import fetchDocByRef from '/imports/api/parenting/fetchDocByRef.js';
import getCollectionByName from '/imports/api/parenting/getCollectionByName.js';
import SimpleSchema from 'simpl-schema';

export function fetchParent({id, collection}){
  return fetchDocByRef({id, collection});
}

export function fetchChildren({ collection, parentId, filter = {}, options = {sort: {order: 1}} }){
  filter["parent.id"] = parentId;
  let children = [];
  children.push(
    ...collection.find({
      "parent.id": parentId
    }, options).fetch()
  );
  return children;
}

export function updateChildren({collection, parentId, filter = {}, modifier, options={}}){
  filter["parent.id"] = parentId;
  options.multi = true;
  collection.update(filter, modifier, options);
}

export function fetchDecendents({ collection, ancestorId, filter = {}, options}){
  filter["ancestors.id"] = ancestorId;
  let decendents = [];
  decendents.push(...collection.find(filter, options).fetch());
  return decendents;
}

export function updateDecendents({collection, ancestorId, filter = {}, modifier, options={}}){
  filter["ancestors.id"] = ancestorId;
  options.multi = true;
  collection.update(filter, modifier, options);
}

export function forEachDecendent({collection, ancestorId, filter = {}, options}, callback){
  filter["ancestors.id"] = ancestorId;
  collection.find(filter, options).forEach(callback);
}

// 1 database read
export function getAncestry({parentRef, inheritedFields = {}}){
  // Ancestry must include ancestors
  inheritedFields.ancestors = 1;

  let parentDoc = fetchDocByRef(parentRef, {fields: inheritedFields});
  let parent = { ...parentRef};
  for (let field in inheritedFields){
    if (inheritedFields[field]){
      parent[field] = parentDoc[field];
    }
  }

  // Ancestors is [...parent's ancestors, parent ref]
  let ancestors = parentDoc.ancestors || [];
  ancestors.push(parent);

  return {parent, ancestors};
}

export function updateParent({docRef, parentRef}){
  let collection = getCollectionByName(docRef.collection);
  let oldDoc = fetchDocByRef(docRef, {fields: {
    parent: 1,
    ancestors: 1,
  }});

  // Skip if we aren't changing the parent id
  if (oldDoc.parent.id === parentRef.id) return;

  // update the document's parenting
  let {parent, ancestors} = getAncestry({parentRef});
  collection.update(docRef.id, {$set: {parent, ancestors}});

  // Remove the old ancestors from the decendents
  updateDecendents({
    ancestorId: docRef.id,
    modifier: {$pullAll: {
      ancestors: oldDoc.ancestors,
    }},
  });

  // Add the new ancestors to the decendents
  updateDecendents({
    ancestorId: docRef.id,
    modifier: {$push: {
      ancestors: {
        $each: ancestors,
        $position: 0,
      },
    }},
  });
}

// TODO move these functions to character properties collection
export function findEnabled(collection, query, options){
  query.enabled = true;
  query['ancestors.$.enabled'] = {$not: false};
  return collection.find(query, options);
}

export function getName(doc){
  if (doc.name) return name;
  var i = doc.ancestors.length;
  while(i--) {
    if (ancestors[i].name) return ancestors[i].name;
  }
}