require 'nokogiri'

require 'caracal/renderers/xml_renderer'
require 'caracal/errors'


module Caracal
  module Renderers
    class DocumentRenderer < XmlRenderer

      #-------------------------------------------------------------
      # Public Methods
      #-------------------------------------------------------------

      # This method produces the xml required for the `word/document.xml`
      # sub-document.
      #
      def to_xml
        builder = ::Nokogiri::XML::Builder.with(declaration_xml) do |xml|
          xml['w'].document root_options do
            xml['w'].background({ 'w:color' => 'FFFFFF' })
            xml['w'].body do

              #============= CONTENTS ===================================

              document.contents.each do |model|
                method = render_method_for_model(model)
                send(method, xml, model)
              end

              #============= PAGE SETTINGS ==============================

              xml['w'].sectPr do
                if rel = document.find_relationship('footer1.xml')
                  xml['w'].footerReference({ 'r:id' => rel.formatted_id, 'w:type' => 'default' })
                end
                if rel = document.find_relationship('header1.xml')
                  xml['w'].headerReference({ 'r:id' => rel.formatted_id, 'w:type' => 'default' })
                end
                xml['w'].pgSz page_size_options
                xml['w'].pgMar page_margin_options
              end

            end
          end
        end
        builder.to_xml(save_options)
      end


      #-------------------------------------------------------------
      # Private Methods
      #-------------------------------------------------------------
      private

      #============= COMMON RENDERERS ==========================

      # This method converts a model class name to a rendering
      # function on this class (e.g., Caracal::Core::Models::ParagraphModel
      # translates to `render_paragraph`).
      #
      def render_method_for_model(model)
        type = model.class.name.split('::').last.downcase.gsub('model', '')
        "render_#{ type }"
      end

      # This method renders a standard node of run properties based on the
      # model's attributes.
      #
      def render_run_attributes(xml, model, paragraph_level=false)
        if model.respond_to? :run_attributes
          attrs = model.run_attributes.delete_if { |k, v| v.nil? }

          if paragraph_level && attrs.empty?
            # skip
          else
            xml['w'].rPr do
              unless attrs.empty?
                xml['w'].rStyle(    { 'w:val'  => attrs[:style] })                            unless attrs[:style].nil?
                xml['w'].color(     { 'w:val'  => attrs[:color] })                            unless attrs[:color].nil?
                xml['w'].sz(        { 'w:val'  => attrs[:size]  })                            unless attrs[:size].nil?
                xml['w'].b(         { 'w:val'  => (attrs[:bold] ? '1' : '0') })               unless attrs[:bold].nil?
                xml['w'].i(         { 'w:val'  => (attrs[:italic] ? '1' : '0') })             unless attrs[:italic].nil?
                xml['w'].u(         { 'w:val'  => (attrs[:underline] ? 'single' : 'none') })  unless attrs[:underline].nil?
                xml['w'].shd(       { 'w:fill' => attrs[:bgcolor], 'w:val' => 'clear' })      unless attrs[:bgcolor].nil?
                xml['w'].highlight( { 'w:val' => attrs[:highlight_color] })                   unless attrs[:highlight_color].nil?
                xml['w'].vertAlign( { 'w:val' => attrs[:vertical_align] })                    unless attrs[:vertical_align].nil?
                unless attrs[:font].nil?
                  f = attrs[:font]
                  xml['w'].rFonts( { 'w:ascii' => f, 'w:hAnsi' => f, 'w:eastAsia' => f, 'w:cs' => f })
                end
              end
              xml['w'].rtl({ 'w:val' => '0' })
            end
          end
        end
      end


      #============= MODEL RENDERERS ===========================

      def render_bookmark(xml, model)
        if model.start?
          xml['w'].bookmarkStart({ 'w:id' => model.bookmark_id, 'w:name' => model.bookmark_name })
        else
          xml['w'].bookmarkEnd({ 'w:id' => model.bookmark_id })
        end
      end

      def render_iframe(xml, model)
        ::Zip::File.open(model.file) do |zip|
          a_href     = 'http://schemas.openxmlformats.org/drawingml/2006/main'
          pic_href   = 'http://schemas.openxmlformats.org/drawingml/2006/picture'
          r_href     = 'http://schemas.openxmlformats.org/officeDocument/2006/relationships'

          entry      = zip.glob('word/document.xml').first
          content    = entry.get_input_stream.read
          doc_xml    = Nokogiri::XML(content)

          fragment = doc_xml.xpath('//w:body').first.children
          fragment.pop

          model.relationships.each do |r_hash|
            id    = r_hash.delete(:id)              # we can't update the fragment until
            model = document.relationship(r_hash)   # the parent document assigns the embedded
            index = model.relationship_id           # relationship an id.

