# -*-Ruby-*-

require 'rubygems'
require 'rexml/document'
include REXML
require 'fox16'
include Fox
require 'time'

# REXML and FXRuby 1.6 internal encoding is UTF-8
# ours  is ISO-8859-1

class Formatter
  Tab = "  "

  def Formatter.utf8ToLatin1(text)
    str = String.new
    converter = Output.new(str, "iso-8859-1")
    converter << text
    return str
  end
end

class Item
  attr_accessor(:title, :link, :description, :pubDate)

  def initialize
    @title = ''
    @link = ''
    @description = ''
    @pubDate = Time.now.rfc822
  end
 
  def computeDescription
    return @description
  end
  
  def computeHtmlDescription
    return @description.gsub(/\[([^\]]*)\]/, '<a href="\1">\1</a>')
  end

  def getLocaltime
    Time.parse(@pubDate).localtime
  end

  def getAnchorLink
    getLink + '#' + getAnchor
  end

  def getAnchor
    getLocaltime.strftime('%d%m%Y%H%M')
  end

  def getLink
    @link.gsub("\\", "/").gsub(/#.*/, "")
  end
    
  def xml(indent='')
    subIndent = indent + Formatter::Tab
    str = "#{indent}<item>\n"
    str << "#{subIndent}<title>#{@title}</title>\n"
    str << "#{subIndent}<link>#{getAnchorLink}</link>\n"
    str << "#{subIndent}<description>#{computeDescription}</description>\n"
    str << "#{subIndent}<pubDate>#{@pubDate}</pubDate>\n" unless @pubDate.empty?
    str << "#{indent}</item>\n"
    return str
  end

  def html(indent='')
    subIndent = indent + Formatter::Tab
    time = getLocaltime
    str = "#{indent}<a name=\"#{getAnchor}\"></a>\n"
    str << "#{indent}<div class=\"item\">\n"
    str << "#{subIndent}<div class=\"title\">#{@title}</div>\n"
    str << "#{subIndent}<div class=\"description\">#{computeHtmlDescription}</div>\n"
    str << "#{subIndent}<div class=\"pubDate\">#{time.strftime('%d.%m.%Y, %H:%M')}</div>\n" unless @pubDate.empty?
    str << "#{indent}</div>\n"
  end
end

class Channel
  attr_accessor(:title, :link, :description, :items)
  def initialize(maxNumOfItems=10)
    @title = ''
    @link = ''
    @description = ''    
    @items = Array.new
    @maxNumOfItems = maxNumOfItems
  end

  def appendOldItem(item)
    @items.push(item) if @items.size < @maxNumOfItems
  end

  def addNewItem(item)
    @items.reverse!
    @items.shift if @items.size == @maxNumOfItems
    @items.push(item)
    @items.reverse!
  end

  def xml(indent='')
    subIndent = indent + Formatter::Tab
    str = String.new
    str << "#{indent}<channel>\n"
    str << "#{subIndent}<title>#{@title}</title>\n"
    str << "#{subIndent}<link>#{@link.gsub("\\", "/")}</link>\n"
    str << "#{subIndent}<description>#{@description}</description>\n"
    @items.each { |i| str << i.xml(subIndent) }
    str << "#{indent}</channel>\n"
    return str
  end

  def html(indent='')
    subIndent = indent + Formatter::Tab
    str = String.new
    @items.each { |i| str << i.html(subIndent) }
    return str
  end
end

class RssFeed
  attr_reader(:channel)
  def initialize
    @channel = Channel.new
  end

  def addItem(item)
    @channel.addNewItem(item)
  end

  def readFile(file)
    doc = Document.new(File.new(file))
    doc.ignore_whitespace_nodes
    @channel = Channel.new
    numChan = 0
    channels = doc.elements.each("rss/channel") do
      |channelsXml|
      Exeption.new("More than one Channel in #{file}") if (numChan += 1) > 1
      channelsXml.elements.each do
	|elemXml|
	case elemXml.name
	  when 'title' then @channel.title = getString(elemXml)
	  when 'link' then @channel.link = getString(elemXml)
	  when 'description' then @channel.description = getString(elemXml)
	  when 'item' then computeItem(elemXml)
	end
      end
    end
  end

