# bivouac/helpers/view/html

module BivouacHelpers
  module HtmlView
    @@javascript_default_sources = %w{prototype.js scriptaculous.js}
    
    # Returns a stylesheet link tag for the sources specified as arguments. If
    # you don't specify an extension, .css will be appended automatically.
    # You can modify the link attributes by passing a hash as the last argument.
    #
    #   stylesheet_link_tag "style" # =>
    #     <link href="/public/stylesheets/style.css" media="screen" rel="Stylesheet" type="text/css" />
    #
    #   stylesheet_link_tag "style", :media => "all" # =>
    #     <link href="/public/stylesheets/style.css" media="all" rel="Stylesheet" type="text/css" />
    #
    #   stylesheet_link_tag "random.styles", "/css/stylish" # =>
    #     <link href="/public/stylesheets/random.styles" media="screen" rel="Stylesheet" type="text/css" />
    #     <link href="/public/stylesheets/css/stylish.css" media="screen" rel="Stylesheet" type="text/css" />
    def stylesheet_link_tag( *data )
      options = data.last.is_a?(Hash) ? data.pop : { }
      options[:rel]   = "Stylesheet"
      options[:type]  = "text/css"
      data.collect do |file|
        file << ".css" if File.extname(file).blank?
        options[:href] = "/public/stylesheets/#{file}"
        link( options )
      end
    end
    
    # Returns an html script tag for each of the +sources+ provided. You
    # can pass in the filename (.js extension is optional) of javascript files
    # that exist in your public/javascripts directory for inclusion into the
    # current page. To include the Prototype and Scriptaculous javascript 
    # libraries in your application, pass :defaults as the source.
    #
    #   javascript_include_tag "xmlhr" # =>
    #     <script type="text/javascript" src="/public/javascripts/xmlhr.js"></script>
    #
    #   javascript_include_tag "common.javascript", "elsewhere/cools" # =>
    #     <script type="text/javascript" src="/public/javascripts/common.javascript"></script>
    #     <script type="text/javascript" src="/public/javascripts/elsewhere/cools.js"></script>
    def javascript_include_tag( *sources )
      options = sources.last.is_a?(Hash) ? sources.pop : { }
      options[:type] = "text/javascript"
      
      if sources.include?(:defaults) 
        sources = sources[0..(sources.index(:defaults))] + 
          @@javascript_default_sources.dup + 
          sources[(sources.index(:defaults) + 1)..sources.length]
      
        sources.delete(:defaults) 
      end
      sources.collect do |file|
        file = file.to_s
        file << ".js" if File.extname(file).blank?
        options[:src] = "/public/javascripts/#{file}"
        script( options ) {}
      end
    end
    
    # Returns an html image tag for the +source+. The +source+ must be a file 
    # that exists in your public images directory (public/images). 
    # You can add html attributes using the +options+. If no alt text is given, 
    # the file name part of the +source+ is used (capitalized and without the 
    # extension)
    #
    #  image_tag("icon.png")  # =>
    #    <img src="/public/images/icon.png" alt="Icon" />
    # 
    #  image_tag("icon.png", :alt => "Edit Entry")  # =>
    #    <img src="/public/images/icon.png" alt="Edit Entry" />
    def image_tag( source, options = {} )
      options[:src] = "/public/images/#{source}"
      options[:alt] ||= File.basename(options[:src], '.*').split('.').first.capitalize
      
      img( options )
    end
    
    # Computes the path to an image asset in the public images directory. 
    # Full paths from the document root will be passed through. 
    # Used internally by image_tag to build the image path.
    #
    #  image_path("edit")                                         # => /public/images/edit
    #  image_path("edit.png")                                     # => /public/images/edit.png
    #  image_path("icons/edit.png")                               # => /public/images/icons/edit.png
    #  image_path("/icons/edit.png")                              # => /icons/edit.png
    #  image_path("http://www.railsapplication.com/img/edit.png") # => http://www.railsapplication.com/img/edit.png
    def image_path( source )
      if /^http:\/\//.match( source ) || /^\//.match( source )
        return source
      else
        return "/public/images/#{source}"
      end
    end
    
    # Creates a link tag of the given +name+ using +address+ has the href for 
    # the link
    #
    # The +options+ will accept a hash of html attributes for the link tag.
    # It also accepts 2 modifiers that specialize the link behavior. 
    # 
    # * <tt>:confirm => 'question?'</tt>: This will add a JavaScript confirm 
    #   prompt with the question specified. If the user accepts, the link is 
    #   processed normally, otherwise no action is taken.
    # * <tt>:popup => true || array of window options</tt>: This will force the
    #   link to open in a popup window. By passing true, a default browser window
    #   will be opened with the URL. You can also specify an array of options 
    #   that are passed-thru to JavaScripts window.open method.
    #   
    # You can mix and match the +options+.
    #   
    #   link_to "Documentation", "http://camping.rubyforge.org/", :confirm => "Are you sure?"
    #   link_to "Help", R( Help ), :popup => true
    #   link_to image_tag( "thumb.png" ), "/public/images/fullsize.png", :popup => ['My house', 'height=300,width=600']
    def link_to(name, address, options = {})
      options = javascript_options( options )
      options[:href] = address
      
      a( options ) do; name; end
    end
    
    private
    
    def javascript_options( options )
      unless options.is_a?(Hash)
        raise ArgumentError, "options must be a Hash!"
      end
      
      confirm, popup = options.delete(:confirm), options.delete(:popup)
      options["onclick"] = case
      when confirm && popup
        "if (#{confirm_javascript_function(confirm)}) { #{popup_javascript_function(popup)} };return false;"
      when confirm
        "return #{confirm_javascript_function(confirm)};"
      when popup
        popup_javascript_function(popup) + 'return false;'
      else
        options["onclick"]        
      end
      
      return options
    end
    
    # From Rails !!!!
    def confirm_javascript_function(confirm)
      "confirm('#{confirm}')"
    end

    # From Rails !!!!
    def popup_javascript_function(popup)
      popup.is_a?(Array) ? "window.open(this.href,'#{popup.first}','#{popup.last}');" : "window.open(this.href);"
    end
  end
end