#include <algorithm>
#include <cstring>
#include <iterator>
#include <fstream>

#include <miniz.h>

#ifdef _WIN32
#define NOMINMAX
#include <Windows.h>
#else

#endif

#include <xlnt/common/zip_file.hpp>

namespace {

std::string get_working_directory()
{
#ifdef _WIN32
    TCHAR buffer[MAX_PATH];
    GetCurrentDirectory(MAX_PATH, buffer);
    std::wstring working_directory(buffer);
    return std::string(working_directory.begin(), working_directory.end());
#else
    return "";
#endif
}
    
#ifdef _WIN32
char directory_separator = '\\';
char alt_directory_separator = '/';
#else
char directory_separator = '/';
char alt_directory_separator = '\\';
#endif
    
std::string join_path(const std::vector<std::string> &parts)
{
    std::string joined;
    std::size_t i = 0;
    for(auto part : parts)
    {
        joined.append(part);
        
        if(i++ != parts.size() - 1)
        {
            joined.append(1, '/');
        }
    }
    return joined;
}
    
std::vector<std::string> split_path(const std::string &path, char delim = directory_separator)
{
    std::vector<std::string> split;
    std::string::size_type previous_index = 0;
    auto separator_index = path.find(delim);
    
    while(separator_index != std::string::npos)
    {
        auto part = path.substr(previous_index, separator_index - previous_index);
        if(part != "..")
        {
            split.push_back(part);
        }
        else
        {
            split.pop_back();
        }
        previous_index = separator_index + 1;
        separator_index = path.find(delim, previous_index);
    }
    
    split.push_back(path.substr(previous_index));

    if(split.size() == 1 && delim == directory_separator)
    {
        auto alternative = split_path(path, alt_directory_separator);
        if(alternative.size() > 1)
        {
            return alternative;
        }
    }
    
    return split;
}
    
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)\
^ ((uint8_t)octet)) & 0xff] ^ ((crc) >> 8))
    
    for ( ; len; --len, ++buf)
    {
        oldcrc32 = UPDC32(*buf, oldcrc32);
    }
    
    return ~oldcrc32;
}

} // namespace

namespace  xlnt {

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

zip_file::zip_file(const std::string &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)
{
    reset();
    buffer_.assign(std::istreambuf_iterator<char>(stream), std::istreambuf_iterator<char>());
    remove_comment();
    start_read();
}

void zip_file::load(const std::string &filename)
{
    filename_ = filename;
    std::ifstream stream(filename, std::ios::binary);
    load(stream);
}

void zip_file::load(const std::vector<unsigned char> &bytes)
{
    reset();
    buffer_.assign(bytes.begin(), bytes.end());
    remove_comment();
    start_read();
}

void zip_file::save(const std::string &filename)
{
    filename_ = filename;
    std::ofstream stream(filename, 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(), 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((uint16_t)comment.length(), std::numeric_limits<uint16_t>::max());
        buffer_[buffer_.size() - 2] = comment_length & 0xFF;
        buffer_[buffer_.size() - 1] = comment_length >> 8 & 0xFF;
        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 = buffer_[position + 1];
    length = (length << 8) + 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;
    case MZ_ZIP_MODE_WRITING_HAS_BEEN_FINALIZED:
        mz_zip_writer_end(archive_.get());
        break;
    case MZ_ZIP_MODE_INVALID:
        break;
    }
    
    if(archive_->m_zip_mode != MZ_ZIP_MODE_INVALID)
    {
        throw std::runtime_error("");
    }

    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 std::string &name)
{
    if(archive_->m_zip_mode != MZ_ZIP_MODE_READING)
    {
        start_read();
    }

    int index = mz_zip_reader_locate_file(archive_.get(), name.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(), index, &stat);

    zip_info result;

    result.filename = 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 = (std::size_t)stat.m_comp_size;
    result.file_size = (std::size_t)stat.m_uncomp_size;
    result.header_offset = (std::size_t)stat.m_local_header_ofs;
    result.crc = stat.m_crc32;
    tm *time = 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");
    }
}

std::size_t write_callback(void *opaque, mz_uint64 file_ofs, const void *pBuf, std::size_t n)
{
    auto buffer = (std::vector<char> *)opaque;
    
    if(file_ofs + n > buffer->size())
    {
        buffer->resize(file_ofs + n);
    }

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

    return n;
}

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(int i = 0; i < (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;
        }
        case MZ_ZIP_MODE_WRITING_HAS_BEEN_FINALIZED:
            mz_zip_writer_end(archive_.get());
            break;
        default:
            break;
    }

