macro_rules! encode_tlv {
	($stream: expr, {$(($type: expr, $field: expr)),*}) => { {
		use util::ser::{BigSize, LengthCalculatingWriter};
		$(
			BigSize($type).write($stream)?;
			let mut len_calc = LengthCalculatingWriter(0);
			$field.write(&mut len_calc)?;
			BigSize(len_calc.0 as u64).write($stream)?;
			$field.write($stream)?;
		)*
	} }
}

macro_rules! encode_varint_length_prefixed_tlv {
	($stream: expr, {$(($type: expr, $field: expr)),*}) => { {
		use util::ser::{BigSize, LengthCalculatingWriter};
		let mut len = LengthCalculatingWriter(0);
		{
			$(
				BigSize($type).write(&mut len)?;
				let mut field_len = LengthCalculatingWriter(0);
				$field.write(&mut field_len)?;
				BigSize(field_len.0 as u64).write(&mut len)?;
				len.0 += field_len.0;
			)*
		}

		BigSize(len.0 as u64).write($stream)?;
		encode_tlv!($stream, {
			$(($type, $field)),*
		});
	} }
}

macro_rules! decode_tlv {
	($stream: expr, {$(($reqtype: expr, $reqfield: ident)),*}, {$(($type: expr, $field: ident)),*}) => { {
		use ln::msgs::DecodeError;
		let mut last_seen_type: Option<u64> = None;
		'tlv_read: loop {
			use util::ser;

			// First decode the type of this TLV:
			let typ: ser::BigSize = {
				// We track whether any bytes were read during the consensus_decode call to
				// determine whether we should break or return ShortRead if we get an
				// UnexpectedEof. This should in every case be largely cosmetic, but its nice to
				// pass the TLV test vectors exactly, which requre this distinction.
				let mut tracking_reader = ser::ReadTrackingReader::new($stream);
				match ser::Readable::read(&mut tracking_reader) {
					Err(DecodeError::ShortRead) => {
						if !tracking_reader.have_read {
							break 'tlv_read
						} else {
							Err(DecodeError::ShortRead)?
						}
					},
					Err(e) => Err(e)?,
					Ok(t) => t,
				}
			};

			// Types must be unique and monotonically increasing:
			match last_seen_type {
				Some(t) if typ.0 <= t => {
					Err(DecodeError::InvalidValue)?
				},
				_ => {},
			}
			// As we read types, make sure we hit every required type:
			$(if (last_seen_type.is_none() || last_seen_type.unwrap() < $reqtype) && typ.0 > $reqtype {
				Err(DecodeError::InvalidValue)?
			})*
			last_seen_type = Some(typ.0);

			// Finally, read the length and value itself:
			let length: ser::BigSize = Readable::read($stream)?;
			let mut s = ser::FixedLengthReader::new($stream, length.0);
			match typ.0 {
				$($reqtype => {
					$reqfield = ser::Readable::read(&mut s)?;
					if s.bytes_remain() {
						s.eat_remaining()?; // Return ShortRead if there's actually not enough bytes
						Err(DecodeError::InvalidValue)?
					}
				},)*
				$($type => {
					$field = Some(ser::Readable::read(&mut s)?);
					if s.bytes_remain() {
						s.eat_remaining()?; // Return ShortRead if there's actually not enough bytes
						Err(DecodeError::InvalidValue)?
					}
				},)*
				x if x % 2 == 0 => {
					Err(DecodeError::UnknownRequiredFeature)?
				},
				_ => {},
			}
			s.eat_remaining()?;
		}
		// Make sure we got to each required type after we've read every TLV:
		$(if last_seen_type.is_none() || last_seen_type.unwrap() < $reqtype {
			Err(DecodeError::InvalidValue)?
		})*
	} }
}

macro_rules! impl_writeable {
	($st:ident, $len: expr, {$($field:ident),*}) => {
		impl ::util::ser::Writeable for $st {
			fn write<W: ::util::ser::Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
				if $len != 0 {
					w.size_hint($len);
				}
				$( self.$field.write(w)?; )*
				Ok(())
			}
		}

