module AmpleAssets
  module ViewHelper
    
    def assets_toolbar(tabs = nil)
      tabs = AmpleAssets.tabs if tabs.nil?
      script = "var ample_assets = {}; ample_assets.load = true; "
      script += "ample_assets.mount_at = '#{AmpleAssets.mount_at}'; "
      script += "ample_assets.pages = #{tabs.to_json}"
      content_tag :script, script.html_safe, :type => "text/javascript"
    end
    
    # Returns image tag for an object's attachment, with optional link element wrapped around it. 
    #
    #   @param Object                   - Required 
    #   @param String :alt              - Defaults to object.title
    #   @param String :title
    #   @param String :class
    #   @param String :style
    #   @param String :dimensions       - Dragonfly-esque dimensions... @see http://markevans.github.com/dragonfly/file.Processing.html
    #   @param String :link             - Destination for link_to tag 
    #   @param Symbol :encode           - :gif, :jpg, :png, etc. Defaults to :png
    #   @param Object :object           - Dragonfly object, defaults to object.file
    #   @param Boolean :video           - Link to an iframe lightbox?
    #   @param String :video_dimensions - (width)x(height), defaults to 500x350
    #
    def image_asset(object, args={})

      # Gracefully handle nil
      return if object.try(:file).nil? && args[:object].nil?

      # Define default opts and merge with parameter args
      opts = {
        :alt => '',
        :video_dimensions => '500x350',
        :encode => :png
      }.merge(args)

      # Override alt text with object title if it exists
      opts[:alt] = escape_javascript(object.title) if object.respond_to?('title')
      
      # See if optional file object actually contains a dfly instance
      if opts[:object]
        attachment = opts[:object].attachment
        attachment_gravity = opts[:object].attachment_gravity
      else 
        attachment = object.file.attachment
        attachment_gravity = object.file.attachment_gravity
      end

      # If this is a crop, try to add gravity
      if opts.try(:[], :dimensions) && opts[:dimensions].include?('#')
        # Strip out image geometry
        opts[:size] = /[0-9]{1,}x[0-9]{1,}/.match(opts[:dimensions]).try(:[], 0)
        width, height = opts[:size].split('x')
        image = attachment.process(:resize_and_crop, :width => width, :height => height, :gravity => attachment_gravity).encode(opts[:encode])
      else
        image = opts.try(:[], :dimensions) ? attachment.process(:thumb, opts[:dimensions]).encode(opts[:encode]) : attachment.encode(opts[:encode])
      end

      # Determine which opts ultimately get passed to image_tag
      valid_opts = [:alt, :class, :style, :title]
      valid_opts.push(:size) unless args[:size] == false

      # Create image tag
      img_tag = image_tag(image.url, opts.slice(*valid_opts))

      # If this is a video link
      if opts[:video]
        link_to img_tag, opts[:link], :rel => 'facebox', :rev => "iframe|#{opts[:video_dimensions]}"
      else
        link_to_if opts[:link], img_tag, opts[:link]
      end

    end
    
  end
end