module ApplicationHelper
  require 'rexml/document'

  def sanitize(text)
    Sanitize.clean(text, Sanitize::Config::OSM)
  end

  def htmlize(text)
    return linkify(sanitize(simple_format(text)))
  end

  def linkify(text)
    return auto_link(text, :link => :urls, :html => { :rel => "nofollow" })
  end

  def html_escape_unicode(text)
    chars = ActiveSupport::Multibyte::Chars.u_unpack(text).map do |c|
      c < 127 ? c.chr : "&##{c.to_s};"
    end

    return chars.join("")
  end

  def rss_link_to(*args)
    return link_to(image_tag("RSS.gif", :size => "16x16", :border => 0), Hash[*args], { :class => "rsssmall" });
  end

  def atom_link_to(*args)
    return link_to(image_tag("RSS.gif", :size => "16x16", :border => 0), Hash[*args], { :class => "rsssmall" });
  end

  def javascript_strings
    js = ""

    js << "<script type='text/javascript'>\n"
    js << "i18n_strings = new Array();\n"
    js << javascript_strings_for_key("javascripts")
    js << "</script>\n"

    return js
  end

  def describe_location(lat, lon, zoom = nil, language = nil)
    zoom = zoom || 14
    language = language || request.user_preferred_languages.join(',')
    url = "http://nominatim.openstreetmap.org/reverse?lat=#{lat}&lon=#{lon}&zoom=#{zoom}&accept-language=#{language}"
    response = REXML::Document.new(Net::HTTP.get(URI.parse(url)))

    if result = response.get_text("reversegeocode/result")
      result.to_s
    else
      "#{number_with_precision(lat, :precision => 3)}, #{number_with_precision(lon, :precision => 3)}"
    end
  end

  def user_image(user, options = {})
    options[:class] ||= "user_image"

    if user.image
      image_tag url_for_file_column(user, "image"), options
    else
      image_tag "anon_large.png", options
    end
  end

  def user_thumbnail(user, options = {})
    options[:class] ||= "user_thumbnail"

    if user.image
      image_tag url_for_file_column(user, "image"), options
    else
      image_tag "anon_small.png", options
    end
  end

private

  def javascript_strings_for_key(key)
    js = ""
    value = t(key, :locale => "en")

    if value.is_a?(String)
      js << "i18n_strings['#{key}'] = '" << escape_javascript(t(key)) << "';\n"
    else
      value.each_key do |k|
        js << javascript_strings_for_key("#{key}.#{k}")
      end
    end

    return js
  end
end