  def writeFile(file, includeFormat=false)
    File.open(file, 'w') do
      | fp |
      fp.print("<?xml version=\"1.0\" encoding=\"iso-8859-1\"?>\n")
      if includeFormat
	fp.print("<?xml-stylesheet href=\"rss.css\" type=\"text/css\"?>\n")
	fp.print("<?xml:stylesheet type=\"text/xsl\" href=\"rss.xsl\" ?>\n")
      end
      fp.print("<rss version=\"2.0\">\n")
      fp.print(Formatter.utf8ToLatin1(@channel.xml))
      fp.print("</rss>\n")
    end
  end

  def replaceInHtmlFile(file)
    lines = File.readlines(file)
    replacing = false
    File.open(file, 'w') { |fp|
      lines.each { |line|
	replacing = false if line =~ /<!--\/FEED-->/
        fp.print(line) unless replacing
	if line =~ /<!--FEED-->/
	  replacing = true
	  fp.print(Formatter.utf8ToLatin1(@channel.html))
	end
      }
    }
  end

private
  def computeItem(xmlItem)
    item = Item.new
    item.pubDate = ''
    xmlItem.elements.each do
      |element|
      case element.name
      when 'title' then item.title = getString(element) 
      when 'link' then item.link = getString(element)
      when 'description' then item.description = getString(element)
      when 'pubDate' then item.pubDate = getString(element)
      end
    end
    @channel.appendOldItem(item)
  end

  def getString(element)
    element.text.nil? ? "" : element.text
  end
end

class RssWriterGui < Fox::FXMainWindow
  include Fox  
  include Responder
  MsgStyle = MBOX_OK|DECOR_TITLE|DECOR_CLOSE|PLACEMENT_DEFAULT
  
  def initialize(app)
    super(app, "Very Simple Rss Feed Editor", nil, nil, DECOR_ALL,
	  0, 0, 160, 160, 0, 0)
    @formattedFeedFile = 'feed.xml'
    @feedFile = 'valid-feed.xml'
    @htmlFile = 'news.htm'
    @feed = RssFeed.new
    @selectedItem = nil
    @titles = Array.new
    initView
  end

  def initFrame(aFrame, fillMode=LAYOUT_FILL_X|LAYOUT_FILL_Y)
    aFrame.setFrameStyle(FRAME_NONE)
    aFrame.setLayoutHints(fillMode)
    return aFrame
  end
	
  def initView
    basicFrame = initFrame(FXVerticalFrame.new(self))

    gridFrame = FXMatrix.new(basicFrame, 3, MATRIX_BY_COLUMNS)
    gridFrame.setLayoutHints(LAYOUT_FILL_X)

    label = FXLabel.new(gridFrame, "Channel-Link:")
    label.setLayoutHints(LAYOUT_CENTER_Y)
    @linkTextField = FXTextField.new(gridFrame, 30)
    @linkTextField.setLayoutHints(LAYOUT_CENTER_Y|LAYOUT_FILL_X|LAYOUT_FILL_COLUMN)
    emptyFrame = initFrame(FXVerticalFrame.new(gridFrame))
    emptyFrame.setLayoutHints(LAYOUT_CENTER_Y|LAYOUT_FILL_X|LAYOUT_FILL_COLUMN)

    label = FXLabel.new(gridFrame, "Item-Title:")
    label.setLayoutHints(LAYOUT_CENTER_Y)
    @itemsCombobox = FXComboBox.new(gridFrame, 24,
				    nil, 0, COMBOBOX_REPLACE)
    @itemsCombobox.setFrameStyle(FRAME_SUNKEN|FRAME_THICK)
    @itemsCombobox.setLayoutHints(LAYOUT_CENTER_Y|LAYOUT_FILL_X|LAYOUT_FILL_COLUMN)
    addItemButton = FXButton.new(gridFrame, "New Item")
    addItemButton.connect(SEL_COMMAND, method(:onCmdAddItem))
    addItemButton.setLayoutHints(LAYOUT_CENTER_Y)

