/*
 * SPDX-FileCopyrightText: 2013, 2015 ljfa-ag <ljfa-ag@web.de>
 *
 * SPDX-License-Identifier: LGPL-3.0-or-later
 */

/*
 * libnbt++ - A library for the Minecraft Named Binary Tag format.
 * Copyright (C) 2013, 2015  ljfa-ag
 *
 * This file is part of libnbt++.
 *
 * libnbt++ is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * libnbt++ 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with libnbt++.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <cxxtest/TestSuite.h>
#include "io/stream_reader.h"
#ifdef NBT_HAVE_ZLIB
#include "io/izlibstream.h"
#endif
#include "nbt_tags.h"
#include <iostream>
#include <fstream>
#include <sstream>

using namespace nbt;

#include "data.h"

class read_test : public CxxTest::TestSuite
{
  public:
	void test_stream_reader_big()
	{
		std::string input{
			1,	// tag_type::Byte
			0,	// tag_type::End
			11, // tag_type::Int_Array

			0x0a, 0x0b, 0x0c, 0x0d, // 0x0a0b0c0d in Big Endian

			0x00, 0x06, // String length in Big Endian
			'f',  'o',	'o',  'b',	'a', 'r',

			0 // tag_type::End (invalid with allow_end = false)
		};
		std::istringstream is(input);
		nbt::io::stream_reader reader(is);

		TS_ASSERT_EQUALS(&reader.get_istr(), &is);
		TS_ASSERT_EQUALS(reader.get_endian(), endian::big);

		TS_ASSERT_EQUALS(reader.read_type(), tag_type::Byte);
		TS_ASSERT_EQUALS(reader.read_type(true), tag_type::End);
		TS_ASSERT_EQUALS(reader.read_type(false), tag_type::Int_Array);

		int32_t i;
		reader.read_num(i);
		TS_ASSERT_EQUALS(i, 0x0a0b0c0d);

		TS_ASSERT_EQUALS(reader.read_string(), "foobar");

		TS_ASSERT_THROWS(reader.read_type(false), io::input_error);
		TS_ASSERT(!is);
		is.clear();

		// Test for invalid tag type 13
		is.str("\x0d");
		TS_ASSERT_THROWS(reader.read_type(), io::input_error);
		TS_ASSERT(!is);
		is.clear();

		// Test for unexpcted EOF on numbers (input too short for int32_t)
		is.str("\x03\x04");
		reader.read_num(i);
		TS_ASSERT(!is);
	}

	void test_stream_reader_little()
	{
		std::string input{
			0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
			0x0c, 0x0d, // 0x0d0c0b0a09080706 in Little Endian

			0x06, 0x00, // String length in Little Endian
			'f',  'o',	'o',  'b',	'a',  'r',

			0x10, 0x00,			  // String length (intentionally too large)
			'a',  'b',	'c',  'd' // unexpected EOF
		};
		std::istringstream is(input);
		nbt::io::stream_reader reader(is, endian::little);

		TS_ASSERT_EQUALS(reader.get_endian(), endian::little);

		int64_t i;
		reader.read_num(i);
		TS_ASSERT_EQUALS(i, 0x0d0c0b0a09080706);

		TS_ASSERT_EQUALS(reader.read_string(), "foobar");

		TS_ASSERT_THROWS(reader.read_string(), io::input_error);
		TS_ASSERT(!is);
	}

	// Tests if comp equals an extended variant of Notch's bigtest NBT
	void verify_bigtest_structure(const tag_compound& comp)
	{
		TS_ASSERT_EQUALS(comp.size(), 13u);

		TS_ASSERT(comp.at("byteTest") == tag_byte(127));
		TS_ASSERT(comp.at("shortTest") == tag_short(32767));
		TS_ASSERT(comp.at("intTest") == tag_int(2147483647));
		TS_ASSERT(comp.at("longTest") == tag_long(9223372036854775807));
		TS_ASSERT(comp.at("floatTest") ==
				  tag_float(std::stof("0xff1832p-25"))); // 0.4982315
		TS_ASSERT(
			comp.at("doubleTest") ==
			tag_double(std::stod("0x1f8f6bbbff6a5ep-54"))); // 0.493128713218231

		// From bigtest.nbt: "the first 1000 values of (n*n*255+n*7)%100,
		// starting with n=0 (0, 62, 34, 16, 8, ...)"
		tag_byte_array byteArrayTest;
		for (int n = 0; n < 1000; ++n)
			byteArrayTest.push_back((n * n * 255 + n * 7) % 100);
		TS_ASSERT(
			comp.at(
				"byteArrayTest (the first 1000 values of (n*n*255+n*7)%100, "
				"starting with n=0 (0, 62, 34, 16, 8, ...))") == byteArrayTest);

		TS_ASSERT(comp.at("stringTest") ==
				  tag_string(
					  "HELLO WORLD THIS IS A TEST STRING \u00C5\u00C4\u00D6!"));

