use axum::{
    extract::{Extension, FromRequestParts, Path, State},
    http::{request::Parts, Method, StatusCode},
    response::IntoResponse,
    routing::{get, post},
    RequestPartsExt, Router,
};
use clap::Parser;
use morethantext::{ActionType, MoreThanText};
use std::{collections::HashMap, 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("/{document}", get(mtt_conn))
        .route("/api/{document}", post(mtt_conn))
        .layer(CookieManagerLayer::new())
        .layer(Extension(state.clone()))
        .with_state(state)
}

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

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,
    method: Method,
    path: Path<HashMap<String, String>>,
    state: State<MoreThanText>,
    body: String,
) -> impl IntoResponse {
    let (tx, mut rx) = channel(1);
    let action = match method {
        Method::GET => ActionType::Get,
        Method::POST => ActionType::Add,
        _ => unreachable!("reouter should prevent this"),
    };
    let doc = match path.get("document") {
        Some(result) => result.clone(),
        None => "root".to_string(),
    };
    spawn(async move {
        tx.send(state.get_document(sess_id.0, action, doc, body))
            .await
            .unwrap();
    });
    let reply = rx.recv().await.unwrap();
    let status = match reply.get_error() {
        Some(_) => StatusCode::NOT_FOUND,
        None => StatusCode::OK,
    };
    (status, reply.get_document())
}

#[cfg(test)]
mod servers {
    use super::*;
    use axum::{
        body::Body,
        http::{
            header::{COOKIE, SET_COOKIE},
            Method, Request,
        },
    };
    use http_body_util::BodyExt;
    use serde_json::json;
    use std::time::Duration;
    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 uri = "/something";
        let app = create_app(MoreThanText::new()).await;
        let response = app
            .oneshot(Request::builder().uri(uri).body(Body::empty()).unwrap())
            .await
            .unwrap();
        assert_eq!(
            response.status(),
            StatusCode::NOT_FOUND,
            "'{}' should not exist",
            uri
        );
    }

    #[tokio::test]
    async fn add_new_page() {
        let base = "/something".to_string();
        let api = format!("/api{}", &base);
        let content = format!("content-{}", Uuid::new_v4());
        let document = json!({
            "template": content.clone()
        });
        let app = create_app(MoreThanText::new()).await;
        let response = app
            .clone()
            .oneshot(
                Request::builder()
                    .method(Method::POST)
                    .uri(&api)
                    .body(document.to_string())
                    .unwrap(),
            )
            .await
            .unwrap();
        assert_eq!(
            response.status(),
            StatusCode::OK,
            "failed to post ro {:?}",
            api
        );
        let response = app
            .oneshot(Request::builder().uri(&base).body(Body::empty()).unwrap())
            .await
            .unwrap();
        assert_eq!(
            response.status(),
            StatusCode::OK,
            "failed to get ro {:?}",
            base
        );
        let body = response.into_body().collect().await.unwrap().to_bytes();
        assert_eq!(body, content);
    }
}