/**
 * Given text in a variety of format codings, this function returns
 * the text as plain text suitable for plain email.
 *
 * @uses FORMAT_MOODLE
 * @uses FORMAT_HTML
 * @uses FORMAT_PLAIN
 * @uses FORMAT_WIKI
 * @uses FORMAT_MARKDOWN
 * @param string $text The text to be formatted. This is raw text originally from user input.
 * @param int $format Identifier of the text format to be used
 *            [FORMAT_MOODLE, FORMAT_HTML, FORMAT_PLAIN, FORMAT_WIKI, FORMAT_MARKDOWN]
 * @return string
 */
function format_text_email($text, $format)
{
    switch ($format) {
        case FORMAT_PLAIN:
            return $text;
            break;
        case FORMAT_WIKI:
            // there should not be any of these any more!
            $text = wikify_links($text);
            return strtr(strip_tags($text), array_flip(get_html_translation_table(HTML_ENTITIES)));
            break;
        case FORMAT_HTML:
            return html_to_text($text);
            break;
        case FORMAT_MOODLE:
        case FORMAT_MARKDOWN:
        default:
            $text = wikify_links($text);
            return strtr(strip_tags($text), array_flip(get_html_translation_table(HTML_ENTITIES)));
            break;
    }
}

/**
 * Given text in a variety of format codings, this function returns the text as plain text suitable for plain email.
 *
 * @param string $text The text to be formatted. This is raw text originally from user input.
 * @param int $format Identifier of the text format to be used
 *            [FORMAT_MOODLE, FORMAT_HTML, FORMAT_PLAIN, FORMAT_WIKI, FORMAT_MARKDOWN]
 * @return string
 */
function format_text_email($text, $format)
{
    switch ($format) {
        case FORMAT_PLAIN:
            return $text;
            break;
        case FORMAT_WIKI:
            // There should not be any of these any more!
            $text = wikify_links($text);
            return core_text::entities_to_utf8(strip_tags($text), true);
            break;
        case FORMAT_HTML:
            return html_to_text($text);
            break;
        case FORMAT_MOODLE:
        case FORMAT_MARKDOWN:
        default:
            $text = wikify_links($text);
            return core_text::entities_to_utf8(strip_tags($text), true);
            break;
    }
}

 public function test_wikify_links()
 {
     $this->assertSame('this is a link [ http://someaddress.com/query ]', wikify_links('this is a <a href="http://someaddress.com/query">link</a>'));
 }

 function test_wikify_links() {
     $this->assertEquals(wikify_links('this is a <a href="http://someaddress.com/query">link</a>'), 'this is a link [ http://someaddress.com/query ]');
 }