/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#if defined(RISCOS)

// Re-enable some forbidden symbols to avoid clashes with stat.h and unistd.h.
#define FORBIDDEN_SYMBOL_EXCEPTION_unistd_h
#define FORBIDDEN_SYMBOL_EXCEPTION_mkdir

#include "backends/platform/sdl/riscos/riscos-utils.h"
#include "backends/fs/riscos/riscos-fs.h"
#include "backends/fs/stdiostream.h"
#include "common/algorithm.h"

#include <limits.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>

#include <unixlib/local.h>
#include <kernel.h>
#include <swis.h>

bool RISCOSFilesystemNode::exists() const {
	return access(_path.c_str(), F_OK) == 0;
}

bool RISCOSFilesystemNode::isReadable() const {
	return access(_path.c_str(), R_OK) == 0;
}

bool RISCOSFilesystemNode::isWritable() const {
	return access(_path.c_str(), W_OK) == 0;
}

RISCOSFilesystemNode::RISCOSFilesystemNode(const Common::String &p) {
	_path = p;
	if (p == "/") {
		_isDirectory = true;
		_isValid = true;
	} else {
		int type = _swi(OS_File, _INR(0,1)|_RETURN(0), 20, RISCOS_Utils::toRISCOS(_path).c_str());
		if (type == 0) {
			_isDirectory = false;
			_isValid = false;
		} else if (type == 2) {
			_isDirectory = true;
			_isValid = true;
		} else {
			_isDirectory = false;
			_isValid = true;
		}
	}
}

AbstractFSNode *RISCOSFilesystemNode::getChild(const Common::String &n) const {
	assert(!_path.empty());
	assert(_isDirectory);

	// Make sure the string contains no slashes
	assert(!n.contains('/'));

	// We assume here that _path is already normalized (hence don't bother to call
	//  Common::normalizePath on the final path).
	Common::String newPath(_path);
	if (_path.lastChar() != '/')
		newPath += '/';
	newPath += n;

	return makeNode(newPath);
}

bool RISCOSFilesystemNode::getChildren(AbstractFSList &myList, ListMode mode, bool hidden) const {
	assert(_isDirectory);

	if (_path == "/") {
		// Special case for the root dir: List all drives
		char fsname[PATH_MAX] = "";
		for (int fsNum = 0; fsNum < 256; fsNum += 1) {
			_swi(OS_FSControl, _INR(0,3), 33, fsNum, fsname, sizeof(fsname));
			if (strcmp(fsname, "") != 0) {
				if (!(fsNum == 46 || fsNum == 53 || fsNum == 99)) {
					int drives = 9;
					if (fsNum == 193)
						drives = 23;

					for (int discnum = 0; discnum <= drives; discnum += 1) {
						const Common::String path = Common::String::format("%s::%d.$", fsname, discnum);
						char outpath[PATH_MAX] = "";
						if(_swix(OS_FSControl, _INR(0,2)|_IN(5), 37, path.c_str(), outpath, sizeof(outpath)) == NULL) {
							int exist;
							if (_swix(OS_File, _INR(0,1)|_OUT(0), 23, outpath, &exist) != NULL || exist != 2)
								continue;

							RISCOSFilesystemNode *entry = new RISCOSFilesystemNode();
							entry->_isDirectory = true;
							entry->_isValid = true;
							entry->_path = Common::String::format("/%s", outpath);
							entry->_displayName = outpath;
							myList.push_back(entry);
						}
					}
				}
			}
		}
		return true;
	}

	int count = 0;
	int read = 0;
	char file[PATH_MAX];
	Common::String dir = _path;

	while (count != -1) {
		_swix(OS_GBPB, _INR(0,5)|_OUTR(3,4), 9, RISCOS_Utils::toRISCOS(dir).c_str(), file, 1, count, sizeof(file), &read, &count);

		if (count == -1)
			continue;

