From c5fb20e96a4e9ec56b63efdb316d0968779093d7 Mon Sep 17 00:00:00 2001
From: PhatPhuckDave <david.majdandzic@hotmail.com>
Date: Wed, 26 Mar 2025 12:27:40 +0100
Subject: [PATCH] Implement named capture groups

---
 processor/regex.go | 48 +++++++++++++++++++++++++++++++++-------------
 1 file changed, 35 insertions(+), 13 deletions(-)

diff --git a/processor/regex.go b/processor/regex.go
index 40cf861..3abdec5 100644
--- a/processor/regex.go
+++ b/processor/regex.go
@@ -145,31 +145,42 @@ func (p *RegexProcessor) ProcessContent(content string, pattern string, luaExpr
 			continue
 		}
 
-		namedCaptures := make(map[string]string)
-		groupNames := compiledPattern.SubexpNames()
-
-		for i, name := range groupNames {
-			if i == 0 {
-				continue
-			}
-			if i < len(match) {
-				namedCaptures[name] = string(match[i])
-			}
-		}
-		log.Printf("Named captures: %v", namedCaptures)
-
 		captures := make([]string, 0, len(groups)/2)
 		for j := 0; j < len(groups); j += 2 {
 			captures = append(captures, content[groups[j]:groups[j+1]])
 		}
 		log.Printf("Captured groups: %v", captures)
 
+		namedCaptures := make(map[string]string)
+		namedCaptureGroups := make(map[string][2]int)
+		groupNames := compiledPattern.SubexpNames()[1:]
+		for i, name := range groupNames {
+			if name == "" {
+				continue
+			}
+			namedCaptures[name] = captures[i]
+			namedCaptureGroups[name] = [2]int{groups[i*2], groups[i*2+1]}
+		}
+
+		log.Printf("Named captures: %v", namedCaptures)
+
 		if err := p.ToLua(L, captures); err != nil {
 			log.Printf("Error setting Lua variables: %v", err)
 			continue
 		}
 		log.Println("Lua variables set successfully")
 
+		for name, capture := range namedCaptures {
+			if name == "" {
+				continue
+			}
+			if val, err := strconv.ParseFloat(capture, 64); err == nil {
+				L.SetGlobal(name, lua.LNumber(val))
+			} else {
+				L.SetGlobal(name, lua.LString(capture))
+			}
+		}
+
 		if err := L.DoString(luaExpr); err != nil {
 			log.Printf("Error executing Lua code %s for group %s: %v", luaExpr, captures, err)
 			continue
@@ -202,6 +213,17 @@ func (p *RegexProcessor) ProcessContent(content string, pattern string, luaExpr
 			replacement = replacement[:groupStart] + newVal + replacement[groupEnd:]
 		}
 
+		for i := len(namedCaptures) - 1; i >= 0; i-- {
+			name := groupNames[i]
+			if name == "" {
+				continue
+			}
+			groupStart := namedCaptureGroups[name][0] - matchIndices[0]
+			groupEnd := namedCaptureGroups[name][1] - matchIndices[0]
+			luaValue := L.GetGlobal(name).String()
+			replacement = replacement[:groupStart] + luaValue + replacement[groupEnd:]
+		}
+
 		modificationCount++
 		result = result[:matchIndices[0]] + replacement + result[matchIndices[1]:]
 		log.Printf("Modification count updated: %d", modificationCount)