use thiserror::Error;

/// Errors that can occur during transaction or session operations.
#[derive(Debug, Error)]
pub enum TransactionError {
    #[error("not found: {0}")]
    NotFound(String),

    #[error("transaction already active for session: {0}")]
    AlreadyActive(String),

    #[error("write conflict detected (code 112): {0}")]
    WriteConflict(String),

    #[error("session expired: {0}")]
    SessionExpired(String),

    #[error("invalid transaction state: {0}")]
    InvalidState(String),
}

impl TransactionError {
    /// Returns the error code.
    pub fn code(&self) -> i32 {
        match self {
            TransactionError::NotFound(_) => 251,
            TransactionError::AlreadyActive(_) => 256,
            TransactionError::WriteConflict(_) => 112,
            TransactionError::SessionExpired(_) => 6100,
            TransactionError::InvalidState(_) => 263,
        }
    }
}

pub type TransactionResult<T> = Result<T, TransactionError>;