/*************************************************************************/
/*  hashing_context.cpp                                                  */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2022 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 "hashing_context.h"

#include "core/crypto/crypto_core.h"

Error HashingContext::start(HashType p_type) {
	ERR_FAIL_COND_V(ctx != nullptr, ERR_ALREADY_IN_USE);
	_create_ctx(p_type);
	ERR_FAIL_COND_V(ctx == nullptr, ERR_UNAVAILABLE);
	switch (type) {
		case HASH_MD5:
			return ((CryptoCore::MD5Context *)ctx)->start();
		case HASH_SHA1:
			return ((CryptoCore::SHA1Context *)ctx)->start();
		case HASH_SHA256:
			return ((CryptoCore::SHA256Context *)ctx)->start();
	}
	return ERR_UNAVAILABLE;
}

Error HashingContext::update(PackedByteArray p_chunk) {
	ERR_FAIL_COND_V(ctx == nullptr, ERR_UNCONFIGURED);
	size_t len = p_chunk.size();
	ERR_FAIL_COND_V(len == 0, FAILED);
	const uint8_t *r = p_chunk.ptr();
	switch (type) {
		case HASH_MD5:
			return ((CryptoCore::MD5Context *)ctx)->update(&r[0], len);
		case HASH_SHA1:
			return ((CryptoCore::SHA1Context *)ctx)->update(&r[0], len);
		case HASH_SHA256:
			return ((CryptoCore::SHA256Context *)ctx)->update(&r[0], len);
	}
	return ERR_UNAVAILABLE;
}

PackedByteArray HashingContext::finish() {
	ERR_FAIL_COND_V(ctx == nullptr, PackedByteArray());
	PackedByteArray out;
	Error err = FAILED;
	switch (type) {
		case HASH_MD5:
			out.resize(16);
			err = ((CryptoCore::MD5Context *)ctx)->finish(out.ptrw());
			break;
		case HASH_SHA1:
			out.resize(20);
			err = ((CryptoCore::SHA1Context *)ctx)->finish(out.ptrw());
			break;
		case HASH_SHA256:
			out.resize(32);
			err = ((CryptoCore::SHA256Context *)ctx)->finish(out.ptrw());
			break;
	}
	_delete_ctx();
	ERR_FAIL_COND_V(err != OK, PackedByteArray());
	return out;
}

void HashingContext::_create_ctx(HashType p_type) {
	type = p_type;
	switch (type) {
		case HASH_MD5:
			ctx = memnew(CryptoCore::MD5Context);
			break;
		case HASH_SHA1:
			ctx = memnew(CryptoCore::SHA1Context);
			break;
		case HASH_SHA256:
			ctx = memnew(CryptoCore::SHA256Context);
			break;
		default:
			ctx = nullptr;
	}
}

void HashingContext::_delete_ctx() {
	switch (type) {
		case HASH_MD5:
			memdelete((CryptoCore::MD5Context *)ctx);
			break;
		case HASH_SHA1:
			memdelete((CryptoCore::SHA1Context *)ctx);
			break;
		case HASH_SHA256:
			memdelete((CryptoCore::SHA256Context *)ctx);
			break;
	}
	ctx = nullptr;
}

void HashingContext::_bind_methods() {
	ClassDB::bind_method(D_METHOD("start", "type"), &HashingContext::start);
	ClassDB::bind_method(D_METHOD("update", "chunk"), &HashingContext::update);
	ClassDB::bind_method(D_METHOD("finish"), &HashingContext::finish);
	BIND_ENUM_CONSTANT(HASH_MD5);
	BIND_ENUM_CONSTANT(HASH_SHA1);
	BIND_ENUM_CONSTANT(HASH_SHA256);
}

HashingContext::~HashingContext() {
	if (ctx != nullptr) {
		_delete_ctx();
	}
}