use bytes::Bytes;
use common_types::{Class, Type};
use common_types::classes;
use errors::*;
use ser::DnsPacketData;
use ser::text::{DnsTextData, DnsTextFormatter};
use std::fmt;
use std::io::Cursor;

pub trait RRDataPacket {
	fn deserialize_rr_data(ttl: u32, rr_class: Class, rr_type: Type, data: &mut Cursor<Bytes>) -> Result<Self>
	where
		Self: Sized,
	;
}

impl<T: DnsPacketData + StaticRRData> RRDataPacket for T {
	fn deserialize_rr_data(_ttl: u32, rr_class: Class, rr_type: Type, data: &mut Cursor<Bytes>) -> Result<Self> {
		ensure!(rr_type == T::TYPE, "type mismatch");
		if T::CLASS != classes::ANY {
			ensure!(rr_class == T::CLASS, "class mismatch");
		}
		T::deserialize(data)
	}
}

pub trait RRDataText: Sized {
	fn dns_parse_rr_data(ttl: u32, rr_class: Class, rr_type: Type, data: &mut &str) -> Result<Self>
	where
		Self: Sized,
	;

	// format might fail if there is no (known) text representation.
	fn dns_format_rr_data(&self, f: &mut DnsTextFormatter) -> fmt::Result;
}

/*
impl<T: DnsTextData> RRDataText for T {
	fn deserialize_rr_data(_ttl: u32, _rr_class: Class, _rr_type: Type, data: &mut Cursor<Bytes>) -> Result<Self> {
		T::deserialize(data)
	}
}
*/

pub trait RRData: RRDataPacket + DnsTextData {
	fn rr_type(&self) -> Type;
}

pub trait StaticRRData: RRData {
	const TYPE: Type;
	const NAME: &'static str;
	// classes::ANY marks class independent types
	const CLASS: Class;
}