practical test

prac.rb

COMMANDS = ['DEPEND', 'INSTALL', 'REMOVE', 'LIST']

@component_dependencies = Hash.new
@installed_components = Array.new

  def validate_command(command)
    command_size = command.size
    command_name = command.split(' ').first
    return false unless COMMANDS.include?(command_name)
    return false if command_name != command_name.upcase
    return false if command_size > 80
    return true
  end

  def execute_command(command)
    command_name = command.split(' ')[0]
    command_in_array = command.split(' ')

    component = command_in_array[1]
    items = command_in_array.drop(2)

    case command_name
      when 'DEPEND'
        create_dependency(component, items)
      when 'INSTALL'
        install_component(component, items)
      when 'REMOVE'
        remove_component(component)
      when 'LIST'
        list_components
    end
  end

  def create_dependency(component, items)
    @component_dependencies.merge!(component=> items)
    print @component_dependencies
    print "\n"
  end

  def install_component(component, items)
    if !@component_dependencies.key?(component)
      print "Installing #{component}\n"
      @installed_components.push component
      print @installed_components
      print "\n"
    else
      @component_dependencies[component].each do |c|
        if !@installed_components.include?(c)
          print "  Installing #{c} \n"
          @installed_components.push c
        else
          next
        end
        #@installed_components.push

      end
      @installed_components.push component
      print "  Installing #{component}\n"
    end
  end

  def remove_component(component)
    if @installed_components.include?(component)
      if @component_dependencies.key?(component)

        print "   Removing #{component}\n"
        @installed_components.delete_if{|i|i== component}

      else
        component_usage = 0
        @component_dependencies.keys.each do |c|
          next unless @installed_components.include?(c)
          if @component_dependencies[c].include?(component)
            component_usage = component_usage + 1
          end
        end

        if component_usage > 1
          print "   #{component} is still needed\n"
        elsif component_usage == 1
          @installed_components.delete_if{|i|i== component}
        elsif component_usage == 0
          print "   #{component} is not installed\n"
        end

      end
    else
      print "   #{component} is not installed. \n"
    end


  end

  def list_components
    @installed_components.each do |c|
      print "  #{c}"
      print "\n"
    end
  end

print 'Enter command: '
print "\n"

while command = gets.chomp
  command_name = command.split(' ')[0]
  case command_name
  when 'END'
    break
  when *COMMANDS
    is_valid_command = validate_command(command)
    print "Invalid Command!\n" unless is_valid_command

    if is_valid_command
      print command+"\n" unless command_name.eql?('LIST')
      execute_command(command)
    end
  else
    print "Invalid Command!\n"
      break
  end
end