// Copyright 2022 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

//go:generate go run invisible/generate.go -v -o ./invisible_gen.go

//go:generate go run ambiguous/generate.go -v -o ./ambiguous_gen.go ambiguous/ambiguous.json

package charset

import (
	"bufio"
	"io"
	"strings"

	"code.gitea.io/gitea/modules/log"
	"code.gitea.io/gitea/modules/translation"
)

// RuneNBSP is the codepoint for NBSP
const RuneNBSP = 0xa0

// EscapeControlHTML escapes the unicode control sequences in a provided html document
func EscapeControlHTML(text string, locale translation.Locale, allowed ...rune) (escaped *EscapeStatus, output string) {
	sb := &strings.Builder{}
	outputStream := &HTMLStreamerWriter{Writer: sb}
	streamer := NewEscapeStreamer(locale, outputStream, allowed...).(*escapeStreamer)

	if err := StreamHTML(strings.NewReader(text), streamer); err != nil {
		streamer.escaped.HasError = true
		log.Error("Error whilst escaping: %v", err)
	}
	return streamer.escaped, sb.String()
}

// EscapeControlReaders escapes the unicode control sequences in a provided reader of HTML content and writer in a locale and returns the findings as an EscapeStatus and the escaped []byte
func EscapeControlReader(reader io.Reader, writer io.Writer, locale translation.Locale, allowed ...rune) (escaped *EscapeStatus, err error) {
	outputStream := &HTMLStreamerWriter{Writer: writer}
	streamer := NewEscapeStreamer(locale, outputStream, allowed...).(*escapeStreamer)

	if err = StreamHTML(reader, streamer); err != nil {
		streamer.escaped.HasError = true
		log.Error("Error whilst escaping: %v", err)
	}
	return streamer.escaped, err
}

// EscapeControlStringReader escapes the unicode control sequences in a provided reader of string content and writer in a locale and returns the findings as an EscapeStatus and the escaped []byte
func EscapeControlStringReader(reader io.Reader, writer io.Writer, locale translation.Locale, allowed ...rune) (escaped *EscapeStatus, err error) {
	bufRd := bufio.NewReader(reader)
	outputStream := &HTMLStreamerWriter{Writer: writer}
	streamer := NewEscapeStreamer(locale, outputStream, allowed...).(*escapeStreamer)

	for {
		line, rdErr := bufRd.ReadString('\n')
		if len(line) > 0 {
			if err := streamer.Text(line); err != nil {
				streamer.escaped.HasError = true
				log.Error("Error whilst escaping: %v", err)
				return streamer.escaped, err
			}
		}
		if rdErr != nil {
			if rdErr != io.EOF {
				err = rdErr
			}
			break
		}
		if err := streamer.SelfClosingTag("br"); err != nil {
			streamer.escaped.HasError = true
			return streamer.escaped, err
		}
	}
	return streamer.escaped, err
}

// EscapeControlString escapes the unicode control sequences in a provided string and returns the findings as an EscapeStatus and the escaped string
func EscapeControlString(text string, locale translation.Locale, allowed ...rune) (escaped *EscapeStatus, output string) {
	sb := &strings.Builder{}
	outputStream := &HTMLStreamerWriter{Writer: sb}
	streamer := NewEscapeStreamer(locale, outputStream, allowed...).(*escapeStreamer)

	if err := streamer.Text(text); err != nil {
		streamer.escaped.HasError = true
		log.Error("Error whilst escaping: %v", err)
	}
	return streamer.escaped, sb.String()
}
