From ee4ed51530371bee6c7ad076d151253f1add4154 Mon Sep 17 00:00:00 2001
From: mappu <mappu04@gmail.com>
Date: Mon, 2 Apr 2018 16:46:22 +1200
Subject: [PATCH] bbcode: separate string/func transformations into an
 interface

---
 bbcode.go | 63 ++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 37 insertions(+), 26 deletions(-)

diff --git a/bbcode.go b/bbcode.go
index aed4780..4495787 100644
--- a/bbcode.go
+++ b/bbcode.go
@@ -32,46 +32,63 @@ func (this *BBCodeRenderer) Reset() {
 	this.CodePresent = false
 }
 
+//
+
+type transformation interface {
+	MatchString(in string) bool
+	Apply(in string) string
+}
+
 type pregReplaceRule struct {
-	match       *regexp.Regexp
-	replace     string
+	*regexp.Regexp
+	replace string
+}
+
+func (this pregReplaceRule) Apply(in string) string {
+	return this.ReplaceAllString(in, this.replace)
+}
+
+type pregReplaceFunc struct {
+	*regexp.Regexp
 	replaceFunc func([]string) string
 }
 
+func (this pregReplaceFunc) Apply(in string) string {
+	return PregReplaceCallback(this.Regexp, this.replaceFunc, in)
+}
+
 // Internal part of BBCode rendering.
 // It handles most leaf-level tags.
 func (this *BBCodeRenderer) bbcode(data string) string {
 
-	s_to_r := []pregReplaceRule{
-		pregReplaceRule{regexp.MustCompile(`(?si)\[h\](.*?)\[/h\]`), `<h2>$1</h2>`, nil},
-		pregReplaceRule{regexp.MustCompile(`(?si)\[b\](.*?)\[/b\]`), `<b>$1</b>`, nil},
-		pregReplaceRule{regexp.MustCompile(`(?si)\[i\](.*?)\[/i\]`), `<i>$1</i>`, nil},
-		pregReplaceRule{regexp.MustCompile(`(?si)\[u\](.*?)\[/u\]`), `<u>$1</u>`, nil},
-		pregReplaceRule{regexp.MustCompile(`(?si)\[s\](.*?)\[/s\]`), `<span class="s">$1</span>`, nil},
-		pregReplaceRule{regexp.MustCompile(`(?si)\[spoiler\](.*?)\[/spoiler\]`), `<span class="spoiler">$1</span>`, nil},
-		pregReplaceRule{regexp.MustCompile(`(?si)\[img\](.*?)\[/img\]`), `<img alt="" src="$1">`, nil},
-		pregReplaceRule{regexp.MustCompile(`(?si)\[list\](.*?)\[/list\]`), `<ul><li>$1</li></ul>`, nil},
-		pregReplaceRule{regexp.MustCompile(`(?si)\[\*\]`), `</li><li>`, nil},
-		pregReplaceRule{regexp.MustCompile(`(?si)\[url=(.*?)\](.*?)\[/url\]`), `<a rel="noreferrer" href="$1">$2</a>`, nil},
-		pregReplaceRule{regexp.MustCompile(`(?si)\[article=(.*?)\](.*?)\[/article\]`), "", func(m []string) string {
+	s_to_r := []transformation{
+		pregReplaceRule{regexp.MustCompile(`(?si)\[h\](.*?)\[/h\]`), `<h2>$1</h2>`},
+		pregReplaceRule{regexp.MustCompile(`(?si)\[b\](.*?)\[/b\]`), `<b>$1</b>`},
+		pregReplaceRule{regexp.MustCompile(`(?si)\[i\](.*?)\[/i\]`), `<i>$1</i>`},
+		pregReplaceRule{regexp.MustCompile(`(?si)\[u\](.*?)\[/u\]`), `<u>$1</u>`},
+		pregReplaceRule{regexp.MustCompile(`(?si)\[s\](.*?)\[/s\]`), `<span class="s">$1</span>`},
+		pregReplaceRule{regexp.MustCompile(`(?si)\[spoiler\](.*?)\[/spoiler\]`), `<span class="spoiler">$1</span>`},
+		pregReplaceRule{regexp.MustCompile(`(?si)\[img\](.*?)\[/img\]`), `<img alt="" src="$1">`},
+		pregReplaceRule{regexp.MustCompile(`(?si)\[list\](.*?)\[/list\]`), `<ul><li>$1</li></ul>`},
+		pregReplaceRule{regexp.MustCompile(`(?si)\[\*\]`), `</li><li>`},
+		pregReplaceRule{regexp.MustCompile(`(?si)\[url=(.*?)\](.*?)\[/url\]`), `<a rel="noreferrer" href="$1">$2</a>`},
+		pregReplaceFunc{regexp.MustCompile(`(?si)\[article=(.*?)\](.*?)\[/article\]`), func(m []string) string {
 			return `<a href="` + template.HTMLEscapeString(this.baseUrl+`view/`+url.PathEscape(m[1])) + `">` + m[2] + `</a>`
 		}},
-		pregReplaceRule{regexp.MustCompile(`(?si)\[rev=(.*?)\](.*?)\[/rev\]`), "", func(m []string) string {
+		pregReplaceFunc{regexp.MustCompile(`(?si)\[rev=(.*?)\](.*?)\[/rev\]`), func(m []string) string {
 			return `<a href="` + template.HTMLEscapeString(this.baseUrl+`archive/`+url.PathEscape(m[1])) + `">` + m[2] + `</a>`
 		}},
 
