Refactor markup package (#32399)

To make the markup package easier to maintain:
1. Split some go files into small files
2. Use a shared util.NopCloser, remove duplicate code
3. Remove unused functions

modules/markup/html_emoji.go

@@ -0,0 +1,115 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package markup
+
+import (
+	"strings"
+
+	"code.gitea.io/gitea/modules/emoji"
+	"code.gitea.io/gitea/modules/setting"
+
+	"golang.org/x/net/html"
+	"golang.org/x/net/html/atom"
+)
+
+func createEmoji(content, class, name string) *html.Node {
+	span := &html.Node{
+		Type: html.ElementNode,
+		Data: atom.Span.String(),
+		Attr: []html.Attribute{},
+	}
+	if class != "" {
+		span.Attr = append(span.Attr, html.Attribute{Key: "class", Val: class})
+	}
+	if name != "" {
+		span.Attr = append(span.Attr, html.Attribute{Key: "aria-label", Val: name})
+	}
+
+	text := &html.Node{
+		Type: html.TextNode,
+		Data: content,
+	}
+
+	span.AppendChild(text)
+	return span
+}
+
+func createCustomEmoji(alias string) *html.Node {
+	span := &html.Node{
+		Type: html.ElementNode,
+		Data: atom.Span.String(),
+		Attr: []html.Attribute{},
+	}
+	span.Attr = append(span.Attr, html.Attribute{Key: "class", Val: "emoji"})
+	span.Attr = append(span.Attr, html.Attribute{Key: "aria-label", Val: alias})
+
+	img := &html.Node{
+		Type:     html.ElementNode,
+		DataAtom: atom.Img,
+		Data:     "img",
+		Attr:     []html.Attribute{},
+	}
+	img.Attr = append(img.Attr, html.Attribute{Key: "alt", Val: ":" + alias + ":"})
+	img.Attr = append(img.Attr, html.Attribute{Key: "src", Val: setting.StaticURLPrefix + "/assets/img/emoji/" + alias + ".png"})
+
+	span.AppendChild(img)
+	return span
+}
+
+// emojiShortCodeProcessor for rendering text like :smile: into emoji
+func emojiShortCodeProcessor(ctx *RenderContext, node *html.Node) {
+	start := 0
+	next := node.NextSibling
+	for node != nil && node != next && start < len(node.Data) {
+		m := emojiShortCodeRegex.FindStringSubmatchIndex(node.Data[start:])
+		if m == nil {
+			return
+		}
+		m[0] += start
+		m[1] += start
+
+		start = m[1]
+
+		alias := node.Data[m[0]:m[1]]
+		alias = strings.ReplaceAll(alias, ":", "")
+		converted := emoji.FromAlias(alias)
+		if converted == nil {
+			// check if this is a custom reaction
+			if _, exist := setting.UI.CustomEmojisMap[alias]; exist {
+				replaceContent(node, m[0], m[1], createCustomEmoji(alias))
+				node = node.NextSibling.NextSibling
+				start = 0
+				continue
+			}
+			continue
+		}
+
+		replaceContent(node, m[0], m[1], createEmoji(converted.Emoji, "emoji", converted.Description))
+		node = node.NextSibling.NextSibling
+		start = 0
+	}
+}
+
+// emoji processor to match emoji and add emoji class
+func emojiProcessor(ctx *RenderContext, node *html.Node) {
+	start := 0
+	next := node.NextSibling
+	for node != nil && node != next && start < len(node.Data) {
+		m := emoji.FindEmojiSubmatchIndex(node.Data[start:])
+		if m == nil {
+			return
+		}
+		m[0] += start
+		m[1] += start
+
+		codepoint := node.Data[m[0]:m[1]]
+		start = m[1]
+		val := emoji.FromCode(codepoint)
+		if val != nil {
+			replaceContent(node, m[0], m[1], createEmoji(codepoint, "emoji", val.Description))
+			node = node.NextSibling.NextSibling
+			start = 0
+		}
+	}
+}