use crate::{
    config::DynNode,
    error::ServiceError,
    modules::{Node, NodeContext, NodeKind, NodeRequest, NodeResponse},
};
use base64::Engine;
use futures::Future;
use http_body_util::{combinators::BoxBody, BodyExt};
use hyper::{
    header::{HeaderValue, AUTHORIZATION, WWW_AUTHENTICATE},
    Response, StatusCode,
};
use log::debug;
use serde::Deserialize;
use serde_yaml::Value;
use std::{pin::Pin, sync::Arc};

use super::Credentials;

pub struct HttpBasicAuthKind;
impl NodeKind for HttpBasicAuthKind {
    fn name(&self) -> &'static str {
        "http_basic_auth"
    }
    fn instanciate(&self, config: Value) -> anyhow::Result<Arc<dyn Node>> {
        Ok(Arc::new(serde_yaml::from_value::<HttpBasicAuth>(config)?))
    }
}

#[derive(Deserialize)]
pub struct HttpBasicAuth {
    realm: String,
    users: Credentials,
    next: DynNode,
}

impl Node for HttpBasicAuth {
    fn handle<'a>(
        &'a self,
        context: &'a mut NodeContext,
        request: NodeRequest,
    ) -> Pin<Box<dyn Future<Output = Result<NodeResponse, ServiceError>> + Send + Sync + 'a>> {
        Box::pin(async move {
            if let Some(auth) = request.headers().get(AUTHORIZATION) {
                let k = auth
                    .as_bytes()
                    .strip_prefix(b"Basic ")
                    .ok_or(ServiceError::BadAuth)?;
                let k = base64::engine::general_purpose::STANDARD.decode(k)?;
                let k = String::from_utf8(k)?;
                let (username, password) = k.split_once(":").ok_or(ServiceError::BadAuth)?;
                if self.users.authentificate(username, password) {
                    debug!("valid auth");
                    return self.next.handle(context, request).await;
                } else {
                    debug!("invalid auth");
                }
            }
            debug!("unauthorized; sending auth challenge");
            let mut r = Response::new(BoxBody::<_, ServiceError>::new(
                String::new().map_err(|_| unreachable!()),
            ));
            *r.status_mut() = StatusCode::UNAUTHORIZED;
            r.headers_mut().insert(
                WWW_AUTHENTICATE,
                HeaderValue::from_str(&format!("Basic realm=\"{}\"", self.realm)).unwrap(),
            );
            Ok(r)
        })
    }
}