#include "stdafx.h"
#include "Log.h"
#include "File.h"

#ifdef _WIN32
#define _WIN32_WINNT 0x0601
#include <Windows.h>
#include <Shlwapi.h>

#define GET_API_ERROR static_cast<u64>(GetLastError())

static std::unique_ptr<wchar_t[]> to_wchar(const std::string& source)
{
	const auto length = source.size() + 1; // size + null terminator

	const int size = source.size() < INT_MAX ? static_cast<int>(length) : throw EXCEPTION("Invalid source length (0x%llx)", source.size());

	std::unique_ptr<wchar_t[]> buffer(new wchar_t[length]); // allocate buffer assuming that length is the max possible size

	if (!MultiByteToWideChar(CP_UTF8, 0, source.c_str(), size, buffer.get(), size))
	{
		throw EXCEPTION("System error 0x%x", GetLastError());
	}

	return buffer;
}

static void to_utf8(std::string& result, const wchar_t* source)
{
	const int length = lstrlenW(source); // source length

	if (length == 0)
	{
		return result.clear();
	}

	const int size = WideCharToMultiByte(CP_UTF8, 0, source, length, NULL, 0, NULL, NULL); // output size

	if (size <= 0)
	{
		throw EXCEPTION("System error 0x%x", GetLastError());
	}

	result.resize(size);

	if (!WideCharToMultiByte(CP_UTF8, 0, source, length, &result.front(), size, NULL, NULL))
	{
		throw EXCEPTION("System error 0x%x", GetLastError());
	}
}

static time_t to_time(const ULARGE_INTEGER& ft)
{
	return ft.QuadPart / 10000000ULL - 11644473600ULL;
}

static time_t to_time(const LARGE_INTEGER& ft)
{
	ULARGE_INTEGER v;
	v.LowPart = ft.LowPart;
	v.HighPart = ft.HighPart;

	return to_time(v);
}

static time_t to_time(const FILETIME& ft)
{
	ULARGE_INTEGER v;
	v.LowPart = ft.dwLowDateTime;
	v.HighPart = ft.dwHighDateTime;

	return to_time(v);
}

static bool truncate_file(const std::string& file, u64 length)
{
	// open the file
	const auto handle = CreateFileW(to_wchar(file).get(), GENERIC_WRITE, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);

	if (handle == INVALID_HANDLE_VALUE)
	{
		return false;
	}

	LARGE_INTEGER distance;
	distance.QuadPart = length;

	// seek and truncate
	if (!SetFilePointerEx(handle, distance, NULL, FILE_BEGIN) || !SetEndOfFile(handle))
	{
		const auto error = GetLastError();
		CloseHandle(handle);
		SetLastError(error);
		return false;
	}

	return CloseHandle(handle);
}

#else
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>
#include <fcntl.h>
#include <libgen.h>
#include <string.h>
#include <unistd.h>
#if defined(__APPLE__) || defined(__FreeBSD__)
#include <copyfile.h>
#include <mach-o/dyld.h>
#else
#include <sys/sendfile.h>
#endif
#include <errno.h>

#define GET_API_ERROR static_cast<u64>(errno)

#endif

thread_local fse fs::g_tls_error = fse::ok;

bool fs::stat(const std::string& path, stat_t& info)
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	WIN32_FILE_ATTRIBUTE_DATA attrs;
	if (!GetFileAttributesExW(to_wchar(path).get(), GetFileExInfoStandard, &attrs))
	{
		return false;
	}

	info.is_directory = (attrs.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
	info.is_writable = (attrs.dwFileAttributes & FILE_ATTRIBUTE_READONLY) == 0;
	info.size = (u64)attrs.nFileSizeLow | ((u64)attrs.nFileSizeHigh << 32);
	info.atime = to_time(attrs.ftLastAccessTime);
	info.mtime = to_time(attrs.ftLastWriteTime);
	info.ctime = to_time(attrs.ftCreationTime);
#else
	struct stat file_info;
	if (stat(path.c_str(), &file_info) < 0)
	{
		return false;
	}

