use netbuf;

use nom::{Err, IResult};

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

pub mod messages;

mod parser;

#[cfg(test)]

pub mod test;

pub struct ProtocolDecoder {

    buf: netbuf::Buf,

    consumed: usize,

}

impl ProtocolDecoder {

    pub fn new() -> ProtocolDecoder {

        ProtocolDecoder {

            buf: netbuf::Buf::new(),

            consumed: 0,

        }

    }

    pub fn read_from<R: Read>(&mut self, stream: &mut R) -> Result<usize> {

        self.buf.read_from(stream)

    }

    pub fn extract_messages(&mut self) -> Vec<messages::HWProtocolMessage> {

        let parse_result = parser::extract_messages(&self.buf[..]);

        match parse_result {

            Ok((tail, msgs)) => {

                self.consumed = self.buf.len() - self.consumed - tail.len();

                msgs

            }

            Err(Err::Incomplete(_)) => unreachable!(),

            Err(Err::Error(_)) | Err(Err::Failure(_)) => unreachable!(),

        }

    }

    pub fn sweep(&mut self) {

        self.buf.consume(self.consumed);

        self.consumed = 0;

    }

}