use axum::{
    async_trait,
    extract::{Extension, FromRequestParts, State},
    http::request::Parts,
    response::IntoResponse,
    routing::{get, post},
    RequestPartsExt, Router,
};
use clap::Parser;
use morethantext::MoreThanText;
use std::convert::Infallible;
use tokio::{spawn, sync::mpsc::channel};
use tower_cookies::{Cookie, CookieManagerLayer, Cookies};
use uuid::Uuid;

const LOCALHOST: &str = "127.0.0.1";
const SESSION_KEY: &str = "sessionid";

#[derive(Parser, Debug)]
#[command(version, about, long_about = None)]
struct Args {
    /// Post used
    #[arg(short, long, default_value_t = 3000)]
    port: u16,
    /// IP used
    #[arg(short, long, default_value_t = LOCALHOST.to_string())]
    address: String,
    /// cluster host
    #[arg(short, long, num_args(0..))]
    node: Vec<String>,
}

#[tokio::main]
async fn main() {
    let args = Args::parse();
    let addr = format!("{}:{}", args.address, args.port);
    let state = MoreThanText::new();
    let app = create_app(state).await;
    let listener = tokio::net::TcpListener::bind(&addr).await.unwrap();
    axum::serve(listener, app.into_make_service())
        .await
        .unwrap();
}

async fn create_app(state: MoreThanText) -> Router {
    Router::new()
        .route("/", get(mtt_conn))
        .route("/api/:document", post(mtt_conn))
        .layer(CookieManagerLayer::new())
        .layer(Extension(state.clone()))
        .with_state(state)
}

#[derive(Clone)]
struct SessionID(Uuid);

#[async_trait]
impl<S> FromRequestParts<S> for SessionID
where
    S: Send + Sync,
{
    type Rejection = Infallible;

    async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self, Self::Rejection> {
        let Extension(cookies) = parts.extract::<Extension<Cookies>>().await.unwrap();
        let Extension(mut state) = parts.extract::<Extension<MoreThanText>>().await.unwrap();
        let req_id = match cookies.get(SESSION_KEY) {
            Some(cookie) => Some(cookie.value().to_string()),
            None => None,
        };
        let requested = req_id.clone();
        let (tx, mut rx) = channel(1);
        spawn(async move {
            tx.send(state.validate_session(requested)).await.unwrap();
        });
        let id = rx.recv().await.unwrap();
        if !req_id.is_some_and(|x| x == id.to_string()) {
            cookies.add(Cookie::new(SESSION_KEY, id.to_string()));
        }
        Ok(SessionID(id))
    }
}

async fn mtt_conn(sess_id: SessionID, state: State<MoreThanText>) -> impl IntoResponse {
    let (tx, mut rx) = channel(1);
    spawn(async move {
        tx.send(state.get_document(sess_id.0)).await.unwrap();
    });
    let content = rx.recv().await.unwrap();
    content
}

#[cfg(test)]
mod servers {
    use super::*;
    use axum::{
        body::Body,
        http::{
            header::{COOKIE, SET_COOKIE},
            Method,
            Request, StatusCode,
        },
    };
    use tower::ServiceExt;

    #[tokio::test]
    async fn get_home_page() {
        let app = create_app(MoreThanText::new()).await;
        let response = app
            .oneshot(Request::builder().uri("/").body(Body::empty()).unwrap())
            .await
            .unwrap();
        assert_eq!(response.status(), StatusCode::OK);
        let sessid = format!("{:?}", response.headers().get(SET_COOKIE).unwrap());
        assert!(sessid.contains(SESSION_KEY), "did not set session id");
    }

    #[tokio::test]
    async fn session_ids_are_unique() {
        let app = create_app(MoreThanText::new()).await;
        let mut holder: Vec<String> = Vec::new();
        for _ in 0..5 {
            let response = app
                .clone()
                .oneshot(Request::builder().uri("/").body(Body::empty()).unwrap())
                .await
                .unwrap();
            let sessid = format!("{:?}", response.headers().get(SET_COOKIE).unwrap());
            assert!(
                !holder.contains(&sessid),
                "found duplicate entry: {:?}",
                holder
            );
            holder.push(sessid);
        }
    }

    #[tokio::test]
    async fn cookie_only_issued_once() {
        let app = create_app(MoreThanText::new()).await;
        let initial = app
            .clone()
            .oneshot(Request::builder().uri("/").body(Body::empty()).unwrap())
            .await
            .unwrap();
        assert_eq!(initial.status(), StatusCode::OK);
        let sessid = initial.headers().get(SET_COOKIE).unwrap();
        let request = Request::builder()
            .uri("/")
            .header(COOKIE, sessid.clone())
            .body(Body::empty())
            .unwrap();
        let response = app.clone().oneshot(request).await.unwrap();
        assert_eq!(response.status(), StatusCode::OK);
        match response.headers().get(SET_COOKIE) {
            Some(info) => assert!(false, "first pass: {:?}, second pass: {:?}", sessid, info),
            None => {}
        }
    }

    #[tokio::test]
    async fn receive_file_not_found() {
        let app = create_app(MoreThanText::new()).await;
        let response = app
            .oneshot(
                Request::builder()
                    .uri("/isomething")
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(response.status(), StatusCode::NOT_FOUND);
    }

    #[tokio::test]
    async fn add_new_page() {
        let base = "/something";
        let api = "/api".to_owned() + base;
        let app = create_app(MoreThanText::new()).await;
        let response = app
            .oneshot(
                Request::builder()
                    .method(Method::POST)
                    .uri(&api)
                    .body(Body::empty())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(response.status(), StatusCode::OK, "failed to post ro {:?}", api);
    }
}