import { GraphNodes } from '../Graph.js';

export function validateGraphLinks(nodes: GraphNodes): string[] {
  const errorList: string[] = [];
  // for each node
  Object.values(nodes).forEach((node) => {
    // for each input socket
    node.inputs.forEach((inputSocket) => {
      // ensure that connected output sockets are the same type
      inputSocket.links.forEach((link) => {
        // check if the node id is correct
        if (!(link.nodeId in nodes)) {
          errorList.push(
            `node ${node.description.typeName}.${inputSocket.name} has link using invalid nodeId: ${link.nodeId}`
          );
          return;
        }

        // check if the socketName is correct
        const upstreamNode = nodes[link.nodeId];
        const outputSocket = upstreamNode.outputs.find(
          (socket) => socket.name === link.socketName
        );
        if (outputSocket === undefined) {
          errorList.push(
            `node ${node.description.typeName}.${inputSocket.name} has link using a non-existent socket name: ` +
              `${link.socketName}, it can not be found on upstream output node: ${upstreamNode.description.typeName}`
          );
          return;
        }

        // check if the socket types align
        if (inputSocket.valueTypeName !== outputSocket.valueTypeName) {
          errorList.push(
            `type mismatch between ${node.description.typeName}.${inputSocket.name} [${inputSocket.valueTypeName}] ` +
              `and ${upstreamNode.description.typeName}.${outputSocket.name} [${outputSocket.valueTypeName}]`
          );
        }
      });
    });
  });
  return errorList;
}