# ********** Copyright Viacom, Inc. Apache 2.0 **********

module RokuBuilder

  class DeviceManager

    def initialize(options:, config:)
      @config = config
      @options = options
      @timeout_duration = 3600
    end

    def reserve_device(no_lock: false)
      message = "No Devices Found"
      if @options[:device]
        device = Device.new(@options[:device], @config.raw[:devices][@options[:device].to_sym])
        return device if device_available!(device: device, no_lock: no_lock)
        message = "Device #{@options[:device]} not found"
      else
        begin
          Timeout::timeout(@timeout_duration) do
            loop do
              device = reserve_any(no_lock: no_lock)
              if device
                Logger.instance.info "Using Device: #{device.to_s}"
                return device
              end
              break unless @options[:device_blocking]
            end
          end
        rescue Timeout::Error
        end
      end
      raise DeviceError, message
    end

    def release_device(device)
      lock = lock_file(device)
      File.delete(lock) if File.exist?(lock)
    end

    private

    def reserve_any(no_lock: false)
      default = @config.device_default
      all_devices = @config.devices.keys.reject{|key, value| default == key}
      all_devices.unshift(default)
      all_devices.each do |device_name|
        device = Device.new(device_name, @config.devices[device_name])
        if device_available!(device: device, no_lock: no_lock)
          return device
        end
      end
      nil
    end

    def device_available!(device:, no_lock: false)
      return false unless device_ping?(device)
      return true if no_lock
      file = lock_file(device)
      lock = file.flock(File::LOCK_EX|File::LOCK_NB)
      return false if lock == false
      text = file.readlines
      return false if text.count > 0
      file.write($$)
      file.pos = 0
      text = file.readlines
      if text[0] != $$.to_s
        file.flock(File::LOCK_UN)
        return false
      end
      true
    end

    def device_ping?(device)
      ping = Net::Ping::External.new
      ping.ping? device.ip, 1, 0.2, 1
    end

    def lock_file(device)
      File.open(File.join(Dir.tmpdir, device.name), File::RDWR | File::APPEND | File::CREAT | File::BINARY | File::SHARE_DELETE) #"a+")
    end

  end

  class Device
    attr_accessor :name, :ip, :user, :password

    def initialize(name, device_config)
      @name = name.to_s
      @ip = device_config[:ip]
      @user = device_config[:user]
      @password = device_config[:password]
    end

    def to_s
      "#{name}:#{ip}"
    end
  end
end