Page History

db.getCollection('nodes').aggregate([
  //get all nodes from the group HQDEV
  {
    $match: { group: "HQDev" }
  },
  //Get all the states for the matched nodes
  {
    $lookup: {
      from: "state",
      localField: "_id",
      foreignField: "node",
      as: "states"
    }
  },
  //unwinds the states array creating a document per state with node config data
  {
    $unwind: {
      path: "$states"
    }
  },
  //We only want open states
  {
    $match: { 'states.state': { $eq: 'open' } }
  },
  //Join with the event which created this state, we will need this later for the priority 
  {
    $lookup: {
      from: "events",
      localField: "states.eventid_down",
      foreignField: "_id",
      as: "_event"
    }
  },
  {
     $unwind: {
        path: "$_event"
      }
    },
  // group by the node, and accumlate its states
  {
    $group: {
      _id: "$_id",
      states: { $push: { state: "$states.state", stateful: "$states.stateful", priority: "$_event.priority" } }
    }
  },

])