/*************************************************************************/
/*  file_cache.cpp                                                       */
/*************************************************************************/
/*                         This file is part of:                         */
/*                          PANDEMONIUM ENGINE                           */
/*             https://github.com/Relintai/pandemonium_engine            */
/*************************************************************************/
/* Copyright (c) 2022-present Péter Magyar.                              */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
/*                                                                       */
/* 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  */
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/*************************************************************************/

#include "file_cache.h"

#include "core/config/project_settings.h"
#include "core/os/dir_access.h"
#include "core/os/file_access.h"
#include "core/os/os.h"
#include "core/string/print_string.h"

String FileCache::get_wwwroot() {
	return _wwwroot_orig;
}
void FileCache::set_wwwroot(const String &val) {
	_wwwroot_orig = val;
	_wwwroot = _wwwroot_orig.path_clean_end_slash();

	if (!_wwwroot.empty()) {
		_wwwroot_abs = DirAccess::get_filesystem_abspath_for(_wwwroot_orig).path_clean_end_slash();
	} else {
		_wwwroot_abs = "";
	}
}

String FileCache::get_wwwroot_abs() {
	return _wwwroot_abs;
}

int FileCache::get_cache_invalidation_time() {
	return static_cast<int>(cache_invalidation_time);
}
void FileCache::set_cache_invalidation_time(const int &val) {
	cache_invalidation_time = static_cast<uint64_t>(val);
}

bool FileCache::wwwroot_has_file(const String &file_path) {
	if (file_path.empty() || file_path == "/") {
		return false;
	}

	String fp = _wwwroot_abs + file_path;

	if (!FileAccess::exists(fp)) {
		return false;
	}

	Error err;
	FileAccess *f = FileAccess::open(fp, FileAccess::READ, &err);

	if (!f) {
		return false;
	}

	if (err != OK) {
		memdelete(f);
		return false;
	}

	if (fp.begins_with("res://")) {
		return true;
	}

	String absp = f->get_path_absolute();
	memdelete(f);

	//likely a directory walking attempt. e.g. ../../../../../etc/passwd
	if (!absp.begins_with(_wwwroot_abs)) {
		return false;
	}

	return true;
}

String FileCache::wwwroot_get_file_abspath(const String &file_path) {
	if (file_path.empty() || file_path == "/") {
		return String();
	}

	String fp = _wwwroot_abs + file_path;

	if (!FileAccess::exists(fp)) {
		return String();
	}

	Error err;
	FileAccess *f = FileAccess::open(fp, FileAccess::READ, &err);

	if (!f) {
		return String();
	}

	if (err != OK) {
		memdelete(f);
		return String();
	}

	if (fp.begins_with("res://")) {
		return fp;
	}

	String absp = f->get_path_absolute();
	memdelete(f);

	//likely a directory walking attempt. e.g. ../../../../../etc/passwd
	if (!absp.begins_with(_wwwroot_abs)) {
		return String();
	}

	return absp;
}

bool FileCache::get_cached_body(const String &path, String *body) {
	//TODO ERROR MACRO body == null

	_body_lock.read_lock();
	CacheEntry *e = cache_map[path];
	_body_lock.read_unlock();

	if (!e) {
		return false;
	}

	if (cache_invalidation_time > 0) {
		uint64_t current_timestamp = OS::get_singleton()->get_unix_time();
		uint64_t diff = current_timestamp - e->timestamp;

		if (diff > cache_invalidation_time) {
			return false;
		}
	}

	body->operator+=(e->body);

	return true;
}

bool FileCache::has_cached_body(const String &path) {
	//TODO ERROR MACRO body == null

	_body_lock.read_lock();
	CacheEntry *e = cache_map[path];
	_body_lock.read_unlock();

	if (!e) {
		return false;
	}

	if (cache_invalidation_time > 0) {
		uint64_t current_timestamp = OS::get_singleton()->get_unix_time();
		uint64_t diff = current_timestamp - e->timestamp;

		if (diff > cache_invalidation_time) {
			return false;
		}
	}

	return true;
}

String FileCache::get_cached_body_bind(const String &path) {
	//TODO ERROR MACRO body == null

	_body_lock.read_lock();
	CacheEntry *e = cache_map[path];
	_body_lock.read_unlock();

	if (!e) {
		return "";
	}

	if (cache_invalidation_time > 0) {
		uint64_t current_timestamp = OS::get_singleton()->get_unix_time();
		uint64_t diff = current_timestamp - e->timestamp;

		if (diff > cache_invalidation_time) {
			return "";
		}
	}

	return e->body;
}

void FileCache::set_cached_body(const String &path, const String &body) {
	_body_lock.write_lock();

	CacheEntry *e = cache_map[path];

	if (!e) {
		e = memnew(CacheEntry());
		cache_map[path] = e;
	}

	uint64_t current_timestamp = OS::get_singleton()->get_unix_time();

	e->timestamp = current_timestamp;
	e->body = body;

	_body_lock.write_unlock();
}

void FileCache::clear() {
	_body_lock.write_lock();

	for (RBMap<String, CacheEntry *>::Element *E = cache_map.front(); E; E++) {
		CacheEntry *ce = E->get();

		if (ce) {
			memdelete(ce);
		}
	}

	cache_map.clear();

	_body_lock.write_unlock();
}

FileCache::FileCache() {
	cache_invalidation_time = 0;
}

FileCache::~FileCache() {
}

void FileCache::_bind_methods() {
	ClassDB::bind_method(D_METHOD("get_wwwroot"), &FileCache::get_wwwroot);
	ClassDB::bind_method(D_METHOD("set_wwwroot", "val"), &FileCache::set_wwwroot);
	ADD_PROPERTY(PropertyInfo(Variant::STRING, "wwwroot"), "set_wwwroot", "get_wwwroot");

	ClassDB::bind_method(D_METHOD("get_wwwroot_abs"), &FileCache::get_wwwroot_abs);

	ClassDB::bind_method(D_METHOD("get_cache_invalidation_time"), &FileCache::get_cache_invalidation_time);
	ClassDB::bind_method(D_METHOD("set_cache_invalidation_time", "val"), &FileCache::set_cache_invalidation_time);
	ADD_PROPERTY(PropertyInfo(Variant::INT, "cache_invalidation_time"), "set_cache_invalidation_time", "get_cache_invalidation_time");

	ClassDB::bind_method(D_METHOD("wwwroot_has_file", "file_path"), &FileCache::wwwroot_has_file);
	ClassDB::bind_method(D_METHOD("wwwroot_get_file_abspath", "file_path"), &FileCache::wwwroot_get_file_abspath);

	ClassDB::bind_method(D_METHOD("get_cached_body", "path"), &FileCache::get_cached_body_bind);
	ClassDB::bind_method(D_METHOD("has_cached_body", "path"), &FileCache::has_cached_body);
	ClassDB::bind_method(D_METHOD("set_cached_body", "path", "body"), &FileCache::set_cached_body);

	ClassDB::bind_method(D_METHOD("clear"), &FileCache::clear);
}