            r_node  = fragment.at_xpath("//a:blip[@r:embed='#{ id }']", { a: a_href, r: r_href })
            if r_attr  = r_node.attributes['embed']
              r_attr.value = "rId#{ index }"
            end

            p_parent = r_node.parent.parent
            p_node   = p_parent.children[0].children[0]
            if p_attr  = p_node.attributes['id']
              p_attr.value = index.to_s
            end
          end

          xml << fragment.to_s
        end
      end

      def render_image(xml, model)
        unless ds = document.default_style
          raise Caracal::Errors::NoDefaultStyleError 'Document must declare a default paragraph style.'
        end

        rel      = document.relationship({ type: :image, target: model.image_url, data: model.image_data })
        rel_id   = rel.relationship_id
        rel_name = rel.formatted_target

        xml['w'].p paragraph_options do
          xml['w'].pPr do
            xml['w'].spacing({ 'w:lineRule' => 'auto', 'w:line' => ds.style_line })
            xml['w'].contextualSpacing({ 'w:val' => '0' })
            xml['w'].jc({ 'w:val' => model.image_align.to_s })
            xml['w'].rPr
          end
          xml['w'].r run_options do
            xml['w'].drawing do
              xml['wp'].inline({ distR: model.formatted_right, distT: model.formatted_top, distB: model.formatted_bottom, distL: model.formatted_left }) do
                xml['wp'].extent({ cx: model.formatted_width, cy: model.formatted_height })
                xml['wp'].effectExtent({ t: 0, b: 0, r: 0, l: 0 })
                xml['wp'].docPr({ id: rel_id, name: rel_name })
                xml['a'].graphic do
                  xml['a'].graphicData({ uri: 'http://schemas.openxmlformats.org/drawingml/2006/picture' }) do
                    xml['pic'].pic do
                      xml['pic'].nvPicPr do
                        xml['pic'].cNvPr({ id: rel_id, name: rel_name })
                        xml['pic'].cNvPicPr
                      end
                      xml['pic'].blipFill do
                        xml['a'].blip({ 'r:embed' => rel.formatted_id })
                        xml['a'].srcRect
                        xml['a'].stretch do
                          xml['a'].fillRect
                        end
                      end
                      xml['pic'].spPr do
                        xml['a'].xfrm do
                          xml['a'].ext({ cx: model.formatted_width, cy: model.formatted_height })
                        end
                        xml['a'].prstGeom({ prst: 'rect' })
                        xml['a'].ln
                      end
                    end
                  end
                end
              end
            end
          end
          xml['w'].r run_options do
            xml['w'].rPr do
              xml['w'].rtl({ 'w:val' => '0' })
            end
          end
        end
      end

      def render_linebreak(xml, model)
        xml['w'].r do
          xml['w'].br
        end
      end

      def render_link(xml, model)
        if model.external?
          rel = document.relationship({ target: model.link_href, type: :link })
          hyperlink_options = { 'r:id' => rel.formatted_id }
        else
          hyperlink_options = { 'w:anchor' => model.link_href }
        end

        xml['w'].hyperlink(hyperlink_options) do
          xml['w'].r run_options do
            render_run_attributes(xml, model, false)
            xml['w'].t({ 'xml:space' => 'preserve' }, model.link_content)
          end
        end
      end

      def render_tableofcontents(xml, model)
        xml['w'].sdt do
          xml['w'].sdtPr do
            xml['w'].docPartObj do
              xml['w'].docPartGallery({ 'w:val' => model.toc_title })
              xml['w'].docPartUnique({ 'w:val' => true })
            end
          end
          xml['w'].sdtContent do
            xml['w'].p do
              xml['w'].pPr do
                xml['w'].pStyle({ 'w:val' => 'ContentsHeading' })
                xml['w'].rPr do
                  xml['w'].b
                  xml['w'].b
                  xml['w'].bCs
                  xml['w'].sz({ 'w:val' => model.toc_size })
                  xml['w'].szCs({ 'w:val' => model.toc_size })
                end
              end
              xml['w'].r do
                  xml['w'].rPr do
                  xml['w'].b
                  xml['w'].bCs
                  xml['w'].sz({ 'w:val' => model.toc_size })
                  xml['w'].szCs({ 'w:val' => model.toc_size })
                end
                xml['w'].t model.toc_title
              end
            end
            xml['w'].p do
              xml['w'].r do
                xml['w'].fldChar({ 'w:fldCharType' => 'begin' })
              end
              xml['w'].r do
                xml['w'].rPr do
                  render_run_attributes(xml, model, false)
                end
                xml['w'].instrText({ 'xml:space' => 'preserve' }) do
                  xml.text " #{model.toc_opts} "
                end
              end
              xml['w'].r do
                xml['w'].fldChar({ 'w:fldCharType' => 'separate' })
              end
              xml['w'].r do
                xml['w'].fldChar({ 'w:fldCharType' => 'end' })
              end
            end
          end
        end
      end

