require 'noumenon/template'
require 'uri'
require 'redcloth'

# Liquid extensions provided by Noumenon.
#
# @see http://github.com/Noumenon/noumenon/wiki/Template-Tags
module Noumenon::Template::CoreTags
  # The core set of filters provided by Noumenon for use in templates.
  #
  # @api public
  module Filters
    # Assigns the data piped in to the named variable.
    #
    # @example
    #   {{ "Jon" | assign_to: "name" }}
    #   {{ name }}
    #
    # @api public
    def assign_to(input, variable)
      @context.scopes.last[variable] = input
      ''
    end
    
    # Loads the content item at the path provided and passes it on.
    # 
    # If nothing was found then nothing will be returned, allowing the presence
    # of some content to be checked before trying to use it.
    # 
    # @example
    #   {{ "/includes/site_details" | item_at_path | assign_to: "site" }}
    #   {% if site %}
    #     <h1>{{ site.title }}</h1>
    #     <p>Written by {{ site.author }}</p>
    #   {% end %}
    #
    # @api public
    def item_at_path(input)
      item = Noumenon.content_repository.get(input)
      item ? item.stringify_keys : nil
    end
    
    # Formats the provided text using Textile.
    #
    # @example
    #   {{ "h1. Hello, world" | textilize }}
    #   <!-- <h1>Hello, world</h1> -->
    #
    # @api public
    def textilize(input)
      RedCloth.new(input).to_html
    end
  end
  Liquid::Template.register_filter(Filters)
  
  # Renders a navigation menu.
  #
  # @api public
  # @example
  #   <header>
  #     {% nav_menu %}
  #   </header>
  #
  #   <div id="sidebar">
  #     <h1>About Our Stuff</h1>
  #     <nav>
  #       {% nav_menu root=/about depth=1 include_root=false %}
  #     </nav>
  #   </div>
  class NavigationTag < Liquid::Tag
    def initialize(tag_name, syntax, tokens)
      super
      
      @options = { depth: 1, root: "/", include_root: true }
     
      syntax.split(" ").each do |option|
        key, value = option.split("=")
        case key
        when "depth"
          @options[:depth] = value.to_i
        when "root"
          @options[:root] = value
        when "include_root"
          @options[:include_root] = [ "true", "yes", "1" ].include?(value)
        end
      end
    end
    
    def render_list(items)
      list = items.collect do |item|
        str  = "<li>"
        str << %Q{<a href="#{item[:path]}">#{item[:nav_title] || item[:title]}</a>}
        str << render_list(item[:children]) if item[:children]
        str << "</li>"
        
        str
      end
      
      "<ul>#{list.join("\n")}</ul>"
    end
    
    def render(context)
      render_list Noumenon.content_repository.children(@options[:root], @options[:depth], @options[:include_root])
    end
  end
  Liquid::Template.register_tag('nav_menu', NavigationTag)

  class ThemeAssetTag < Liquid::Tag
    def initialize(tag_name, asset, tokens)
      @asset = asset.strip
    end

    def render(context)
      File.join("/themes", URI.escape(Noumenon.theme.name), @asset)
    end
  end
  Liquid::Template.register_tag('theme_asset', ThemeAssetTag)

  class ContentAssetTag < Liquid::Tag
    def initialize(tag_name, asset, tokens)
      @asset = asset.strip
    end

    def render(context)
      Noumenon.asset_repository.url_for(@asset)
    end
  end
  Liquid::Template.register_tag('asset', ContentAssetTag)
end