use crate::schema;
use crate::Db;
use anyhow::Result;
use chrono::Utc;
use diesel::prelude::*;
use diesel_async::RunQueryDsl;
use feedsignal_core::TopicAffinities;

impl Db {
    pub async fn load_affinities(&self) -> Result<TopicAffinities> {
        use schema::topic_affinities::dsl;
        let mut conn = self.pool.get().await?;
        let row: Option<String> = dsl::topic_affinities
            .filter(dsl::user_id.eq("default"))
            .select(dsl::affinities)
            .first(&mut conn)
            .await
            .optional()?;
        Ok(match row {
            Some(json) => serde_json::from_str(&json)?,
            None => TopicAffinities::default(),
        })
    }

    pub async fn save_affinities(&self, affinities: &TopicAffinities) -> Result<()> {
        use schema::topic_affinities::dsl;
        let mut conn = self.pool.get().await?;
        let json = serde_json::to_string(affinities)?;
        let updated_at = Utc::now().to_rfc3339();
        diesel::insert_into(dsl::topic_affinities)
            .values((
                dsl::user_id.eq("default"),
                dsl::affinities.eq(&json),
                dsl::updated_at.eq(&updated_at),
            ))
            .on_conflict(dsl::user_id)
            .do_update()
            .set((dsl::affinities.eq(&json), dsl::updated_at.eq(&updated_at)))
            .execute(&mut conn)
            .await?;
        Ok(())
    }
}