From 8cc11c52a88ec78d175b3ec8de854916f631caab Mon Sep 17 00:00:00 2001
From: Ruben Beltran del Rio <jj@r.bdr.sh>
Date: Thu, 30 Apr 2026 15:17:30 +0200
Subject: Initial build

---
 src/render.rs | 102 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 src/render.rs

(limited to 'src/render.rs')
diff --git a/src/render.rs b/src/render.rs
new file mode 100644
index 0000000..8e366dd
--- /dev/null
+++ b/src/render.rs
@@ -0,0 +1,102 @@
+use std::path::Path;
+
+use syntect::highlighting::ThemeSet;
+use syntect::html::highlighted_html_for_string;
+use syntect::parsing::SyntaxSet;
+
+const THEME: &str = "base16-ocean.dark";
+const STYLE: &str = "html,body{margin:0;background:#2b303b}\
+pre{margin:0;padding:1rem;font:14px/1.5 ui-monospace,SFMono-Regular,Menlo,monospace;overflow:auto}";
+
+pub fn page(path: &Path, text: &str) -> String {
+    let title = path
+        .file_name()
+        .and_then(|n| n.to_str())
+        .unwrap_or("paste");
+
+    let body = highlight(path, text);
+
+    let mut out = String::with_capacity(body.len() + 256);
+    out.push_str("<!doctype html>\n<meta charset=\"utf-8\">\n<title>");
+    push_escaped(&mut out, title);
+    out.push_str("</title>\n<style>");
+    out.push_str(STYLE);
+    out.push_str("</style>\n");
+    out.push_str(&body);
+    out.push('\n');
+    out
+}
+
+fn highlight(path: &Path, text: &str) -> String {
+    let syntaxes = SyntaxSet::load_defaults_newlines();
+    let themes = ThemeSet::load_defaults();
+
+    let syntax = path
+        .extension()
+        .and_then(|e| e.to_str())
+        .and_then(|e| syntaxes.find_syntax_by_extension(e))
+        .or_else(|| syntaxes.find_syntax_by_first_line(text))
+        .unwrap_or_else(|| syntaxes.find_syntax_plain_text());
+
+    let Some(theme) = themes.themes.get(THEME) else {
+        return fallback_pre(text);
+    };
+
+    match highlighted_html_for_string(text, &syntaxes, syntax, theme) {
+        Ok(html) => html,
+        Err(_) => fallback_pre(text),
+    }
+}
+
+fn fallback_pre(text: &str) -> String {
+    let mut out = String::with_capacity(text.len() + 16);
+    out.push_str("<pre>");
+    push_escaped(&mut out, text);
+    out.push_str("</pre>");
+    out
+}
+
+fn push_escaped(out: &mut String, s: &str) {
+    for c in s.chars() {
+        match c {
+            '&' => out.push_str("&amp;"),
+            '<' => out.push_str("&lt;"),
+            '>' => out.push_str("&gt;"),
+            '"' => out.push_str("&quot;"),
+            '\'' => out.push_str("&#39;"),
+            other => out.push(other),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn page_contains_filename_in_title() {
+        let html = page(Path::new("/srv/x.rs"), "fn main() {}\n");
+        assert!(html.contains("<title>x.rs</title>"));
+    }
+
+    #[test]
+    fn page_escapes_filename() {
+        let html = page(Path::new("/srv/<script>.txt"), "hi");
+        assert!(html.contains("&lt;script&gt;.txt"));
+        assert!(!html.contains("<title><script>"));
+    }
+
+    #[test]
+    fn page_emits_pre_block() {
+        let html = page(Path::new("/srv/x.txt"), "hello");
+        assert!(html.contains("<pre"));
+        assert!(html.contains("hello"));
+    }
+
+    #[test]
+    fn page_highlights_known_extension() {
+        // Rust syntax should produce styled spans, not just a plain <pre>hello</pre>.
+        let html = page(Path::new("/srv/x.rs"), "fn main() {}\n");
+        assert!(html.contains("<span"));
+    }
+}
-- 
cgit 

