module NostrManager
  class FetchEvent < NostrManagerService
    TIMEOUT = 1

    def initialize(filter:, relay_url:)
      @filter = filter
      @relay = new_relay(relay_url)
      @client = Nostr::Client.new
    end

    def call
      filter, client, relay = @filter, @client, @relay
      event = nil
      mutex = Mutex.new
      received_event = ConditionVariable.new
      log_prefix = "[nostr][#{@relay.name}]"

      thread = Thread.new do
        client.on :connect do
          client.subscribe(filter: filter)
        end

        client.on :error do |e|
          Rails.logger.info "#{log_prefix} Error: #{e}"
          Thread.current.exit
        end

        client.on :message do |m|
          msg = JSON.parse(m) rescue nil
          if msg && msg[0] == "EVENT" && msg[2]
            puts "#{log_prefix} Event received: #{msg[2]["id"]}"
            mutex.synchronize do
              event = msg[2]
              received_event.signal
            end
          elsif msg && msg[0] == "EOSE"
            Thread.current.exit
          end
        end

        client.connect relay
      end

      begin
        Timeout.timeout(TIMEOUT) do
          mutex.synchronize do
            received_event.wait(mutex) if event.nil?
          end
        end
      rescue Timeout::Error
        puts "#{log_prefix} Timeout: No event received within #{TIMEOUT} seconds"
      ensure
        thread.exit
      end

      event
    end
  end
end