use std::env;

use anyhow::Context;
use axum::extract::FromRef;
use axum::http::{HeaderValue, Method};
use axum::Router;
use axum_sessions::async_session::MemoryStore;
use como_infrastructure::register::ServiceRegister;
use oauth2::basic::BasicClient;
use tower::ServiceBuilder;
use tower_http::{cors::CorsLayer, trace::TraceLayer};

use crate::controllers::auth::AuthController;
use crate::controllers::graphql::GraphQLController;
use crate::zitadel::client::oauth_client;
use crate::zitadel::{IntrospectionState, IntrospectionStateBuilder};

pub struct Api;

impl Api {
    pub async fn new(
        port: u32,
        cors_origin: &str,
        service_register: ServiceRegister,
    ) -> anyhow::Result<()> {
        let client_id = env::var("CLIENT_ID").expect("Missing CLIENT_ID!");
        let client_secret = env::var("CLIENT_SECRET").expect("Missing CLIENT_SECRET!");
        let zitadel_url = env::var("ZITADEL_URL").expect("missing ZITADEL_URL");

        let is = IntrospectionStateBuilder::new(&zitadel_url)
            .with_basic_auth(&client_id, &client_secret)
            .build()
            .await?;

        let store = MemoryStore::new();
        let oauth_client = oauth_client();
        let app_state = AppState {
            oauth_client,
            store,
            introspection_state: is,
        };

        let router = Router::new()
            .nest(
                "/auth",
                AuthController::new_router(service_register.clone(), app_state.clone()).await?,
            )
            .nest(
                "/graphql",
                GraphQLController::new_router(service_register.clone(), app_state.clone()),
            )
            .layer(
                ServiceBuilder::new()
                    .layer(TraceLayer::new_for_http())
                    .layer(
                        CorsLayer::new()
                            .allow_origin(
                                cors_origin
                                    .parse::<HeaderValue>()
                                    .context("could not parse cors origin as header")?,
                            )
                            .allow_headers([axum::http::header::CONTENT_TYPE])
                            .allow_methods([Method::GET, Method::POST, Method::OPTIONS]),
                    ),
            );

        let host = env::var("HOST").unwrap_or("0.0.0.0".to_string());

        tracing::info!("running on: {host}:{}", port);

        axum::Server::bind(&format!("{host}:{}", port).parse().unwrap())
            .serve(router.into_make_service())
            .await
            .context("error while starting API")?;

        Ok(())
    }
}

#[derive(Clone)]
pub struct AppState {
    oauth_client: BasicClient,
    introspection_state: IntrospectionState,
    store: MemoryStore,
}

impl FromRef<AppState> for BasicClient {
    fn from_ref(state: &AppState) -> Self {
        state.oauth_client.clone()
    }
}

impl FromRef<AppState> for MemoryStore {
    fn from_ref(state: &AppState) -> Self {
        state.store.clone()
    }
}

impl FromRef<AppState> for IntrospectionState {
    fn from_ref(input: &AppState) -> Self {
        input.introspection_state.clone()
    }
}