use futures::stream::BoxStream;

use serde::{de::DeserializeOwned, Deserialize, Serialize};

use crate::{

    error::ResourceError,

    resource::{Resource, ResourceObject},

};

pub type WatchStream<T> = BoxStream<'static, Result<WatchEvent<T>, ResourceError>>;

#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]

pub enum WatchStart {

    /// Deliver future events only. No replay of current state.

    Now,

    /// Resume from a specific version, delivering all events since that point.

    FromVersion(String),

}

#[derive(Debug, Clone, Serialize, Deserialize)]

#[serde(bound(

    serialize = "T::Spec: Serialize, T::Status: Serialize",

    deserialize = "T::Spec: DeserializeOwned, T::Status: DeserializeOwned"

))]

pub enum WatchEvent<T: Resource> {

    Added(ResourceObject<T>),

    Modified(ResourceObject<T>),

    Deleted(ResourceObject<T>),

}

#[derive(Debug, Clone, Serialize, Deserialize)]

#[serde(bound(

    serialize = "T::Spec: Serialize, T::Status: Serialize",

    deserialize = "T::Spec: DeserializeOwned, T::Status: DeserializeOwned"

))]

pub struct ResourceList<T: Resource> {

    pub items: Vec<ResourceObject<T>>,

    pub resource_version: String,

}

#[cfg(test)]

mod tests {

    use super::WatchStart;

    #[test]

    fn watch_start_roundtrips_through_serde() {

        let encoded = serde_json::to_string(&WatchStart::FromVersion("7".to_string())).expect("serialize watch start");

        let decoded: WatchStart = serde_json::from_str(&encoded).expect("deserialize watch start");

        assert_eq!(decoded, WatchStart::FromVersion("7".to_string()));

    }

}