require 'open-uri'
require 'fileutils'
require 'optparse'
require 'yaml'


class ThemeManager
  THEME_ROOT = 'http://retrospectiva.googlecode.com/svn/themes'
  PUBLIC_ROOT = File.expand_path(File.dirname(__FILE__) + "/../public")

  def initialize
    @script_name = File.basename($0)     
    options.parse!(ARGV)
    command = ARGV.shift
    name = ARGV.shift
    if command == 'list'
      list_themes
    elsif command == 'install' && !name.nil? && !name.empty?
      install_theme(name)
    else
      puts options
      exit 1
    end
  end

	def options
    OptionParser.new do |o|
      o.set_summary_indent('  ')
      o.banner = "\nRetrospectiva theme manager"            
      o.separator "Usage: #{@script_name} command"
      o.separator ""
      o.separator "COMMANDS"      
      o.separator "  list       List available themes."
      o.separator "  install    Installs a theme."
      o.separator ""
      o.separator "EXAMPLES"
      o.separator "  List all available themes: #{@script_name} list"
      o.separator "  Install the default theme: #{@script_name} install default"
      o.separator ""
    end
  end

  def install_theme(name)
    theme = Theme.new(name)
    unless theme.valid?
      puts "\nInvalid theme '#{name}'.\n\n"
      exit 1
    end
    theme.files.each do |path|	    	    
	    File.open("#{PUBLIC_ROOT}/#{path}", 'wb') do |local|
	    	open("#{THEME_ROOT}/#{theme.name}/#{path}").each do |line|
					local.write(line)					    	
	    	end
	    end    	
    end    
    puts "\nTheme '#{theme.name}' was successfully installed.\n\n"
  end

  def list_themes
    themes = []
    
    open(THEME_ROOT).each do |line|
      line.scan(/<a[^>]*href=\"(\w+)\/\">(\w+)\/<\/a><\/li>/) do |name,|
        theme = Theme.new(name)
        themes << theme if theme.valid?
      end
    end
    
    puts "\nAvailable themes:"
    themes.each do |theme|
      puts "  #{theme.name}  -  #{theme.description}"
    end
    puts "\n"
  end

  class Theme   
    attr_reader :name
    
    def initialize(name)
      @name = name
    end
    
    def valid?
      files.any?
    end
    
    def description
      conf['description'] || ''
    end

    def files
      conf['files'].is_a?(Array) ? conf['files'] : []
    end
  
    def conf
      @conf ||= YAML.load(info) rescue {}
    end
    
    def info
      @info ||= open("#{THEME_ROOT}/#{name}/info.yml") rescue nil
    end    
  end  
end

ThemeManager.new