// Copyright 2022 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package charset

import (
	"html/template"
	"io"
	"strings"

	"gitea.dev/modules/htmlutil"
	"gitea.dev/modules/setting"
	"gitea.dev/modules/translation"
)

type EscapeOptions struct {
	Allowed map[rune]bool
}

func AllowRuneNBSP() map[rune]bool {
	return map[rune]bool{0xa0: true}
}

func EscapeOptionsForView() EscapeOptions {
	return EscapeOptions{
		// it's safe to see NBSP in the view, but maybe not in the diff
		Allowed: AllowRuneNBSP(),
	}
}

func EscapeControlHTMLTo(html template.HTML, locale translation.Locale, w htmlutil.HTMLWriter, opts ...EscapeOptions) *EscapeStatus {
	if !setting.UI.AmbiguousUnicodeDetection {
		w.WriteHTML(html)
		return &EscapeStatus{}
	}
	escaped, _ := EscapeControlReader(strings.NewReader(string(html)), w.OriginWriter(), locale, opts...)
	return escaped
}

// EscapeControlHTML escapes the Unicode control sequences in a provided html document
func EscapeControlHTML(html template.HTML, locale translation.Locale, opts ...EscapeOptions) (escaped *EscapeStatus, output template.HTML) {
	sb, w := htmlutil.NewHTMLStringWriter()
	escaped = EscapeControlHTMLTo(html, locale, w, opts...)
	return escaped, template.HTML(sb.String())
}

// EscapeControlReader escapes the Unicode control sequences in a provided reader of HTML content and writer in a locale and returns the findings as an EscapeStatus
func EscapeControlReader(reader io.Reader, writer io.Writer, locale translation.Locale, opts ...EscapeOptions) (*EscapeStatus, error) {
	return escapeStream(locale, reader, writer, opts...)
}