fn publishCondOf

use std.rpc { asScoped }

data Ev {
  userId: str
  amount: i64
}

topic Evs: Ev sharded by .userId

// a condition of a rule can look at the key, the element and the caller
policy Evs {
  allow publish if caller.isUser(key) && element.amount <= 100
  deny publish if element.amount < 0
}

cluster demo {
  role store { journal }
}

fn user(id: str) -> Principal {
  Principal.User(id, [], Map.new(), false, none)
}

fn tryPublish(e: Ev) -> str io, db {
  match Evs.publish(e) {
    TopicError _ => "denied"
    _ => "ok"
  }
}

fn main() io, db {
  asScoped(user("a")) {
    print("{tryPublish(Ev{ userId: "a", amount: 5 })} {tryPublish(Ev{ userId: "a", amount: 500 })} {tryPublish(Ev{ userId: "b", amount: 5 })}")
  }
}

ok denied denied