import { Connection, ReactFlowInstance } from 'reactflow'

import { getNodeSpecJSON } from './getNodeSpecJSON'
import { getSocketsByNodeTypeAndHandleType } from './getSocketsByNodeTypeAndHandleType'
import { isHandleConnected } from './isHandleConnected'

const specJSON = getNodeSpecJSON()

export const isValidConnection = (connection: Connection, instance: ReactFlowInstance) => {
  if (connection.source === null || connection.target === null) return false

  const sourceNode = instance.getNode(connection.source)
  const targetNode = instance.getNode(connection.target)
  const edges = instance.getEdges()

  if (sourceNode === undefined || targetNode === undefined) return false

  const sourceSockets = getSocketsByNodeTypeAndHandleType(specJSON, sourceNode.type, 'source')

  const sourceSocket = sourceSockets?.find((socket) => socket.name === connection.sourceHandle)

  const targetSockets = getSocketsByNodeTypeAndHandleType(specJSON, targetNode.type, 'target')

  const targetSocket = targetSockets?.find((socket) => socket.name === connection.targetHandle)

  if (sourceSocket === undefined || targetSocket === undefined) return false

  // only flow sockets can have two inputs
  if (targetSocket.valueType !== 'flow' && isHandleConnected(edges, targetNode.id, targetSocket.name, 'target')) {
    return false
  }

  return sourceSocket.valueType === targetSocket.valueType
}