/**
 * Flow Bridge — bridges arrow data pipes with LayerFlow entries in Automerge.
 *
 * When an arrow pipe connects two folk-rapp shapes, a LayerFlow is auto-created
 * in the Automerge doc. Deleting the arrow removes the LayerFlow.
 */

import { inferFlowKind } from "./data-types";
import type { LayerFlow, Layer } from "./layer-types";

interface SyncLike {
	getLayers(): Layer[];
	addFlow(flow: LayerFlow): void;
	removeFlow(flowId: string): void;
}

/**
 * Create a LayerFlow when an arrow pipe is created between two folk-rapp shapes.
 * Returns the new flowId, or null if layers couldn't be matched.
 */
export function onArrowPipeCreated(
	arrowId: string,
	sourcePort: string,
	targetPort: string,
	srcModuleId: string,
	tgtModuleId: string,
	sync: SyncLike,
): string | null {
	const layers = sync.getLayers();

	// Find layers matching the source and target modules
	const srcLayer = layers.find(l => l.moduleId === srcModuleId);
	const tgtLayer = layers.find(l => l.moduleId === tgtModuleId);

	if (!srcLayer || !tgtLayer) return null;

	const flowKind = inferFlowKind(sourcePort);
	const flowId = `flow-${arrowId}`;

	const flow: LayerFlow = {
		id: flowId,
		kind: flowKind,
		sourceLayerId: srcLayer.id,
		targetLayerId: tgtLayer.id,
		label: `${srcModuleId} → ${tgtModuleId}`,
		strength: 1,
		active: true,
		meta: {
			arrowId,
			sourcePort,
			targetPort,
		},
	};

	sync.addFlow(flow);
	return flowId;
}

/**
 * Remove a LayerFlow when the corresponding arrow is deleted.
 */
export function onArrowRemoved(flowId: string, sync: SyncLike): void {
	if (flowId) {
		sync.removeFlow(flowId);
	}
}