text: /*************************************************************************/
  /*  file_access_pack.cpp                                                 */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://godotengine.org                          */
  /*************************************************************************/
  /* Copyright (c) 2007-2019 Juan Linietsky, Ariel Manzur.                 */
  /* Copyright (c) 2014-2019 Godot Engine contributors (cf. AUTHORS.md)    */
  /*                                                                       */
  /* Permission is hereby granted, free of charge, to any person obtaining */
  /* a copy of this software and associated documentation files (the       */
  /* "Software"), to deal in the Software without restriction, including   */
  /* without limitation the rights to use, copy, modify, merge, publish,   */
  /* distribute, sublicense, and/or sell copies of the Software, and to    */
  /* permit persons to whom the Software is furnished to do so, subject to */
  /* the following conditions:                                             */
  /*                                                                       */
  /* The above copyright notice and this permission notice shall be        */
  /* included in all copies or substantial portions of the Software.       */
  /*                                                                       */
  /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
  /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
  /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
  /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
  /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
  /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
  /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
  /*************************************************************************/
  
  #include "file_access_pack.h"
  
  #include "core/version.h"
  
  #include <stdio.h>
  
  #define PACK_VERSION 1
  
  Error PackedData::add_pack(const String &p_path) {
  
  	for (int i = 0; i < sources.size(); i++) {
  
  		if (sources[i]->try_open_pack(p_path)) {
  
  			return OK;
  		};
  	};
  
  	return ERR_FILE_UNRECOGNIZED;
  };
  
  void PackedData::add_path(const String &pkg_path, const String &path, uint64_t ofs, uint64_t size, const uint8_t *p_md5, PackSource *p_src) {
  
  	PathMD5 pmd5(path.md5_buffer());
  	//printf("adding path %ls, %lli, %lli\n", path.c_str(), pmd5.a, pmd5.b);
  
  	bool exists = files.has(pmd5);
  
  	PackedFile pf;
  	pf.pack = pkg_path;
  	pf.offset = ofs;
  	pf.size = size;
  	for (int i = 0; i < 16; i++)
  		pf.md5[i] = p_md5[i];
  	pf.src = p_src;
  
  	files[pmd5] = pf;
  
  	if (!exists) {
  		//search for dir
  		String p = path.replace_first("res://", "");
  		PackedDir *cd = root;
  
  		if (p.find("/") != -1) { //in a subdir
  
  			Vector<String> ds = p.get_base_dir().split("/");
  
  			for (int j = 0; j < ds.size(); j++) {
  
  				if (!cd->subdirs.has(ds[j])) {
  
  					PackedDir *pd = memnew(PackedDir);
  					pd->name = ds[j];
  					pd->parent = cd;
  					cd->subdirs[pd->name] = pd;
  					cd = pd;
  				} else {
  					cd = cd->subdirs[ds[j]];
  				}
  			}
  		}
  		String filename = path.get_file();
  		// Don't add as a file if the path points to a directory
  		if (!filename.empty()) {
  			cd->files.insert(filename);
  		}
  	}
  }
  
  void PackedData::add_pack_source(PackSource *p_source) {
  
  	if (p_source != NULL) {
  		sources.push_back(p_source);
  	}
  };
  
  PackedData *PackedData::singleton = NULL;
  
  PackedData::PackedData() {
  
  	singleton = this;
  	root = memnew(PackedDir);
  	root->parent = NULL;
  	disabled = false;
  
  	add_pack_source(memnew(PackedSourcePCK));
  }
  
  void PackedData::_free_packed_dirs(PackedDir *p_dir) {
  
  	for (Map<String, PackedDir *>::Element *E = p_dir->subdirs.front(); E; E = E->next())
  		_free_packed_dirs(E->get());
  	memdelete(p_dir);
  }
  
  PackedData::~PackedData() {
  
  	for (int i = 0; i < sources.size(); i++) {
  		memdelete(sources[i]);
  	}
  	_free_packed_dirs(root);
  }
  
  //////////////////////////////////////////////////////////////////
  
  bool PackedSourcePCK::try_open_pack(const String &p_path) {
  
  	FileAccess *f = FileAccess::open(p_path, FileAccess::READ);
  	if (!f)
  		return false;
  
