# encoding: utf-8

# wrap.rb: Handles text wrapping for for formatted text
#
# Contributed by Daniel Nelson
#
# This is free software. Please see the LICENSE and COPYING files for details.

require_relative "line_wrap"
require_relative "arranger"

module Prawn
  module Text
    module Formatted #:nodoc:
      # @private

      module Wrap #:nodoc:

        def initialize(array, options)
          @line_wrap = Prawn::Text::Formatted::LineWrap.new
          @arranger = Prawn::Text::Formatted::Arranger.new(@document,
            :kerning => options[:kerning])
        end


        # See the developer documentation for PDF::Core::Text#wrap
        #
        # Formatted#wrap should set the following variables:
        #   <tt>@line_height</tt>::
        #        the height of the tallest fragment in the last printed line
        #   <tt>@descender</tt>::
        #        the descender height of the tallest fragment in the last
        #        printed line
        #   <tt>@ascender</tt>::
        #        the ascender heigth of the tallest fragment in the last
        #        printed line
        #   <tt>@baseline_y</tt>::
        #       the baseline of the current line
        #   <tt>@nothing_printed</tt>::
        #       set to true until something is printed, then false
        #   <tt>@everything_printed</tt>::
        #       set to false until everything printed, then true
        #
        # Returns any formatted text that was not printed
        #
        def wrap(array) #:nodoc:
          initialize_wrap(array)

          stop = false
          while !stop
            # wrap before testing if enough height for this line because the
            # height of the highest fragment on this line will be used to
            # determine the line height
            @line_wrap.wrap_line(:document => @document,
                                 :kerning => @kerning,
                                 :width => available_width,
                                 :arranger => @arranger)

            if enough_height_for_this_line?
              move_baseline_down
              print_line
            else
              stop = true
            end

            stop ||= @single_line || @arranger.finished?
          end
          @text = @printed_lines.join("\n")
          @everything_printed = @arranger.finished?
          @arranger.unconsumed
        end

        private

        def print_line
          @nothing_printed = false
          printed_fragments = []
          fragments_this_line = []

          word_spacing = word_spacing_for_this_line
          while fragment = @arranger.retrieve_fragment
            fragment.word_spacing = word_spacing
            if fragment.text == "\n"
              printed_fragments << "\n" if @printed_lines.last == ""
              break
            end
            printed_fragments << fragment.text
            fragments_this_line << fragment
          end

          accumulated_width = 0
          fragments_this_line.reverse! if @direction == :rtl
          fragments_this_line.each do |fragment_this_line|
            fragment_this_line.default_direction = @direction
            format_and_draw_fragment(fragment_this_line, accumulated_width,
                                     @line_wrap.width, word_spacing)
            accumulated_width += fragment_this_line.width
          end

          @printed_lines << printed_fragments.map { |s| s.force_encoding(::Encoding::UTF_8) }.join
        end

        def word_spacing_for_this_line
          if @align == :justify &&
              @line_wrap.space_count > 0 &&
              !@line_wrap.paragraph_finished?
            (available_width - @line_wrap.width) / @line_wrap.space_count
          else
            0
          end
        end

        def enough_height_for_this_line?
          @line_height = @arranger.max_line_height
          @descender   = @arranger.max_descender
          @ascender    = @arranger.max_ascender
          if @baseline_y == 0
            diff = @ascender + @descender
          else
            diff = @descender + @line_height + @leading
          end
          require_relatived_total_height = @baseline_y.abs + diff
          if require_relatived_total_height > @height + 0.0001
            # no room for the full height of this line
            @arranger.repack_unretrieved
            false
          else
            true
          end
        end

        def initialize_wrap(array)
          @text = nil
          @arranger.format_array = array

          # these values will depend on the maximum value within a given line
          @line_height = 0
          @descender   = 0
          @ascender    = 0
          @baseline_y  = 0

          @printed_lines = []
          @nothing_printed = true
          @everything_printed = false
        end

        def format_and_draw_fragment(fragment, accumulated_width,
                                     line_width, word_spacing)
          @arranger.apply_color_and_font_settings(fragment) do
            draw_fragment(fragment, accumulated_width,
                          line_width, word_spacing)
          end
        end

      end
    end
  end
end