	info.is_directory = S_ISDIR(file_info.st_mode);
	info.is_writable = file_info.st_mode & 0200; // HACK: approximation
	info.size = file_info.st_size;
	info.atime = file_info.st_atime;
	info.mtime = file_info.st_mtime;
	info.ctime = file_info.st_ctime;
#endif

	return true;
}

bool fs::exists(const std::string& path)
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	return GetFileAttributesW(to_wchar(path).get()) != 0xFFFFFFFF;
#else
	struct stat buffer;
	return stat(path.c_str(), &buffer) == 0;
#endif
}

bool fs::is_file(const std::string& file)
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	DWORD attrs;
	if ((attrs = GetFileAttributesW(to_wchar(file).get())) == INVALID_FILE_ATTRIBUTES)
	{
		return false;
	}

	return (attrs & FILE_ATTRIBUTE_DIRECTORY) == 0;
#else
	struct stat file_info;
	if (stat(file.c_str(), &file_info) < 0)
	{
		return false;
	}

	return !S_ISDIR(file_info.st_mode);
#endif
}

bool fs::is_dir(const std::string& dir)
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	DWORD attrs;
	if ((attrs = GetFileAttributesW(to_wchar(dir).get())) == INVALID_FILE_ATTRIBUTES)
	{
		return false;
	}

	return (attrs & FILE_ATTRIBUTE_DIRECTORY) != 0;
#else
	struct stat file_info;
	if (stat(dir.c_str(), &file_info) < 0)
	{
		return false;
	}

	return S_ISDIR(file_info.st_mode);
#endif
}

bool fs::create_dir(const std::string& dir)
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	if (!CreateDirectoryW(to_wchar(dir).get(), NULL))
#else
	if (mkdir(dir.c_str(), S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH))
#endif
	{
		LOG_WARNING(GENERAL, "Error creating directory '%s': 0x%llx", dir, GET_API_ERROR);
		return false;
	}

	return true;
}

bool fs::create_path(const std::string& path)
{
	g_tls_error = fse::ok;

	std::string parent;
	{
#ifdef _WIN32
		auto copy = to_wchar(path);
		// PathRemoveFileSpecW only works on paths delimited by '\\'
		std::replace(copy.get(), copy.get() + path.length(), '/', '\\');
		PathRemoveFileSpecW(copy.get());
		to_utf8(parent, copy.get());
#else
		std::unique_ptr<char, decltype(std::free) *> copy{ strdup(path.c_str()), std::free };
		parent = dirname(copy.get());
#endif
	}

	if (!is_dir(parent) && !create_path(parent))
		return false;

	return create_dir(path);
}

bool fs::remove_dir(const std::string& dir)
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	if (!RemoveDirectoryW(to_wchar(dir).get()))
#else
	if (rmdir(dir.c_str()))
#endif
	{
		LOG_WARNING(GENERAL, "Error deleting directory '%s': 0x%llx", dir, GET_API_ERROR);
		return false;
	}

	return true;
}

bool fs::rename(const std::string& from, const std::string& to)
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	if (!MoveFileW(to_wchar(from).get(), to_wchar(to).get()))
#else
	if (rename(from.c_str(), to.c_str()))
#endif
	{
		LOG_WARNING(GENERAL, "Error renaming '%s' to '%s': 0x%llx", from, to, GET_API_ERROR);
		return false;
	}

	return true;
}

#ifndef _WIN32

static int OSCopyFile(const char* source, const char* destination, bool overwrite)
{
	/* Source: http://stackoverflow.com/questions/2180079/how-can-i-copy-a-file-on-unix-using-c */

	const int input = open(source, O_RDONLY);
	if (input == -1)
	{
		return -1;
	}

	const int output = open(destination, O_WRONLY | O_CREAT | (overwrite ? O_TRUNC : O_EXCL), 0666);
	if (output == -1)
	{
		close(input);
		return -1;
	}

