/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

use error_support::{ErrorHandling, GetErrorHandling};
use rc_crypto::hawk;
use std::string;

/// Public error type thrown by many [`FirefoxAccount`] operations.
///
/// Precise details of the error are hidden from consumers. The type of the error indicates how the
/// calling code should respond.
#[derive(Debug, thiserror::Error)]
pub enum FxaError {
    /// Thrown when there was a problem with the authentication status of the account,
    /// such as an expired token. The application should [check its authorization status](
    /// FirefoxAccount::check_authorization_status) to see whether it has been disconnected,
    /// or retry the operation with a freshly-generated token.
    #[error("authentication error")]
    Authentication,
    /// Thrown when an authenticated account isn't allowed to perform some operation. Unlike
    /// `Authentication`, there's no problem with the account status. In some cases it
    /// might be possible to request additional scopes, and once granted, the operation
    /// may succeed.
    #[error("forbidden")]
    Forbidden,
    /// Thrown if an operation fails due to network access problems.
    /// The application may retry at a later time once connectivity is restored.
    #[error("network error")]
    Network,
    /// Thrown if the application attempts to complete an OAuth flow when no OAuth flow
    /// has been initiated. This may indicate a user who navigated directly to the OAuth
    /// `redirect_uri` for the application.
    ///
    /// **Note:** This error is currently only thrown in the Swift language bindings.
    #[error("no authentication flow was active")]
    NoExistingAuthFlow,
    /// Thrown if the application attempts to complete an OAuth flow, but the state
    /// tokens returned from the Firefox Account server do not match with the ones
    /// expected by the client.
    /// This may indicate a stale OAuth flow, or potentially an attempted hijacking
    /// of the flow by an attacker. The signin attempt cannot be completed.
    ///
    /// **Note:** This error is currently only thrown in the Swift language bindings.
    #[error("the requested authentication flow was not active")]
    WrongAuthFlow,
    /// Origin mismatch when handling a pairing flow
    ///
    /// The most likely cause of this is that a user tried to pair together two firefox instances
    /// that are configured to use different servers.
    #[error("Origin mismatch")]
    OriginMismatch,
    /// A scoped key was missing in the server response when requesting the OLD_SYNC scope.
    #[error("The sync scoped key was missing")]
    SyncScopedKeyMissingInServerResponse,
    /// Thrown if there is a panic in the underlying Rust code.
    ///
    /// **Note:** This error is currently only thrown in the Kotlin language bindings.
    #[error("panic in native code")]
    Panic,
    /// A catch-all for other unspecified errors.
    #[error("other error: {0}")]
    Other(String),
}

/// FxA internal error type
/// These are used in the internal code. This error type is never returned to the consumer.
#[derive(Debug, thiserror::Error)]
pub enum Error {
    #[error("Server asked the client to back off, please wait {0} seconds to try again")]
    BackoffError(u64),

    #[error("Unknown OAuth State")]
    UnknownOAuthState,

    #[error("Multiple OAuth scopes requested")]
    MultipleScopesRequested,

    #[error("No cached scoped keys for scope {0}")]
    NoScopedKey(String),

    #[error("No stored refresh token")]
    NoRefreshToken,

    #[error("No stored session token")]
    NoSessionToken,

    #[error("No stored migration data")]
    NoMigrationData,

    #[error("No stored current device id")]
    NoCurrentDeviceId,

    #[error("Device target is unknown (Device ID: {0})")]
    UnknownTargetDevice(String),

    #[error("Api client error {0}")]
    ApiClientError(&'static str),

    #[error("Illegal state: {0}")]
    IllegalState(&'static str),

    #[error("Unknown command: {0}")]
    UnknownCommand(String),

    #[error("Send Tab diagnosis error: {0}")]
    SendTabDiagnosisError(&'static str),

    #[error("Cannot xor arrays with different lengths: {0} and {1}")]
    XorLengthMismatch(usize, usize),

    #[error("Origin mismatch: {0}")]
    OriginMismatch(String),

    #[error("Remote key and local key mismatch")]
    MismatchedKeys,

    // For example, we requested an access token, the server responded with a 200, but the response body
    // had no token. This is a little bit vague, because in many cases you would get a JSON error if the
    // shape of the payload was entirely wrong.
    #[error("The response from the server, or the content in that reponse, was unexpected")]
    UnexpectedServerResponse,

    // This should probably be rolled up into `UnexpectedServerResponse`, but the way it is implemented
    // and even exposed to consumers makes that a little tricky - but at the end of the day, this can
    // only happen when the server gave us a confused response.
    #[error("The sync scoped key was missing in the server response")]
    SyncScopedKeyMissingInServerResponse,

