use crate::storage::StorageError;
use thiserror::Error;

#[derive(Debug, Error)]
pub enum Error {
    #[error("database: {0}")]
    Storage(#[from] StorageError),
    #[error("I/O: {0}")]
    Io(#[from] std::io::Error),
    #[error("task panicked: {0}")]
    TaskPanic(#[from] tokio::task::JoinError),
    #[error(transparent)]
    Resync(#[from] crate::sync::resync::ResyncError),
    #[error("collection mortality: {0}")]
    MstMortality(#[from] crate::mst::mortality::MstMortalityError),
    #[error("{0}")]
    Other(String),
}

impl Error {
    /// True if this error indicates the database is in an unrecoverable state.
    ///
    /// `fjall::Error::Poisoned` is fjall's signal that a prior flush/commit
    /// failed and subsequent writes can't be trusted — fjall's own docs say
    /// to crash the application. `Unrecoverable` is a similar terminal state.
    /// Callers should force-exit the process rather than attempt graceful
    /// shutdown, since the blocking thread pool may be stuck on the same
    /// underlying failure.
    pub fn is_db_fatal(&self) -> bool {
        matches!(
            self,
            Error::Storage(StorageError::Fjall(
                fjall::Error::Poisoned | fjall::Error::Unrecoverable
            ))
        )
    }
}

pub type Result<T> = std::result::Result<T, Error>;