module UserNotificationsHelper

  def indent(text, by = 2)
    spacer = " " * by
    result = ""
    text.each_line do |line|
      result << spacer << line
    end
    result
  end

  def correct_top_margin(html, desired)
    fragment = Nokogiri::HTML.fragment(html)
    if para = fragment.css("p:first").first
      para["style"] = "margin-top: #{desired};"
    end
    fragment.to_html.html_safe
  end

  def logo_url
    logo_url = SiteSetting.digest_logo_url
    logo_url = SiteSetting.logo_url if logo_url.blank? || logo_url =~ /\.svg$/i

    return nil if logo_url.blank? || logo_url =~ /\.svg$/i
    if logo_url !~ /http(s)?\:\/\//
      logo_url = "#{Discourse.base_url}#{logo_url}"
    end
    logo_url
  end

  def html_site_link(color)
    "<a href='#{Discourse.base_url}' style='color: ##{color}'>#{@site_name}</a>"
  end

  def first_paragraphs_from(html)
    doc = Nokogiri::HTML(html)

    result = ""
    length = 0

    doc.css('body > p, aside.onebox, body > ul, body > blockquote').each do |node|
      if node.text.present?
        result << node.to_s
        length += node.inner_text.length
        return result if length >= SiteSetting.digest_min_excerpt_length
      end
    end

    return result unless result.blank?

    # If there is no first paragaph, return the first div (onebox)
    doc.css('div').first
  end

  def email_excerpt(html_arg)
    html = (first_paragraphs_from(html_arg) || html_arg).to_s
    PrettyText.format_for_email(html).html_safe
  end

  def normalize_name(name)
    name.downcase.gsub(/[\s_-]/, '')
  end

  def show_username_on_post(post)
    return true if SiteSetting.prioritize_username_in_ux
    return true unless SiteSetting.enable_names?
    return true unless SiteSetting.display_name_on_posts?
    return true unless post.user.name.present?

    normalize_name(post.user.name) != normalize_name(post.user.username)
  end

  def show_name_on_post(post)
    return true unless SiteSetting.prioritize_username_in_ux

    SiteSetting.enable_names? &&
      SiteSetting.display_name_on_posts? &&
      post.user.name.present? &&
      normalize_name(post.user.name) != normalize_name(post.user.username)
  end

  def format_for_email(post, use_excerpt)
    html = use_excerpt ? post.excerpt : post.cooked
    PrettyText.format_for_email(html, post).html_safe
  end

  def digest_custom_html(position_key)
    digest_custom "user_notifications.digest.custom.html.#{position_key}"
  end

  def digest_custom_text(position_key)
    digest_custom "user_notifications.digest.custom.text.#{position_key}"
  end

  def digest_custom(i18n_key)
    PrettyText.format_for_email(I18n.t(i18n_key)).html_safe
  end

  def show_image_with_url(url)
    !(url.nil? || url.downcase.end_with?('svg'))
  end

  def email_image_url(basename)
    UrlHelper.absolute("#{Discourse.base_uri}/images/emails/#{basename}")
  end

  def url_for_email(href)
    URI(href).host.present? ? href : UrlHelper.absolute("#{Discourse.base_uri}#{href}")
  rescue URI::InvalidURIError, URI::InvalidComponentError
    href
  end

end