    #[error("Client: {0} is not allowed to request scope: {1}")]
    ScopeNotAllowed(String, String),

    #[error("Unsupported command: {0}")]
    UnsupportedCommand(&'static str),

    #[error("Missing URL parameter: {0}")]
    MissingUrlParameter(&'static str),

    #[error("Null pointer passed to FFI")]
    NullPointer,

    #[error("Invalid buffer length: {0}")]
    InvalidBufferLength(i32),

    #[error("Too many calls to auth introspection endpoint")]
    AuthCircuitBreakerError,

    #[error("Remote server error: '{code}' '{errno}' '{error}' '{message}' '{info}'")]
    RemoteError {
        code: u64,
        errno: u64,
        error: String,
        message: String,
        info: String,
    },

    // Basically reimplement error_chain's foreign_links. (Ugh, this sucks).
    #[error("Crypto/NSS error: {0}")]
    CryptoError(#[from] rc_crypto::Error),

    #[error("http-ece encryption error: {0}")]
    EceError(#[from] rc_crypto::ece::Error),

    #[error("Hex decode error: {0}")]
    HexDecodeError(#[from] hex::FromHexError),

    #[error("Base64 decode error: {0}")]
    Base64Decode(#[from] base64::DecodeError),

    #[error("JSON error: {0}")]
    JsonError(#[from] serde_json::Error),

    #[error("JWCrypto error: {0}")]
    JwCryptoError(#[from] jwcrypto::JwCryptoError),

    #[error("UTF8 decode error: {0}")]
    UTF8DecodeError(#[from] string::FromUtf8Error),

    #[error("Network error: {0}")]
    RequestError(#[from] viaduct::ViaductError),

    #[error("Malformed URL: {sanitized_url} ({when})")]
    MalformedUrl {
        /// URL without any query or fragment parts.
        /// This is safe to send in an error report because there's no auth information.
        sanitized_url: String,
        when: String,
    },

    #[error("Unexpected HTTP status: {0}")]
    UnexpectedStatus(#[from] viaduct::UnexpectedStatus),

    #[error("Sync15 error: {0}")]
    SyncError(#[from] sync15::Error),

    #[error("HAWK error: {0}")]
    HawkError(#[from] hawk::Error),

    #[error("Integer conversion error: {0}")]
    IntegerConversionError(#[from] std::num::TryFromIntError),

    #[error("Command not found by fxa")]
    CommandNotFound,

    #[error("Invalid Push Event")]
    InvalidPushEvent,

    #[error("Invalid state transition: {0}")]
    InvalidStateTransition(String),

    #[error("Internal error in the state machine: {0}")]
    StateMachineLogicError(String),
}

// Define how our internal errors are handled and converted to external errors
// See `support/error/README.md` for how this works, especially the warning about PII.
impl GetErrorHandling for Error {
    type ExternalError = FxaError;

    fn get_error_handling(&self) -> ErrorHandling<Self::ExternalError> {
        match self {
            Error::RemoteError { code: 401, .. }
            | Error::NoRefreshToken
            | Error::NoSessionToken
            | Error::NoScopedKey(_) => {
                ErrorHandling::convert(FxaError::Authentication).log_warning()
            }
            Error::RemoteError { code: 403, .. } => {
                ErrorHandling::convert(FxaError::Forbidden).log_warning()
            }
            Error::RequestError(_) => ErrorHandling::convert(FxaError::Network).log_warning(),
            Error::SyncScopedKeyMissingInServerResponse => {
                ErrorHandling::convert(FxaError::SyncScopedKeyMissingInServerResponse)
                    .report_error("fxa-client-scoped-key-missing")
            }
            Error::UnknownOAuthState => {
                ErrorHandling::convert(FxaError::NoExistingAuthFlow).log_warning()
            }
            Error::BackoffError(_) => ErrorHandling::convert(FxaError::Other(self.to_string()))
                .report_error("fxa-client-backoff"),
            Error::InvalidStateTransition(_) | Error::StateMachineLogicError(_) => {
                ErrorHandling::convert(FxaError::Other(self.to_string()))
                    .report_error("fxa-state-machine-error")
            }
            Error::OriginMismatch(_) => ErrorHandling::convert(FxaError::OriginMismatch),
            // Just log a warning for these.  They're already reported in `parse_url` and
            // `join_url`.
            Error::MalformedUrl { .. } => {
                ErrorHandling::convert(FxaError::Other(self.to_string())).log_warning()
            }
            _ => ErrorHandling::convert(FxaError::Other(self.to_string()))
                .report_error("fxa-client-other-error"),
        }
    }
}