		TS_ASSERT(comp.at("listTest (compound)") ==
				  tag_list::of<tag_compound>(
					  {{{"created-on", tag_long(1264099775885)},
						{"name", "Compound tag #0"}},
					   {{"created-on", tag_long(1264099775885)},
						{"name", "Compound tag #1"}}}));
		TS_ASSERT(comp.at("listTest (long)") ==
				  tag_list::of<tag_long>({11, 12, 13, 14, 15}));
		TS_ASSERT(comp.at("listTest (end)") == tag_list());

		TS_ASSERT(
			(comp.at("nested compound test") ==
			 tag_compound{
				 {"egg", tag_compound{{"value", 0.5f}, {"name", "Eggbert"}}},
				 {"ham", tag_compound{{"value", 0.75f}, {"name", "Hampus"}}}}));

		TS_ASSERT(
			comp.at("intArrayTest") ==
			tag_int_array({0x00010203, 0x04050607, 0x08090a0b, 0x0c0d0e0f}));
	}

	void test_read_bigtest()
	{
		// Uses an extended variant of Notch's original bigtest file
		std::string input(__binary_bigtest_uncompr_start,
						  __binary_bigtest_uncompr_end);
		std::istringstream file(input, std::ios::binary);

		auto pair = nbt::io::read_compound(file);
		TS_ASSERT_EQUALS(pair.first, "Level");
		verify_bigtest_structure(*pair.second);
	}

	void test_read_littletest()
	{
		// Same as bigtest, but little endian
		std::string input(__binary_littletest_uncompr_start,
						  __binary_littletest_uncompr_end);
		std::istringstream file(input, std::ios::binary);

		auto pair = nbt::io::read_compound(file, endian::little);
		TS_ASSERT_EQUALS(pair.first, "Level");
		TS_ASSERT_EQUALS(pair.second->get_type(), tag_type::Compound);
		verify_bigtest_structure(*pair.second);
	}

	void test_read_eof1()
	{
		std::string input(__binary_errortest_eof1_start,
						  __binary_errortest_eof1_end);
		std::istringstream file(input, std::ios::binary);
		nbt::io::stream_reader reader(file);

		// EOF within a tag_double payload
		TS_ASSERT(file);
		TS_ASSERT_THROWS(reader.read_tag(), io::input_error);
		TS_ASSERT(!file);
	}

	void test_read_eof2()
	{
		std::string input(__binary_errortest_eof2_start,
						  __binary_errortest_eof2_end);
		std::istringstream file(input, std::ios::binary);
		nbt::io::stream_reader reader(file);

		// EOF within a key in a compound
		TS_ASSERT(file);
		TS_ASSERT_THROWS(reader.read_tag(), io::input_error);
		TS_ASSERT(!file);
	}

	void test_read_errortest_noend()
	{
		std::string input(__binary_errortest_noend_start,
						  __binary_errortest_noend_end);
		std::istringstream file(input, std::ios::binary);
		nbt::io::stream_reader reader(file);

		// Missing tag_end
		TS_ASSERT(file);
		TS_ASSERT_THROWS(reader.read_tag(), io::input_error);
		TS_ASSERT(!file);
	}

	void test_read_errortest_neg_length()
	{
		std::string input(__binary_errortest_neg_length_start,
						  __binary_errortest_neg_length_end);
		std::istringstream file(input, std::ios::binary);
		nbt::io::stream_reader reader(file);

		// Negative list length
		TS_ASSERT(file);
		TS_ASSERT_THROWS(reader.read_tag(), io::input_error);
		TS_ASSERT(!file);
	}

	void test_read_misc()
	{
		std::string input(__binary_toplevel_string_start,
						  __binary_toplevel_string_end);
		std::istringstream file(input, std::ios::binary);
		nbt::io::stream_reader reader(file);

		// Toplevel tag other than compound
		TS_ASSERT(file);
		TS_ASSERT_THROWS(reader.read_compound(), io::input_error);
		TS_ASSERT(!file);

		// Rewind and try again with read_tag
		file.clear();
		TS_ASSERT(file.seekg(0));
		auto pair = reader.read_tag();
		TS_ASSERT_EQUALS(pair.first, "Test (toplevel tag_string)");
		TS_ASSERT(*pair.second ==
				  tag_string("Even though unprovided for by NBT, the library "
							 "should also handle "
							 "the case where the file consists of something "
							 "else than tag_compound"));
	}
	void test_read_gzip()
	{
#ifdef NBT_HAVE_ZLIB
		std::string input(__binary_bigtest_nbt_start, __binary_bigtest_nbt_end);
		std::istringstream file(input, std::ios::binary);
		zlib::izlibstream igzs(file);
		TS_ASSERT(file && igzs);

		auto pair = nbt::io::read_compound(igzs);
		TS_ASSERT(igzs);
		TS_ASSERT_EQUALS(pair.first, "Level");
		verify_bigtest_structure(*pair.second);
#endif
	}
};
