use crate::common::errors::DomainError;

#[derive(Debug, Clone, PartialEq, Eq, Hash, serde::Serialize, serde::Deserialize)]
pub struct Checksum(String);

impl Checksum {
    pub fn new(hex: impl Into<String>) -> Result<Self, DomainError> {
        let hex = hex.into().to_lowercase();
        if hex.len() != 64 {
            return Err(DomainError::Validation(
                format!("Checksum must be 64 hex characters, got {}", hex.len()),
            ));
        }
        if !hex.chars().all(|c| c.is_ascii_hexdigit()) {
            return Err(DomainError::Validation(
                "Checksum contains non-hex characters".to_string(),
            ));
        }
        Ok(Self(hex))
    }

    pub fn as_str(&self) -> &str { &self.0 }
}

impl std::fmt::Display for Checksum {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "{}", self.0)
    }
}