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

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

void zip_file::write(const std::string &filename)
{
    auto split = split_path(filename);
    if(split.size() > 1)
    {
        split.erase(split.begin());
    }
    auto arcname = join_path(split);
    write(filename, arcname);
}

void zip_file::write(const std::string &filename, const std::string &arcname)
{
    std::fstream file(filename, std::ios::binary | std::ios::in);
    std::stringstream ss;
    ss << file.rdbuf();
    std::string bytes = ss.str();

    writestr(arcname, bytes);
}

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

    if(!mz_zip_writer_add_mem(archive_.get(), arcname.c_str(), bytes.data(), bytes.size(), MZ_BEST_COMPRESSION))
    {
        throw std::runtime_error("write error");
    }
}

void zip_file::writestr(const zip_info &info, const std::string &bytes)
{
    if(info.filename.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());
    
    if(!mz_zip_writer_add_mem_ex(archive_.get(), info.filename.c_str(), bytes.data(), bytes.size(), info.comment.c_str(), (mz_uint16)info.comment.size(), MZ_BEST_COMPRESSION, 0, crc))
    {
        throw std::runtime_error("write error");
    }
}

std::string zip_file::read(const zip_info &info)
{
    std::size_t size;
    char *data = (char *)mz_zip_reader_extract_file_to_heap(archive_.get(), info.filename.c_str(), &size, 0);
    if(data == nullptr)
    {
	throw std::runtime_error("file couldn't be read");
    }
    std::string extracted(data, data + size);
    mz_free(data);
    return extracted;
}

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

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

    int index = mz_zip_reader_locate_file(archive_.get(), name.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((int)i));
    }

    return info;
}

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

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

    return names;
}

std::ostream &zip_file::open(const std::string &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_;
}

void zip_file::extract(const std::string &member)
{
    extract(member, get_working_directory());
}

void zip_file::extract(const std::string &member, const std::string &path)
{
    std::fstream stream(join_path({path, member}), std::ios::binary | std::ios::out);
    stream << open(member).rdbuf();
}

void zip_file::extract(const zip_info &member)
{
    extract(member, get_working_directory());
}

void zip_file::extract(const zip_info &member, const std::string &path)
{
    std::fstream stream(join_path({path, member.filename}), std::ios::binary | std::ios::out);
    stream << open(member).rdbuf();
}

void zip_file::extractall(const std::string &path)
{
    extractall(path, infolist());
}

void zip_file::extractall(const std::string &path, const std::vector<std::string> &members)
{
    for(auto &member : members)
    {
        extract(member, path);
    }
}

void zip_file::extractall(const std::string &path, const std::vector<zip_info> &members)
{
    for(auto &member : members)
    {
        extract(member, path);
    }
}

void zip_file::printdir()
{
    printdir(std::cout);
}

void zip_file::printdir(std::ostream &stream)
{
    stream << "  Length " << "  " << "   " << "Date" << "   " << " " << "Time " << "   " << "Name" << std::endl;
    stream << "---------  ---------- -----   ----" << std::endl;
    
    std::size_t sum_length = 0;
    std::size_t file_count = 0;

    for(auto &member : infolist())
    {
        sum_length += member.file_size;
        file_count++;

        std::string length_string = std::to_string(member.file_size);
        while(length_string.length() < 9)
        {
            length_string = " " + length_string;
        }
        stream << length_string;

        stream << "  ";
        stream << (member.date_time.month < 10 ? "0" : "") << member.date_time.month;
        stream << "/";
        stream << (member.date_time.day < 10 ? "0" : "") << member.date_time.day;
        stream << "/";
        stream << member.date_time.year;
        stream << " ";
        stream << (member.date_time.hours < 10 ? "0" : "") << member.date_time.hours;
        stream << ":";
        stream << (member.date_time.minutes < 10 ? "0" : "") << member.date_time.minutes;
        stream << "   ";
        stream << member.filename;
        stream << std::endl;
    }

    stream << "---------                     -------" << std::endl;

    std::string length_string = std::to_string(sum_length);
    while(length_string.length() < 9)
    {
        length_string = " " + length_string;
    }
    stream << length_string << "                     " << file_count << " " << (file_count == 1 ? "file" : "files");
    stream << std::endl;
}

std::pair<bool, std::string> zip_file::testzip()
{
    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 {false, file.filename};
        }
    }

    return {true, ""};
}

} // namespace xlnt