use std::io::{Cursor, Result};

use arcode::{bitbit::BitWriter, ArithmeticEncoder, EOFKind, Model};

/// Encodes bytes and returns the compressed form
#[allow(dead_code)]
fn encode(data: &[u8]) -> Result<Vec<u8>> {
    let mut model = Model::builder().num_bits(8).eof(EOFKind::EndAddOne).build();

    // make a stream to collect the compressed data
    let compressed = Cursor::new(vec![]);
    let mut compressed_writer = BitWriter::new(compressed);

    let mut encoder = ArithmeticEncoder::new(48);

    for &sym in data {
        encoder.encode(sym.into(), &model, &mut compressed_writer)?;
        model.update_symbol(sym.into());
    }

    encoder.encode(model.eof(), &model, &mut compressed_writer)?;
    encoder.finish_encode(&mut compressed_writer)?;
    compressed_writer.pad_to_byte()?;

    // retrieves the bytes from the writer. This will
    // be cleaner when bitbit updates. Not necessary if
    // using files or a stream
    Ok(compressed_writer.get_ref().get_ref().clone())
}