//! The encoder and decoder of the ZLIB format.
//!
//! The ZLIB format is defined in [RFC-1950](https://tools.ietf.org/html/rfc1950).
//!
//! # Examples
//! ```
//! use std::io::{self, Read};
//! use libflate::zlib::{Encoder, Decoder};
//!
//! // Encoding
//! let mut encoder = Encoder::new(Vec::new()).unwrap();
//! io::copy(&mut &b"Hello World!"[..], &mut encoder).unwrap();
//! let encoded_data = encoder.finish().into_result().unwrap();
//!
//! // Decoding
//! let mut decoder = Decoder::new(&encoded_data[..]).unwrap();
//! let mut decoded_data = Vec::new();
//! decoder.read_to_end(&mut decoded_data).unwrap();
//!
//! assert_eq!(decoded_data, b"Hello World!");
//! ```
use crate::checksum;
use crate::deflate;
use crate::finish::{Complete, Finish};
use crate::lz77;
use std::io;

const COMPRESSION_METHOD_DEFLATE: u8 = 8;

/// Compression levels defined by the ZLIB format.
#[derive(Debug, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]
pub enum CompressionLevel {
    /// Compressor used fastest algorithm.
    Fastest = 0,

    /// Compressor used fast algorithm.
    Fast = 1,

    /// Compressor used default algorithm.
    Default = 2,

    /// Compressor used maximum compression, slowest algorithm.
    Slowest = 3,
}
impl CompressionLevel {
    fn from_u2(level: u8) -> Self {
        match level {
            0 => CompressionLevel::Fastest,
            1 => CompressionLevel::Fast,
            2 => CompressionLevel::Default,
            3 => CompressionLevel::Slowest,
            _ => unreachable!(),
        }
    }
    fn as_u2(&self) -> u8 {
        self.clone() as u8
    }
}
impl From<lz77::CompressionLevel> for CompressionLevel {
    fn from(f: lz77::CompressionLevel) -> Self {
        match f {
            lz77::CompressionLevel::None => CompressionLevel::Fastest,
            lz77::CompressionLevel::Fast => CompressionLevel::Fast,
            lz77::CompressionLevel::Balance => CompressionLevel::Default,
            lz77::CompressionLevel::Best => CompressionLevel::Slowest,
        }
    }
}

/// LZ77 Window sizes defined by the ZLIB format.
#[derive(Debug, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]
pub enum Lz77WindowSize {
    /// 256 bytes
    B256 = 0,

    /// 512 btyes
    B512 = 1,

    /// 1 kilobyte
    KB1 = 2,

    /// 2 kilobytes
    KB2 = 3,

    /// 4 kitobytes
    KB4 = 4,

    /// 8 kitobytes
    KB8 = 5,

    /// 16 kitobytes
    KB16 = 6,

    /// 32 kitobytes
    KB32 = 7,
}
impl Lz77WindowSize {
    fn from_u4(compression_info: u8) -> Option<Self> {
        match compression_info {
            0 => Some(Lz77WindowSize::B256),
            1 => Some(Lz77WindowSize::B512),
            2 => Some(Lz77WindowSize::KB1),
            3 => Some(Lz77WindowSize::KB2),
            4 => Some(Lz77WindowSize::KB4),
            5 => Some(Lz77WindowSize::KB8),
            6 => Some(Lz77WindowSize::KB16),
            7 => Some(Lz77WindowSize::KB32),
            _ => None,
        }
    }
    fn as_u4(&self) -> u8 {
        self.clone() as u8
    }

    /// Converts from `u16` to Lz77WindowSize`.
    ///
    /// Fractions are rounded to next upper window size.
    /// If `size` exceeds maximum window size,
    /// `lz77::MAX_WINDOW_SIZE` will be used instead.
    ///
    /// # Examples
    /// ```
    /// use libflate::zlib::Lz77WindowSize;
    ///
    /// assert_eq!(Lz77WindowSize::from_u16(15000), Lz77WindowSize::KB16);
    /// assert_eq!(Lz77WindowSize::from_u16(16384), Lz77WindowSize::KB16);
    /// assert_eq!(Lz77WindowSize::from_u16(16385), Lz77WindowSize::KB32);
    /// assert_eq!(Lz77WindowSize::from_u16(40000), Lz77WindowSize::KB32);
    /// ```
    pub fn from_u16(size: u16) -> Self {
        use self::Lz77WindowSize::*;
        if 16_384 < size {
            KB32
        } else if 8192 < size {
            KB16
        } else if 4096 < size {
            KB8
        } else if 2048 < size {
            KB4
        } else if 1024 < size {
            KB2
        } else if 512 < size {
            KB1
        } else if 256 < size {
            B512
        } else {
            B256
        }
    }

