use redis::AsyncCommands;
use std::time::Duration;
use uuid::Uuid;

#[derive(Clone)]
pub struct DeduplicationManager {
    cache: db::cache::AppCache,
    window: Duration,
}

impl DeduplicationManager {
    pub fn new(cache: db::cache::AppCache) -> Self {
        Self {
            cache,
            window: Duration::from_secs(300),
        }
    }

    pub async fn check_and_mark(
        &self,
        message_id: Uuid,
        room_id: Uuid,
    ) -> Result<bool, crate::error::AppTransportError> {
        let key = format!("dedup:{}:{}", room_id, message_id);

        let mut conn = self.cache.conn().await
            .map_err(|_| crate::error::AppTransportError::Internal)?;

        let exists: bool = conn.exists(&key).await
            .map_err(|_| crate::error::AppTransportError::Internal)?;

        if exists {
            return Ok(false);
        }

        let _: () = conn.set_ex(&key, "1", self.window.as_secs())
            .await
            .map_err(|_| crate::error::AppTransportError::Internal)?;

        Ok(true)
    }

    pub async fn is_duplicate(
        &self,
        message_id: Uuid,
        room_id: Uuid,
    ) -> Result<bool, crate::error::AppTransportError> {
        let key = format!("dedup:{}:{}", room_id, message_id);

        let mut conn = self.cache.conn().await
            .map_err(|_| crate::error::AppTransportError::Internal)?;

        let exists: bool = conn.exists(&key).await
            .map_err(|_| crate::error::AppTransportError::Internal)?;

        Ok(exists)
    }

    pub async fn cleanup_expired(&self) -> Result<(), crate::error::AppTransportError> {
        Ok(())
    }
}