use std::cell::RefCell;

#[derive(Debug, Clone)]
pub struct Client {
    client: influxdb2::Client,

    // We should get two buckets, one temp and a permanent, but for now we'll use just one
    bucket: String,
}

pub enum Bucket {
    Tmp,
    Perm,
}

thread_local! {
    static INFLUX_CLIENT : RefCell<Client> = Client::new();
}

impl Client {
    fn new() -> RefCell<Client> {
        let host = dotenv::var("INFLUX_HOST").unwrap_or_else(|_| {
            println! {"INFLUX_HOST not found in .env file, using default: http://localhost:8086"};
            "http://localhost:8086".to_string()
        });
        let bucket = dotenv::var("INFLUX_BUCKET").expect("INFLUX_BUCKET not defined in .env file");
        let org = dotenv::var("INFLUX_ORG").expect("INFLUX_ORG not defined in .env file");
        let token = dotenv::var("INFLUX_TOKEN").expect("INFLUX_TOKEN not defined in .env file");

        RefCell::new(Client {
            client: influxdb2::Client::new(host, org, token),
            bucket,
        })
    }
    pub fn get() -> Client {
        INFLUX_CLIENT.with(|rc| rc.borrow().clone())
    }

    pub async fn write(
        &self,
        _bucket: Bucket,
        body: impl futures::Stream<Item = impl influxdb2::models::WriteDataPoint>
            + Send
            + Sync
            + 'static,
    ) -> Result<(), influxdb2::RequestError> {
        // TODO: use _bucket to choose from internal list

        self.client.write(self.bucket.as_str(), body).await
    }

    pub async fn query<T>(
        &self,
        _bucket: Bucket,
        q: String,
    ) -> Result<Vec<T>, influxdb2::RequestError>
    where
        T: influxdb2_structmap::FromMap,
    {
        // TODO: use _bucket to choose from internal list
        let from_bucket = format!("from(bucket: \"{}\")", self.bucket);
        let query = from_bucket + &q;
        let query = influxdb2::models::Query::new(query);

        self.client.query::<T>(Some(query)).await
    }
}

#[cfg(test)]
mod test {
    use crate::influx::{Bucket, Client};

    #[tokio::test]
    async fn test_new_get_cli() {
        let health = Client::get().client.health().await;
        assert!(health.is_ok())
    }

    use influxdb2_derive::{FromDataPoint, WriteDataPoint};
    #[derive(Default, Debug, PartialEq, FromDataPoint, WriteDataPoint)]
    #[measurement = "stock_prices"]
    struct StockPrice {
        #[influxdb(tag)]
        ticker: String,
        #[influxdb(field)]
        value: f64,
        #[influxdb(timestamp)]
        time: i64,
    }

    #[tokio::test]
    async fn test_write_then_query() {
        let time = chrono::Utc::now().timestamp_nanos();
        let w = StockPrice {
            ticker: "ASDF".into(),
            value: 150.5,
            time: time,
        };

        let res = Client::get()
            .write(Bucket::Perm, futures::stream::iter([w]))
            .await;
        assert!(res.is_ok());

        let query = format!(
            "
            |> range(start: -1s)
            |> filter(fn: (r) => r[\"_measurement\"] == \"stock_prices\")
            |> filter(fn: (r) => r[\"ticker\"] == \"ASDF\")
            |> sort(columns: [\"time\"], desc: true)                
        "
        );

        let r = Client::get()
            .query::<StockPrice>(Bucket::Perm, query)
            .await
            .unwrap();

        assert!(r.len() > 0);
        assert_eq!(r[0].ticker, "ASDF");
        assert_eq!(r[0].value, 150.5);
    }
}