use thiserror::Error;
pub type Result<T> = std::result::Result<T, ProtoError>;
#[derive(Debug, Error, PartialEq, Eq)]
pub enum ProtoError {
#[error("packet is too short: needed {needed} bytes, got {actual}")]
PacketTooShort { needed: usize, actual: usize },
#[error("bad packet length: expected {expected} bytes, got {actual}")]
PacketLengthMismatch { expected: usize, actual: usize },
#[error("bad magic bytes")]
BadMagic,
#[error("reserved flag bits are set: 0x{0:02x}")]
ReservedFlags(u8),
#[error("required flag 0x{0:02x} is missing")]
MissingFlag(u8),
#[error("unexpected flag 0x{0:02x} is set")]
UnexpectedFlag(u8),
#[error("HMAC flag/key mismatch")]
HmacPresenceMismatch,
#[error("HMAC verification failed")]
BadHmac,
#[error("invalid HMAC field offset")]
InvalidHmacOffset,
#[error("varint is truncated")]
TruncatedVarint,
#[error("varint is too long")]
VarintOverflow,
#[error("string value is not valid UTF-8")]
InvalidUtf8,
#[error("invalid enum value {value} for {name}")]
InvalidEnum { name: &'static str, value: i64 },
#[error("packet length {length} cannot be represented as a buffer length")]
PacketLengthUnrepresentable { length: i64 },
#[error("parameter {tag} length is too large: {length} bytes")]
ParameterLengthTooLarge { tag: u64, length: u64 },
#[error("open reply has zero token without close flag")]
ZeroToken,
#[error("trailing or malformed parameter payload")]
MalformedParams,
#[error("payload is too large: {provided} bytes provided, {available} bytes available")]
PayloadTooLarge { available: usize, provided: usize },
#[error("required packet field {0} is missing")]
MissingField(&'static str),
#[error("packet field {0} is not present in the negotiated layout")]
UnexpectedField(&'static str),
}