    /// Converts from `Lz77WindowSize` to `u16`.
    ///
    /// # Examples
    /// ```
    /// use libflate::zlib::Lz77WindowSize;
    ///
    /// assert_eq!(Lz77WindowSize::KB16.to_u16(), 16384u16);
    /// ```
    pub fn to_u16(&self) -> u16 {
        use self::Lz77WindowSize::*;
        match *self {
            B256 => 256,
            B512 => 512,
            KB1 => 1024,
            KB2 => 2048,
            KB4 => 4096,
            KB8 => 8192,
            KB16 => 16_384,
            KB32 => 32_768,
        }
    }
}

/// ZLIB header.
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct Header {
    window_size: Lz77WindowSize,
    compression_level: CompressionLevel,
}
impl Header {
    /// Returns the LZ77 window size stored in the header.
    pub fn window_size(&self) -> Lz77WindowSize {
        self.window_size.clone()
    }
    /// Returns the compression level stored in the header.
    pub fn compression_level(&self) -> CompressionLevel {
        self.compression_level.clone()
    }
    fn from_lz77<E>(lz77: &E) -> Self
    where
        E: lz77::Lz77Encode,
    {
        Header {
            compression_level: From::from(lz77.compression_level()),
            window_size: Lz77WindowSize::from_u16(lz77.window_size()),
        }
    }
    pub(crate) fn read_from<R>(mut reader: R) -> io::Result<Self>
    where
        R: io::Read,
    {
        let mut buf = [0; 2];
        reader.read_exact(&mut buf)?;
        let (cmf, flg) = (buf[0], buf[1]);
        let check = (u16::from(cmf) << 8) + u16::from(flg);
        if check % 31 != 0 {
            return Err(invalid_data_error!(
                "Inconsistent ZLIB check bits: `CMF({}) * 256 + \
                 FLG({})` must be a multiple of 31",
                cmf,
                flg
            ));
        }

        let compression_method = cmf & 0b1111;
        let compression_info = cmf >> 4;
        if compression_method != COMPRESSION_METHOD_DEFLATE {
            return Err(invalid_data_error!(
                "Compression methods other than DEFLATE(8) are \
                 unsupported: method={}",
                compression_method
            ));
        }
        let window_size = Lz77WindowSize::from_u4(compression_info).ok_or_else(|| {
            invalid_data_error!("CINFO above 7 are not allowed: value={}", compression_info)
        })?;

        let dict_flag = (flg & 0b100_000) != 0;
        if dict_flag {
            let mut buf = [0; 4];
            reader.read_exact(&mut buf)?;
            let dictionary_id = u32::from_be_bytes(buf);
            return Err(invalid_data_error!(
                "Preset dictionaries are not supported: \
                 dictionary_id=0x{:X}",
                dictionary_id
            ));
        }
        let compression_level = CompressionLevel::from_u2(flg >> 6);
        Ok(Header {
            window_size,
            compression_level,
        })
    }
    fn write_to<W>(&self, mut writer: W) -> io::Result<()>
    where
        W: io::Write,
    {
        let cmf = (self.window_size.as_u4() << 4) | COMPRESSION_METHOD_DEFLATE;
        let mut flg = self.compression_level.as_u2() << 6;
        let check = (u16::from(cmf) << 8) + u16::from(flg);
        if check % 31 != 0 {
            flg += (31 - check % 31) as u8;
        }
        writer.write_all(&[cmf, flg])?;
        Ok(())
    }
}

/// ZLIB decoder.
#[derive(Debug)]
pub struct Decoder<R> {
    header: Header,
    reader: deflate::Decoder<R>,
    adler32: checksum::Adler32,
    eos: bool,
}
impl<R> Decoder<R>
where
    R: io::Read,
{
    /// Makes a new decoder instance.
    ///
    /// `inner` is to be decoded ZLIB stream.
    ///
    /// # Examples
    /// ```
    /// use std::io::Read;
    /// use libflate::zlib::Decoder;
    ///
    /// let encoded_data = [120, 156, 243, 72, 205, 201, 201, 87, 8, 207, 47,
    ///                     202, 73, 81, 4, 0, 28, 73, 4, 62];
    ///
    /// let mut decoder = Decoder::new(&encoded_data[..]).unwrap();
    /// let mut buf = Vec::new();
    /// decoder.read_to_end(&mut buf).unwrap();
    ///
    /// assert_eq!(buf, b"Hello World!");
    /// ```
    pub fn new(mut inner: R) -> io::Result<Self> {
        let header = Header::read_from(&mut inner)?;
        Ok(Decoder {
            header,
            reader: deflate::Decoder::new(inner),
            adler32: checksum::Adler32::new(),
            eos: false,
        })
    }

