defmodule HtmlSanitizeEx.Scrubber.BasicHTML do
  @moduledoc """
  Allows basic HTML tags to support user input for writing relatively
  plain text but allowing headings, links, bold, and so on.

  Does not allow any mailto-links, styling, HTML5 tags, video embeds etc.
  """

  require HtmlSanitizeEx.Scrubber.Meta
  alias HtmlSanitizeEx.Scrubber.Meta

  @valid_schemes ["http", "https"]

  # Removes any CDATA tags before the traverser/scrubber runs.
  Meta.remove_cdata_sections_before_scrub

  Meta.strip_comments

  Meta.allow_tag_with_uri_attributes   "a", ["href"], @valid_schemes
  Meta.allow_tag_with_these_attributes "a", ["name", "title"]

  Meta.allow_tag_with_these_attributes "b", []
  Meta.allow_tag_with_these_attributes "blockquote", []
  Meta.allow_tag_with_these_attributes "br", []
  Meta.allow_tag_with_these_attributes "code", []
  Meta.allow_tag_with_these_attributes "del", []
  Meta.allow_tag_with_these_attributes "em", []
  Meta.allow_tag_with_these_attributes "h1", []
  Meta.allow_tag_with_these_attributes "h2", []
  Meta.allow_tag_with_these_attributes "h3", []
  Meta.allow_tag_with_these_attributes "h4", []
  Meta.allow_tag_with_these_attributes "h5", []
  Meta.allow_tag_with_these_attributes "hr", []
  Meta.allow_tag_with_these_attributes "i", []

  Meta.allow_tag_with_uri_attributes   "img", ["src"], @valid_schemes
  Meta.allow_tag_with_these_attributes "img", ["width", "height", "title", "alt"]

  Meta.allow_tag_with_these_attributes "li", []
  Meta.allow_tag_with_these_attributes "ol", []
  Meta.allow_tag_with_these_attributes "p", []
  Meta.allow_tag_with_these_attributes "pre", []
  Meta.allow_tag_with_these_attributes "span", []
  Meta.allow_tag_with_these_attributes "strong", []
  Meta.allow_tag_with_these_attributes "table", []
  Meta.allow_tag_with_these_attributes "tbody", []
  Meta.allow_tag_with_these_attributes "td", []
  Meta.allow_tag_with_these_attributes "th", []
  Meta.allow_tag_with_these_attributes "thead", []
  Meta.allow_tag_with_these_attributes "tr", []
  Meta.allow_tag_with_these_attributes "u", []
  Meta.allow_tag_with_these_attributes "ul", []

  Meta.strip_everything_not_covered
end