Add template

Cargo.toml

@@ -8,4 +8,6 @@ edition = "2021"
 [dependencies]
 pulldown-cmark = "0.9.1"
 notify = "4.0.16"
-clap = { version = "3.1.8", features = ["derive"] }
+clap = { version = "3.1.8", features = ["derive"] }
+handlebars = "4.2.2"
+serde_json = "1.0.79"

src/main.rs

@@ -1,6 +1,8 @@
 use clap::Parser as ClapParser;
+use handlebars::Handlebars;
 use notify::{RecommendedWatcher, RecursiveMode, Watcher};
 use pulldown_cmark::{html, Options, Parser};
+use serde_json::json;
 use std::fs;
 use std::fs::File;
 use std::io::Write;
@@ -19,6 +21,10 @@ struct Args {
     /// Specify the output destination for the converted HTML file (optional)
     #[clap(short, long, default_value = ".")]
     output: String,
+
+    /// Specify the file path of the template file
+    #[clap(short, long, default_value = "")]
+    template: String,
 }
 
 fn read_md_file(file_path: &std::path::Path) -> Result<String, Box<dyn std::error::Error>> {
@@ -29,13 +35,27 @@ fn read_md_file(file_path: &std::path::Path) -> Result<String, Box<dyn std::erro
 fn write_html_file(
     file_path: &std::path::Path,
     html: &str,
+    template: &str,
 ) -> Result<(), Box<dyn std::error::Error>> {
     let mut file = File::create(file_path)?;
-    write!(file, "{}", html)?;
+
+    if template != "" {
+        let template_path = Path::new(template);
+        let mut handlebars = Handlebars::new();
+        match handlebars.register_template_file("template", template_path) {
+            Err(err) => {
+                eprintln!("ERROR: {}", err.reason);
+                std::process::exit(1);
+            }
+            _ => handlebars.render_to_write("template", &json!({ "html": html }), &mut file)?,
+        }
+    } else {
+        write!(file, "{}", html)?;
+    }
     Ok(())
 }
 
-fn markdown_to_html(input_path: &std::path::Path, output_path: &std::path::Path) {
+fn markdown_to_html(input_path: &std::path::Path, output_path: &std::path::Path, template: &str) {
     let markdown_input = read_md_file(input_path).unwrap();
 
     let mut options = Options::empty();
@@ -45,13 +65,14 @@ fn markdown_to_html(input_path: &std::path::Path, output_path: &std::path::Path)
     let mut html_output = String::new();
     html::push_html(&mut html_output, parser);
 
-    write_html_file(output_path, &html_output).unwrap();
+    write_html_file(output_path, &html_output, template).unwrap();
 }
 
 fn main() -> notify::Result<()> {
     let args = Args::parse();
     let input = &args.input;
     let output = &args.output;
+    let template = &args.template;
 
     let (tx, rx) = channel();
     let mut watcher: RecommendedWatcher = Watcher::new(tx, Duration::from_secs(1))?;
@@ -84,7 +105,11 @@ fn main() -> notify::Result<()> {
                                     md_file_name.to_str().unwrap().replace(".md", ".html");
                                 let output_file_path = output_dir_path.join(html_file_name);
 
-                                markdown_to_html(input_file_path, output_file_path.as_path());
+                                markdown_to_html(
+                                    input_file_path,
+                                    output_file_path.as_path(),
+                                    template,
+                                );
 
                                 println!("=== Generated HTML ===");
                                 println!("Input file path: {:?}", input_file_path);