use axum::extract::State;
use axum::http::HeaderMap;
use axum::{
    Form, Router,
    extract::Query,
    response::{IntoResponse, Redirect},
    routing::{get, post},
};
use maud::{DOCTYPE, html};
use serde::Deserialize;

use crate::models::user::{AuthSession, Credentials};
use crate::{AppError, AppState};

#[derive(Deserialize, Debug)]
struct NextUrl {
    next: Option<String>,
}

pub fn router() -> Router<AppState> {
    Router::new()
        .route("/login", post(self::post::login))
        .route("/login", get(self::get::login))
        .route("/logout", get(self::get::logout))
}

mod post {
    use super::*;

    #[axum::debug_handler]
    pub async fn login(
        mut auth_session: AuthSession,
        State(mut state): State<AppState>,
        Query(NextUrl { next }): Query<NextUrl>,
        Form(creds): Form<Credentials>,
    ) -> Result<impl IntoResponse, AppError> {
        let mut headers = HeaderMap::new();

        let user = match auth_session.authenticate(creds.clone()).await {
            Ok(Some(user)) => user,
            Ok(None) => {
                return Err(AppError(anyhow::Error::msg(
                    "Username and password do not match",
                )));
            }
            Err(_) => return Err(AppError(anyhow::Error::msg("Internal server error"))),
        };

        if auth_session.login(&user).await.is_err() {
            return Err(AppError(anyhow::Error::msg("Server error during login")));
        }

        state.init(&user).await?;

        if let Some(url) = next {
            headers.insert("HX-Redirect", url.parse()?);
        } else {
            headers.insert("HX-Redirect", "/".parse()?);
        }

        Ok((headers, "ok"))
    }
}

mod get {
    use super::*;

    pub async fn login(Query(NextUrl { next }): Query<NextUrl>) -> impl IntoResponse {
        let post_url = format!(
            "/login{}",
            next.map_or("".to_string(), |n| format!("?next={}", n))
        );
        html! {
            (DOCTYPE)
            html {
            head {
                meta name="viewport" content="width=device-width";
                script src="https://cdn.jsdelivr.net/npm/htmx.org@2.0.7/dist/htmx.min.js" {}
                script src="https://cdn.jsdelivr.net/npm/htmx-ext-response-targets@2.0.4" integrity="sha384-T41oglUPvXLGBVyRdZsVRxNWnOOqCynaPubjUVjxhsjFTKrFJGEMm3/0KGmNQ+Pg" crossorigin="anonymous" {}
                script src="https://cdn.jsdelivr.net/npm/alpinejs@3.15.0/dist/cdn.min.js" defer {}
                link rel="stylesheet" type="text/css" href="/static/index.css";
                link rel="stylesheet" type="text/css" href="/static/login.css";
                title { "Mascarpone" }
            }
            body hx-ext="response-targets" {
                h1 { "Mascarpone" }
                form hx-post=(post_url) hx-target-error="#error" x-data="{ user: '', pass: '' }" {
                    label for="username" { "Username" }
                    input name="username" #username autofocus x-model="user";
                    label for="password" { "Password" }
                    input name="password" #password type="password" x-model="pass";

                    input type="submit" value="login" x-bind:disabled="!(user.length && pass.length)";
                    #error {}
                }
            }
            }
        }
    }

    pub async fn logout(
        mut auth_session: AuthSession,
        State(mut state): State<AppState>,
    ) -> Result<impl IntoResponse, AppError> {
        let user = auth_session.user.clone();
        auth_session.logout().await?;

        if let Some(user) = user {
            state.remove(&user);
        }

        Ok(Redirect::to("/login").into_response())
    }
}