From bde2d866b6f57e8df443660dba97d7780877a9a4 Mon Sep 17 00:00:00 2001
From: Nikos Filippakis <nikolaos.filippakis@cern.ch>
Date: Tue, 1 Oct 2019 17:46:00 +0200
Subject: [PATCH] Display current commit and its references' names

Signed-off-by: Nikos Filippakis <nikolaos.filippakis@cern.ch>
---
 src/main.rs | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 63 insertions(+), 1 deletion(-)

diff --git a/src/main.rs b/src/main.rs
index e5d94daf4..f3c5a901f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -8,7 +8,7 @@ extern crate clap;
 
 use colored::Color;
 use colored::*;
-use git2::Repository;
+use git2::{Repository, Oid};
 use license::License;
 use clap::{App, Arg};
 use std::{
@@ -28,6 +28,7 @@ type Result<T> = result::Result<T, Error>;
 
 struct Info {
     project_name: String,
+    current_commit: CommitInfo,
     version: String,
     dominant_language: Language,
     languages: Vec<(Language, f64)>,
@@ -54,6 +55,13 @@ impl fmt::Display for Info {
             self.project_name
         )?;
 
+        writeln!(
+            buffer,
+            "{}{}",
+            "HEAD: ".color(color).bold(),
+            self.current_commit
+        )?;
+
         writeln!(
             buffer,
             "{}{}",
@@ -220,6 +228,30 @@ fn true_len(line: &str) -> usize {
         .len()
 }
 
+struct CommitInfo {
+    commit: Oid,
+    refs: Vec<String>,
+}
+
+impl CommitInfo {
+    fn new(commit: Oid, refs: Vec<String>) -> CommitInfo {
+        CommitInfo { commit, refs }
+    }
+}
+
+impl fmt::Display for CommitInfo {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        if self.refs.len() > 0 {
+            let refs_str = self.refs.iter().map(|ref_name| {
+                ref_name.as_str()
+            }).collect::<Vec<&str>>().join(", ");
+            write!(f, "{} ({})", self.commit, refs_str)
+        } else {
+            write!(f, "{}", self.commit)
+        }
+    }
+}
+
 #[derive(PartialEq, Eq, Hash, Clone)]
 enum Language {
     Assembly,
@@ -303,6 +335,7 @@ fn main() -> Result<()> {
     let dominant_language = languages_stat_vec[0].0.clone();
 
     let authors = get_authors(&dir, 3);
+    let current_commit_info = get_current_commit_info(&dir)?;
     let config = get_configuration(&dir)?;
     let version = get_version(&dir)?;
     let commits = get_commits(&dir)?;
@@ -310,6 +343,7 @@ fn main() -> Result<()> {
 
     let info = Info {
         project_name: config.repository_name,
+        current_commit: current_commit_info,
         version,
         dominant_language,
         languages: languages_stat_vec,
@@ -527,6 +561,31 @@ fn get_authors(dir: &str, n: usize) -> Vec<String> {
     authors
 }
 
+fn get_current_commit_info(dir: &str) -> Result<CommitInfo> {
+    let repo = Repository::open(dir).map_err(|_| Error::NotGitRepo)?;
+    let head = repo.head().map_err(|_| Error::ReferenceInfoError)?;
+    let head_oid = head.target().ok_or(Error::ReferenceInfoError)?;
+    let refs = repo.references().map_err(|_| Error::ReferenceInfoError)?;
+    let refs_info = refs.into_iter().filter_map(|reference| {
+        match reference {
+            Ok(reference) => {
+                match (reference.target(), reference.shorthand()) {
+                    (Some(oid), Some(shorthand)) if oid == head_oid => {
+                        Some(if reference.is_tag() {
+                            String::from("tags/") + shorthand
+                        } else {
+                            String::from(shorthand)
+                        })
+                    },
+                    _ => None
+                }
+            },
+            Err(_) => None,
+        }
+    }).collect::<Vec<String>>();
+    Ok(CommitInfo::new(head_oid, refs_info))
+}
+
 fn get_total_loc(languages: &tokei::Languages) -> usize {
     languages
         .values()
@@ -670,6 +729,8 @@ enum Error {
     ReadDirectory,
     /// Not in a Git Repo
     NotGitRepo,
+    /// Error while getting branch info
+    ReferenceInfoError,
 }
 
 impl fmt::Debug for Error {
@@ -680,6 +741,7 @@ impl fmt::Debug for Error {
             Error::NoGitData => "Could not retrieve git configuration data",
             Error::ReadDirectory => "Could not read directory",
             Error::NotGitRepo => "This is not a Git Repo",
+            Error::ReferenceInfoError => "Error while retrieving reference information",
         };
         write!(f, "{}", content)
     }