// Copyright (c) 2024-2026 Tencent Zhuque Lab. All rights reserved.
//
// 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.
//
// Requirement: Any integration or derivative work must explicitly attribute
// Tencent Zhuque Lab (https://github.com/Tencent/AI-Infra-Guard) in its
// documentation or user interface, as detailed in the NOTICE file.

// Package httpx title
package httpx

import (
	"regexp"
	"strings"

	"golang.org/x/net/html"
)

// ExtractTitle from a response
func ExtractTitle(resp string) (title string) {
	var re = regexp.MustCompile(`(?im)<\s*title.*>(.*?)<\s*/\s*title>`)
	for _, match := range re.FindAllString(resp, -1) {
		title = html.UnescapeString(trimTitleTags(match))
		break
	}
	return
}

func trimTitleTags(title string) string {
	// trim <title>*</title>
	titleBegin := strings.Index(title, ">")
	titleEnd := strings.Index(title, "</")
	return title[titleBegin+1 : titleEnd]
}