use crate::{to_cookie_page, to_home, AcceptedCookies, Authenticated, Error, State};
use actix_session::Session;
use actix_web::{error::BlockingError, web, HttpResponse};

pub type LoginPageArgs = (
    Option<AcceptedCookies>,
    Option<Authenticated>,
    web::Data<State>,
);

pub type LoginArgs = (
    Option<AcceptedCookies>,
    Option<Authenticated>,
    web::Data<State>,
    Session,
    web::Form<LoginForm>,
);

#[derive(Debug, serde::Deserialize)]
pub struct LoginForm {
    username: String,
    password: String,
}

#[derive(Debug)]
pub struct LoginState {
    state: State,
    form: Option<LoginForm>,
    error: Option<LoginError>,
}

pub fn login_page(
    (cookies, authenticated, state): LoginPageArgs,
) -> Result<LoginState, HttpResponse> {
    if cookies.is_none() {
        return Err(to_cookie_page(&state));
    }

    if authenticated.is_some() {
        return Err(to_home(&state));
    }

    Ok(LoginState::new_empty(&state))
}

pub async fn login(
    (cookies, authenticated, state, session, form): LoginArgs,
) -> Result<Result<LoginState, HttpResponse>, Error> {
    if cookies.is_none() {
        return Ok(Err(to_cookie_page(&state)));
    }

    if authenticated.is_some() {
        return Ok(Err(to_home(&state)));
    }

    let form = form.into_inner();

    match try_login(session, &form, &state).await? {
        Ok(res) => Ok(Err(res)),
        Err(e) => Ok(Ok(LoginState::new_from_request(&state, form, e))),
    }
}

impl LoginState {
    fn new_empty(state: &State) -> Self {
        LoginState {
            state: state.clone(),
            form: None,
            error: None,
        }
    }

    fn new_from_request(state: &State, form: LoginForm, error: LoginError) -> Self {
        LoginState {
            state: state.clone(),
            form: Some(form),
            error: Some(error),
        }
    }

    pub fn register_path(&self) -> String {
        self.state.pages.register_path()
    }

    pub fn login_path(&self) -> String {
        self.state.pages.login_path()
    }

    pub fn home_path(&self) -> String {
        self.state.pages.home_path()
    }

    pub fn username(&self) -> Option<String> {
        self.form.as_ref().map(|form| form.username.clone())
    }

    pub fn username_error(&self) -> Option<String> {
        self.error.as_ref().and_then(|e| e.username())
    }

    pub fn password(&self) -> Option<String> {
        self.form.as_ref().map(|form| form.password.clone())
    }
}

#[derive(Debug)]
enum LoginError {
    Invalid,
}

impl LoginError {
    fn username(&self) -> Option<String> {
        match self {
            LoginError::Invalid => Some("Username or Password is incorrect".to_owned()),
        }
    }
}

async fn try_login(
    session: Session,
    form: &LoginForm,
    state: &State,
) -> Result<Result<HttpResponse, LoginError>, Error> {
    let res = state
        .user_store
        .exec(crate::store::Login {
            username: form.username.clone(),
            password: form.password.clone(),
        })
        .await;

    let user = match res {
        Ok(user) => user,
        Err(BlockingError::Error(crate::store::StoreError::AuthenticationFailed))
        | Err(BlockingError::Error(crate::store::StoreError::NoUser)) => {
            return Ok(Err(LoginError::Invalid))
        }
        Err(e) => return Err(e.into()),
    };

    crate::extractors::UserData::set_data(user.id(), &session)?;

    Ok(Ok(to_home(&state)))
}