	//Here we use kernel-space copying for performance reasons
#if defined(__APPLE__) || defined(__FreeBSD__)
	//fcopyfile works on FreeBSD and OS X 10.5+ 
	const int result = fcopyfile(input, output, 0, COPYFILE_ALL);
#else
	//sendfile will work with non-socket output (i.e. regular file) on Linux 2.6.33+
	off_t bytesCopied = 0;
	struct stat fileinfo = { 0 };
	const int result = fstat(input, &fileinfo) == -1 || sendfile(output, input, &bytesCopied, fileinfo.st_size) == -1 ? -1 : 0;
#endif

	close(input);
	close(output);

	return result;
}
#endif

bool fs::copy_file(const std::string& from, const std::string& to, bool overwrite)
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	if (!CopyFileW(to_wchar(from).get(), to_wchar(to).get(), !overwrite))
#else
	if (OSCopyFile(from.c_str(), to.c_str(), overwrite))
#endif
	{
		LOG_WARNING(GENERAL, "Error copying '%s' to '%s': 0x%llx", from, to, GET_API_ERROR);
		return false;
	}

	return true;
}

bool fs::remove_file(const std::string& file)
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	if (!DeleteFileW(to_wchar(file).get()))
#else
	if (unlink(file.c_str()))
#endif
	{
		LOG_WARNING(GENERAL, "Error deleting file '%s': 0x%llx", file, GET_API_ERROR);
		return false;
	}

	return true;
}

bool fs::truncate_file(const std::string& file, u64 length)
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	if (!::truncate_file(file, length))
#else
	if (::truncate(file.c_str(), length))
#endif
	{
		LOG_WARNING(GENERAL, "Error resizing file '%s' to 0x%llx: 0x%llx", file, length, GET_API_ERROR);
		return false;
	}

	return true;
}

fs::file::~file()
{
	if (m_fd != null)
	{
#ifdef _WIN32
		CloseHandle((HANDLE)m_fd);
#else
		::close(m_fd);
#endif
	}
}

bool fs::file::open(const std::string& filename, u32 mode)
{
	this->close();

	g_tls_error = fse::ok;

#ifdef _WIN32
	DWORD access = 0;
	switch (mode & (fom::read | fom::write | fom::append))
	{
	case fom::read: access |= GENERIC_READ; break;
	case fom::read | fom::append: access |= GENERIC_READ; break;
	case fom::write: access |= GENERIC_WRITE; break;
	case fom::write | fom::append: access |= FILE_APPEND_DATA; break;
	case fom::read | fom::write: access |= GENERIC_READ | GENERIC_WRITE; break;
	case fom::read | fom::write | fom::append: access |= GENERIC_READ | FILE_APPEND_DATA; break;
	default:
	{
		LOG_ERROR(GENERAL, "fs::file::open('%s') failed: neither fom::read nor fom::write specified (0x%x)", filename, mode);
		return false;
	}
	}

	DWORD disp = 0;
	switch (mode & (fom::create | fom::trunc | fom::excl))
	{
	case 0: disp = OPEN_EXISTING; break;
	case fom::create: disp = OPEN_ALWAYS; break;
	case fom::trunc: disp = TRUNCATE_EXISTING; break;
	case fom::create | fom::trunc: disp = CREATE_ALWAYS; break;
	case fom::create | fom::excl: disp = CREATE_NEW; break;
	case fom::create | fom::excl | fom::trunc: disp = CREATE_NEW; break;
	}

	if (!disp || (mode & ~(fom::read | fom::write | fom::append | fom::create | fom::trunc | fom::excl)))
	{
		LOG_ERROR(GENERAL, "fs::file::open('%s') failed: unknown mode specified (0x%x)", filename, mode);
		return false;
	}

	m_fd = (std::intptr_t)CreateFileW(to_wchar(filename).get(), access, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, disp, FILE_ATTRIBUTE_NORMAL, NULL);
#else
	int flags = 0;

