nil-server 0.5.1

// Copyright (C) Call of Nil contributors
// SPDX-License-Identifier: AGPL-3.0-only

use crate::error::Result;
use crate::res;
use axum::RequestExt;
use axum::extract::Request;
use axum::middleware::Next;
use axum::response::Response;
use axum_extra::TypedHeader;
use derive_more::{Deref, From, Into};
use futures::TryFutureExt;
use headers::Authorization;
use headers::authorization::Bearer;
use jiff::{SignedDuration, Zoned};
use jsonwebtoken::{DecodingKey, EncodingKey, Header, TokenData, Validation, decode, encode};
use nil_core::player::PlayerId;
use nil_core::ruler::Ruler;
use nil_server_database::sql_types::player_id::PlayerId as DbPlayerId;
use nil_server_types::auth::Token;
use serde::{Deserialize, Serialize};
use std::env;
use std::sync::LazyLock;
use tokio::task::spawn_blocking;

// Using a known secret is not a problem for local servers.
static JWT_SECRET: LazyLock<Box<str>> = LazyLock::new(|| {
  env::var("NIL_JWT_SECRET")
    .map(String::into_boxed_str)
    .unwrap_or_else(|_| Box::from("CALL-OF-NIL"))
});

pub async fn authorization(mut request: Request, next: Next) -> Response {
  let Ok(token) = request
    .extract_parts::<TypedHeader<Authorization<Bearer>>>()
    .map_ok(|header| Token::new(header.token()))
    .await
  else {
    tracing::warn!("Missing authorization header");
    return res!(UNAUTHORIZED);
  };

  match decode_jwt(token).await {
    Ok(data) => {
      request
        .extensions_mut()
        .insert(CurrentPlayer(data.claims.sub));

      next.run(request).await
    }
    Err(err) => {
      tracing::warn!("Failed to decode token: {err}");
      res!(UNAUTHORIZED)
    }
  }
}

#[derive(Serialize, Deserialize)]
pub(crate) struct Claims {
  pub sub: PlayerId,
  pub exp: usize,
  pub iat: usize,
}

pub(crate) async fn encode_jwt(player: PlayerId) -> Result<Token> {
  let token = spawn_blocking(move || {
    let now = Zoned::now();
    let iat = now.timestamp().as_second().try_into()?;
    let exp = now
      .saturating_add(SignedDuration::from_hours(24 * 7))
      .timestamp()
      .as_second()
      .try_into()?;

    let token = encode(
      &Header::default(),
      &Claims { sub: player, iat, exp },
      &EncodingKey::from_secret(JWT_SECRET.as_bytes()),
    )?;

    Ok::<_, anyhow::Error>(Token::new(token))
  })
  .await??;

  Ok(token)
}

pub(crate) async fn decode_jwt(token: Token) -> Result<TokenData<Claims>> {
  let claims = spawn_blocking(move || {
    decode(
      &token,
      &DecodingKey::from_secret(JWT_SECRET.as_bytes()),
      &Validation::default(),
    )
    .map_err(Into::<anyhow::Error>::into)
  })
  .await??;

  Ok(claims)
}

#[derive(Clone, Debug, Deref, From, Into, PartialEq, Eq)]
pub struct CurrentPlayer(pub(crate) PlayerId);

impl From<CurrentPlayer> for Ruler {
  fn from(player: CurrentPlayer) -> Self {
    Ruler::Player { id: player.0 }
  }
}

impl From<CurrentPlayer> for DbPlayerId {
  fn from(player: CurrentPlayer) -> Self {
    DbPlayerId::from(player.0)
  }
}

impl PartialEq<PlayerId> for CurrentPlayer {
  fn eq(&self, other: &PlayerId) -> bool {
    self.0.eq(other)
  }
}