    /// Returns the header of the ZLIB stream.
    ///
    /// # Examples
    /// ```
    /// use libflate::zlib::{Decoder, CompressionLevel};
    ///
    /// let encoded_data = [120, 156, 243, 72, 205, 201, 201, 87, 8, 207, 47,
    ///                     202, 73, 81, 4, 0, 28, 73, 4, 62];
    ///
    /// let decoder = Decoder::new(&encoded_data[..]).unwrap();
    /// assert_eq!(decoder.header().compression_level(),
    ///            CompressionLevel::Default);
    /// ```
    pub fn header(&self) -> &Header {
        &self.header
    }

    /// Returns the immutable reference to the inner stream.
    pub fn as_inner_ref(&self) -> &R {
        self.reader.as_inner_ref()
    }

    /// Returns the mutable reference to the inner stream.
    pub fn as_inner_mut(&mut self) -> &mut R {
        self.reader.as_inner_mut()
    }

    /// Unwraps this `Decoder`, returning the underlying reader.
    ///
    /// # Examples
    /// ```
    /// use std::io::Cursor;
    /// use libflate::zlib::Decoder;
    ///
    /// let encoded_data = [120, 156, 243, 72, 205, 201, 201, 87, 8, 207, 47,
    ///                     202, 73, 81, 4, 0, 28, 73, 4, 62];
    ///
    /// let decoder = Decoder::new(Cursor::new(&encoded_data)).unwrap();
    /// assert_eq!(decoder.into_inner().into_inner(), &encoded_data);
    /// ```
    pub fn into_inner(self) -> R {
        self.reader.into_inner()
    }
}
impl<R> io::Read for Decoder<R>
where
    R: io::Read,
{
    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
        if self.eos {
            Ok(0)
        } else {
            let read_size = self.reader.read(buf)?;
            if read_size == 0 {
                self.eos = true;
                let mut buf = [0; 4];
                self.reader.as_inner_mut().read_exact(&mut buf)?;
                let adler32 = u32::from_be_bytes(buf);

                // checksum verification is skipped during fuzzing
                // so that random data from fuzzer can reach actually interesting code
                // Compilation flag 'fuzzing' is automatically set by all 3 Rust fuzzers.
                if cfg!(not(fuzzing)) && adler32 != self.adler32.value() {
                    Err(invalid_data_error!(
                        "Adler32 checksum mismatched: value={}, expected={}",
                        self.adler32.value(),
                        adler32
                    ))
                } else {
                    Ok(0)
                }
            } else {
                self.adler32.update(&buf[..read_size]);
                Ok(read_size)
            }
        }
    }
}

/// Options for a ZLIB encoder.
#[derive(Debug)]
pub struct EncodeOptions<E>
where
    E: lz77::Lz77Encode,
{
    header: Header,
    options: deflate::EncodeOptions<E>,
}
impl Default for EncodeOptions<lz77::DefaultLz77Encoder> {
    fn default() -> Self {
        EncodeOptions {
            header: Header::from_lz77(&lz77::DefaultLz77Encoder::new()),
            options: Default::default(),
        }
    }
}
impl EncodeOptions<lz77::DefaultLz77Encoder> {
    /// Makes a default instance.
    ///
    /// # Examples
    /// ```
    /// use libflate::zlib::{Encoder, EncodeOptions};
    ///
    /// let options = EncodeOptions::new();
    /// let encoder = Encoder::with_options(Vec::new(), options).unwrap();
    /// ```
    pub fn new() -> Self {
        Self::default()
    }
}
impl<E> EncodeOptions<E>
where
    E: lz77::Lz77Encode,
{
    /// Specifies the LZ77 encoder used to compress input data.
    ///
    /// # Example
    /// ```
    /// use libflate::lz77::DefaultLz77Encoder;
    /// use libflate::zlib::{Encoder, EncodeOptions};
    ///
    /// let options = EncodeOptions::with_lz77(DefaultLz77Encoder::new());
    /// let encoder = Encoder::with_options(Vec::new(), options).unwrap();
    /// ```
    pub fn with_lz77(lz77: E) -> Self {
        EncodeOptions {
            header: Header::from_lz77(&lz77),
            options: deflate::EncodeOptions::with_lz77(lz77),
        }
    }