	switch (mode & (fom::read | fom::write))
	{
	case fom::read: flags |= O_RDONLY; break;
	case fom::write: flags |= O_WRONLY; break;
	case fom::read | fom::write: flags |= O_RDWR; break;
	default:
	{
		LOG_ERROR(GENERAL, "fs::file::open('%s') failed: neither fom::read nor fom::write specified (0x%x)", filename, mode);
		return false;
	}
	}

	if (mode & fom::append) flags |= O_APPEND;
	if (mode & fom::create) flags |= O_CREAT;
	if (mode & fom::trunc) flags |= O_TRUNC;
	if (mode & fom::excl) flags |= O_EXCL;

	if (((mode & fom::excl) && !(mode & fom::create)) || (mode & ~(fom::read | fom::write | fom::append | fom::create | fom::trunc | fom::excl)))
	{
		LOG_ERROR(GENERAL, "fs::file::open('%s') failed: unknown mode specified (0x%x)", filename, mode);
		return false;
	}

	m_fd = ::open(filename.c_str(), flags, 0666);
#endif

	if (m_fd == null)
	{
		LOG_WARNING(GENERAL, "fs::file::open('%s', 0x%x) failed: error 0x%llx", filename, mode, GET_API_ERROR);
		return false;
	}

	return true;
}

bool fs::file::trunc(u64 size) const
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	LARGE_INTEGER old, pos;

	pos.QuadPart = 0;
	SetFilePointerEx((HANDLE)m_fd, pos, &old, FILE_CURRENT); // get old position

	pos.QuadPart = size;
	SetFilePointerEx((HANDLE)m_fd, pos, NULL, FILE_BEGIN); // set new position

	SetEndOfFile((HANDLE)m_fd); // change file size

	SetFilePointerEx((HANDLE)m_fd, old, NULL, FILE_BEGIN); // restore position

	return true; // TODO
#else
	return !::ftruncate(m_fd, size);
#endif
}

bool fs::file::stat(stat_t& info) const
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	FILE_BASIC_INFO basic_info;

	if (!GetFileInformationByHandleEx((HANDLE)m_fd, FileBasicInfo, &basic_info, sizeof(FILE_BASIC_INFO)))
	{
		return false;
	}

	info.is_directory = (basic_info.FileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
	info.is_writable = (basic_info.FileAttributes & FILE_ATTRIBUTE_READONLY) == 0;
	info.size = this->size();
	info.atime = to_time(basic_info.LastAccessTime);
	info.mtime = to_time(basic_info.ChangeTime);
	info.ctime = to_time(basic_info.CreationTime);
#else
	struct stat file_info;
	if (fstat(m_fd, &file_info) < 0)
	{
		return false;
	}

	info.is_directory = S_ISDIR(file_info.st_mode);
	info.is_writable = file_info.st_mode & 0200; // HACK: approximation
	info.size = file_info.st_size;
	info.atime = file_info.st_atime;
	info.mtime = file_info.st_mtime;
	info.ctime = file_info.st_ctime;
#endif

	return true;
}

bool fs::file::close()
{
	g_tls_error = fse::ok;

	if (m_fd == null)
	{
		return false;
	}

	auto fd = m_fd;
	m_fd = null;

#ifdef _WIN32
	return CloseHandle((HANDLE)fd);
#else
	return !::close(fd);
#endif
}

u64 fs::file::read(void* buffer, u64 count) const
{
	g_tls_error = fse::ok;

	// TODO (call ReadFile multiple times if count is too big)
	const int size = count <= INT_MAX ? static_cast<int>(count) : throw EXCEPTION("Invalid count (0x%llx)", count);

#ifdef _WIN32
	DWORD nread;
	if (!ReadFile((HANDLE)m_fd, buffer, size, &nread, NULL))
	{
		return -1;
	}

	return nread;
#else
	return ::read(m_fd, buffer, size);
#endif
}

u64 fs::file::write(const void* buffer, u64 count) const
{
	g_tls_error = fse::ok;

