# Title: Simple Image Figure tag for Jekyll
 # Author: Brandon Mathis http://brandonmathis.com
 # Description: Easily output images in <figure> with an optional <figcaption> and class names.
 #
 # Syntax {% figure [class name(s)] url [caption text] %}
 #
 # Example:
 # {% figure left half http://site.com/images/ninja.png Ninja Attack! %}
 #
 # Output:
 # <figure class='left half'><img src="http://site.com/images/ninja.png"><figcaption>Ninja Attack!</figcaption></figure>
 #
 # Example 2 (image with caption)
 # {% figure /images/ninja.png Ninja Attack! %}
 #
 # Output:
 # <figure><img src="/images/ninja.png"><figcaption>Ninja Attack!</figcaption></figure>
 #
 # Example 3 (just an image with classes)
 # {% figure right /images/ninja.png %}
 #
 # Output:
 # <figure><img class="right" src="/images/ninja.png"></figure>
 #
 
 module Jekyll
 
   class FigureImageTag < Liquid::Tag
     ClassImgCaption = /(\S[\S\s]*)\s+(https?:\/\/|\/)(\S+)\s+(.+)/i
     ClassImg = /(\S[\S\s]*)\s+(https?:\/\/|\/)(\S+)/i
     ImgCaption = /^\s*(https?:\/\/|\/)(\S+)\s+(.+)/i
     Img = /^\s*(https?:\/\/|\/)(\S+\s)/i
 
     @img = nil
     @caption = nil
     @class = ''
 
     def initialize(tag_name, markup, tokens)
       if markup =~ ClassImgCaption
         @class = $1
         @img = $2 + $3
         @caption = $4
       elsif markup =~ ClassImg
         @class = $1
         @img = $2 + $3
       elsif markup =~ ImgCaption
         @img = $1 + $2
         @caption = $3
       elsif markup =~ Img
         @img = $1 + $2
       end
       super
     end
 
     def render(context)
       output = super
       if @img
         figure =  "<figure class='#{@class}'>"
         figure += "<img src='#{@img}'>"
         figure += "<figcaption>#{@caption}</figcaption>" if @caption
         figure += "</figure>"
       else
         "Error processing input, expected syntax: {% figure [class name(s)] /url/to/image [caption] %}"
       end
     end
   end
 end
 
 Liquid::Template.register_tag('figure', Jekyll::FigureImageTag)