

	void File::Rename_32(const Str_32& filePath, const Str_32& newName)
	{
		Rename_8(UTF::To_8(filePath), UTF::To_8(newName));
	}

	void File::Rename_16(const Str_16& filePath, const Str_16& newName)
	{
		Rename_8(UTF::To_8(filePath), UTF::To_8(newName));
	}

	void File::Rename_8(const Str_8& filePath, const Str_8& newName)
	{
		UInt_64 index = 0;
		Str_8 path;

		if (filePath.Find("/", &index, SearchPattern::RIGHT_LEFT) || filePath.Find("\\", &index, SearchPattern::RIGHT_LEFT))
			path = filePath.Sub(0, index);

		if (rename(filePath, path + newName) == -1)
			EHS_LOG_INT("Error", 0, "Failed to rename file with error #" + Str_8::FromNum(errno) + ".");
	}
}