// Copyright (c) 2014-2016 Thomas Fussell
// Copyright (c) 2010-2015 openpyxl
//
// 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, WRISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE
//
// @license: http://www.opensource.org/licenses/mit-license.php
// @author: see AUTHORS file

#include <algorithm>
#include <cassert>
#include <cstring>
#include <fstream>
#include <iterator>
#include <miniz.h>

#include <xlnt/packaging/zip_file.hpp>
#include <xlnt/utils/path.hpp>
#include <xlnt/utils/exceptions.hpp>

namespace {

uint32_t crc32buf(const char *buf, std::size_t len)
{
    uint32_t oldcrc32 = 0xFFFFFFFF;

    uint32_t crc_32_tab[] = {
        /* CRC polynomial 0xedb88320 */
        0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832,
        0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
        0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a,
        0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
        0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
        0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
        0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab,
        0xb6662d3d, 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
        0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4,
        0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
        0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074,
        0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
        0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525,
        0x206f85b3, 0xb966d409, 0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
        0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
        0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
        0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76,
        0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
        0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 0x36034af6,
        0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
        0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7,
        0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
        0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7,
        0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
        0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
        0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
        0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c, 0xcabac28a, 0x53b39330,
        0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
        0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
    };

#define UPDC32(octet, crc) (crc_32_tab[((crc) ^ static_cast<uint8_t>(octet)) & 0xff] ^ ((crc) >> 8))

    for (; len; --len, ++buf)
    {
        oldcrc32 = UPDC32(*buf, oldcrc32);
    }

    return ~oldcrc32;
}

tm safe_localtime(const time_t &t)
{
#ifdef _WIN32
    tm time;
    localtime_s(&time, &t);
    return time;
#else
    tm *time = localtime(&t);
    assert(time != nullptr);
    return *time;
#endif
}

std::size_t write_callback(void *opaque, mz_uint64 file_ofs, const void *pBuf, std::size_t n)
{
    auto buffer = static_cast<std::vector<char> *>(opaque);

    if (file_ofs + n > buffer->size())
    {
        auto new_size = static_cast<std::vector<char>::size_type>(file_ofs + n);
        buffer->resize(new_size);
    }

    for (std::size_t i = 0; i < n; i++)
    {
        (*buffer)[static_cast<std::size_t>(file_ofs + i)] = (static_cast<const char *>(pBuf))[i];
    }

    return n;
}

} // namespace

namespace xlnt {

zip_info::zip_info()
    : create_system(0),
      create_version(0),
      extract_version(0),
      flag_bits(0),
      volume(0),
      internal_attr(0),
      external_attr(0),
      header_offset(0),
      crc(0),
      compress_size(0),
      file_size(0)
{
    date_time.year = 1980;
    date_time.month = 0;
    date_time.day = 0;
    date_time.hours = 0;
    date_time.minutes = 0;
    date_time.seconds = 0;
}

zip_file::zip_file() : archive_(new mz_zip_archive())
{
    reset();
}

zip_file::zip_file(const path &filename) : zip_file()
{
    load(filename);
}

zip_file::zip_file(std::istream &stream) : zip_file()
{
    load(stream);
}

zip_file::zip_file(const std::vector<unsigned char> &bytes) : zip_file()
{
    load(bytes);
}

zip_file::~zip_file()
{
    reset();
}

void zip_file::load(std::istream &stream)
{
	if (!stream.good())
	{
		throw invalid_file("((std::istream))");
	}

    reset();
    buffer_.assign(std::istreambuf_iterator<char>(stream), std::istreambuf_iterator<char>());

	if (buffer_.empty())
	{
		throw invalid_file("((stream)) - empty file");
	}

    remove_comment();
    start_read();
}

void zip_file::load(const path &filename)
{
    filename_ = filename;
    std::ifstream stream(filename.to_string(), std::ios::binary);