    /// Disables LZ77 compression.
    ///
    /// # Example
    /// ```
    /// use libflate::lz77::DefaultLz77Encoder;
    /// use libflate::zlib::{Encoder, EncodeOptions};
    ///
    /// let options = EncodeOptions::new().no_compression();
    /// let encoder = Encoder::with_options(Vec::new(), options).unwrap();
    /// ```
    pub fn no_compression(mut self) -> Self {
        self.options = self.options.no_compression();
        self.header.compression_level = CompressionLevel::Fastest;
        self
    }

    /// Specifies the hint of the size of a DEFLATE block.
    ///
    /// The default value is `deflate::DEFAULT_BLOCK_SIZE`.
    ///
    /// # Example
    /// ```
    /// use libflate::zlib::{Encoder, EncodeOptions};
    ///
    /// let options = EncodeOptions::new().block_size(512 * 1024);
    /// let encoder = Encoder::with_options(Vec::new(), options).unwrap();
    /// ```
    pub fn block_size(mut self, size: usize) -> Self {
        self.options = self.options.block_size(size);
        self
    }

    /// Specifies to compress with fixed huffman codes.
    ///
    /// # Example
    /// ```
    /// use libflate::zlib::{Encoder, EncodeOptions};
    ///
    /// let options = EncodeOptions::new().fixed_huffman_codes();
    /// let encoder = Encoder::with_options(Vec::new(), options).unwrap();
    /// ```
    pub fn fixed_huffman_codes(mut self) -> Self {
        self.options = self.options.fixed_huffman_codes();
        self
    }
}

/// ZLIB encoder.
#[derive(Debug)]
pub struct Encoder<W, E = lz77::DefaultLz77Encoder> {
    header: Header,
    writer: deflate::Encoder<W, E>,
    adler32: checksum::Adler32,
}
impl<W> Encoder<W, lz77::DefaultLz77Encoder>
where
    W: io::Write,
{
    /// Makes a new encoder instance.
    ///
    /// Encoded ZLIB stream is written to `inner`.
    ///
    /// # Examples
    /// ```
    /// use std::io::Write;
    /// use libflate::zlib::Encoder;
    ///
    /// let mut encoder = Encoder::new(Vec::new()).unwrap();
    /// encoder.write_all(b"Hello World!").unwrap();
    ///
    /// assert_eq!(encoder.finish().into_result().unwrap(),
    ///            vec![120, 156, 5, 192, 49, 13, 0, 0, 8, 3, 65, 43, 224, 6, 7, 24, 128,
    ///                 237, 147, 38, 245, 63, 244, 230, 65, 181, 50, 215, 1, 28, 73, 4, 62]);
    /// ```
    pub fn new(inner: W) -> io::Result<Self> {
        Self::with_options(inner, EncodeOptions::default())
    }
}
impl<W, E> Encoder<W, E>
where
    W: io::Write,
    E: lz77::Lz77Encode,
{
    /// Makes a new encoder instance with specified options.
    ///
    /// Encoded ZLIB stream is written to `inner`.
    ///
    /// # Examples
    /// ```
    /// use std::io::Write;
    /// use libflate::zlib::{Encoder, EncodeOptions};
    ///
    /// let options = EncodeOptions::new().no_compression();
    /// let mut encoder = Encoder::with_options(Vec::new(), options).unwrap();
    /// encoder.write_all(b"Hello World!").unwrap();
    ///
    /// assert_eq!(encoder.finish().into_result().unwrap(),
    ///            [120, 1, 1, 12, 0, 243, 255, 72, 101, 108, 108, 111, 32, 87, 111,
    ///             114, 108, 100, 33, 28, 73, 4, 62]);
    /// ```
    pub fn with_options(mut inner: W, options: EncodeOptions<E>) -> io::Result<Self> {
        options.header.write_to(&mut inner)?;
        Ok(Encoder {
            header: options.header,
            writer: deflate::Encoder::with_options(inner, options.options),
            adler32: checksum::Adler32::new(),
        })
    }

