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class FollowSuggestion
def self.get(for_account_id, limit = 6)
neo = Neography::Rest.new
query = <<END
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, count(b), c.nodeRank
ORDER BY count(b) DESC, c.nodeRank DESC
LIMIT {limit}
END
results = neo.execute_query(query, id: for_account_id, limit: limit)
return fallback(for_account_id, limit) if results.empty? || results['data'].empty?
map_to_accounts(for_account_id, results)
rescue Neography::NeographyError, Excon::Error::Socket => e
Rails.logger.error e
return []
end
private
def self.fallback(for_account_id, limit)
neo = Neography::Rest.new
query = 'MATCH (a) WHERE a.account_id <> {id} RETURN a.account_id ORDER BY a.nodeRank DESC LIMIT {limit}'
results = neo.execute_query(query, id: for_account_id, limit: limit)
map_to_accounts(for_account_id, results)
rescue Neography::NeographyError, Excon::Error::Socket => e
Rails.logger.error e
return []
end
def self.map_to_accounts(for_account_id, results)
return [] if results.empty? || results['data'].empty?
account_ids = results['data'].map(&:first)
blocked_ids = Block.where(account_id: for_account_id).pluck(:target_account_id)
accounts_map = Account.where(id: account_ids - blocked_ids).map { |a| [a.id, a] }.to_h
account_ids.map { |id| accounts_map[id] }.compact
end
end
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