// SPDX-License-Identifier: Apache-2.0

// SPDX-FileCopyrightText: Copyright the Vortex contributors

use std::sync::Arc;

use vortex_error::VortexResult;

use vortex_session::VortexSession;

use crate::aggregate_fn::AggregateFn;

use crate::aggregate_fn::AggregateFnId;

use crate::aggregate_fn::AggregateFnRef;

use crate::aggregate_fn::AggregateFnVTable;

/// Reference-counted pointer to an aggregate function plugin.

pub type AggregateFnPluginRef = Arc<dyn AggregateFnPlugin>;

/// Registry trait for ID-based deserialization of aggregate functions.

///

/// Plugins are registered in the session by their [`AggregateFnId`]. When a serialized aggregate

/// function is encountered, the session resolves the ID to the plugin and calls [`deserialize`]

/// to reconstruct the value as an [`AggregateFnRef`].

///

/// [`deserialize`]: AggregateFnPlugin::deserialize

pub trait AggregateFnPlugin: 'static + Send + Sync {

/// Returns the ID for this aggregate function.

fn id(&self) -> AggregateFnId;

/// Deserialize an aggregate function from serialized metadata.

fn deserialize(&self, metadata: &[u8], session: &VortexSession)

-> VortexResult<AggregateFnRef>;

}

impl std::fmt::Debug for dyn AggregateFnPlugin {

fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {

f.debug_tuple("AggregateFnPlugin")

.field(&self.id())

.finish()

}

}

impl<V: AggregateFnVTable> AggregateFnPlugin for V {

fn id(&self) -> AggregateFnId {

AggregateFnVTable::id(self)

}

fn deserialize(

&self,

metadata: &[u8],

session: &VortexSession,

) -> VortexResult<AggregateFnRef> {

let options = AggregateFnVTable::deserialize(self, metadata, session)?;

Ok(AggregateFn::new(self.clone(), options).erased())

}

}