		impl ::util::ser::Readable for $st {
			fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
				Ok(Self {
					$($field: ::util::ser::Readable::read(r)?),*
				})
			}
		}
	}
}
macro_rules! impl_writeable_len_match {
	($st:ident, {$({$m: pat, $l: expr}),*}, {$($field:ident),*}) => {
		impl Writeable for $st {
			fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
				w.size_hint(match *self {
					$($m => $l,)*
				});
				$( self.$field.write(w)?; )*
				Ok(())
			}
		}

		impl ::util::ser::Readable for $st {
			fn read<R: ::std::io::Read>(r: &mut R) -> Result<Self, DecodeError> {
				Ok(Self {
					$($field: Readable::read(r)?),*
				})
			}
		}
	}
}

#[cfg(test)]
mod tests {
	use std::io::{Cursor, Read};
	use ln::msgs::DecodeError;
	use util::ser::{Readable, Writeable, HighZeroBytesDroppedVarInt, VecWriter};
	use secp256k1::PublicKey;

	// The BOLT TLV test cases don't include any tests which use our "required-value" logic since
	// the encoding layer in the BOLTs has no such concept, though it makes our macros easier to
	// work with so they're baked into the decoder. Thus, we have a few additional tests below
	fn tlv_reader(s: &[u8]) -> Result<(u64, u32, Option<u32>), DecodeError> {
		let mut s = Cursor::new(s);
		let mut a: u64 = 0;
		let mut b: u32 = 0;
		let mut c: Option<u32> = None;
		decode_tlv!(&mut s, {(2, a), (3, b)}, {(4, c)});
		Ok((a, b, c))
	}

	#[test]
	fn tlv_v_short_read() {
		// We only expect a u32 for type 3 (which we are given), but the L says its 8 bytes.
		if let Err(DecodeError::ShortRead) = tlv_reader(&::hex::decode(
				concat!("0100", "0208deadbeef1badbeef", "0308deadbeef")
				).unwrap()[..]) {
		} else { panic!(); }
	}

	#[test]
	fn tlv_types_out_of_order() {
		if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
				concat!("0100", "0304deadbeef", "0208deadbeef1badbeef")
				).unwrap()[..]) {
		} else { panic!(); }
		// ...even if its some field we don't understand
		if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
				concat!("0208deadbeef1badbeef", "0100", "0304deadbeef")
				).unwrap()[..]) {
		} else { panic!(); }
	}

	#[test]
	fn tlv_req_type_missing_or_extra() {
		// It's also bad if they included even fields we don't understand
		if let Err(DecodeError::UnknownRequiredFeature) = tlv_reader(&::hex::decode(
				concat!("0100", "0208deadbeef1badbeef", "0304deadbeef", "0600")
				).unwrap()[..]) {
		} else { panic!(); }
		// ... or if they're missing fields we need
		if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
				concat!("0100", "0208deadbeef1badbeef")
				).unwrap()[..]) {
		} else { panic!(); }
		// ... even if that field is even
		if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
				concat!("0304deadbeef", "0500")
				).unwrap()[..]) {
		} else { panic!(); }
	}

	#[test]
	fn tlv_simple_good_cases() {
		assert_eq!(tlv_reader(&::hex::decode(
				concat!("0208deadbeef1badbeef", "03041bad1dea")
				).unwrap()[..]).unwrap(),
			(0xdeadbeef1badbeef, 0x1bad1dea, None));
		assert_eq!(tlv_reader(&::hex::decode(
				concat!("0208deadbeef1badbeef", "03041bad1dea", "040401020304")
				).unwrap()[..]).unwrap(),
			(0xdeadbeef1badbeef, 0x1bad1dea, Some(0x01020304)));
	}

	impl Readable for (PublicKey, u64, u64) {
		#[inline]
		fn read<R: Read>(reader: &mut R) -> Result<(PublicKey, u64, u64), DecodeError> {
			Ok((Readable::read(reader)?, Readable::read(reader)?, Readable::read(reader)?))
		}
	}

