//! An error type for the `tor-keymgr` crate.

use tor_basic_utils::PathExt;

use tor_error::HasKind;

use dyn_clone::DynClone;

use tor_persist::slug::BadSlug;

use std::error::Error as StdError;

use std::fmt;

use std::path::PathBuf;

use std::sync::Arc;

use crate::KeyPathError;

/// An Error type for this crate.

#[derive(thiserror::Error, Debug, Clone)]

#[non_exhaustive]

pub enum Error {

    /// Detected keustore corruption.

    #[error("{0}")]

    Corruption(#[from] KeystoreCorruptionError),

    /// An opaque error returned by a [`Keystore`](crate::Keystore).

    #[error("{0}")]

    Keystore(#[from] Arc<dyn KeystoreError>),

    /// An error returned when the [`KeyMgr`](crate::KeyMgr) is asked to generate a key that already exists.

    ///

    /// Note that because there is no locking of the keystore,

    /// this situation is not reliably detected

    /// in the presence of concurrent tasks trying to generate the same key.

    ///

    /// So this error is provided to help the human user,

    /// but mustn't be relied on for correctness.

    #[error("Key already exists")]

    KeyAlreadyExists,

    /// Error coming from the tor-key-forgecrate

    #[error("{0}")]

    KeyForge(#[from] tor_key_forge::Error),

    /// An error caused by an invalid certificate.

    #[error("{0}")]

    InvalidCert(#[from] tor_key_forge::InvalidCertError),

    /// An internal error.

    #[error("Internal error")]

    Bug(#[from] tor_error::Bug),

}

/// An error returned by a [`Keystore`](crate::Keystore).

pub trait KeystoreError:

    HasKind + StdError + DynClone + fmt::Debug + fmt::Display + Send + Sync + 'static

{

}

impl HasKind for Error {

        use tor_error::ErrorKind as EK;

        use Error as E;

        }

}

/// An error caused by a syntactically invalid [`ArtiPath`](crate::ArtiPath).

///

/// The `ArtiPath` is not in the legal syntax: it contains bad characters,

/// or a syntactically invalid components.

///

/// (Does not include any errors arising from paths which are invalid

/// *for the particular key*.)

#[derive(thiserror::Error, Debug, Clone)]

#[error("Invalid ArtiPath")]

#[non_exhaustive]

pub enum ArtiPathSyntaxError {

    /// One of the path slugs was invalid.

    #[error("{0}")]

    Slug(#[from] BadSlug),

    /// An internal error.

    #[error("Internal error")]

    Bug(#[from] tor_error::Bug),

}

/// An error caused by keystore corruption.

#[derive(thiserror::Error, Debug, Clone)]

#[error("Keystore corruption")]

#[non_exhaustive]

pub enum KeystoreCorruptionError {

    /// A keystore contains a key that has an invalid [`KeyPath`](crate::KeyPath).

    #[error("{0}")]

    KeyPath(#[from] KeyPathError),

    /// Missing certificate for key.

    #[error("Missing certificate for key")]

    MissingCertificate,

    /// Missing the subject key of a certificate we own.

    #[error("Subject key of certificate not found")]

    MissingSubjectKey,

    /// Missing signing key for certificate.

    #[error("Missing signing key for certificate")]

    MissingSigningKey,

}

/// An error that happens when we encounter an unknown key type.

#[derive(thiserror::Error, PartialEq, Eq, Debug, Clone)]

#[error("unknown key type: arti_extension={arti_extension}")]

pub struct UnknownKeyTypeError {

    /// The extension used for keys of this type in an Arti keystore.

    pub(crate) arti_extension: String,

}

/// An unrecognized keystore entry.

#[derive(Clone, Debug, amplify::Getters, thiserror::Error)]

#[error("Unrecognized keystore entry {}", entry)]

pub struct UnrecognizedEntryError {

    /// An identifier of the entry that caused the error.

    entry: UnrecognizedEntryId,

    /// The underlying error that occurred.

    // TODO: This should be an `Error` specific for the situation.

    //

    // [`KeystoreError`] is a provvisory solution that presents

    // some issues, for example:

    //

    // * not all variants of `KeystoreError` are relevant

    // * redundancy with some other Error types like

    // [`MalformedServiceKeyError::NotAKey`](crate::keystore::ctor::err::MalformedServiceKeyError)

    // * [`Keystore::list`](crate::Keystore) returns

    // `StdResult<Vec<StdResult<(KeyPath, KeystoreItemType), UnrecognizedEntryError>>, KeystoreError>`,

    // `KeystoreError` presents itself twice at 2 different levels, there is abiguity

    #[source]

    error: Arc<dyn KeystoreError>,

}

impl UnrecognizedEntryError {

    /// Create a new instance of `KeystoreListError` given an `UnrecognizedEntryId`

    /// and an `Arc<dyn KeystoreError>`.

}

/// The identifier of an unrecognized key inside a [`Keystore`](crate::Keystore).

///

/// The exact type of the identifier depends on the backing storage of the keystore

/// (for example, an on-disk keystore will identify its entries by [`Path`](UnrecognizedEntryId::Path)).

#[non_exhaustive]

#[derive(Debug, Clone, PartialEq, derive_more::Display)]

pub enum UnrecognizedEntryId {

    /// An entry identified by path inside an on-disk keystore.

    // NOTE: this will only be used by on-disk keystores like

    // [`ArtiNativeKeystore`](crate::ArtiNativeKeystore)

    #[display("{}", _0.display_lossy())]

    Path(PathBuf),

    // TODO: when/if we add support for non on-disk keystores,

    // new variants will be added

}

#[cfg(test)]

mod tests {

    // @@ begin test lint list maintained by maint/add_warning @@

    #![allow(clippy::bool_assert_comparison)]

    #![allow(clippy::clone_on_copy)]

    #![allow(clippy::dbg_macro)]

    #![allow(clippy::mixed_attributes_style)]

    #![allow(clippy::print_stderr)]

    #![allow(clippy::print_stdout)]

    #![allow(clippy::single_char_pattern)]

    #![allow(clippy::unwrap_used)]

    #![allow(clippy::unchecked_duration_subtraction)]

    #![allow(clippy::useless_vec)]

    #![allow(clippy::needless_pass_by_value)]

    //! <!-- @@ end test lint list maintained by maint/add_warning @@ -->

    use super::*;

    use tor_error::ErrorKind;

    #[derive(Debug, Copy, Clone, PartialEq, thiserror::Error)]

    #[error("The source of a test error")]

    struct TestErrorSource;

    #[derive(Debug, Clone, thiserror::Error)]

    #[error("A test error")]

    struct TestError(#[from] TestErrorSource);

    impl KeystoreError for TestError {}

    impl HasKind for TestError {

        fn kind(&self) -> ErrorKind {

            ErrorKind::Other

        }

    }

    #[test]

    fn error_source() {

        let e: Error = (Arc::new(TestError(TestErrorSource)) as Arc<dyn KeystoreError>).into();

        assert_eq!(

            e.source().unwrap().to_string(),

            TestError(TestErrorSource).to_string()

        );

    }

}