use axum::{
    extract::{FromRequest, Form, Json, State},
    http::{self, Request, StatusCode},
    response::{IntoResponse, Response},
    RequestExt,
};
use axum_typed_multipart::{TryFromMultipart, TypedMultipart};
use snafu::prelude::*;
use tower_cookies::{Cookies, Cookie};
use yunohost_api::{Username, Password};

use crate::{
    error::*,
    state::{COOKIE_NAME, RoutableAppState, sessions::LoggedInUser},
};

#[derive(Debug, TryFromMultipart, Deserialize)]
pub struct LoginForm {
    username: Username,
    #[allow(dead_code)]
    password: Password,
}

#[async_trait]
impl<S, B> FromRequest<S, B> for LoginForm
where
    Json<LoginForm>: FromRequest<(), B>,
    Form<LoginForm>: FromRequest<(), B>,
    TypedMultipart<LoginForm>: FromRequest<S, B>,
    B::Data: Into<axum::body::Bytes>,
    B::Error: Into<axum::BoxError> + Send + std::error::Error,
    B: Send + 'static + axum::body::HttpBody,
    S: Send
{
    type Rejection = Response;

    async fn from_request(req: Request<B>, _state: &S) -> Result<Self, Self::Rejection> {
        let headers = req.headers();

        if let Some(mime) = headers.get(http::header::CONTENT_TYPE).and_then(|v| v.to_str().ok()) {
            if mime.starts_with("application/json") {
                let Json(login_form): Json<LoginForm> = req.extract().await.map_err(IntoResponse::into_response)?;
                return Ok(login_form);
            }

            if mime.starts_with("application/x-www-form-urlencoded") {
                let Form(login_form) = req.extract().await.map_err(IntoResponse::into_response)?;
                return Ok(login_form);
            }

            if mime.starts_with("multipart/form-data") {
                let TypedMultipart(login_form): TypedMultipart<LoginForm> = req.extract().await.map_err(IntoResponse::into_response)?;
                return Ok(login_form);
            }
            Err(StatusCode::UNSUPPORTED_MEDIA_TYPE.into_response())
        } else {
            Err("No POST Content-Type".into_response())
        }
    }
}

#[debug_handler]
pub async fn route(user: Option<LoggedInUser>, cookies: Cookies, state: State<RoutableAppState>, form: LoginForm) -> Result<String, Error> {
    trace!("ROUTE: /login/");

    if let Some(username) = user {
        return Ok(format!("Welcome back, {}! You were already logged in.", username));
    }

    debug!("Performing login attempt for user {}", &form.username);

    // No cookie, or cookie is invalid. Perform login.
    if state.check_login(&form.username, &form.password).await.unwrap() {
        debug!("Login was successful for user {}. Saving cookie now.", &form.username);
        let session = state.sessions.make_session(COOKIE_NAME, &form.username).await;
        cookies.add(session.cookie());
        Ok(format!("Welcome {}", &form.username))
    } else {
        debug!("Login failed for user {}", &form.username);
        Ok(format!("Invalid login for {}", &form.username))
    }
}