module Checkbox

# File lib/inquirer/prompts/checkbox.rb, line 10
def prompt opts = {}

  # finish if there's nothing to do
  return opts[:default] if Array(opts[:choices]).empty?

  @question  = opts[:message]
  @position  = 0
  @paginator = Paginator.new
  @choices   = []
  opts[:choices].each { |choice|

    if choice[:when].is_a?(Proc)

      when_parameter = opts.merge(
        choice: choice,
      )

      ask_choice = choice[:when].call( when_parameter )

      next if !ask_choice
    elsif [true, false].include? choice[:when]
      next if !choice[:when]
    end

    choice[:value] ||= choice[:name]

    if !choice[:checked] && opts[:default].is_a?(Array)
      choice[:checked] = opts[:default].include?( choice[:value] )
    end

    @choices.push(choice)
  }

  IOHelper.without_cursor do

    question_backup = @question
    @question      += ' '
    @question      += Inquirer::Style::Checkbox.selection_help

    render_prompt

    @question = question_backup

    # loop through user input
    IOHelper.read_char do |char|

      key = IOChar.char_to_key(char)

      if @error_message
        @error_message = nil
      end

      case key
      when 'up'
        @position = (@position - 1) % @choices.length
      when 'down'
        @position = (@position + 1) % @choices.length
      when 'space'
        @choices[@position][:checked] = !@choices[@position][:checked]
      when 'escape'
        @choices.map! { |choice|
          choice[:checked] = false
          choice
        }
      when 'return'
        if opts[:validate] and opts[:validate].is_a?(Proc)

          value = @choices.reject { |choice|
            !choice[:checked]
          }.collect { |choice|
            choice[:value]
          }

          validation_result = opts[:validate].call( value )

          if !validation_result
            @error_message = Inquirer::Style::Checkbox.error_message_invalid_value
          elsif validation_result && validation_result.is_a?(String)
            @error_message = validation_result
          end
        end
      end

      IOHelper.clear

      render_prompt

      # we are done if the user hits return
      @error_message || key != 'return'
    end
  end

  render_result

  @choices.reject { |choice|
    !choice[:checked]
  }.collect { |choice|
    choice[:value]
  }
end

# File lib/inquirer/prompts/checkbox.rb, line 111
def render_prompt
  # start with the question prefix
  prompt = Inquirer::Style.question_prefix

  # render the question
  prompt += Inquirer::Style::Checkbox.question % @question

  prompt += IOChar.newline

  # render the list
  prompt += @choices.map.with_index(0) do |choice, position|

    choice_prompt = ''

    if position == @position
      choice_prompt += Inquirer::Style::Checkbox.selector
    else
      choice_prompt += ' '
    end

    if choice[:checked]
      choice_prompt += Inquirer::Style::Checkbox.checkbox_on
      choice_prompt += ' '
      choice_prompt += Inquirer::Style::Checkbox.checked_item % choice[:name]
    else
      choice_prompt += Inquirer::Style::Checkbox.checkbox_off
      choice_prompt += ' '
      choice_prompt += Inquirer::Style::Checkbox.item % choice[:name]
    end

    choice_prompt
  end.join('')

  paginated_prompt = @paginator.paginate(prompt, @position)

  # render error message
  if @error_message
    paginated_prompt += Inquirer::Style::Checkbox.error_message % @error_message
  end

  paginated_prompt += IOChar.carriage_return

  IOHelper.render( paginated_prompt )
end

# File lib/inquirer/prompts/checkbox.rb, line 156
def render_result
  # start with the question prefix
  result = Inquirer::Style.question_prefix

  # render the question
  result += Inquirer::Style::Checkbox.question % @question

  selected_choices = @choices.reject { |choice|
    !choice[:checked]
  }.collect { |choice|
    choice[:short] || choice[:name]
  }.join(', ')

  if !selected_choices.empty?
    result += Inquirer::Style::Checkbox.response % selected_choices
  end

  result += IOChar.newline

  IOHelper.clear

  IOHelper.render( result )
end