use bytes::Bytes;
use common_types::*;
use failure::{ResultExt, Fail};
use ser::text::{DnsTextFormatter, next_field};
use ser::packet::remaining_bytes;
use common_types::binary::HEXLOWER_PERMISSIVE_ALLOW_WS;
use std::fmt;
use errors::*;

#[derive(Clone, PartialEq, Eq, Debug)]
pub struct UnknownRecord {
	rr_type: Type,
	raw: Bytes,
}

impl UnknownRecord {
	pub fn new(rr_type: Type, raw: Bytes) -> Self {
		UnknownRecord {
			rr_type: rr_type,
			raw: raw,
		}
	}

	pub fn deserialize(rr_type: Type, data: &mut ::std::io::Cursor<Bytes>) -> Result<Self> {
		Ok(UnknownRecord::new(rr_type, remaining_bytes(data)))
	}

	pub fn dns_parse(rr_type: Type, data: &mut &str) -> Result<Self> {
		let field = next_field(data)?;
		ensure!(field == r"\#", "expect \\# token to mark generic encoding");
		let field = next_field(data).context("generic record data length")?;
		let len: usize = field.parse()?;

		let result = HEXLOWER_PERMISSIVE_ALLOW_WS.decode(data.as_bytes())
			.with_context(|e| e.context(format!("invalid hex: {:?}", data)))?;
		ensure!(len == result.len(), "length {} doesn't match length of encoded data {}", len, result.len());

		Ok(UnknownRecord {
			rr_type,
			raw: result.into(),
		})
	}

	pub fn dns_format(&self, f: &mut DnsTextFormatter) -> fmt::Result {
		write!(f, "TYPE{} \\# {} {}", self.rr_type.0, self.raw.len(), HEXLOWER_PERMISSIVE_ALLOW_WS.encode(&self.raw))
	}
}