use thiserror::Error;

/// Represents errors that can occur during user login and authentication.
///
/// These errors typically happen during the authentication process when users
/// are logging in to the application, including OAuth flows and DID validation.
#[derive(Debug, Error)]
pub(crate) enum LoginError {
    #[error("error-smokesignal-login-1 DID document does not contain a handle identifier")]
    NoHandle,

    /// Error when a DID document does not contain a PDS endpoint.
    ///
    /// This error occurs during authentication when the user's DID document
    /// is retrieved but does not contain a required AT Protocol Personal
    /// Data Server (PDS) endpoint.
    #[error("error-smokesignal-login-2 DID document does not contain an AT Protocol PDS endpoint")]
    NoPDS,

    /// Error when an OAuth callback is incomplete.
    ///
    /// This error occurs when the OAuth authentication flow callback
    /// returns with incomplete information, preventing successful authentication.
    #[error("error-smokesignal-login-3 OAuth callback incomplete")]
    OAuthCallbackIncomplete,

    /// Error when there is an OAuth issuer mismatch.
    ///
    /// This error occurs when the issuer in the OAuth response does not
    /// match the expected issuer, which could indicate a security issue.
    #[error("error-smokesignal-login-4 OAuth issuer mismatch")]
    OAuthIssuerMismatch,

    /// Error when the login input appears to be an incomplete AT-handle.
    ///
    /// This error occurs when a user enters what appears to be a partial
    /// AT-handle (alphanumeric without a domain). The user should append
    /// ".bsky.social" and resubmit the form.
    #[error("error-smokesignal-login-5 Please add '.bsky.social' to your handle and try again")]
    IncompleteHandle,

    /// Error when an OAuth request is not found in storage.
    ///
    /// This error occurs during the OAuth callback when the system cannot
    /// find the corresponding OAuth request that was initiated, possibly
    /// due to expiration or invalid state parameter.
    #[error("error-smokesignal-login-6 oauth request not found in storage")]
    OAuthRequestNotFound,
}