use actix_session::Session;
use actix_web::{
    dev::Payload,
    http::{header::LOCATION, StatusCode},
    web::Data,
    FromRequest, HttpRequest, HttpResponse, ResponseError,
};
use futures::future::LocalBoxFuture;
use uuid::Uuid;

use crate::{store::User, State};

#[derive(serde::Deserialize, serde::Serialize)]
pub(crate) struct CookieData {
    accepted: bool,
}

impl CookieData {
    pub(crate) fn set_accepted(session: &Session) -> Result<(), SessionError> {
        session
            .set("accepted", CookieData { accepted: true })
            .map_err(|_| SessionError::Set)
    }

    fn accepted(session: &Session) -> bool {
        session
            .get::<CookieData>("accepted")
            .map(|opt| opt.is_some())
            .unwrap_or(false)
    }
}

#[derive(serde::Deserialize, serde::Serialize)]
pub(crate) struct UserData {
    id: Uuid,
}

impl UserData {
    pub(crate) fn set_data(id: Uuid, session: &Session) -> Result<(), SessionError> {
        session
            .set("user-data", UserData { id })
            .map_err(|_| SessionError::Set)
    }

    pub(crate) fn remove(session: &Session) {
        session.remove("user-data")
    }

    fn data(session: &Session) -> Result<Option<UserData>, actix_web::Error> {
        Ok(session.get::<UserData>("user-data")?)
    }
}

pub struct AcceptedCookies(());

pub struct Authenticated {
    user: User,
}

impl Authenticated {
    pub fn user(self) -> User {
        self.user
    }
}

#[derive(Debug, thiserror::Error)]
#[error("{0}")]
struct ServerError(String);

impl ResponseError for ServerError {
    fn status_code(&self) -> StatusCode {
        StatusCode::SEE_OTHER
    }

    fn error_response(&self) -> HttpResponse {
        HttpResponse::build(self.status_code())
            .header(LOCATION, self.0.clone())
            .finish()
    }
}

#[derive(Debug, thiserror::Error)]
pub enum SessionError {
    #[error("Failed to set sesion data")]
    Set,
}

impl FromRequest for AcceptedCookies {
    type Error = actix_web::Error;
    type Future = LocalBoxFuture<'static, Result<Self, Self::Error>>;
    type Config = ();

    fn from_request(req: &HttpRequest, _: &mut Payload) -> Self::Future {
        let session_fut = Session::extract(req);
        let state_fut = Data::<State>::extract(req);

        Box::pin(async move {
            let session = session_fut.await?;
            let state = state_fut.await?;

            if CookieData::accepted(&session) {
                Ok(AcceptedCookies(()))
            } else {
                log::debug!("Browser has not accepted cookies");
                Err(ServerError(state.pages.not_found_path()).into())
            }
        })
    }
}

impl FromRequest for Authenticated {
    type Error = actix_web::Error;
    type Future = LocalBoxFuture<'static, Result<Self, Self::Error>>;
    type Config = ();

    fn from_request(req: &HttpRequest, _: &mut Payload) -> Self::Future {
        let session_fut = Session::extract(req);
        let state_fut = Data::<State>::extract(req);

        Box::pin(async move {
            let session = session_fut.await?;
            let state = state_fut.await?;

            if let Some(UserData { id }) = UserData::data(&session)? {
                let res = state.user_store.user_by_id(id).await;

                let user_opt = match res {
                    Ok(user_opt) => user_opt,
                    Err(_) => {
                        log::debug!("Error fetching user data from store");
                        return Err(ServerError(state.pages.internal_server_error_path()).into());
                    }
                };

                if let Some(user) = user_opt {
                    return Ok(Authenticated { user });
                }
            }

            log::debug!("No user data found for browser");
            Err(ServerError(state.pages.not_found_path()).into())
        })
    }
}