    FXLabel.new(basicFrame, "Description:")
    @descriptionTextField = FXText.new(basicFrame)
    @descriptionTextField.setLayoutHints(LAYOUT_FILL_X|LAYOUT_FILL_Y)
    @descriptionTextField.connect(SEL_CHANGED, method(:onCmdDescriptionChanged))

    buttonFrame = initFrame(FXHorizontalFrame.new(basicFrame), LAYOUT_FILL_X)

    generateButton = FXButton.new(buttonFrame, "Save Feed")
    generateButton.setButtonStyle(BUTTON_DEFAULT)
    generateButton.setDefault
    generateButton.connect(SEL_COMMAND, method(:onCmdGenerate))	
    setDefaults
  end

  def setDefaults
    urlString = $*.size > 0 ? $*[0] : "http://<news item url>"
    @linkTextField.setText(urlString)
    @descriptionTextField.setText("<news item text>")
  end

  # Create and show window
  def create
    position(0, 0, 340, 300)
    super
    show(PLACEMENT_SCREEN)
    readFeed
  end
  
  def readFeed
    begin
      @feed = RssFeed.new
      @feed.readFile(@feedFile)
      initCombobox
      @linkTextField.setText(@feed.channel.link)
    rescue Exception => err
      msg = "Failed with error: #{err.message}\n"
      msg << "Quit, otherwise I'll start with an empty feed"
      @descriptionTextField.setText "Failed with error: #{err.message}"
      @feed = RssFeed.new
    end
  end
  
  def initCombobox
    newComboBoxList
    numVisible = @titles.size >= 10 && @titles.size <= 20 ? @titles.size : 10
    @itemsCombobox.setNumVisible(numVisible)
    @itemsCombobox.connect(SEL_COMMAND, method(:onCmdSelectItem))
    @itemsCombobox.connect(SEL_CHANGED, method(:onCmdTitleChanged))
    selectItem(@feed.channel.items.first)
    @itemsCombobox.setCurrentItem(0)
  end

  def newComboBoxList
    @itemsCombobox.clearItems
    @titles = @feed.channel.items.collect{ |item| item.title }
    @titles.each { |title| @itemsCombobox.appendItem(title) }
  end

  def selectItem(item)
    @descriptionTextField.setText(item.description)
    @selectedItem = item
  end

  def copyViewToSelectedItem
    return if(@selectedItem.nil?)
    @selectedItem.title = @itemsCombobox.getText
    @selectedItem.link = @linkTextField.getText
    @selectedItem.description = @descriptionTextField.getText
  end

  def overwriteFeed
    begin
      @feed.writeFile(@feedFile, false)
      @feed.writeFile(@formattedFeedFile, true)
      @feed.replaceInHtmlFile(@htmlFile)
    rescue Exception => err
      msg = "Failed with error: #{err.message}\n"
      msg << "Unable to recover - files might be damaged"
      @descriptionTextField.setText "Failed with error: #{err.message}"
    end
  end

  def onCmdQuit(sender, sel, ptr)
    getApp.exit(0)
  end

  def onCmdTitleChanged(sender, sel, data)
    copyViewToSelectedItem
  end

  def onCmdDescriptionChanged(sender, sel, data)
    copyViewToSelectedItem
  end

  def onCmdSelectItem(sender, sel, selectedTitle)
    index = @itemsCombobox.getCurrentItem
    selectItem(@feed.channel.items[index]) unless(index.nil?)
  end

  def onCmdAddItem(sender, sel, index)
    copyViewToSelectedItem
    item = Item.new
    item.title = "New Item"
    item.link = @linkTextField.getText
    item.description = ""
    @feed.addItem(item)
    newComboBoxList
    @itemsCombobox.setCurrentItem(0)
    selectItem(item)
  end
  
  def onCmdGenerate(sender, sel, index)
    getApp.beginWaitCursor
    overwriteFeed
    getApp.endWaitCursor
  end
end
  
def runRssWriterGui
  application = Fox::FXApp.new("RssWriterGui", "Sascha Dördelmann")
  window = RssWriterGui.new(application)
  application.addSignal("SIGINT", window.method(:onCmdQuit))
  application.create
  application.run
end

runRssWriterGui