//! Extractor for the "Bearer" HTTP Authentication Scheme

use std::borrow::Cow;
use std::default::Default;

use actix_web::dev::{Payload, ServiceRequest};
use actix_web::http::header::Header;
use actix_web::{FromRequest, HttpRequest};

use super::config::ExtractorConfig;
use super::errors::AuthenticationError;
use crate::headers::authorization;
use crate::headers::www_authenticate::bearer;
pub use crate::headers::www_authenticate::bearer::Error;

/// [BearerAuth](./struct/BearerAuth.html) extractor configuration.
#[derive(Debug, Clone, Default)]
pub struct Config(bearer::Bearer);

impl Config {
    /// Set challenge `scope` attribute.
    ///
    /// The `"scope"` attribute is a space-delimited list of case-sensitive scope values
    /// indicating the required scope of the access token for accessing the requested resource.
    pub fn scope<T: Into<Cow<'static, str>>>(mut self, value: T) -> Config {
        self.0.scope = Some(value.into());
        self
    }

    /// Set challenge `realm` attribute.
    ///
    /// The "realm" attribute indicates the scope of protection in the manner described in HTTP/1.1
    /// [RFC2617](https://tools.ietf.org/html/rfc2617#section-1.2).
    pub fn realm<T: Into<Cow<'static, str>>>(mut self, value: T) -> Config {
        self.0.realm = Some(value.into());
        self
    }
}

impl AsRef<bearer::Bearer> for Config {
    fn as_ref(&self) -> &bearer::Bearer {
        &self.0
    }
}

impl ExtractorConfig for Config {
    type Inner = bearer::Bearer;

    fn into_inner(self) -> Self::Inner {
        self.0
    }
}

/// Extractor for HTTP Bearer auth
///
/// # Example
///
/// ```rust
/// use actix_web_httpauth::extractors::bearer::BearerAuth;
///
/// fn index(auth: BearerAuth) -> String {
///     format!("Hello, user with token {}!", auth.token())
/// }
/// ```
///
/// If authentication fails, this extractor fetches the [`Config`] instance
/// from the [app data] in order to properly form the `WWW-Authenticate` response header.
///
/// ## Example
///
/// ```rust
/// use actix_web::{web, App};
/// use actix_web_httpauth::extractors::bearer::{BearerAuth, Config};
///
/// fn index(auth: BearerAuth) -> String {
///     format!("Hello, {}!", auth.token())
/// }
///
/// fn main() {
///     let app = App::new()
///         .data(Config::default().realm("Restricted area").scope("email photo"))
///         .service(web::resource("/index.html").route(web::get().to(index)));
/// }
/// ```
#[derive(Debug, Clone)]
pub struct BearerAuth(authorization::Bearer);

impl BearerAuth {
    /// Returns bearer token provided by client.
    pub fn token(&self) -> &str {
        self.0.token()
    }

    /// Try to parse actix-web' `ServiceRequest` and fetch the `BasicAuth` from it.
    ///
    /// ## Warning
    ///
    /// This function is used right now for middleware creation only
    /// and might change or be totally removed,
    /// depends on `actix-web = "1.0"` release changes.
    ///
    /// This issue will be resolved in the `0.3.0` release.
    /// Before that -- brace yourselves!
    pub fn from_service_request(req: &mut ServiceRequest, config: &Config) -> <Self as FromRequest>::Future {
        authorization::Authorization::<authorization::Bearer>::parse(&req)
            .map(|auth| BearerAuth(auth.into_scheme()))
            .map_err(|_| {
                // TODO: debug! the original error
                let challenge = config.clone().into_inner();

                AuthenticationError::new(challenge)
            })
    }
}

impl FromRequest for BearerAuth {
    type Config = Config;
    type Future = Result<Self, Self::Error>;
    type Error = AuthenticationError<bearer::Bearer>;

    fn from_request(req: &HttpRequest, _payload: &mut Payload) -> <Self as FromRequest>::Future {
        authorization::Authorization::<authorization::Bearer>::parse(req)
            .map(|auth| BearerAuth(auth.into_scheme()))
            .map_err(|_| {
                let bearer = req
                    .app_data::<Self::Config>()
                    .map(|config| config.0.clone())
                    .unwrap_or_else(Default::default);

                AuthenticationError::new(bearer)
            })
    }
}

/// Extended error customization for HTTP `Bearer` auth.
impl AuthenticationError<bearer::Bearer> {
    /// Attach `Error` to the current Authentication error.
    ///
    /// Error status code will be changed to the one provided by the `kind` Error.
    pub fn with_error(mut self, kind: Error) -> Self {
        *self.status_code_mut() = kind.status_code();
        self.challenge_mut().error = Some(kind);
        self
    }

    /// Attach error description to the current Authentication error.
    pub fn with_error_description<T>(mut self, desc: T) -> Self
    where
        T: Into<Cow<'static, str>>,
    {
        self.challenge_mut().error_description = Some(desc.into());
        self
    }

    /// Attach error URI to the current Authentication error.
    ///
    /// It is up to implementor to provide properly formed absolute URI.
    pub fn with_error_uri<T>(mut self, uri: T) -> Self
    where
        T: Into<Cow<'static, str>>,
    {
        self.challenge_mut().error_uri = Some(uri.into());
        self
    }
}