  	//printf("try open %ls!\n", p_path.c_str());
  
  	uint32_t magic = f->get_32();
  
  	if (magic != 0x43504447) {
  		//maybe at the end.... self contained exe
  		f->seek_end();
  		f->seek(f->get_position() - 4);
  		magic = f->get_32();
  		if (magic != 0x43504447) {
  
  			memdelete(f);
  			return false;
  		}
  		f->seek(f->get_position() - 12);
  
  		uint64_t ds = f->get_64();
  		f->seek(f->get_position() - ds - 8);
  
  		magic = f->get_32();
  		if (magic != 0x43504447) {
  
  			memdelete(f);
  			return false;
  		}
  	}
  
  	uint32_t version = f->get_32();
  	uint32_t ver_major = f->get_32();
  	uint32_t ver_minor = f->get_32();
  	f->get_32(); // ver_rev
  
  	ERR_FAIL_COND_V_MSG(version != PACK_VERSION, false, "Pack version unsupported: " + itos(version) + ".");
  	ERR_FAIL_COND_V_MSG(ver_major > VERSION_MAJOR || (ver_major == VERSION_MAJOR && ver_minor > VERSION_MINOR), false, "Pack created with a newer version of the engine: " + itos(ver_major) + "." + itos(ver_minor) + ".");
  
  	for (int i = 0; i < 16; i++) {
  		//reserved
  		f->get_32();
  	}
  
  	int file_count = f->get_32();
  
  	for (int i = 0; i < file_count; i++) {
  
  		uint32_t sl = f->get_32();
  		CharString cs;
  		cs.resize(sl + 1);
  		f->get_buffer((uint8_t *)cs.ptr(), sl);
  		cs[sl] = 0;
  
  		String path;
  		path.parse_utf8(cs.ptr());
  
  		uint64_t ofs = f->get_64();
  		uint64_t size = f->get_64();
  		uint8_t md5[16];
  		f->get_buffer(md5, 16);
  		PackedData::get_singleton()->add_path(p_path, path, ofs, size, md5, this);
  	};
  
  	return true;
  };
  
  FileAccess *PackedSourcePCK::get_file(const String &p_path, PackedData::PackedFile *p_file) {
  
  	return memnew(FileAccessPack(p_path, *p_file));
  };
  
  //////////////////////////////////////////////////////////////////
  
  Error FileAccessPack::_open(const String &p_path, int p_mode_flags) {
  
  	ERR_FAIL_V(ERR_UNAVAILABLE);
  	return ERR_UNAVAILABLE;
  }
  
  void FileAccessPack::close() {
  
  	f->close();
  }
  
  bool FileAccessPack::is_open() const {
  
  	return f->is_open();
  }
  
  void FileAccessPack::seek(size_t p_position) {
  
  	if (p_position > pf.size) {
  		eof = true;
  	} else {
  		eof = false;
  	}
  
  	f->seek(pf.offset + p_position);
  	pos = p_position;
  }
  void FileAccessPack::seek_end(int64_t p_position) {
  
  	seek(pf.size + p_position);
  }
  size_t FileAccessPack::get_position() const {
  
  	return pos;
  }
  size_t FileAccessPack::get_len() const {
  
  	return pf.size;
  }
  
  bool FileAccessPack::eof_reached() const {
  
  	return eof;
  }
  
  uint8_t FileAccessPack::get_8() const {
  
  	if (pos >= pf.size) {
  		eof = true;
  		return 0;
  	}
  
  	pos++;
  	return f->get_8();
  }
  
  int FileAccessPack::get_buffer(uint8_t *p_dst, int p_length) const {
  
  	if (eof)
  		return 0;
  
  	uint64_t to_read = p_length;
  	if (to_read + pos > pf.size) {
  		eof = true;
  		to_read = int64_t(pf.size) - int64_t(pos);
  	}
  
  	pos += p_length;
  
  	if (to_read <= 0)
  		return 0;
  	f->get_buffer(p_dst, to_read);
  
  	return to_read;
  }
  
  void FileAccessPack::set_endian_swap(bool p_swap) {
  	FileAccess::set_endian_swap(p_swap);
  	f->set_endian_swap(p_swap);
  }
  
  Error FileAccessPack::get_error() const {
  
  	if (eof)
  		return ERR_FILE_EOF;
  	return OK;
  }
  
  void FileAccessPack::flush() {
  
  	ERR_FAIL();
  }
  
  void FileAccessPack::store_8(uint8_t p_dest) {
  
  	ERR_FAIL();
  }
  
  void FileAccessPack::store_buffer(const uint8_t *p_src, int p_length) {
  
  	ERR_FAIL();
  }
  
  bool FileAccessPack::file_exists(const String &p_name) {
  
  	return false;
  }
  
  FileAccessPack::FileAccessPack(const String &p_path, const PackedData::PackedFile &p_file) :
  		pf(p_file),
  		f(FileAccess::open(pf.pack, FileAccess::READ)) {
  