      def render_field(xml, model)
        xml['w'].r do
          xml['w'].fldChar({ 'w:fldCharType' => 'begin' })
        end
        xml['w'].r do
          xml['w'].rPr do
            render_run_attributes(xml, model, false)
          end
          xml['w'].instrText({ 'xml:space' => 'preserve' }) do
            xml.text " #{model.formatted_type} "
          end
        end
        xml['w'].r do
          xml['w'].fldChar({ 'w:fldCharType' => 'separate' })
        end
        xml['w'].r do
          xml['w'].fldChar({ 'w:fldCharType' => 'end' })
        end
      end

      def render_list(xml, model)
        if model.list_level == 0
          document.toplevel_lists << model
          list_num = document.toplevel_lists.length   # numbering uses 1-based index
        end

        model.recursive_items.each do |item|
          render_listitem(xml, item, list_num)
        end
      end

      def render_listitem(xml, model, list_num)
        ls      = document.find_list_style(model.list_item_type, model.list_item_level)
        hanging = ls.style_left.to_i - ls.style_indent.to_i - 1

        xml['w'].p paragraph_options do
          xml['w'].pPr do
            xml['w'].numPr do
              xml['w'].ilvl({ 'w:val' => model.list_item_level })
              xml['w'].numId({ 'w:val' => list_num })
            end
            xml['w'].ind({ 'w:left' => ls.style_left, 'w:hanging' => hanging })
            xml['w'].contextualSpacing({ 'w:val' => '1' })
            xml['w'].rPr do
              xml['w'].u({ 'w:val' => 'none' })
            end
          end
          model.runs.each do |run|
            method = render_method_for_model(run)
            send(method, xml, run)
          end
        end
      end

      def render_pageflip(xml, model)
        xml['w'].p paragraph_options do
          xml['w'].pPr do
            xml['w'].sectPr do
              if rel = document.find_relationship('footer1.xml')
                xml['w'].footerReference({ 'r:id' => rel.formatted_id, 'w:type' => 'default' })
              end
              if rel = document.find_relationship('header1.xml')
                xml['w'].headerReference({ 'r:id' => rel.formatted_id, 'w:type' => 'default' })
              end
              xml['w'].pgSz({
                'w:w' => document.page_width,
                'w:h' => document.page_height
              })
            end
          end
        end
        model.contents.each do |model|
          method = render_method_for_model(model)
          send(method, xml, model)
        end
        xml['w'].p paragraph_options do
          xml['w'].pPr do
            xml['w'].sectPr do
              if rel = document.find_relationship('footer1.xml')
                xml['w'].footerReference({ 'r:id' => rel.formatted_id, 'w:type' => 'default' })
              end
              if rel = document.find_relationship('header1.xml')
                xml['w'].headerReference({ 'r:id' => rel.formatted_id, 'w:type' => 'default' })
              end
              xml['w'].pgSz({
                'w:w' => document.page_height,
                'w:h' => document.page_width
              })
            end
          end
        end
      end

      def render_pagebreak(xml, model)
        @pagebreak_on_next_paragraph = true
      end

      def render_paragraph(xml, model)
        run_props = [:color, :size, :bold, :italic, :underline].map { |m| model.send("paragraph_#{ m }") }.compact

        xml['w'].p paragraph_options do
          xml['w'].pPr do
            xml['w'].pStyle({ 'w:val' => model.paragraph_style })  unless model.paragraph_style.nil?
            xml['w'].contextualSpacing({ 'w:val' => '0' })
            xml['w'].jc({ 'w:val' => model.paragraph_align })  unless model.paragraph_align.nil?
            render_run_attributes(xml, model, true)
            if @pagebreak_on_next_paragraph
              xml['w'].pageBreakBefore
              @pagebreak_on_next_paragraph = false
            end
          end
          model.runs.each do |run|
            method = render_method_for_model(run)
            send(method, xml, run)
          end
        end
      end

      def render_rule(xml, model)
        options = { 'w:color' => model.rule_color, 'w:sz' => model.rule_size, 'w:val' => model.rule_line, 'w:space' => model.rule_spacing }