	// TODO (call WriteFile multiple times if count is too big)
	const int size = count <= INT_MAX ? static_cast<int>(count) : throw EXCEPTION("Invalid count (0x%llx)", count);

#ifdef _WIN32
	DWORD nwritten;
	if (!WriteFile((HANDLE)m_fd, buffer, size, &nwritten, NULL))
	{
		return -1;
	}

	return nwritten;
#else
	return ::write(m_fd, buffer, size);
#endif
}

u64 fs::file::seek(s64 offset, fsm seek_mode) const
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	LARGE_INTEGER pos;
	pos.QuadPart = offset;

	const DWORD mode =
		seek_mode == fsm::begin ? FILE_BEGIN :
		seek_mode == fsm::cur ? FILE_CURRENT :
		seek_mode == fsm::end ? FILE_END :
		throw EXCEPTION("Unknown seek_mode (0x%x)", seek_mode);

	if (!SetFilePointerEx((HANDLE)m_fd, pos, &pos, mode))
	{
		return -1;
	}

	return pos.QuadPart;
#else
	const int whence =
		seek_mode == fsm::begin ? SEEK_SET :
		seek_mode == fsm::cur ? SEEK_CUR :
		seek_mode == fsm::end ? SEEK_END :
		throw EXCEPTION("Unknown seek_mode (0x%x)", seek_mode);

	return ::lseek(m_fd, offset, whence);
#endif
}

u64 fs::file::size() const
{
	g_tls_error = fse::ok;

#ifdef _WIN32
	LARGE_INTEGER size;
	if (!GetFileSizeEx((HANDLE)m_fd, &size))
	{
		return -1;
	}

	return size.QuadPart;
#else
	struct stat file_info;
	if (::fstat(m_fd, &file_info) < 0)
	{
		return -1;
	}

	return file_info.st_size;
#endif
}

fs::dir::~dir()
{
	if (m_path)
	{
#ifdef _WIN32
		if (m_dd != -1) FindClose((HANDLE)m_dd);
#else
		::closedir((DIR*)m_dd);
#endif
	}
}

void fs::file_ptr::reset(const file& f)
{
	reset();

	if (f)
	{
#ifdef _WIN32
		const HANDLE handle = ::CreateFileMapping((HANDLE)f.m_fd, NULL, PAGE_READONLY, 0, 0, NULL);
		m_ptr = (char*)::MapViewOfFile(handle, FILE_MAP_READ, 0, 0, 0);
		m_size = f.size();
		::CloseHandle(handle);
#else
		m_ptr = (char*)::mmap(nullptr, m_size = f.size(), PROT_READ, MAP_SHARED, f.m_fd, 0);
		if (m_ptr == (void*)-1) m_ptr = nullptr;
#endif
	}
}

void fs::file_ptr::reset()
{
	if (m_ptr)
	{
#ifdef _WIN32
		::UnmapViewOfFile(m_ptr);
#else
		::munmap(m_ptr, m_size);
#endif
	}
}

bool fs::dir::open(const std::string& dirname)
{
	this->close();

	g_tls_error = fse::ok;

	if (!is_dir(dirname))
	{
		return false;
	}

	m_path.reset(new char[dirname.size() + 1]);
	std::memcpy(m_path.get(), dirname.c_str(), dirname.size() + 1);

#ifdef _WIN32
	m_dd = -1;
#else
	m_dd = (std::intptr_t)::opendir(m_path.get());
#endif

	return true;
}

bool fs::dir::close()
{
	g_tls_error = fse::ok;

	if (!m_path)
	{
		return false;
	}

	m_path.reset();