  	ERR_FAIL_COND_MSG(!f, "Can't open pack-referenced file: " + String(pf.pack) + ".");
  
  	f->seek(pf.offset);
  	pos = 0;
  	eof = false;
  }
  
  FileAccessPack::~FileAccessPack() {
  	if (f)
  		memdelete(f);
  }
  
  //////////////////////////////////////////////////////////////////////////////////
  // DIR ACCESS
  //////////////////////////////////////////////////////////////////////////////////
  
  Error DirAccessPack::list_dir_begin() {
  
  	list_dirs.clear();
  	list_files.clear();
  
  	for (Map<String, PackedData::PackedDir *>::Element *E = current->subdirs.front(); E; E = E->next()) {
  
  		list_dirs.push_back(E->key());
  	}
  
  	for (Set<String>::Element *E = current->files.front(); E; E = E->next()) {
  
  		list_files.push_back(E->get());
  	}
  
  	return OK;
  }
  
  String DirAccessPack::get_next() {
  
  	if (list_dirs.size()) {
  		cdir = true;
  		String d = list_dirs.front()->get();
  		list_dirs.pop_front();
  		return d;
  	} else if (list_files.size()) {
  		cdir = false;
  		String f = list_files.front()->get();
  		list_files.pop_front();
  		return f;
  	} else {
  		return String();
  	}
  }
  bool DirAccessPack::current_is_dir() const {
  
  	return cdir;
  }
  bool DirAccessPack::current_is_hidden() const {
  
  	return false;
  }
  void DirAccessPack::list_dir_end() {
  
  	list_dirs.clear();
  	list_files.clear();
  }
  
  int DirAccessPack::get_drive_count() {
  
  	return 0;
  }
  String DirAccessPack::get_drive(int p_drive) {
  
  	return "";
  }
  
  Error DirAccessPack::change_dir(String p_dir) {
  
  	String nd = p_dir.replace("\\", "/");
  	bool absolute = false;
  	if (nd.begins_with("res://")) {
  		nd = nd.replace_first("res://", "");
  		absolute = true;
  	}
  
  	nd = nd.simplify_path();
  
  	if (nd == "") nd = ".";
  
  	if (nd.begins_with("/")) {
  		nd = nd.replace_first("/", "");
  		absolute = true;
  	}
  
  	Vector<String> paths = nd.split("/");
  
  	PackedData::PackedDir *pd;
  
  	if (absolute)
  		pd = PackedData::get_singleton()->root;
  	else
  		pd = current;
  
  	for (int i = 0; i < paths.size(); i++) {
  
  		String p = paths[i];
  		if (p == ".") {
  			continue;
  		} else if (p == "..") {
  			if (pd->parent) {
  				pd = pd->parent;
  			}
  		} else if (pd->subdirs.has(p)) {
  
  			pd = pd->subdirs[p];
  
  		} else {
  
  			return ERR_INVALID_PARAMETER;
  		}
  	}
  
  	current = pd;
  
  	return OK;
  }
  
  String DirAccessPack::get_current_dir() {
  
  	PackedData::PackedDir *pd = current;
  	String p = current->name;
  
  	while (pd->parent) {
  		pd = pd->parent;
  		p = pd->name.plus_file(p);
  	}
  
  	return "res://" + p;
  }
  
  bool DirAccessPack::file_exists(String p_file) {
  
  	p_file = fix_path(p_file);
  
  	return current->files.has(p_file);
  }
  
  bool DirAccessPack::dir_exists(String p_dir) {
  
  	p_dir = fix_path(p_dir);
  
  	return current->subdirs.has(p_dir);
  }
  
  Error DirAccessPack::make_dir(String p_dir) {
  
  	return ERR_UNAVAILABLE;
  }
  
  Error DirAccessPack::rename(String p_from, String p_to) {
  
  	return ERR_UNAVAILABLE;
  }
  Error DirAccessPack::remove(String p_name) {
  
  	return ERR_UNAVAILABLE;
  }
  
  size_t DirAccessPack::get_space_left() {
  
  	return 0;
  }
  
  String DirAccessPack::get_filesystem_type() const {
  	return "PCK";
  }
  
  DirAccessPack::DirAccessPack() {
  
  	current = PackedData::get_singleton()->root;
  	cdir = false;
  }
  
  DirAccessPack::~DirAccessPack() {
  }
  