// Copyright 2013 com authors
//
// Licensed under the Apache License, Version 2.0 (the "License"): you may
// not use this file except in compliance with the License. You may obtain
// a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations
// under the License.

package com

import (
	"html"
	"regexp"
	"strings"
)

// Html2JS converts []byte type of HTML content into JS format.
func Html2JS(data []byte) []byte {
	s := string(data)
	s = strings.Replace(s, `\`, `\\`, -1)
	s = strings.Replace(s, "\n", `\n`, -1)
	s = strings.Replace(s, "\r", "", -1)
	s = strings.Replace(s, "\"", `\"`, -1)
	s = strings.Replace(s, "<table>", "&lt;table>", -1)
	return []byte(s)
}

// encode html chars to string
func HtmlEncode(str string) string {
	return html.EscapeString(str)
}

// HtmlDecode decodes string to html chars
func HtmlDecode(str string) string {
	return html.UnescapeString(str)
}

// strip tags in html string
func StripTags(src string) string {
	//去除style,script,html tag
	re := regexp.MustCompile(`(?s)<(?:style|script)[^<>]*>.*?</(?:style|script)>|</?[a-z][a-z0-9]*[^<>]*>|<!--.*?-->`)
	src = re.ReplaceAllString(src, "")

	//trim all spaces(2+) into \n
	re = regexp.MustCompile(`\s{2,}`)
	src = re.ReplaceAllString(src, "\n")

	return strings.TrimSpace(src)
}

// change \n to <br/>
func Nl2br(str string) string {
	return strings.Replace(str, "\n", "<br/>", -1)
}