		// Start with a clone of this node, with the correct path set
		RISCOSFilesystemNode entry(*this);
		entry._displayName = file;
		entry._displayName = RISCOS_Utils::toUnix(entry._displayName);
		if (_path.lastChar() != '/')
			entry._path += '/';
		entry._path += entry._displayName;

		int type = _swi(OS_File, _INR(0,1)|_RETURN(0), 20, RISCOS_Utils::toRISCOS(entry._path).c_str());
		if (type == 0) {
			continue;
		} else if (type == 2) {
			entry._isDirectory = true;
		} else {
			entry._isDirectory = false;
		}

		// Honor the chosen mode
		if ((mode == Common::FSNode::kListFilesOnly && entry._isDirectory) ||
			(mode == Common::FSNode::kListDirectoriesOnly && !entry._isDirectory))
			continue;

		myList.push_back(new RISCOSFilesystemNode(entry));
	}

	return true;
}

AbstractFSNode *RISCOSFilesystemNode::getParent() const {
	if (_path == "/")
		return 0;	// The filesystem root has no parent

	const char *start = _path.c_str();
	const char *end = start + _path.size();

	// Strip of the last component. We make use of the fact that at this
	// point, _path is guaranteed to be normalized
	while (end > start && *(end-1) != '/')
		end--;

	if (end == start) {
		// This only happens if we were called with a relative path, for which
		// there simply is no parent.
		// TODO: We could also resolve this by assuming that the parent is the
		//       current working directory, and returning a node referring to that.
		return 0;
	}

	if (*(end-1) == '/' && end != start + 1)
		end--;

	return makeNode(Common::String(start, end));
}

Common::SeekableReadStream *RISCOSFilesystemNode::createReadStream() {
	return StdioStream::makeFromPath(getPath(), false);
}

Common::WriteStream *RISCOSFilesystemNode::createWriteStream() {
	return StdioStream::makeFromPath(getPath(), true);
}

bool RISCOSFilesystemNode::create(bool isDirectoryFlag) {
	bool success;

	if (isDirectoryFlag) {
		success = _swix(OS_File, _INR(0,1), 8, RISCOS_Utils::toRISCOS(_path).c_str()) == NULL;
	} else {
		int fd = open(_path.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0755);
		success = fd >= 0;

		if (fd >= 0) {
			close(fd);
		}
	}

	if (success) {
		if (exists()) {
			_isDirectory = _swi(OS_File, _INR(0,1)|_RETURN(0), 20, RISCOS_Utils::toRISCOS(_path).c_str()) == 2;
			if (_isDirectory != isDirectoryFlag) warning("failed to create %s: got %s", isDirectoryFlag ? "directory" : "file", _isDirectory ? "directory" : "file");
			return _isDirectory == isDirectoryFlag;
		}

		warning("RISCOSFilesystemNode: Attempting to create a %s was a success, but access indicates there is no such %s",
			isDirectoryFlag ? "directory" : "file", isDirectoryFlag ? "directory" : "file");
		return false;
	}

	return false;
}

namespace Riscos {

bool assureDirectoryExists(const Common::String &dir, const char *prefix) {
	AbstractFSNode *node;

	// Check whether the prefix exists if one is supplied.
	if (prefix) {
		node = new RISCOSFilesystemNode(prefix);
		if (!node->isDirectory()) {
			return false;
		}
	}

	// Obtain absolute path.
	Common::String path;
	if (prefix) {
		path = prefix;
		path += '/';
		path += dir;
	} else {
		path = dir;
	}

	path = Common::normalizePath(path, '/');

	const Common::String::iterator end = path.end();
	Common::String::iterator cur = path.begin();
	if (*cur == '/')
		++cur;

	do {
		if (cur + 1 != end) {
			if (*cur != '/') {
				continue;
			}

			// It is kind of ugly and against the purpose of Common::String to
			// insert 0s inside, but this is just for a local string and
			// simplifies the code a lot.
			*cur = '\0';
		}

		node = new RISCOSFilesystemNode(path);
		if (!node->create(true)) {
			if (node->exists()) {
				if (!node->isDirectory()) {
					return false;
				}
			} else {
				return false;
			}
		}

		*cur = '/';
	} while (cur++ != end);

	return true;
}

} // End of namespace RISCOS

#endif //#if defined(RISCOS)