    /// Returns the header of the ZLIB stream.
    ///
    /// # Examples
    /// ```
    /// use libflate::zlib::{Encoder, Lz77WindowSize};
    ///
    /// let encoder = Encoder::new(Vec::new()).unwrap();
    /// assert_eq!(encoder.header().window_size(), Lz77WindowSize::KB32);
    /// ```
    pub fn header(&self) -> &Header {
        &self.header
    }

    /// Writes the ZLIB trailer and returns the inner stream.
    ///
    /// # Examples
    /// ```
    /// use std::io::Write;
    /// use libflate::zlib::Encoder;
    ///
    /// let mut encoder = Encoder::new(Vec::new()).unwrap();
    /// encoder.write_all(b"Hello World!").unwrap();
    ///
    /// assert_eq!(encoder.finish().into_result().unwrap(),
    ///            vec![120, 156, 5, 192, 49, 13, 0, 0, 8, 3, 65, 43, 224, 6, 7, 24, 128,
    ///                 237, 147, 38, 245, 63, 244, 230, 65, 181, 50, 215, 1, 28, 73, 4, 62]);
    /// ```
    ///
    /// # Note
    ///
    /// If you are not concerned the result of this encoding,
    /// it may be convenient to use `AutoFinishUnchecked` instead of the explicit invocation of this method.
    ///
    /// ```
    /// use std::io;
    /// use libflate::finish::AutoFinishUnchecked;
    /// use libflate::zlib::Encoder;
    ///
    /// let plain = b"Hello World!";
    /// let mut buf = Vec::new();
    /// let mut encoder = AutoFinishUnchecked::new(Encoder::new(&mut buf).unwrap());
    /// io::copy(&mut &plain[..], &mut encoder).unwrap();
    /// ```
    pub fn finish(self) -> Finish<W, io::Error> {
        let mut inner = finish_try!(self.writer.finish());
        match inner
            .write_all(&self.adler32.value().to_be_bytes())
            .and_then(|_| inner.flush())
        {
            Ok(_) => Finish::new(inner, None),
            Err(e) => Finish::new(inner, Some(e)),
        }
    }

    /// Returns the immutable reference to the inner stream.
    pub fn as_inner_ref(&self) -> &W {
        self.writer.as_inner_ref()
    }

    /// Returns the mutable reference to the inner stream.
    pub fn as_inner_mut(&mut self) -> &mut W {
        self.writer.as_inner_mut()
    }

    /// Unwraps the `Encoder`, returning the inner stream.
    pub fn into_inner(self) -> W {
        self.writer.into_inner()
    }
}
impl<W, E> io::Write for Encoder<W, E>
where
    W: io::Write,
    E: lz77::Lz77Encode,
{
    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
        let written_size = self.writer.write(buf)?;
        self.adler32.update(&buf[..written_size]);
        Ok(written_size)
    }
    fn flush(&mut self) -> io::Result<()> {
        self.writer.flush()
    }
}
impl<W, E> Complete for Encoder<W, E>
where
    W: io::Write,
    E: lz77::Lz77Encode,
{
    fn complete(self) -> io::Result<()> {
        self.finish().into_result().map(|_| ())
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::finish::AutoFinish;
    use std::io;

    fn decode_all(buf: &[u8]) -> io::Result<Vec<u8>> {
        let mut decoder = Decoder::new(buf).unwrap();
        let mut buf = Vec::with_capacity(buf.len());
        io::copy(&mut decoder, &mut buf)?;
        Ok(buf)
    }
    fn default_encode(buf: &[u8]) -> io::Result<Vec<u8>> {
        let mut encoder = Encoder::new(Vec::new()).unwrap();
        io::copy(&mut &buf[..], &mut encoder).unwrap();
        encoder.finish().into_result()
    }
    macro_rules! assert_encode_decode {
        ($input:expr) => {{
            let encoded = default_encode(&$input[..]).unwrap();
            assert_eq!(decode_all(&encoded).unwrap(), &$input[..]);
        }};
    }

    const DECODE_WORKS_TESTDATA: [u8; 20] = [
        120, 156, 243, 72, 205, 201, 201, 87, 8, 207, 47, 202, 73, 81, 4, 0, 28, 73, 4, 62,
    ];
    #[test]
    fn decode_works() {
        let encoded = DECODE_WORKS_TESTDATA;
        let mut decoder = Decoder::new(&encoded[..]).unwrap();
        assert_eq!(
            *decoder.header(),
            Header {
                window_size: Lz77WindowSize::KB32,
                compression_level: CompressionLevel::Default,
            }
        );

        let mut buf = Vec::new();
        io::copy(&mut decoder, &mut buf).unwrap();

        let expected = b"Hello World!";
        assert_eq!(buf, expected);
    }

    #[test]
    fn default_encode_works() {
        let plain = b"Hello World! Hello ZLIB!!";
        let mut encoder = Encoder::new(Vec::new()).unwrap();
        io::copy(&mut &plain[..], &mut encoder).unwrap();
        let encoded = encoder.finish().into_result().unwrap();
        assert_eq!(decode_all(&encoded).unwrap(), plain);
    }