	// BOLT TLV test cases
	fn tlv_reader_n1(s: &[u8]) -> Result<(Option<HighZeroBytesDroppedVarInt<u64>>, Option<u64>, Option<(PublicKey, u64, u64)>, Option<u16>), DecodeError> {
		let mut s = Cursor::new(s);
		let mut tlv1: Option<HighZeroBytesDroppedVarInt<u64>> = None;
		let mut tlv2: Option<u64> = None;
		let mut tlv3: Option<(PublicKey, u64, u64)> = None;
		let mut tlv4: Option<u16> = None;
		decode_tlv!(&mut s, {}, {(1, tlv1), (2, tlv2), (3, tlv3), (254, tlv4)});
		Ok((tlv1, tlv2, tlv3, tlv4))
	}

	#[test]
	fn bolt_tlv_bogus_stream() {
		macro_rules! do_test {
			($stream: expr, $reason: ident) => {
				if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
				} else { panic!(); }
			}
		}

		// TLVs from the BOLT test cases which should not decode as either n1 or n2
		do_test!(concat!("fd01"), ShortRead);
		do_test!(concat!("fd0001", "00"), InvalidValue);
		do_test!(concat!("fd0101"), ShortRead);
		do_test!(concat!("0f", "fd"), ShortRead);
		do_test!(concat!("0f", "fd26"), ShortRead);
		do_test!(concat!("0f", "fd2602"), ShortRead);
		do_test!(concat!("0f", "fd0001", "00"), InvalidValue);
		do_test!(concat!("0f", "fd0201", "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"), ShortRead);

		do_test!(concat!("12", "00"), UnknownRequiredFeature);
		do_test!(concat!("fd0102", "00"), UnknownRequiredFeature);
		do_test!(concat!("fe01000002", "00"), UnknownRequiredFeature);
		do_test!(concat!("ff0100000000000002", "00"), UnknownRequiredFeature);
	}

	#[test]
	fn bolt_tlv_bogus_n1_stream() {
		macro_rules! do_test {
			($stream: expr, $reason: ident) => {
				if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
				} else { panic!(); }
			}
		}

		// TLVs from the BOLT test cases which should not decode as n1
		do_test!(concat!("01", "09", "ffffffffffffffffff"), InvalidValue);
		do_test!(concat!("01", "01", "00"), InvalidValue);
		do_test!(concat!("01", "02", "0001"), InvalidValue);
		do_test!(concat!("01", "03", "000100"), InvalidValue);
		do_test!(concat!("01", "04", "00010000"), InvalidValue);
		do_test!(concat!("01", "05", "0001000000"), InvalidValue);
		do_test!(concat!("01", "06", "000100000000"), InvalidValue);
		do_test!(concat!("01", "07", "00010000000000"), InvalidValue);
		do_test!(concat!("01", "08", "0001000000000000"), InvalidValue);
		do_test!(concat!("02", "07", "01010101010101"), ShortRead);
		do_test!(concat!("02", "09", "010101010101010101"), InvalidValue);
		do_test!(concat!("03", "21", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb"), ShortRead);
		do_test!(concat!("03", "29", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001"), ShortRead);
		do_test!(concat!("03", "30", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb000000000000000100000000000001"), ShortRead);
		do_test!(concat!("03", "31", "043da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"), InvalidValue);
		do_test!(concat!("03", "32", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001000000000000000001"), InvalidValue);
		do_test!(concat!("fd00fe", "00"), ShortRead);
		do_test!(concat!("fd00fe", "01", "01"), ShortRead);
		do_test!(concat!("fd00fe", "03", "010101"), InvalidValue);
		do_test!(concat!("00", "00"), UnknownRequiredFeature);

		do_test!(concat!("02", "08", "0000000000000226", "01", "01", "2a"), InvalidValue);
		do_test!(concat!("02", "08", "0000000000000231", "02", "08", "0000000000000451"), InvalidValue);
		do_test!(concat!("1f", "00", "0f", "01", "2a"), InvalidValue);
		do_test!(concat!("1f", "00", "1f", "01", "2a"), InvalidValue);

