From ab3a64993c87fdb433e0bd89a67c3d2e527ff68d Mon Sep 17 00:00:00 2001
From: Runxi Yu <me@runxiyu.org>
Date: Mon, 10 Feb 2025 14:42:13 +0800
Subject: handle_repo_tree: Syntax highlighting

---
 go.mod                        |  2 ++
 go.sum                        |  4 ++++
 handle_category_index.go      |  2 +-
 handle_repo_tree.go           | 21 ++++++++++++++++++++-
 static/style.css              |  2 +-
 templates/repo_tree_file.html |  2 +-
 6 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/go.mod b/go.mod
index dd70af0..ddccf94 100644
--- a/go.mod
+++ b/go.mod
@@ -13,9 +13,11 @@ require (
 	dario.cat/mergo v1.0.0 // indirect
 	github.com/Microsoft/go-winio v0.6.1 // indirect
 	github.com/ProtonMail/go-crypto v1.1.5 // indirect
+	github.com/alecthomas/chroma/v2 v2.15.0 // indirect
 	github.com/aymerick/douceur v0.2.0 // indirect
 	github.com/cloudflare/circl v1.3.7 // indirect
 	github.com/cyphar/filepath-securejoin v0.3.6 // indirect
+	github.com/dlclark/regexp2 v1.11.4 // indirect
 	github.com/emirpasic/gods v1.18.1 // indirect
 	github.com/go-git/gcfg v1.5.1-0.20230307220236-3a3c6141e376 // indirect
 	github.com/go-git/go-billy/v5 v5.6.2 // indirect
diff --git a/go.sum b/go.sum
index a204a46..95ee7a8 100644
--- a/go.sum
+++ b/go.sum
@@ -5,6 +5,8 @@ github.com/Microsoft/go-winio v0.6.1 h1:9/kr64B9VUZrLm5YYwbGtUJnMgqWVOdUAXu6Migc
 github.com/Microsoft/go-winio v0.6.1/go.mod h1:LRdKpFKfdobln8UmuiYcKPot9D2v6svN5+sAH+4kjUM=
 github.com/ProtonMail/go-crypto v1.1.5 h1:eoAQfK2dwL+tFSFpr7TbOaPNUbPiJj4fLYwwGE1FQO4=
 github.com/ProtonMail/go-crypto v1.1.5/go.mod h1:rA3QumHc/FZ8pAHreoekgiAbzpNsfQAosU5td4SnOrE=
+github.com/alecthomas/chroma/v2 v2.15.0 h1:LxXTQHFoYrstG2nnV9y2X5O94sOBzf0CIUpSTbpxvMc=
+github.com/alecthomas/chroma/v2 v2.15.0/go.mod h1:gUhVLrPDXPtp/f+L1jo9xepo9gL4eLwRuGAunSZMkio=
 github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be h1:9AeTilPcZAjCFIImctFaOjnTIavg87rW78vTPkQqLI8=
 github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be/go.mod h1:ySMOLuWl6zY27l47sB3qLNK6tF2fkHG55UZxx8oIVo4=
 github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5 h1:0CwZNZbxp69SHPdPJAN/hZIm0C4OItdklCFmMRWYpio=
@@ -18,6 +20,8 @@ github.com/cyphar/filepath-securejoin v0.3.6/go.mod h1:Sdj7gXlvMcPZsbhwhQ33GguGL
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dlclark/regexp2 v1.11.4 h1:rPYF9/LECdNymJufQKmri9gV604RvvABwgOA8un7yAo=
+github.com/dlclark/regexp2 v1.11.4/go.mod h1:DHkYz0B9wPfa6wondMfaivmHpzrQ3v9q8cnmRbL6yW8=
 github.com/elazarl/goproxy v1.4.0 h1:4GyuSbFa+s26+3rmYNSuUVsx+HgPrV1bk1jXI0l9wjM=
 github.com/elazarl/goproxy v1.4.0/go.mod h1:X/5W/t+gzDyLfHW4DrMdpjqYjpXsURlBt9lpBDxZZZQ=
 github.com/emirpasic/gods v1.18.1 h1:FXtiHYKDGKCW2KzwZKx0iC0PQmdlorYgdFG9jPXJ1Bc=
diff --git a/handle_category_index.go b/handle_category_index.go
index 953557a..d81899a 100644
--- a/handle_category_index.go
+++ b/handle_category_index.go
@@ -2,8 +2,8 @@ package main
 
 import (
 	"net/http"
-	"path/filepath"
 	"os"
+	"path/filepath"
 	"strings"
 )
 
diff --git a/handle_repo_tree.go b/handle_repo_tree.go
index cc79202..c2810d9 100644
--- a/handle_repo_tree.go
+++ b/handle_repo_tree.go
@@ -7,6 +7,9 @@ import (
 	"path/filepath"
 	"strings"
 
+	chroma_formatters_html "github.com/alecthomas/chroma/v2/formatters/html"
+	chroma_lexers "github.com/alecthomas/chroma/v2/lexers"
+	chroma_styles "github.com/alecthomas/chroma/v2/styles"
 	"github.com/go-git/go-git/v5"
 	"github.com/go-git/go-git/v5/plumbing/object"
 	"github.com/microcosm-cc/bluemonday"
@@ -63,11 +66,27 @@ func handle_repo_tree(w http.ResponseWriter, r *http.Request) {
 			_, _ = w.Write([]byte("Error retrieving path: " + err.Error()))
 			return
 		}
-		data["file_contents"], err = file.Contents()
+		file_contents, err := file.Contents()
 		if err != nil {
 			_, _ = w.Write([]byte("Error reading file: " + err.Error()))
 			return
 		}
+		lexer := chroma_lexers.Match(path_spec)
+		if lexer == nil {
+			lexer = chroma_lexers.Fallback
+		}
+		iterator, err := lexer.Tokenise(nil, file_contents)
+		if err != nil {
+			_, _ = w.Write([]byte("Error rendering code: " + err.Error()))
+			return
+		}
+		var formatted_unencapsulated bytes.Buffer
+		style := chroma_styles.Get("emacs")
+		formatter := chroma_formatters_html.New(chroma_formatters_html.WithClasses(true), chroma_formatters_html.TabWidth(8))
+		formatter.Format(&formatted_unencapsulated, style, iterator)
+		formatted_encapsulated := template.HTML(formatted_unencapsulated.Bytes())
+		data["file_contents"] = formatted_encapsulated
+
 		err = templates.ExecuteTemplate(w, "repo_tree_file", data)
 		if err != nil {
 			_, _ = w.Write([]byte("Error rendering template: " + err.Error()))
diff --git a/static/style.css b/static/style.css
index e816df1..bde80a8 100644
--- a/static/style.css
+++ b/static/style.css
@@ -20,7 +20,7 @@ a:link, a:visited {
 	text-decoration-color: var(--text-decoration-color);
 	color: var(--link-color);
 }
-code {
+code:not(pre > code) {
 	background-color: var(--box-background-color);
 	border-radius: 2px;
 	padding: 2px;
diff --git a/templates/repo_tree_file.html b/templates/repo_tree_file.html
index 72bf42b..d561485 100644
--- a/templates/repo_tree_file.html
+++ b/templates/repo_tree_file.html
@@ -9,7 +9,7 @@
 <p>
 /{{ .path_spec }}
 </p>
-<pre>{{ .file_contents }}</pre>
+{{ .file_contents }}
 </body>
 </html>
 {{- end -}}
-- 
cgit v1.2.3