    #[test]
    fn best_speed_encode_works() {
        let plain = b"Hello World! Hello ZLIB!!";
        let mut encoder =
            Encoder::with_options(Vec::new(), EncodeOptions::default().fixed_huffman_codes())
                .unwrap();
        io::copy(&mut &plain[..], &mut encoder).unwrap();
        let encoded = encoder.finish().into_result().unwrap();
        assert_eq!(decode_all(&encoded).unwrap(), plain);
    }

    const RAW_ENCODE_WORKS_EXPECTED: [u8; 23] = [
        120, 1, 1, 12, 0, 243, 255, 72, 101, 108, 108, 111, 32, 87, 111, 114, 108, 100, 33, 28, 73,
        4, 62,
    ];
    #[test]
    fn raw_encode_works() {
        let plain = b"Hello World!";
        let mut encoder =
            Encoder::with_options(Vec::new(), EncodeOptions::new().no_compression()).unwrap();
        io::copy(&mut &plain[..], &mut encoder).unwrap();
        let encoded = encoder.finish().into_result().unwrap();
        let expected = RAW_ENCODE_WORKS_EXPECTED;
        assert_eq!(encoded, expected);
        assert_eq!(decode_all(&encoded).unwrap(), plain);
    }

    #[test]
    fn encoder_auto_finish_works() {
        let plain = b"Hello World! Hello ZLIB!!";
        let mut buf = Vec::new();
        {
            let mut encoder = AutoFinish::new(Encoder::new(&mut buf).unwrap());
            io::copy(&mut &plain[..], &mut encoder).unwrap();
        }
        assert_eq!(decode_all(&buf).unwrap(), plain);
    }

    #[test]
    fn test_issue_2() {
        // See: https://github.com/sile/libflate/issues/2
        assert_encode_decode!([
            163, 181, 167, 40, 62, 239, 41, 125, 189, 217, 61, 122, 20, 136, 160, 178, 119, 217,
            217, 41, 125, 189, 97, 195, 101, 47, 170,
        ]);
        assert_encode_decode!([
            162, 58, 99, 211, 7, 64, 96, 36, 57, 155, 53, 166, 76, 14, 238, 66, 66, 148, 154, 124,
            162, 58, 99, 188, 138, 131, 171, 189, 54, 229, 192, 38, 29, 240, 122, 28,
        ]);
        assert_encode_decode!([
            239, 238, 212, 42, 5, 46, 186, 67, 122, 247, 30, 61, 219, 62, 228, 202, 164, 205, 139,
            109, 99, 181, 99, 181, 99, 122, 30, 12, 62, 46, 27, 145, 241, 183, 137,
        ]);
        assert_encode_decode!([
            88, 202, 64, 12, 125, 108, 153, 49, 164, 250, 71, 19, 4, 108, 111, 108, 237, 205, 208,
            77, 217, 100, 118, 49, 10, 64, 12, 125, 51, 202, 69, 67, 181, 146, 86,
        ]);
    }

    #[test]
    fn test_issues_16() {
        // See: https://github.com/sile/libflate/issues/16

        let encoded =
            include_bytes!("../data/issues_16/crash-1bb6d408475a5bd57247ee40f290830adfe2086e");
        assert_eq!(
            decode_all(&encoded[..]).err().map(|e| e.to_string()),
            Some("The value of HDIST is too big: max=30, actual=32".to_owned())
        );

        let encoded =
            include_bytes!("../data/issues_16/crash-369e8509a0e76356f4549c292ceedee429cfe125");
        assert_eq!(
            decode_all(&encoded[..]).err().map(|e| e.to_string()),
            Some("The value of HDIST is too big: max=30, actual=32".to_owned())
        );

        let encoded =
            include_bytes!("../data/issues_16/crash-e75959d935650306881140df7f6d1d73e33425cb");
        assert_eq!(
            decode_all(&encoded[..]).err().map(|e| e.to_string()),
            Some("The value of HDIST is too big: max=30, actual=32".to_owned())
        );
    }
}