 		pregReplaceRule{regexp.MustCompile(`(?si)\[imgur\](.*?)\.(...)\[/imgur\]`),
 			`<a href="https://i.imgur.com/${1}.${2}"><img class="imgur" alt="" src="https://i.imgur.com/${1}s.${2}" ></a>`,
-			nil,
 		},
 
 		pregReplaceRule{
 			regexp.MustCompile(`(?si)\[youtube](.*?)\[/youtube\]`),
 			`<iframe width="560" height="315" src="https://www.youtube-nocookie.com/embed/${1}" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>`,
-			nil,
 		},
 
-		pregReplaceRule{regexp.MustCompile(`(?si)\[section=(.*?)](.*?)\[/section\]`), "", func(m []string) string {
+		pregReplaceFunc{regexp.MustCompile(`(?si)\[section=(.*?)](.*?)\[/section\]`), func(m []string) string {
 			return `<div class="section"><a class="sectionheader" href="javascript:;" onclick="ts(this);">` + m[1] + `</a><span style="display:none;">` + strings.TrimSpace(m[2]) + `</span></div>`
 		}},
 	}
@@ -80,20 +97,14 @@ func (this *BBCodeRenderer) bbcode(data string) string {
 		s_to_r = append(s_to_r,
 			pregReplaceRule{regexp.MustCompile(`(?si)\[` + regexp.QuoteMeta(this.ContentedTag) + `\](.*?)\[/` + regexp.QuoteMeta(this.ContentedTag) + `\]`),
 				`<a href="` + html.EscapeString(this.ContentedURL) + `p/${1}"><img class="imgur" alt="" src="` + html.EscapeString(this.ContentedURL) + `thumb/s/${1}" ></a>`,
-				nil,
 			},
 		)
 	}
 
 	for _, prr := range s_to_r {
 
-		for prr.match.MatchString(data) { // repeat until all recursive replacements are consumed
-			if len(prr.replace) > 0 {
-				data = prr.match.ReplaceAllString(data, prr.replace)
-
-			} else {
-				data = PregReplaceCallback(prr.match, prr.replaceFunc, data)
-			}
+		for prr.MatchString(data) { // repeat until all recursive replacements are consumed
+			data = prr.Apply(data)
 		}
 	}
 	return data