From 85eb337e3b2e74389a5322a0f82311d76c25451e Mon Sep 17 00:00:00 2001
From: Elara Musayelyan <elara@elara.ws>
Date: Tue, 24 Jan 2023 01:24:03 -0800
Subject: [PATCH] Add TmplContext struct with reply information

---
 config.go                    |  1 -
 lemmy-reply-bot.example.toml |  2 +-
 main.go                      | 69 +++++++++++++++++++++++++++---------
 tmpl.go                      | 24 -------------
 4 files changed, 54 insertions(+), 42 deletions(-)
 delete mode 100644 tmpl.go

diff --git a/config.go b/config.go
index c1def07..c0beef5 100644
--- a/config.go
+++ b/config.go
@@ -77,7 +77,6 @@ func compileReplies(replies []Reply) error {
 
 		tmpl, err := template.
 			New(strconv.Itoa(i)).
-			Funcs(tmplFuncs).
 			Funcs(sprig.TxtFuncMap()).
 			Parse(reply.Msg)
 		if err != nil {
diff --git a/lemmy-reply-bot.example.toml b/lemmy-reply-bot.example.toml
index 7f9d21c..5a25474 100644
--- a/lemmy-reply-bot.example.toml
+++ b/lemmy-reply-bot.example.toml
@@ -9,4 +9,4 @@ password = "ExamplePassword123"
 # after "!!BOT_TEST"
 [[reply]]
 regex = "!!BOT_TEST (.*)"
-msg = "{{match . 0 1}}"
\ No newline at end of file
+msg = "{{.Match 0 1}}"
\ No newline at end of file
diff --git a/main.go b/main.go
index 6feab12..a1d265d 100644
--- a/main.go
+++ b/main.go
@@ -7,6 +7,7 @@ import (
 	"strings"
 	"syscall"
 	"text/template"
+	"unsafe"
 
 	"github.com/spf13/pflag"
 	"github.com/vmihailenco/msgpack/v5"
@@ -15,6 +16,44 @@ import (
 	"go.arsenm.dev/logger/log"
 )
 
+type itemType uint8
+
+const (
+	comment itemType = iota
+	post
+)
+
+type item struct {
+	Type itemType
+	ID   int
+}
+
+func (it itemType) String() string {
+	switch it {
+	case comment:
+		return "comment"
+	case post:
+		return "post"
+	default:
+		return "<unknown>"
+	}
+}
+
+type Submatches []string
+
+func (sm Submatches) Item(i int) string {
+	return sm[i]
+}
+
+type TmplContext struct {
+	Matches []Submatches
+	Type    itemType
+}
+
+func (tc TmplContext) Match(i, j int) string {
+	return tc.Matches[i][j]
+}
+
 func main() {
 	configPath := pflag.StringP("config", "c", "./lemmy-reply-bot.toml", "Path to the config file")
 	dryRun := pflag.BoolP("dry-run", "D", false, "Don't actually send comments, just check for matches")
@@ -60,18 +99,6 @@ func main() {
 	commentWorker(ctx, c, replyCh)
 }
 
-type itemType uint8
-
-const (
-	comment itemType = iota
-	post
-)
-
-type item struct {
-	Type itemType
-	ID   int
-}
-
 func commentWorker(ctx context.Context, c *lemmy.WSClient, replyCh chan<- replyJob) {
 	repliedIDs := map[item]struct{}{}
 
@@ -116,7 +143,10 @@ func commentWorker(ctx context.Context, c *lemmy.WSClient, replyCh chan<- replyJ
 					}
 
 					matches := re.FindAllStringSubmatch(cr.CommentView.Comment.Content, -1)
-					job.Content, err = executeTmpl(compiledTmpls[reply.Regex], matches)
+					job.Content, err = executeTmpl(compiledTmpls[reply.Regex], TmplContext{
+						Matches: toSubmatches(matches),
+						Type:    comment,
+					})
 					if err != nil {
 						log.Warn("Error while executing template").Err(err).Send()
 						continue
@@ -153,7 +183,10 @@ func commentWorker(ctx context.Context, c *lemmy.WSClient, replyCh chan<- replyJ
 					job := replyJob{PostID: pr.PostView.Post.ID}
 
 					matches := re.FindAllStringSubmatch(body, -1)
-					job.Content, err = executeTmpl(compiledTmpls[reply.Regex], matches)
+					job.Content, err = executeTmpl(compiledTmpls[reply.Regex], TmplContext{
+						Matches: toSubmatches(matches),
+						Type:    post,
+					})
 					if err != nil {
 						log.Warn("Error while executing template").Err(err).Send()
 						continue
@@ -213,9 +246,9 @@ func commentReplyWorker(ctx context.Context, c *lemmy.WSClient, ch <-chan replyJ
 	}
 }
 
-func executeTmpl(tmpl *template.Template, matches [][]string) (string, error) {
+func executeTmpl(tmpl *template.Template, tc TmplContext) (string, error) {
 	sb := &strings.Builder{}
-	err := tmpl.Execute(sb, matches)
+	err := tmpl.Execute(sb, tc)
 	return sb.String(), err
 }
 
@@ -232,3 +265,7 @@ func joinAll(c *lemmy.WSClient) {
 		log.Fatal("Error joining WebSocket community context").Err(err).Send()
 	}
 }
+
+func toSubmatches(s [][]string) []Submatches {
+	return *(*[]Submatches)(unsafe.Pointer(&s))
+}
diff --git a/tmpl.go b/tmpl.go
deleted file mode 100644
index 3151f24..0000000
--- a/tmpl.go
+++ /dev/null
@@ -1,24 +0,0 @@
-package main
-
-import "text/template"
-
-var tmplFuncs = template.FuncMap{
-	"match": func(matches [][]string, i int, j int) string {
-		if len(matches) <= i {
-			return ""
-		}
-
-		if len(matches[i]) <= j {
-			return ""
-		}
-
-		return matches[i][j]
-	},
-	"item": func(items []string, i int) string {
-		if len(items) <= i {
-			return ""
-		}
-
-		return items[i]
-	},
-}