osirisdb 0.4.0

use std::path::PathBuf;

/// Errors that can occur during storage operations.
///
/// All variants carry enough context for the caller to produce
/// a useful error message without the storage layer needing to
/// know about the interner or symbol resolution.
#[derive(Debug, Clone, PartialEq)]
pub enum StorageError {
    /// A directory that was expected to already exist was not found.
    DirectoryNotFound(PathBuf),

    /// A directory already exists where we tried to create one.
    ///
    /// This should not happen in normal operation since the binder
    /// checks existence first — indicates a race condition or
    /// manual filesystem interference.
    DirectoryAlreadyExists(PathBuf),

    /// A filesystem operation failed.
    ///
    /// Carries the path that was being operated on and the
    /// OS-level error description.
    Io { path: PathBuf, reason: String },
}

impl StorageError {
    /// Wraps a `std::io::Error` with the path that caused it.
    pub(crate) fn io(path: impl Into<PathBuf>, e: std::io::Error) -> Self {
        StorageError::Io {
            path: path.into(),
            reason: e.to_string(),
        }
    }
}

impl std::fmt::Display for StorageError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            StorageError::DirectoryNotFound(p) => {
                write!(f, "directory not found: {}", p.display())
            }
            StorageError::DirectoryAlreadyExists(p) => {
                write!(f, "directory already exists: {}", p.display())
            }
            StorageError::Io { path, reason } => {
                write!(f, "I/O error at {}: {}", path.display(), reason)
            }
        }
    }
}

impl std::error::Error for StorageError {}