tdiary/tdiary-style-gfm

# -*- coding: utf-8; -*-

require 'commonmarker'
require 'twitter-text'

module TDiary
    module Style
        class GfmSection
            def initialize(fragment, author = nil)
                @author = author
                @subtitle, @body = fragment.split(/\n/, 2)
                @subtitle.sub!(/^\#\s*/,'')
                @body ||= ''

                @categories = get_categories
                @stripped_subtitle = strip_subtitle

                @subtitle_to_html = @subtitle ? to_html('# ' + @subtitle).gsub(/\A<h\d>|<\/h\d>\z/io, '') : nil
                @stripped_subtitle_to_html = @stripped_subtitle ? to_html('# ' + @stripped_subtitle).gsub(/\A<h\d>|<\/h\d>\z/io, '') : nil
                @body_to_html = to_html(@body)
            end

            def subtitle=(subtitle)
                @subtitle = (subtitle || '').sub(/^# /,"\##{categories_to_string} ")
                @strip_subtitle = strip_subtitle
            end

            def categories=(categories)
                @subtitle = "#{categories_to_string} " + (strip_subtitle || '')
                @strip_subtitle = strip_subtitle
            end

            def to_src
                r = ''
                r << "\# #{@subtitle}\n" if @subtitle
                r << @body
            end

            def do_html4(date, idx, opt)
                subtitle = to_html('# ' + @subtitle)
                subtitle.sub!( %r!<h3>(.+?)</h3>!m ) do
                    "<h3><%= subtitle_proc( Time.at( #{date.to_i} ), #{$1.dump.gsub( /%/, '\\\\045' )} ) %></h3>"
                end
                if opt['multi_user'] and @author then
                    subtitle.sub!(/<\/h3>/,%Q|[#{@author}]</h3>|)
                end
                r = subtitle
                r << @body_to_html
            end

            private

            def to_html(string)
                r = string.dup

                # 1. Stash plugin calls
                plugin_stashes = []
                plugin_blocks, replaced_r = extract_plugin_blocks_and_replace(r)
                plugin_blocks.each do |plugin_block|
                    # Convert `{{ }}' to erb tags
                    plugin_stashes.push(["{{#{plugin_block}}}", "<%=#{plugin_block}%>"])
                end
                r = replaced_r

                # 2. Apply markdown conversion
                r = CommonMarker.render_html(r, [:DEFAULT, :UNSAFE], [:autolink, :table])

                # 3. Stash <pre> and <code> tags
                pre_tag_stashes = []
                r.gsub!(/<pre(.*?)<\/pre>/m) do |matched|
                    pre_tag_stashes.push(matched)
                    "@@tdiary_style_gfm_pre_tag#{pre_tag_stashes.length - 1}@@"
                end

                code_tag_stashes = []
                r.gsub!(/<code(.*?)<\/code>/m) do |matched|
                    code_tag_stashes.push(matched)
                    "@@tdiary_style_gfm_code_tag#{code_tag_stashes.length - 1}@@"
                end

                # 4. Convert miscellaneous
                if pre_tag_stashes.none? && code_tag_stashes.none?
                    r = Twitter::TwitterText::Autolink.auto_link_usernames_or_lists(r)
                end

                r = r.emojify

                # diary anchor
                r.gsub!(/<h(\d)/) { "<h#{$1.to_i + 2}" }
                r.gsub!(/<\/h(\d)/) { "</h#{$1.to_i + 2}" }

                # my syntax
                r.gsub!(/<a href="(\d{4}|\d{6}|\d{8}|\d{8}-\d+)[^\d]*?#?([pct]\d+)?">(.*?)<\/a>/) {
                    unless $3.empty?
                        %Q|<%=my "#{$1}#{$2}", "#{$3}" %>|
                    else
                        %Q|<%=my "#{$1}#{$2}", "#{$1}#{$2}" %>|
                    end
                }

                # 5. Unstash <pre>, <code> and plugin call
                pre_tag_stashes.each.with_index do |str, i|
                    plugin_stashes.each.with_index do |(p_str, p_erb), j|
                        if str["@@tdiary_style_gfm_plugin#{j}@@"]
                            str["@@tdiary_style_gfm_plugin#{j}@@"] = CGI.escapeHTML(p_str)
                        end
                    end
                    r["@@tdiary_style_gfm_pre_tag#{i}@@"] = str
                end
                code_tag_stashes.each.with_index do |str, i|
                    plugin_stashes.each.with_index do |(p_str, p_erb), j|
                        if str["@@tdiary_style_gfm_plugin#{j}@@"]
                            str["@@tdiary_style_gfm_plugin#{j}@@"] = CGI.escapeHTML(p_str)
                        end
                    end
                    r["@@tdiary_style_gfm_code_tag#{i}@@"] = str
                end
                plugin_stashes.each.with_index do |(str, erb), i|
                    if r["@@tdiary_style_gfm_plugin#{i}@@"]
                        r["@@tdiary_style_gfm_plugin#{i}@@"] = erb
                    end
                end

                r
            end

            def get_categories
                return [] unless @subtitle
                cat = /(\\?\[([^\[]+?)\\?\])+/.match(@subtitle).to_a[0]
                return [] unless cat
                cat.scan(/\\?\[(.*?)\\?\]/).collect do |c|
                    c[0].split(/,/)
                end.flatten
            end

            def strip_subtitle
                return nil unless @subtitle
                r = @subtitle.sub(/^((\\?\[[^\[]+?\]\\?)+\s+)?/, '')
                if r.empty?
                    nil
                else
                    r
                end
            end

            def extract_plugin_blocks_and_replace(text)
                s = StringScanner.new(text)
                blocks = []
                count = 0
                replaced_text = ""
                while chunk = s.scan_until(/\{\{/)
                    chunk[-2, 2] = ""
                    replaced_text << chunk
                    if plugin_str = extract_plugin_block(s)
                        replaced_text << "@@tdiary_style_gfm_plugin#{count}@@"
                        blocks << plugin_str
                        count += 1
                    end
                end
                replaced_text << s.rest
                return blocks, replaced_text
            end

            def extract_plugin_block(s)
                pos = s.pos
                buf = ""
                while chunk = s.scan_until(/\}\}/)
                    buf << chunk
                    buf.chomp!("}}")
                    return buf
                end
                s.pos = pos
                nil
            end

        end

        class GfmDiary
            def initialize(date, title, body, modified = Time.now)
                init_diary
                replace( date, title, body )
                @last_modified = modified
            end

            def style
                'GFM'
            end

            def append(body, author = nil)
                in_code_block = false
                section = nil
                body.each_line do |l|
                    case l
                    when /^\#[^\#]/
                        if in_code_block
                            section << l
                        else
                            @sections << GfmSection.new(section, author) if section
                            section = l
                        end
                    when /^```/
                        in_code_block = !in_code_block
                        section << l
                    else
                        section = '' unless section
                        section << l
                    end
                end
                if section
                    section << "\n" unless section =~ /\n\n\z/
                    @sections << GfmSection.new(section, author)
                end
                @last_modified = Time.now
                self
            end

            def add_section(subtitle, body)
                @sections = GfmSection.new("\# #{subtitle}\n\n#{body}")
                @sections.size
            end
        end
    end
end

# Local Variables:
# mode: ruby
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# tab-width: 3
# ruby-indent-level: 3
# End: