use serde::{Deserialize, Serialize};

/// Server response to `POST /api/upload`. Shape is stable across all clients.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AckResponse {
    pub case_id: String,
    pub recorded_at: String,
    pub status: AckStatus,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
#[serde(rename_all = "lowercase")]
pub enum AckStatus {
    /// Recording accepted and persisted.
    Received,
    /// Case no longer exists server-side; client should delete its local copy.
    Gone,
}

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

    #[test]
    fn status_serializes_lowercase() {
        assert_eq!(
            serde_json::to_string(&AckStatus::Received).unwrap(),
            "\"received\""
        );
        assert_eq!(serde_json::to_string(&AckStatus::Gone).unwrap(), "\"gone\"");
    }

    #[test]
    fn status_deserializes_lowercase() {
        let got: AckStatus = serde_json::from_str("\"received\"").unwrap();
        assert_eq!(got, AckStatus::Received);
        let got: AckStatus = serde_json::from_str("\"gone\"").unwrap();
        assert_eq!(got, AckStatus::Gone);
    }

    #[test]
    fn response_roundtrip() {
        let original = AckResponse {
            case_id: "550e8400-e29b-41d4-a716-446655440000".into(),
            recorded_at: "2026-04-15T10:32:00Z".into(),
            status: AckStatus::Received,
        };
        let json = serde_json::to_string(&original).unwrap();
        let decoded: AckResponse = serde_json::from_str(&json).unwrap();
        assert_eq!(decoded.case_id, original.case_id);
        assert_eq!(decoded.recorded_at, original.recorded_at);
        assert_eq!(decoded.status, original.status);
    }
}