celestia-types 1.0.0

use crate::consts::appconsts;
use crate::{Error, Result};

#[cfg(feature = "uniffi")]
use crate::error::UniffiResult;

/// The part of [`Share`] containing the `version` and `sequence_start` information.
///
/// [`InfoByte`] is a single byte with the following structure:
///
///  - the first 7 bits are reserved for version information in big endian form
///  - last bit is a `sequence_start` flag. If it's set then this [`Share`] is
///    a first of a sequence, otherwise it's a continuation share.
///
///  [`Share`]: crate::Share
#[repr(transparent)]
#[derive(Debug, PartialEq)]
#[cfg_attr(feature = "uniffi", derive(uniffi::Object))]
pub struct InfoByte(u8);

impl InfoByte {
    /// Create a new [`InfoByte`] with given version and `sequence_start`.
    pub fn new(version: u8, is_sequence_start: bool) -> Result<Self> {
        if version > appconsts::MAX_SHARE_VERSION {
            Err(Error::MaxShareVersionExceeded(version))
        } else {
            let prefix = version << 1;
            let sequence_start = if is_sequence_start { 1 } else { 0 };
            Ok(Self(prefix + sequence_start))
        }
    }

    /// Get the `version`.
    pub fn version(&self) -> u8 {
        self.0 >> 1
    }

    /// Get the `sequence_start` indicator.
    pub fn is_sequence_start(&self) -> bool {
        self.0 % 2 == 1
    }

    /// Convert the [`InfoByte`] to a byte.
    pub fn as_u8(&self) -> u8 {
        self.0
    }

    pub(crate) fn from_raw(byte: u8) -> Result<Self> {
        let version = byte >> 1;
        if version > appconsts::MAX_SHARE_VERSION {
            Err(Error::MaxShareVersionExceeded(version))
        } else {
            Ok(InfoByte(byte))
        }
    }

    pub(crate) fn from_raw_unchecked(byte: u8) -> Self {
        InfoByte(byte)
    }
}

#[cfg(feature = "uniffi")]
#[uniffi::export]
impl InfoByte {
    /// Create a new [`InfoByte`] with given version and `sequence_start`.
    #[uniffi::constructor(name = "create")]
    pub fn uniffi_new(version: u8, is_sequence_start: bool) -> UniffiResult<Self> {
        Ok(InfoByte::new(version, is_sequence_start)?)
    }

    /// Get the `version`.
    #[uniffi::method(name = "version")]
    pub fn uniffi_version(&self) -> u8 {
        self.version()
    }

    /// Get the `sequence_start` indicator.
    #[uniffi::method(name = "is_sequence_start")]
    pub fn uniffi_is_sequence_start(&self) -> bool {
        self.is_sequence_start()
    }

    /// Convert the [`InfoByte`] to a byte.
    #[uniffi::method(name = "as_u8")]
    pub fn uniffi_as_u8(&self) -> u8 {
        self.as_u8()
    }
}