import type { PropertyBag } from '../model/Properties';

/**
 * Port data types. `exec` carries control flow (Blueprint-style white arrows); the others
 * carry values. `any` accepts every value type (variables, logging).
 */
export type PortType = 'exec' | 'number' | 'boolean' | 'string' | 'object' | 'any';

export interface PortRef {
  node: string;
  port: string;
}

/**
 * One node of a behavior graph. `type` names a NodeDef in the registry; `params` holds
 * the node's own settings (e.g. which key) and inline values of unconnected data inputs,
 * both keyed by the param / port key.
 */
export interface GraphNode {
  id: string;
  type: string;
  x: number;
  y: number;
  params: PropertyBag;
}

/** A connection from an output port to an input port. */
export interface GraphEdge {
  id: string;
  from: PortRef;
  to: PortRef;
}

export interface Graph {
  nodes: GraphNode[];
  edges: GraphEdge[];
}

export function createEmptyGraph(): Graph {
  return { nodes: [], edges: [] };
}

export function findNode(graph: Graph, nodeId: string): GraphNode | undefined {
  return graph.nodes.find((n) => n.id === nodeId);
}

/** Edges arriving at one input port (data inputs allow at most one, exec inputs any number). */
export function edgesInto(graph: Graph, nodeId: string, port: string): GraphEdge[] {
  return graph.edges.filter((e) => e.to.node === nodeId && e.to.port === port);
}

/** Edges leaving one output port. */
export function edgesOutOf(graph: Graph, nodeId: string, port: string): GraphEdge[] {
  return graph.edges.filter((e) => e.from.node === nodeId && e.from.port === port);
}

/** Every edge touching a node (used when removing it). */
export function edgesOfNode(graph: Graph, nodeId: string): GraphEdge[] {
  return graph.edges.filter((e) => e.from.node === nodeId || e.to.node === nodeId);
}

/** Whether a value may flow from an output of type `from` into an input of type `to`. */
export function portsCompatible(from: PortType, to: PortType): boolean {
  if (from === 'exec' || to === 'exec') return from === to;
  return from === to || from === 'any' || to === 'any';
}