/*
 * 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_writer.h"
#include "io/stream_reader.h"
#include "nbt_tags.h"
#include <iostream>
#include <fstream>
#include <sstream>

using namespace nbt;

class read_test : public CxxTest::TestSuite
{
public:
    void test_stream_writer_big()
    {
        std::ostringstream os;
        nbt::io::stream_writer writer(os);

        TS_ASSERT_EQUALS(&writer.get_ostr(), &os);
        TS_ASSERT_EQUALS(writer.get_endian(), endian::big);

        writer.write_type(tag_type::End);
        writer.write_type(tag_type::Long);
        writer.write_type(tag_type::Int_Array);

        writer.write_num(int64_t(0x0102030405060708));

        writer.write_string("foobar");

        TS_ASSERT(os);
        std::string expected{
            0, //tag_type::End
            4, //tag_type::Long
            11, //tag_type::Int_Array

            0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, //0x0102030405060708 in Big Endian

            0x00, 0x06, //string length in Big Endian
            'f', 'o', 'o', 'b', 'a', 'r'
        };
        TS_ASSERT_EQUALS(os.str(), expected);

        //too long for NBT
        TS_ASSERT_THROWS(writer.write_string(std::string(65536, '.')), std::length_error);
        TS_ASSERT(!os);
    }

    void test_stream_writer_little()
    {
        std::ostringstream os;
        nbt::io::stream_writer writer(os, endian::little);

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

        writer.write_num(int32_t(0x0a0b0c0d));

        writer.write_string("foobar");

        TS_ASSERT(os);
        std::string expected{
            0x0d, 0x0c, 0x0b, 0x0a, //0x0a0b0c0d in Little Endian

            0x06, 0x00, //string length in Little Endian
            'f', 'o', 'o', 'b', 'a', 'r'
        };
        TS_ASSERT_EQUALS(os.str(), expected);

        TS_ASSERT_THROWS(writer.write_string(std::string(65536, '.')), std::length_error);
        TS_ASSERT(!os);
    }

    void test_write_payload_big()
    {
        std::ostringstream os;
        nbt::io::stream_writer writer(os);

        //tag_primitive
        writer.write_payload(tag_byte(127));
        writer.write_payload(tag_short(32767));
        writer.write_payload(tag_int(2147483647));
        writer.write_payload(tag_long(9223372036854775807));

        //Same values as in endian_str_test
        writer.write_payload(tag_float(std::stof("-0xCDEF01p-63")));
        writer.write_payload(tag_double(std::stod("-0x1DEF0102030405p-375")));

        TS_ASSERT_EQUALS(os.str(), (std::string{
            '\x7F',
            '\x7F', '\xFF',
            '\x7F', '\xFF', '\xFF', '\xFF',
            '\x7F', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF',

            '\xAB', '\xCD', '\xEF', '\x01',
            '\xAB', '\xCD', '\xEF', '\x01', '\x02', '\x03', '\x04', '\x05'
        }));
        os.str(""); //clear and reuse the stream

        //tag_string
        writer.write_payload(tag_string("barbaz"));
        TS_ASSERT_EQUALS(os.str(), (std::string{
            0x00, 0x06, //string length in Big Endian
            'b', 'a', 'r', 'b', 'a', 'z'
        }));
        TS_ASSERT_THROWS(writer.write_payload(tag_string(std::string(65536, '.'))), std::length_error);
        TS_ASSERT(!os);
        os.clear();

        //tag_byte_array
        os.str("");
        writer.write_payload(tag_byte_array{0, 1, 127, -128, -127});
        TS_ASSERT_EQUALS(os.str(), (std::string{
            0x00, 0x00, 0x00, 0x05, //length in Big Endian
            0, 1, 127, -128, -127
        }));
        os.str("");

        //tag_int_array
        writer.write_payload(tag_int_array{0x01020304, 0x05060708, 0x090a0b0c});
        TS_ASSERT_EQUALS(os.str(), (std::string{
            0x00, 0x00, 0x00, 0x03, //length in Big Endian
            0x01, 0x02, 0x03, 0x04,
            0x05, 0x06, 0x07, 0x08,
            0x09, 0x0a, 0x0b, 0x0c
        }));
        os.str("");

