src/commit.rs: add a revert option

src/commit.rs

-use crate::init;
+use crate::{init, checkout};
 use std::{
     path::PathBuf,
     process::{exit, Command, Stdio},
@@ -68,6 +68,35 @@ pub fn check_if_borgignore_exists(borg_folder: &PathBuf) -> (bool, PathBuf) {
     (project_folder.is_file(), project_folder)
 }
 
+
+/// Function that checks if the archive with the name of the current commit id
+/// exits in borg repository
+pub fn is_a_commit(borg_path: &PathBuf, commit_id: &str) -> bool{
+    // Trying to create an archive with the current git commit id
+    let output = Command::new("borg")
+        .arg("list")
+        .arg(format!("{}::{}", borg_path.to_str().unwrap(), commit_id))
+        .output()
+        .unwrap();
+    match output.status.code().unwrap() {
+        0 => true,
+        _ => false
+    }
+}
+
+
+/// Revert the result folder back to the current commit archive
+pub fn revert_commit() {
+    let commit_id = get_current_commit();
+    let (borg_path, _) = check_path();
+    if is_a_commit(&borg_path, &commit_id) {
+        checkout::checkout("hard");
+    } else {
+        eprintln!("Cannot revert the content of the results folder previously saved for that commit: No archive found for this commit !");
+        exit(17);
+    }
+}
+
 /// Create a commit of the results folder named as the current git commit id
 pub fn commit(compression: String, mut commit_id: String, update: bool) {
     let (borg_folder, results_folder) = check_path();