// =====================================================================================================================
//  fennec, a free and open source game engine
//  Copyright © 2025  Medusa Slockbower
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <https://www.gnu.org/licenses/>.
// =====================================================================================================================

#include <fennec/fproc/io/common.h>

#ifdef _WIN32

namespace fennec
{

string getcwd() {
	char cstr[MAX_PATH];
	if (GetCurrentDirectory(sizeof(str), str) == 0) {
		return string("");
	}
	string result(cstr);
	return result;
}

}

#else

#include <unistd.h>
#include <linux/limits.h>

namespace fennec
{

string getcwd() {
	char cstr[PATH_MAX];
	if (::getcwd(cstr, sizeof(cstr)) == NULL) {
		return string("");
	}
	return string(cstr, strlen(cstr));
}

string absolute(const cstring& path) {

	// first determine if this is already an absolute path
#ifdef _WIN32
	if (path[1] == ':') {
		return path;
	}
#else
	if (path[0] == '/') {
		return path;
	}
#endif

	string parse = path;
	string res = getcwd();

	size_t len = res.length();
#ifdef _WIN32
	if (res[len - 1] == '/' || res[len - 1] == '\\') {
#else
	if (res[len - 1] == '/') {
#endif
		res = res.substring(0, len);
	}

	while (parse.size() > 1) {

		// Parse for relative symbols
		while (parse[0] == '.') {

#ifdef _WIN32
			// up
			if (parse[1] == '.' && (parse[2] == '/' || parse[2] == '\\')) {
				size_t r = res.rfind('/');
				size_t l = res.rfind('\\');
				size_t size = res.size();
				if (r == size) {
					size = l;
				}
				else if (l == size) {
					size = r;
				}
				else {
					size = max(r, l);
				}
				size = max(size, 1);
				res = res.substring(0, size);
			}
			// rel
			else if (parse[1] == '/' || parse[1] == '\\') {
				parse = parse.substring(2);
			}
#else
			// up
			if (parse[1] == '.' && parse[2] == '/') {
				size_t r = res.rfind('/');
				res = res.substring(0, max(res.rfind('/'), static_cast<size_t>(1)));
				parse = parse.substring(2);
			}
			// rel
			else if (parse[1] == '/') {
				parse = parse.substring(1);
			}
#endif
			else {
				break;
			}
		}

		// get the pos of the first directory separator
#ifdef _WIN32
		size_t pos = min(parse.find('\\', 1), parse.find('/', 1));
#else
		size_t pos = parse.find('/', 1);
		size_t off = 0;
#endif
		if (pos != parse.size()) {
			if (parse[pos + 1] == '.') {
				if (parse[pos + 2] == '/') {
					off = 1;
				}
				else if (parse[pos + 2] == '.' && parse[pos + 3] == '/') {
					off = 1;
				}
			}
			else if (parse[pos + 1] == '/') {
				off = 1;
			}
		}

		// add this part
		string sub = parse.substring(0, pos);
		parse = parse.substring(pos + off);
		res += sub;
	}

	return res;
}

string absolute(const string& path) {

	// first determine if this is already an absolute path
#ifdef _WIN32
	if (path[1] == ':') {
		return path;
	}
#else
	if (path[0] == '/') {
		return path;
	}
#endif

	string parse = path;
	string res = getcwd();

	size_t len = res.length();
#ifdef _WIN32
	if (res[len - 1] == '/' || res[len - 1] == '\\') {
#else
	if (res[len - 1] == '/') {
#endif
		res = res.substring(0, len);
	}

	while (parse.size() > 1) {

		// Parse for relative symbols
		while (parse[0] == '.') {

#ifdef _WIN32
			// up
			if (parse[1] == '.' && (parse[2] == '/' || parse[2] == '\\')) {
				size_t r = res.rfind('/');
				size_t l = res.rfind('\\');
				size_t size = res.size();
				if (r == size) {
					size = l;
				}
				else if (l == size) {
					size = r;
				}
				else {
					size = max(r, l);
				}
				size = max(size, 1);
				res = res.substring(0, size);
			}
			// rel
			else if (parse[1] == '/' || parse[1] == '\\') {
				parse = parse.substring(2);
			}
#else
			// up
			if (parse[1] == '.' && parse[2] == '/') {
				size_t r = res.rfind('/');
				res = res.substring(0, max(res.rfind('/'), static_cast<size_t>(1)));
				parse = parse.substring(2);
			}
			// rel
			else if (parse[1] == '/') {
				parse = parse.substring(1);
			}
#endif
			else {
				break;
			}
		}

		// get the pos of the first directory separator
#ifdef _WIN32
		size_t pos = min(parse.find('\\', 1), parse.find('/', 1));
		size_t off = 0;
		if (pos != parse.size()) {
			if (parse[pos + 1] == '.') {
				if (parse[pos + 2] == '/' || parse[pos + 2] == '\\') {
					off = 1;
				}
				else if (parse[pos + 2] == '.' && (parse[pos + 3] == '/' || parse[pos + 3] == '\\')) {
					off = 1;
				}
			}
			else if (parse[pos + 1] == '/' || parse[pos + 1] == '\\') {
				off = 1;
			}
		}
#else
		size_t pos = parse.find('/', 1);
		size_t off = 0;
		if (pos != parse.size()) {
			if (parse[pos + 1] == '.') {
				if (parse[pos + 2] == '/') {
					off = 1;
				}
				else if (parse[pos + 2] == '.' && parse[pos + 3] == '/') {
					off = 1;
				}
			}
			else if (parse[pos + 1] == '/') {
				off = 1;
			}
		}
#endif

		// add this part
		string sub = parse.substring(0, pos);
		parse = parse.substring(pos + off);
		res += sub;
	}

	return res;
}

#endif

}