        //tag_list
        writer.write_payload(tag_list()); //empty list with undetermined type, should be written as list of tag_end
        writer.write_payload(tag_list(tag_type::Int)); //empty list of tag_int
        writer.write_payload(tag_list{ //nested list
            tag_list::of<tag_short>({0x3456, 0x789a}),
            tag_list::of<tag_byte>({0x0a, 0x0b, 0x0c, 0x0d})
        });
        TS_ASSERT_EQUALS(os.str(), (std::string{
            0, //tag_type::End
            0x00, 0x00, 0x00, 0x00, //length

            3, //tag_type::Int
            0x00, 0x00, 0x00, 0x00, //length

            9, //tag_type::List
            0x00, 0x00, 0x00, 0x02, //length
            //list 0
            2, //tag_type::Short
            0x00, 0x00, 0x00, 0x02, //length
            '\x34', '\x56',
            '\x78', '\x9a',
            //list 1
            1, //tag_type::Byte
            0x00, 0x00, 0x00, 0x04, //length
            0x0a,
            0x0b,
            0x0c,
            0x0d
        }));
        os.str("");

        //tag_compound
        /* Testing if writing compounds works properly is problematic because the
        order of the tags is not guaranteed. However with only two tags in a
        compound we only have two possible orderings.
        See below for a more thorough test that uses writing and re-reading. */
        writer.write_payload(tag_compound{});
        writer.write_payload(tag_compound{
            {"foo", "quux"},
            {"bar", tag_int(0x789abcde)}
        });

        std::string endtag{0x00};
        std::string subtag1{
            8, //tag_type::String
            0x00, 0x03, //key length
            'f', 'o', 'o',
            0x00, 0x04, //string length
            'q', 'u', 'u', 'x'
        };
        std::string subtag2{
            3, //tag_type::Int
            0x00, 0x03, //key length
            'b', 'a', 'r',
            '\x78', '\x9A', '\xBC', '\xDE'
        };

        TS_ASSERT(os.str() == endtag + subtag1 + subtag2 + endtag
               || os.str() == endtag + subtag2 + subtag1 + endtag);

        //Now for write_tag:
        os.str("");
        writer.write_tag("foo", tag_string("quux"));
        TS_ASSERT_EQUALS(os.str(), subtag1);
        TS_ASSERT(os);

        //too long key for NBT
        TS_ASSERT_THROWS(writer.write_tag(std::string(65536, '.'), tag_long(-1)), std::length_error);
        TS_ASSERT(!os);
    }

    void test_write_bigtest()
    {
        /* Like already stated above, because no order is guaranteed for
        tag_compound, we cannot simply test it by writing into a stream and directly
        comparing the output to a reference value.
        Instead, we assume that reading already works correctly and re-read the
        written tag.
        Smaller-grained tests are already done above. */
        std::ifstream file("bigtest_uncompr", std::ios::binary);
        const auto orig_pair = io::read_compound(file);
        std::stringstream sstr;

        //Write into stream in Big Endian
        io::write_tag(orig_pair.first, *orig_pair.second, sstr);
        TS_ASSERT(sstr);

        //Read from stream in Big Endian and compare
        auto written_pair = io::read_compound(sstr);
        TS_ASSERT_EQUALS(orig_pair.first, written_pair.first);
        TS_ASSERT(*orig_pair.second == *written_pair.second);

        sstr.str(""); //Reset and reuse stream
        //Write into stream in Little Endian
        io::write_tag(orig_pair.first, *orig_pair.second, sstr, endian::little);
        TS_ASSERT(sstr);

        //Read from stream in Little Endian and compare
        written_pair = io::read_compound(sstr, endian::little);
        TS_ASSERT_EQUALS(orig_pair.first, written_pair.first);
        TS_ASSERT(*orig_pair.second == *written_pair.second);
    }
};