	if (!stream.good())
	{
		throw invalid_file(filename.to_string());
	}

	reset();
	buffer_.assign(std::istreambuf_iterator<char>(stream), std::istreambuf_iterator<char>());

	if (buffer_.empty())
	{
		throw invalid_file(filename.to_string() + " - empty file");
	}

	remove_comment();
	start_read();
}

void zip_file::load(const std::vector<unsigned char> &bytes)
{
	if (bytes.empty())
	{
		throw invalid_file("((bytes))");
	}

    reset();
    buffer_.assign(bytes.begin(), bytes.end());
    remove_comment();
    start_read();
}

void zip_file::save(const path &filename)
{
    filename_ = filename;
    std::ofstream stream(filename.to_string(), std::ios::binary);
    save(stream);
}

void zip_file::save(std::ostream &stream)
{
    if (archive_->m_zip_mode == MZ_ZIP_MODE_WRITING)
    {
        mz_zip_writer_finalize_archive(archive_.get());
    }

    if (archive_->m_zip_mode == MZ_ZIP_MODE_WRITING_HAS_BEEN_FINALIZED)
    {
        mz_zip_writer_end(archive_.get());
    }

    if (archive_->m_zip_mode == MZ_ZIP_MODE_INVALID)
    {
        start_read();
    }

    append_comment();
    stream.write(buffer_.data(), static_cast<long>(buffer_.size()));
}

void zip_file::save(std::vector<unsigned char> &bytes)
{
    if (archive_->m_zip_mode == MZ_ZIP_MODE_WRITING)
    {
        mz_zip_writer_finalize_archive(archive_.get());
    }

    if (archive_->m_zip_mode == MZ_ZIP_MODE_WRITING_HAS_BEEN_FINALIZED)
    {
        mz_zip_writer_end(archive_.get());
    }

    if (archive_->m_zip_mode == MZ_ZIP_MODE_INVALID)
    {
        start_read();
    }

    append_comment();
    bytes.assign(buffer_.begin(), buffer_.end());
}

void zip_file::append_comment()
{
    if (!comment.empty())
    {
        auto comment_length = std::min(static_cast<uint16_t>(comment.length()), std::numeric_limits<uint16_t>::max());
        buffer_[buffer_.size() - 2] = static_cast<char>(comment_length);
        buffer_[buffer_.size() - 1] = static_cast<char>(comment_length >> 8);
        std::copy(comment.begin(), comment.end(), std::back_inserter(buffer_));
    }
}

void zip_file::remove_comment()
{
    if (buffer_.empty()) return;

    std::size_t position = buffer_.size() - 1;

    for (; position >= 3; position--)
    {
        if (buffer_[position - 3] == 'P' && buffer_[position - 2] == 'K' && buffer_[position - 1] == '\x05' &&
            buffer_[position] == '\x06')
        {
            position = position + 17;
            break;
        }
    }

    if (position <= 3)
    {
        throw std::runtime_error("didn't find end of central directory signature");
    }

    uint16_t length = static_cast<uint16_t>(buffer_[position + 1]);
    length = static_cast<uint16_t>(length << 8) + static_cast<uint16_t>(buffer_[position]);
    position += 2;

    if (length != 0)
    {
        comment = std::string(buffer_.data() + position, buffer_.data() + position + length);
        buffer_.resize(buffer_.size() - length);
        buffer_[buffer_.size() - 1] = 0;
        buffer_[buffer_.size() - 2] = 0;
    }
}

void zip_file::reset()
{
    switch (archive_->m_zip_mode)
    {
    case MZ_ZIP_MODE_READING:
        mz_zip_reader_end(archive_.get());
        break;
    case MZ_ZIP_MODE_WRITING:
        mz_zip_writer_finalize_archive(archive_.get());
        mz_zip_writer_end(archive_.get());
        break;
    default:
        break;
    }

    buffer_.clear();
    comment.clear();

    start_write();
    mz_zip_writer_finalize_archive(archive_.get());
    mz_zip_writer_end(archive_.get());
}