#ifdef _WIN32
	CHECK_ASSERTION(m_dd == -1 || FindClose((HANDLE)m_dd));
#else
	CHECK_ASSERTION(!::closedir((DIR*)m_dd));
#endif

	return true;
}

bool fs::dir::read(std::string& name, stat_t& info)
{
	g_tls_error = fse::ok;

	if (!m_path)
	{
		return false;
	}

#ifdef _WIN32
	WIN32_FIND_DATAW found;

	if (m_dd == -1)
	{
		m_dd = (std::intptr_t)FindFirstFileW(to_wchar(m_path.get() + "/*"s).get(), &found);

		if (m_dd == -1)
		{
			return false;
		}
	}
	else if (!FindNextFileW((HANDLE)m_dd, &found))
	{
		return false;
	}

	to_utf8(name, found.cFileName);

	info.is_directory = (found.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
	info.is_writable = (found.dwFileAttributes & FILE_ATTRIBUTE_READONLY) == 0;
	info.size = ((u64)found.nFileSizeHigh << 32) | (u64)found.nFileSizeLow;
	info.atime = to_time(found.ftLastAccessTime);
	info.mtime = to_time(found.ftLastWriteTime);
	info.ctime = to_time(found.ftCreationTime);
#else
	const auto found = ::readdir((DIR*)m_dd);

	struct stat file_info;
	if (!found || ::fstatat(::dirfd((DIR*)m_dd), found->d_name, &file_info, 0) < 0)
	{
		return false;
	}

	name = found->d_name;

	info.is_directory = S_ISDIR(file_info.st_mode);
	info.is_writable = file_info.st_mode & 0200; // HACK: approximation
	info.size = file_info.st_size;
	info.atime = file_info.st_atime;
	info.mtime = file_info.st_mtime;
	info.ctime = file_info.st_ctime;
#endif

	return true;
}

bool fs::dir::first(std::string& name, stat_t& info)
{
#ifdef _WIN32
	if (m_path && m_dd != -1)
	{
		CHECK_ASSERTION(FindClose((HANDLE)m_dd));
		m_dd = -1;
	}
#else
	if (m_path)
	{
		::rewinddir((DIR*)m_dd);
	}
#endif

	return read(name, info);
}

std::string fs::get_config_dir()
{
	// Use magic static for dir initialization
	static const std::string s_dir = []
	{
#ifdef _WIN32
		return get_executable_dir(); // ?
#else
		std::string dir;

		if (const char* home = ::getenv("XDG_CONFIG_HOME"))
			dir = home;
		else if (const char* home = ::getenv("HOME"))
			dir = home + "/.config"s;
		else // Just in case
			dir = "./config";

		dir += "/rpcs3/";

		if (!is_dir(dir) && !create_path(dir))
		{
			std::printf("Failed to create configuration directory '%s' (%d).\n", dir.c_str(), errno);
		}

		return dir;
#endif
	}();

	return s_dir;
}

std::string fs::get_executable_dir()
{
	// Use magic static for dir initialization
	static const std::string s_dir = []
	{
		std::string dir;

#ifdef _WIN32
		wchar_t buf[2048];
		if (GetModuleFileName(NULL, buf, ::size32(buf)) - 1 >= ::size32(buf) - 1)
		{
			MessageBoxA(0, fmt::format("GetModuleFileName() failed (0x%x).", GetLastError()).c_str(), "fs::get_config_dir()", MB_ICONERROR);
			return dir; // empty
		}
	
		to_utf8(dir, buf); // Convert to UTF-8

#elif __APPLE__
		char buf[4096];
		u32 size = sizeof(buf);
		if (_NSGetExecutablePath(buf, &size))
		{
			std::printf("_NSGetExecutablePath() failed (size=0x%x).\n", size);
			return dir; // empty
		}

		dir = buf;
#else
		char buf[4096];
		const auto size = ::readlink("/proc/self/exe", buf, sizeof(buf));
		if (size <= 0 || size >= sizeof(buf))
		{
			std::printf("readlink(/proc/self/exe) failed (%d).\n", errno);
			return dir; // empty
		}

		dir = { buf, static_cast<std::size_t>(size) };
#endif

		// Replace "\"
		for (auto& c : dir)
		{
			if (c == '\\') c = '/';
		}

		// Leave only path
		dir.resize(dir.rfind('/') + 1);
		return dir;
	}();

	return s_dir;
}