use async_graphql::{EmptyMutation, EmptySubscription, Object, Schema};
use serde_json;

struct Query;

#[Object]
impl Query {
    async fn pointless(&self) -> String {
        "this is pointless.".to_string()
    }
}

#[derive(Clone)]
pub struct Database {
    schema: Schema<Query, EmptyMutation, EmptySubscription>,
}

impl Database {
    pub fn new() -> Self {
        Self {
            schema: Schema::new(Query, EmptyMutation, EmptySubscription),
        }
    }

    pub async fn execute(&self, qry: &str) -> String {
        let res = self.schema.execute(qry).await;
        serde_json::to_string(&res).unwrap()
    }
}

#[cfg(test)]
mod queries {
    use super::*;

    #[async_std::test]
    async fn working() {
        let db = Database::new();
        let output = db.execute("{pointless}").await;
        let expected = r#"{"data":{"pointless":"this is pointless."}}"#;
        assert!(
            output == expected,
            "Got '{}' instead of '{}'.",
            output,
            expected
        )
    }
}