        xml['w'].p paragraph_options do
          xml['w'].pPr do
            xml['w'].pBdr do
              xml['w'].top options
            end
          end
        end
      end

      def render_text(xml, model)
        xml['w'].r run_options do
          render_run_attributes(xml, model, false)
          xml['w'].t({ 'xml:space' => 'preserve' }, model.text_content)
        end
      end

      def render_table(xml, model)
        borders = %w(top left bottom right horizontal vertical).select do |m|
          model.send("table_border_#{ m }_size") > 0
        end

        xml['w'].tbl do
          xml['w'].tblPr do
            xml['w'].tblStyle({ 'w:val' => 'DefaultTable' })
            xml['w'].bidiVisual({ 'w:val' => '0' })
            xml['w'].tblW({ 'w:w'   => model.table_width.to_f, 'w:type' => 'dxa' })
            xml['w'].tblInd({ 'w:w'   => '0.0', 'w:type' => 'dxa' })
            xml['w'].jc({ 'w:val' => model.table_align })
            unless borders.empty?
              xml['w'].tblBorders do
                borders.each do |m|
                  options = {
                    'w:color' => model.send("table_border_#{ m }_color"),
                    'w:val'   => model.send("table_border_#{ m }_line"),
                    'w:sz'    => model.send("table_border_#{ m }_size"),
                    'w:space' => model.send("table_border_#{ m }_spacing")
                  }
                  xml['w'].method_missing "#{ Caracal::Core::Models::BorderModel.formatted_type(m) }", options
                end
              end
            end
            xml['w'].tblLayout({ 'w:type' => 'fixed' })
            xml['w'].tblLook({ 'w:val'  => '0600'  })
          end
          xml['w'].tblGrid do
            model.rows.first.each do |tc|
              (tc.cell_colspan || 1).times do
                xml['w'].gridCol({ 'w:w' => tc.cell_width })
              end
            end
            xml['w'].tblGridChange({ 'w:id' => '0' }) do
              xml['w'].tblGrid do
                model.rows.first.each do |tc|
                  (tc.cell_colspan || 1).times do
                    xml['w'].gridCol({ 'w:w' => tc.cell_width })
                  end
                end
              end
            end
          end

          rowspan_hash = {}
          model.rows.each do |row|
            xml['w'].tr do
              tc_index = 0
              row.each do |tc|
                xml['w'].tc do
                  xml['w'].tcPr do
                    xml['w'].shd({ 'w:fill' => tc.cell_background })
                    xml['w'].vAlign({ 'w:val' => tc.cell_vertical_align })

                    # applying rowspan
                    if tc.cell_rowspan && tc.cell_rowspan > 0
                      rowspan_hash[tc_index] = tc.cell_rowspan - 1
                      xml['w'].vMerge({ 'w:val' => 'restart' })
                    elsif rowspan_hash[tc_index] && rowspan_hash[tc_index] > 0
                      xml['w'].vMerge({ 'w:val' => 'continue' })
                      rowspan_hash[tc_index] -= 1
                    end

                    # applying colspan
                    xml['w'].gridSpan({ 'w:val' => tc.cell_colspan }) if tc.cell_colspan

                    xml['w'].tcMar do
                      %w(top left bottom right).each do |d|
                        xml['w'].method_missing "#{ d }", { 'w:w' => tc.send("cell_margin_#{ d }").to_f, 'w:type' => 'dxa' }
                      end
                    end
                  end
                  tc.contents.each do |m|
                    method = render_method_for_model(m)
                    send(method, xml, m)
                  end
                end

                # adjust tc_index for next cell taking into account current cell's colspan
                tc_index += (tc.cell_colspan && tc.cell_colspan > 0) ? tc.cell_colspan : 1
              end
            end
          end
        end
      end


      #============= OPTIONS ===================================

      def root_options
        opts = {}
        document.namespaces.each do |model|
          opts[model.namespace_prefix] = model.namespace_href
        end
        unless document.ignorables.empty?
          v = document.ignorables.join(' ')
          opts['mc:Ignorable'] = v
        end
        opts
      end

      def page_margin_options
        {
          'w:top'    => document.page_margin_top,
          'w:bottom' => document.page_margin_bottom,
          'w:left'   => document.page_margin_left,
          'w:right'  => document.page_margin_right
        }
      end

      def page_size_options
        {
          'w:w'       => document.page_width,
          'w:h'       => document.page_height,
          'w:orient'  => document.page_orientation
        }
      end

    end
  end
end