feat: implement signoff feature for git commits ✍️

- Add support for signed-off-by line in commit messages with configurable option
- Refactor commit function to accept signoff parameter in git.rs
- Retrieve author name and email from repository config for signoff
- Remove redundant signoff logic from main.rs and centralize in git.rs
- Update commit call in main.rs to pass signoff requirement

Signed-off-by: mingcheng <mingcheng@apache.org>

Author: mingcheng

src/git.rs

@@ -9,10 +9,10 @@
  * File Created: 2025-03-01 21:55:54
  *
  * Modified By: mingcheng (mingcheng@apache.org)
- * Last Modified: 2025-07-11 17:42:56
+ * Last Modified: 2025-07-11 18:36:58
  */
 
-use git2::{Repository, RepositoryOpenFlags, StatusOptions};
+use git2::{Repository, RepositoryOpenFlags, Signature, StatusOptions};
 use log::trace;
 use std::error::Error;
 use std::path::Path;
@@ -37,8 +37,10 @@ impl Git {
     }
 
     /// Commit the changes in the repository
-    pub fn commit(&self, message: &str) -> Result<(), Box<dyn Error>> {
+    pub fn commit(&self, message: &str, need_signoff: bool) -> Result<(), Box<dyn Error>> {
         // Get the current index (staged changes)
+
+        let mut message = message.to_string();
         let mut index = self.repository.index()?;
 
         // Write the index to the repository
@@ -49,12 +51,29 @@ impl Git {
         let head = self.repository.head()?.peel_to_commit()?;
 
         // Create a new commit
-        let author = head.author();
-        let committer = head.committer();
-        match self
-            .repository
-            .commit(Some("HEAD"), &author, &committer, message, &tree, &[&head])
-        {
+        let author_name = self.get_author_name()?;
+        let author_email = self.get_author_email()?;
+
+        // Create a signature for the author and committer
+        let signature = Signature::now(&author_name, &author_email)?;
+
+        // If the --signoff option is enabled, add signoff to the commit message
+        if need_signoff {
+            trace!("signoff option is enabled, will add signoff to the commit message");
+
+            // Add signoff to the commit message
+            let signoff = format!("\n\nSigned-off-by: {author_name} <{author_email}>");
+            message.push_str(&signoff);
+        }
+
+        match self.repository.commit(
+            Some("HEAD"),
+            &signature,
+            &signature,
+            &message,
+            &tree,
+            &[&head],
+        ) {
             Ok(_) => {
                 trace!("commit created successfully");
                 Ok(())
@@ -66,6 +85,7 @@ impl Git {
         }
     }
 
+    /// Get the author email and name from the repository configuration
     pub fn get_author_email(&self) -> Result<String, Box<dyn Error>> {
         // Get the configuration of the repository
         let config = self.repository.config()?;
@@ -102,6 +122,7 @@ impl Git {
         }
     }
 
+    /// Get the diff of the current repository
     pub fn get_diff(&self) -> Result<Vec<String>, Box<dyn Error>> {
         // Get the current index (staged changes)
         let index = self.repository.index()?;
@@ -149,6 +170,7 @@ impl Git {
         Ok(result)
     }
 
+    /// Get the latest `size` commit messages from the repository
     pub fn get_logs(&self, size: usize) -> Result<Vec<String>, Box<dyn Error>> {
         // Get the `size` latest commits starting from HEAD
         let mut revwalk = self.repository.revwalk()?;

src/main.rs

@@ -9,7 +9,7 @@
  * File Created: 2025-03-01 17:17:30
  *
  * Modified By: mingcheng (mingcheng@apache.org)
- * Last Modified: 2025-07-11 17:45:57
+ * Last Modified: 2025-07-11 18:39:26
  */
 
 use aigitcommit::cli::Cli;
@@ -114,7 +114,7 @@ async fn main() -> std::result::Result<(), Box<dyn Error>> {
     ];
 
     // Send the request to OpenAI API and get the response
-    let mut result = match client.chat(&model_name.to_string(), messages).await {
+    let result = match client.chat(&model_name.to_string(), messages).await {
         Ok(s) => s,
         Err(e) => {
             let message = match e {
@@ -139,38 +139,7 @@ async fn main() -> std::result::Result<(), Box<dyn Error>> {
             .map(|v| v == "1" || v.eq_ignore_ascii_case("true"))
             .unwrap_or(false);
 
-    // If the --signoff option is enabled, add signoff to the commit message
-    if need_signoff {
-        trace!("signoff option is enabled, will add signoff to the commit message");
-        let (author_name, author_email) = (
-            repository.get_author_name()?,
-            repository.get_author_email()?,
-        );
-
-        // Add signoff to the commit message
-        let signoff = format!("\n\nSigned-off-by: {author_name} <{author_email}>");
-        result.push_str(&signoff);
-    }
-
-    // Detect auto signoff from environment variable
-    let need_signoff = cli.signoff
-        || env::var("GIT_AUTO_SIGNOFF")
-            .map(|v| v == "1" || v.eq_ignore_ascii_case("true"))
-            .unwrap_or(false);
-
-    // If the --signoff option is enabled, add signoff to the commit message
-    if need_signoff {
-        trace!("signoff option is enabled, will add signoff to the commit message");
-        let (author_name, author_email) = (
-            repository.get_author_name()?,
-            repository.get_author_email()?,
-        );
-
-        // Add signoff to the commit message
-        let signoff = format!("\n\nSigned-off-by: {author_name} <{author_email}>");
-        result.push_str(&signoff);
-    }
-
+    // Write the commit message to stdout
     trace!("write to stdout, and finish the process");
     writeln!(std::io::stdout(), "{result}")?;
 
@@ -194,7 +163,7 @@ async fn main() -> std::result::Result<(), Box<dyn Error>> {
 
         // Prompt the user for confirmation if --yes option is not enabled
         if cli.yes || confirm.interact()? {
-            match repository.commit(&result) {
+            match repository.commit(&result, need_signoff) {
                 Ok(_) => {
                     writeln!(std::io::stdout(), "commit successful!")?;
                 }