/*!
 * Copyright (c) Microsoft Corporation and contributors. All rights reserved.
 * Licensed under the MIT License.
 */

import type { IFluidHandleInternal } from "@fluidframework/core-interfaces/internal";
import type { ISerializedHandle } from "@fluidframework/runtime-utils/internal";

import { FluidSerializer } from "./serializer.js";

/**
 * Implementation of IFluidSerializer used by GC to visit all the handles in the DDS to collect its outbound routes
 *
 * @remarks This is given to DDS code that typically produces a serialization of the data, which is then ignored.
 * All that is needed is getSerializedRoutes() to get the routes. This strategy could be optimized if needed.
 */
export class GCHandleVisitor extends FluidSerializer {
	private readonly visitedHandlePaths: Set<string> = new Set();
	public getVisitedHandlePaths(): string[] {
		return [...this.visitedHandlePaths];
	}

	protected bindAndEncodeHandle(handle: IFluidHandleInternal): ISerializedHandle {
		this.visitedHandlePaths.add(handle.absolutePath);

		// Just return a dummy value. The serialization itself is not used.
		// It's especially important we don't bind since that has side effects that are irrelevant to GC.
		return {
			type: "__fluid_handle__",
			url: "UNUSED (see GCHandleVisitor)",
		};
	}
}