};

      fields.entry(tag).or_insert(value);
    }

    Self { fields, body }
  }
}

impl Runestone {
  pub fn from_transaction(transaction: &Transaction) -> Option<Self> {
    Self::decipher(transaction).ok().flatten()
  }

  fn decipher(transaction: &Transaction) -> Result<Option<Self>> {
    let Some(payload) = Runestone::payload(transaction)? else {
      return Ok(None);
    };

    let mut integers = Vec::new();
    let mut i = 0;

    while i < payload.len() {
      let (integer, length) = varint::decode(&payload[i..])?;
      integers.push(integer);
      i += length;
    }

    let Message { mut fields, body } = Message::from_integers(&integers);

    let etching = fields.remove(&TAG_RUNE).map(|rune| Etching {
      divisibility: fields
        .remove(&TAG_DIVISIBILITY)
        .and_then(|divisibility| u8::try_from(divisibility).ok())
        .and_then(|divisibility| (divisibility <= MAX_DIVISIBILITY).then_some(divisibility))
        .unwrap_or_default(),
      limit: fields
        .remove(&TAG_LIMIT)