Adding sync of follow relationships to Neo4J, accounts/suggestions API

app/assets/javascripts/components/actions/suggestions.jsx

@@ -0,0 +1,15 @@
+import api from '../api';
+
+export const SUGGESTIONS_FETCH_REQUEST = 'SUGGESTIONS_FETCH_REQUEST';
+export const SUGGESTIONS_FETCH_SUCCESS = 'SUGGESTIONS_FETCH_SUCCESS';
+export const SUGGESTIONS_FETCH_FAIL    = 'SUGGESTIONS_FETCH_FAIL';
+
+export function fetchSuggestions() {
+  return (dispatch, getState) => {
+    api(getState).get('/api/v1/accounts/suggestions').then(response => {
+      console.log(response.data);
+    }).catch(error => {
+      console.error(error);
+    });
+  };
+};

app/controllers/api/v1/accounts_controller.rb

@@ -1,6 +1,6 @@
 class Api::V1::AccountsController < ApiController
   before_action :doorkeeper_authorize!
-  before_action :set_account, except: :verify_credentials
+  before_action :set_account, except: [:verify_credentials, :suggestions]
   respond_to    :json
 
   def show
@@ -19,6 +19,10 @@ class Api::V1::AccountsController < ApiController
     @followers = @account.followers
   end
 
+  def suggestions
+    @accounts = FollowSuggestion.get(current_user.account_id)
+  end
+
   def statuses
     @statuses = @account.statuses.with_includes.with_counters.paginate_by_max_id(20, params[:max_id], params[:since_id]).to_a
   end

app/models/follow.rb

@@ -22,4 +22,28 @@ class Follow < ApplicationRecord
   def title
     destroyed? ? "#{account.acct} is no longer following #{target_account.acct}" : "#{account.acct} started following #{target_account.acct}"
   end
+
+  after_create  :add_to_graph
+  after_destroy :remove_from_graph
+
+  private
+
+  def add_to_graph
+    neo = Neography::Rest.new
+
+    a = neo.create_unique_node('account_index', 'Account', account_id.to_s, account_id: account_id)
+    b = neo.create_unique_node('account_index', 'Account', target_account_id.to_s, account_id: target_account_id)
+
+    neo.create_unique_relationship('follow_index', 'Follow', id.to_s, 'follows', a, b)
+  rescue Neography::NeographyError => e
+    Rails.logger.error e
+  end
+
+  def remove_from_graph
+    neo = Neography::Rest.new
+    rel = neo.get_relationship_index('follow_index', 'Follow', id.to_s)
+    neo.delete_relationship(rel)
+  rescue Neography::NeographyError => e
+    Rails.logger.error e
+  end
 end

app/models/follow_suggestion.rb

@@ -0,0 +1,7 @@
+class FollowSuggestion
+  def self.get(for_account_id)
+    neo = Neography::Rest.new
+    account_ids = neo.execute_query('START a=node:account_index(Account={id}) MATCH (a)-[:follows]->(b)-[:follows]->(c) WHERE a <> c AND NOT (a)-[:follows]->(c) RETURN DISTINCT c.account_id', id: for_account_id)
+    Account.where(id: account_ids['data'].first) unless account_ids.empty?
+  end
+end

app/views/api/v1/accounts/suggestions.rabl

@@ -0,0 +1,2 @@
+collection @accounts
+extends('api/v1/accounts/show')