use std::sync::Arc;

use async_trait::async_trait;
use time::OffsetDateTime;

use crate::{AgentId, InvocationSource, InvocationStatus, OperationId, WorkspaceId};

#[derive(Clone, Debug, PartialEq, Eq)]
pub struct MeteringEvent {
    pub workspace_id: WorkspaceId,
    pub agent_id: Option<AgentId>,
    pub operation_id: OperationId,
    pub source: InvocationSource,
    pub status: InvocationStatus,
    pub duration_ms: u64,
    pub created_at: OffsetDateTime,
}

#[async_trait]
pub trait MeteringSink: Send + Sync {
    async fn record(&self, event: MeteringEvent);
}

pub type SharedMeteringSink = Arc<dyn MeteringSink>;

#[derive(Clone, Copy, Debug, Default)]
pub struct NoopMeteringSink;

#[async_trait]
impl MeteringSink for NoopMeteringSink {
    async fn record(&self, _event: MeteringEvent) {}
}

#[cfg(test)]
mod tests {
    use time::OffsetDateTime;

    use super::{MeteringEvent, MeteringSink, NoopMeteringSink};
    use crate::{InvocationSource, InvocationStatus, OperationId, WorkspaceId};

    #[tokio::test]
    async fn noop_metering_sink_accepts_event() {
        NoopMeteringSink
            .record(MeteringEvent {
                workspace_id: WorkspaceId::new("ws_01"),
                agent_id: None,
                operation_id: OperationId::new("op_01"),
                source: InvocationSource::AgentToolCall,
                status: InvocationStatus::Ok,
                duration_ms: 42,
                created_at: OffsetDateTime::now_utc(),
            })
            .await;
    }
}