		// The last BOLT test modified to not require creating a new decoder for one trivial test.
		do_test!(concat!("ffffffffffffffffff", "00", "01", "00"), InvalidValue);
	}

	#[test]
	fn bolt_tlv_valid_n1_stream() {
		macro_rules! do_test {
			($stream: expr, $tlv1: expr, $tlv2: expr, $tlv3: expr, $tlv4: expr) => {
				if let Ok((tlv1, tlv2, tlv3, tlv4)) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
					assert_eq!(tlv1.map(|v| v.0), $tlv1);
					assert_eq!(tlv2, $tlv2);
					assert_eq!(tlv3, $tlv3);
					assert_eq!(tlv4, $tlv4);
				} else { panic!(); }
			}
		}

		do_test!(concat!(""), None, None, None, None);
		do_test!(concat!("21", "00"), None, None, None, None);
		do_test!(concat!("fd0201", "00"), None, None, None, None);
		do_test!(concat!("fd00fd", "00"), None, None, None, None);
		do_test!(concat!("fd00ff", "00"), None, None, None, None);
		do_test!(concat!("fe02000001", "00"), None, None, None, None);
		do_test!(concat!("ff0200000000000001", "00"), None, None, None, None);

		do_test!(concat!("01", "00"), Some(0), None, None, None);
		do_test!(concat!("01", "01", "01"), Some(1), None, None, None);
		do_test!(concat!("01", "02", "0100"), Some(256), None, None, None);
		do_test!(concat!("01", "03", "010000"), Some(65536), None, None, None);
		do_test!(concat!("01", "04", "01000000"), Some(16777216), None, None, None);
		do_test!(concat!("01", "05", "0100000000"), Some(4294967296), None, None, None);
		do_test!(concat!("01", "06", "010000000000"), Some(1099511627776), None, None, None);
		do_test!(concat!("01", "07", "01000000000000"), Some(281474976710656), None, None, None);
		do_test!(concat!("01", "08", "0100000000000000"), Some(72057594037927936), None, None, None);
		do_test!(concat!("02", "08", "0000000000000226"), None, Some((0 << 30) | (0 << 5) | (550 << 0)), None, None);
		do_test!(concat!("03", "31", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"),
			None, None, Some((
				PublicKey::from_slice(&::hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]).unwrap(), 1, 2)),
			None);
		do_test!(concat!("fd00fe", "02", "0226"), None, None, None, Some(550));
	}

	fn do_simple_test_tlv_write() -> Result<(), ::std::io::Error> {
		let mut stream = VecWriter(Vec::new());

		stream.0.clear();
		encode_varint_length_prefixed_tlv!(&mut stream, { (1, 1u8) });
		assert_eq!(stream.0, ::hex::decode("03010101").unwrap());

		stream.0.clear();
		encode_varint_length_prefixed_tlv!(&mut stream, { (4, 0xabcdu16) });
		assert_eq!(stream.0, ::hex::decode("040402abcd").unwrap());

		stream.0.clear();
		encode_varint_length_prefixed_tlv!(&mut stream, { (0xff, 0xabcdu16) });
		assert_eq!(stream.0, ::hex::decode("06fd00ff02abcd").unwrap());

		stream.0.clear();
		encode_varint_length_prefixed_tlv!(&mut stream, { (0, 1u64), (0xff, HighZeroBytesDroppedVarInt(0u64)) });
		assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());

		Ok(())
	}

	#[test]
	fn simple_test_tlv_write() {
		do_simple_test_tlv_write().unwrap();
	}
}