crown-engine/engine/core/strings/path.cpp

/*
 * Copyright (c) 2012-2014 Daniele Bartolini and individual contributors.
 * License: https://github.com/taylor001/crown/blob/master/LICENSE
 */

#include "path.h"
#include <ctype.h> // isalpha

namespace crown
{
namespace path
{
	bool is_valid_segment(const char* segment)
	{
		CE_ASSERT(segment != NULL, "Segment must be != NULL");

		size_t segment_len = strlen(segment);

		// Empty segment is not valid
		if (segment_len == 0)
		{
			return false;
		}

		// Segments containing only '.' are non valid
		if (segment_len == 1 && segment[0] == '.')
		{
			return false;
		}

		// Segments containing only ".." are not valid
		if (segment_len == 2 && segment[0] == '.' && segment[1] == '.')
		{
			return false;
		}

		// The segment does not have to contain any forward slashes ('/')
		// nor back slashes ('\'), nor colon signs (':')
		for (size_t i = 0; i < segment_len; i++)
		{
			if (segment[i] == '/' ||
				segment[i] == '\\' ||
				segment[i] == ':')
			{
				return false;
			}
		}

		return true;
	}

	/// Returns whether the path is valid.
	/// @note
	/// The rules for valid paths are as follows:
	/// a) The empty string is not valid.
	/// b) If the path is absolute, it mustn't contain any leading character.
	bool is_valid_path(const char* path)
	{
		(void)path;
	//	size_t path_len = strlen(path);

	//	if (pathLen == 0)
	//	{
	//		return false;
	//	}

	//	if (is_root_path(path))
	//	{
	//		return true;
	//	}

	//	Array<Str> segmentList;
	//	if (!get_segments(Str(path), segmentList))
	//	{
	//		return false;
	//	}

	//	size_t i = 0;
	//	if (IsAbsolutePath(path) && path[0] != '/')
	//	{
	//		i = 1;
	//	}

	//	for (; i < segmentList.GetSize(); i++)
	//	{
	//		if (!IsValidSegment(segmentList[i].c_str()))
	//		{
	//			return false;
	//		}
	//	}

		return true;
	}

	bool is_absolute_path(const char* path)
	{
		CE_ASSERT(path != NULL, "Path must be != NULL");
#if CROWN_PLATFORM_POSIX
		return strlen(path) > 0 && path[0] == '/';
#elif CROWN_PLATFORM_WINDOWS
		return strlen(path) > 2 && isalpha(path[0]) && path[1] == ':' && path[2] == '\\';
#endif
	}

	bool is_root_path(const char* path)
	{
		CE_ASSERT(path != NULL, "Path must be != NULL");
#if CROWN_PLATFORM_POSIX
		return is_absolute_path(path) && strlen(path) == 1;
#elif CROWN_PLATFORM_WINDOWS
		return is_absolute_path(path) && strlen(path) == 3;
#endif
	}

	/// Returns the pathname of the path.
	/// @note
	/// e.g. "/home/project/texture.tga" -> "/home/project"
	/// e.g. "/home/project" -> "/home"
	/// e.g. "/home" -> "/"
	/// e.g. "home" -> ""
	///
	/// The @a path must be valid.
	void pathname(const char* path, char* str, size_t len)
	{
		CE_ASSERT(path != NULL, "Path must be != NULL");
		CE_ASSERT(str != NULL, "Str must be != NULL");

		const char* last_separator = find_last(path, '/');

		if (last_separator == end(path))
		{
			strncpy(str, "", len);
		}
		else
		{
			substring(begin(path), last_separator, str, len);
		}
	}

	/// Returns the filename of the path.
	/// @note
	/// e.g. "/home/project/texture.tga" -> "texture.tga"
	/// e.g. "/home/project/texture" -> "texture"
	/// e.g. "/home -> "home"
	/// e.g. "/" -> ""
	///
	/// The @a path must be valid.
	void filename(const char* path, char* str, size_t len)
	{
		CE_ASSERT(path != NULL, "Path must be != NULL");
		CE_ASSERT(str != NULL, "Str must be != NULL");

		const char* last_separator = find_last(path, '/');

		if (last_separator == end(path))
		{
			strncpy(str, "", len);
		}
		else
		{
			substring(last_separator + 1, end(path), str, len);
		}
	}

	/// Returns the basename of the path.
	/// @note
	/// e.g. "/home/project/texture.tga" -> "texture"
	/// e.g. "/home/project" -> "project"
	/// e.g. "/" -> ""
	///
	/// The @a path must be valid.
	void basename(const char* path, char* str, size_t len)
	{
		CE_ASSERT(path != NULL, "Path must be != NULL");
		CE_ASSERT(str != NULL, "Str must be != NULL");

		const char* last_separator = find_last(path, '/');
		const char* last_dot = find_last(path, '.');

		if (last_separator == end(path) && last_dot != end(path))
		{
			substring(begin(path), last_dot, str, len);
		}
		else if (last_separator != end(path) && last_dot == end(path))
		{
			substring(last_separator + 1, end(path), str, len);
		}
		else if (last_separator == end(path) && last_dot == end(path))
		{
			strncpy(str, path, len);
		}
		else
		{
			substring(last_separator + 1, last_dot, str, len);
		}
	}

	/// Returns the extension of the path.
	/// @note
	/// e.g. "/home/project/texture.tga" -> "tga"
	/// e.g. "/home/project.x/texture" -> ""
	///
	/// The @a path must be valid.
	void extension(const char* path, char* str, size_t len)
	{
		CE_ASSERT(path != NULL, "Path must be != NULL");
		CE_ASSERT(str != NULL, "Str must be != NULL");

		const char* last_dot = find_last(path, '.');

		if (last_dot == end(path))
		{
			strncpy(str, "", len);
		}
		else
		{
			substring(last_dot + 1, end(path), str, len);
		}
	}

	/// Returns the filename without the extension.
	/// @note
	/// e.g. "/home/project/texture.tga" -> "/home/project/texture"
	/// e.g. "/home/project/texture" -> "/home/project/texture"
	///
	/// The @a path must be valid.
	void filename_without_extension(const char* path, char* str, size_t len)
	{
		CE_ASSERT(path != NULL, "Path must be != NULL");
		CE_ASSERT(str != NULL, "Str must be != NULL");

		const char* last_dot = find_last(path, '.');

		substring(begin(path), last_dot, str, len);
	}

	/// Returns the segments contained in path.
	//bool segments(const char* path, Array<Str>& ret)
	//{
	//	path.Split(os::PATH_SEPARATOR, ret);

	//	if (ret.GetSize() > 0)
	//	{
	//		return true;
	//	}

	//	return false;
	//}

	/// Fills 'ret' with the same path but without the trailing directory separator.
	/// @note
	/// e.g. "/home/project/texture.tga/" -> "/home/project/texture.tga"
	/// e.g. "/home/project/texture.tga" -> "/home/project/texture.tga"
	///
	/// The @a path must be valid.
	void strip_trailing_separator(const char* path, char* str, size_t len)
	{
		CE_ASSERT(path != NULL, "Path must be != NULL");
		CE_ASSERT(str != NULL, "Str must be != NULL");

		size_t path_len = strlen(path);

		if (path[path_len - 1] == '/')
		{
			substring(begin(path), end(path) - 2, str, len);
		}
		else
		{
			substring(begin(path), end(path), str, len);
		}
	}
} // namespace path
} // namespace crown