get_watched_entity_ids_from_patterns.rb

require 'pg'
require 'fileutils'

watched_entity_id_patterns_filename = 'watched_entity_id_patterns.txt'
watched_entity_ids_from_patterns_filename = 'watched_entity_ids_from_patterns.txt'
min_state_id_seen_filename = 'min_state_id_seen.txt'

FileUtils.touch watched_entity_id_patterns_filename
FileUtils.touch min_state_id_seen_filename
patterns = File.readlines(watched_entity_id_patterns_filename).map(&:chomp).reject(&:empty?).map { |pattern| Regexp.new(pattern) }
min_state_id = File.read(min_state_id_seen_filename).to_i

# TODO: Move connection details into env
conn = PG.connect(dbname: 'homeassistant', port: 5432)
entity_ids = conn.exec("select distinct sm.entity_id from states_meta sm join states s using (metadata_id) where s.state_id >= #{min_state_id} order by sm.entity_id").map { |row| row['entity_id'] }

watched_entity_ids = entity_ids.select { |entity_id| patterns.any? { |pattern| entity_id.match? pattern } }

File.write( watched_entity_ids_from_patterns_filename, "#{watched_entity_ids.join("\n")}\n" )

puts "Wrote #{watched_entity_ids.length} watched entity IDs to #{watched_entity_ids_from_patterns_filename}"