zip_info zip_file::getinfo(const path &name)
{
    if (archive_->m_zip_mode != MZ_ZIP_MODE_READING)
    {
        start_read();
    }

    int index = mz_zip_reader_locate_file(archive_.get(), name.to_string('/').c_str(), nullptr, 0);

    if (index == -1)
    {
        throw std::runtime_error("not found");
    }

    return getinfo(index);
}

zip_info zip_file::getinfo(int index)
{
    if (archive_->m_zip_mode != MZ_ZIP_MODE_READING)
    {
        start_read();
    }

    mz_zip_archive_file_stat stat;
    mz_zip_reader_file_stat(archive_.get(), static_cast<mz_uint>(index), &stat);

    zip_info result;

    result.filename = path(std::string(stat.m_filename, stat.m_filename + std::strlen(stat.m_filename)));
    result.comment = std::string(stat.m_comment, stat.m_comment + stat.m_comment_size);
    result.compress_size = static_cast<std::size_t>(stat.m_comp_size);
    result.file_size = static_cast<std::size_t>(stat.m_uncomp_size);
    result.header_offset = static_cast<std::size_t>(stat.m_local_header_ofs);
    result.crc = stat.m_crc32;
    auto time = safe_localtime(stat.m_time);
    result.date_time.year = 1900 + time.tm_year;
    result.date_time.month = 1 + time.tm_mon;
    result.date_time.day = time.tm_mday;
    result.date_time.hours = time.tm_hour;
    result.date_time.minutes = time.tm_min;
    result.date_time.seconds = time.tm_sec;
    result.flag_bits = stat.m_bit_flag;
    result.internal_attr = stat.m_internal_attr;
    result.external_attr = stat.m_external_attr;
    result.extract_version = stat.m_version_needed;
    result.create_version = stat.m_version_made_by;
    result.volume = stat.m_file_index;
    result.create_system = stat.m_method;

    return result;
}

void zip_file::start_read()
{
    if (archive_->m_zip_mode == MZ_ZIP_MODE_READING) return;

    if (archive_->m_zip_mode == MZ_ZIP_MODE_WRITING)
    {
        mz_zip_writer_finalize_archive(archive_.get());
    }

    if (archive_->m_zip_mode == MZ_ZIP_MODE_WRITING_HAS_BEEN_FINALIZED)
    {
        mz_zip_writer_end(archive_.get());
    }

    if (!mz_zip_reader_init_mem(archive_.get(), buffer_.data(), buffer_.size(), 0))
    {
        throw std::runtime_error("bad zip");
    }
}

void zip_file::start_write()
{
    if (archive_->m_zip_mode == MZ_ZIP_MODE_WRITING) return;

    switch (archive_->m_zip_mode)
    {
    case MZ_ZIP_MODE_READING:
    {
        mz_zip_archive archive_copy;
        std::memset(&archive_copy, 0, sizeof(mz_zip_archive));
        std::vector<char> buffer_copy(buffer_.begin(), buffer_.end());

        if (!mz_zip_reader_init_mem(&archive_copy, buffer_copy.data(), buffer_copy.size(), 0))
        {
            throw std::runtime_error("bad zip");
        }

        mz_zip_reader_end(archive_.get());

        archive_->m_pWrite = &write_callback;
        archive_->m_pIO_opaque = &buffer_;
        buffer_ = std::vector<char>();

        if (!mz_zip_writer_init(archive_.get(), 0))
        {
            throw std::runtime_error("bad zip");
        }

        for (unsigned int i = 0; i < static_cast<unsigned int>(archive_copy.m_total_files); i++)
        {
            if (!mz_zip_writer_add_from_zip_reader(archive_.get(), &archive_copy, i))
            {
                throw std::runtime_error("fail");
            }
        }

        mz_zip_reader_end(&archive_copy);
        return;
    }
    default:
        break;
    }

    archive_->m_pWrite = &write_callback;
    archive_->m_pIO_opaque = &buffer_;

