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pub mod base64_public_key;
pub mod client_secret;
pub mod error;
pub mod event_id;
pub mod key_id;
pub mod mxc_uri;
pub mod room_alias_id;
pub mod room_id;
pub mod room_id_or_alias_id;
pub mod room_version_id;
pub mod server_name;
pub mod server_signing_key_version;
pub mod user_id;
pub mod voip_version_id;

pub use error::Error;

/// All identifiers must be 255 bytes or less.
#[cfg(not(feature = "compat-arbitrary-length-ids"))]
pub const MAX_BYTES: usize = 255;

/// Checks if an identifier is valid.
fn validate_id(id: &str, sigil: u8) -> Result<(), Error> {
    #[cfg(not(feature = "compat-arbitrary-length-ids"))]
    if id.len() > MAX_BYTES {
        return Err(Error::MaximumLengthExceeded);
    }

    match id.as_bytes().first() {
        Some(&first_byte) if first_byte == sigil => Ok(()),
        Some(_) => Err(Error::MissingLeadingSigil),
        None => Err(Error::Empty),
    }
}

/// Checks an identifier that contains a localpart and hostname for validity.
fn parse_id(id: &str, first_byte: u8) -> Result<usize, Error> {
    validate_id(id, first_byte)?;
    let colon_idx = id.find(':').ok_or(Error::MissingColon)?;
    server_name::validate(&id[colon_idx + 1..])?;
    Ok(colon_idx)
}

/// Checks an identifier that contains a localpart and hostname for validity.
fn validate_delimited_id(id: &str, first_byte: u8) -> Result<(), Error> {
    parse_id(id, first_byte)?;
    Ok(())
}

/// Helper trait to validate the name of a key.
pub trait KeyName: AsRef<str> {
    /// Validate the given string for this name.
    fn validate(s: &str) -> Result<(), Error>;
}