    mz_zip_writer_init(archive_.get(), 0);
}

void zip_file::write_file(const path &filename)
{
	path arcname(filename);

	if (filename.is_absolute())
	{
		arcname = path();
		bool first = true;

		for (auto part : filename)
		{
			if (first)
			{
				first = false;
				continue;
			}

			arcname.append(part);
		}
	}

    write_file(filename, arcname);
}

void zip_file::write_file(const path &filename, const path &arcname)
{
    std::fstream file(filename.to_string(), std::ios::binary | std::ios::in);

    std::stringstream ss;
    ss << file.rdbuf();

    write_string(ss.str(), arcname);
}

void zip_file::write_string(const std::string &bytes, const path &arcname)
{
    if (archive_->m_zip_mode != MZ_ZIP_MODE_WRITING)
    {
        start_write();
    }

    mz_zip_writer_add_mem(archive_.get(), arcname.to_string('/').c_str(),
		bytes.data(), bytes.size(), MZ_BEST_COMPRESSION);
}

void zip_file::write_string(const std::string &bytes, const zip_info &info)
{
    if (info.filename.to_string().empty() || info.date_time.year < 1980)
    {
        throw std::runtime_error("must specify a filename and valid date (year >= 1980");
    }

    if (archive_->m_zip_mode != MZ_ZIP_MODE_WRITING)
    {
        start_write();
    }

    auto crc = crc32buf(bytes.c_str(), bytes.size());

    mz_zip_writer_add_mem_ex(archive_.get(), info.filename.to_string('/').c_str(), bytes.data(), bytes.size(),
        info.comment.c_str(), static_cast<mz_uint16>(info.comment.size()),
        MZ_BEST_COMPRESSION, 0, crc);
}

std::string zip_file::read(const zip_info &info)
{
    std::size_t size;
	void *data_raw = mz_zip_reader_extract_file_to_heap(archive_.get(), 
		info.filename.to_string('/').c_str(), &size, 0);

    if (data_raw == nullptr)
    {
        throw std::runtime_error("file couldn't be read");
    }

	auto data = static_cast<char *>(data_raw);
    std::string extracted(data, data + size);
    mz_free(data);

    return extracted;
}

std::string zip_file::read(const path &name)
{
    return read(getinfo(name));
}

bool zip_file::has_file(const path &name)
{
    if (archive_->m_zip_mode != MZ_ZIP_MODE_READING)
    {
        start_read();
    }

    int index = mz_zip_reader_locate_file(archive_.get(), name.to_string('/').c_str(), nullptr, 0);

    return index != -1;
}

bool zip_file::has_file(const zip_info &name)
{
    return has_file(name.filename);
}

std::vector<zip_info> zip_file::infolist()
{
    if (archive_->m_zip_mode != MZ_ZIP_MODE_READING)
    {
        start_read();
    }

    std::vector<zip_info> info;

    for (std::size_t i = 0; i < mz_zip_reader_get_num_files(archive_.get()); i++)
    {
        info.push_back(getinfo(static_cast<int>(i)));
    }

    return info;
}

std::vector<path> zip_file::namelist()
{
    std::vector<path> names;

    for (auto &info : infolist())
    {
        names.push_back(info.filename);
    }

	return names;
}

std::ostream &zip_file::open(const path &name)
{
    return open(getinfo(name));
}

std::ostream &zip_file::open(const zip_info &name)
{
    auto data = read(name);
    std::string data_string(data.begin(), data.end());
    open_stream_ << data_string;
    return open_stream_;
}

bool zip_file::check_crc()
{
    if (archive_->m_zip_mode == MZ_ZIP_MODE_INVALID)
    {
        throw std::runtime_error("not open");
    }

    for (auto &file : infolist())
    {
        auto content = read(file);
        auto crc = crc32buf(content.c_str(), content.size());

        if (crc != file.crc)
        {
			return true;
        }
    }

    return false;
}

path zip_file::get_filename() const
{
    return filename_;
}

} // namespace xlnt