From 6dbfc533a6157bd47408d9c7b0f9ef70230d49e8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gon=C3=A7alo=20Val=C3=A9rio?= <gon@ovalerio.net>
Date: Sun, 1 Nov 2020 23:01:24 +0000
Subject: [PATCH] step sixteen: set parent to HEAD

---
 src/base.rs | 5 +++++
 src/data.rs | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/src/base.rs b/src/base.rs
index f540be9..1e44efb 100644
--- a/src/base.rs
+++ b/src/base.rs
@@ -64,6 +64,11 @@ pub fn read_tree(oid: String) {
 
 pub fn commit(message: &str) -> String {
     let mut commit = format!("tree {}\n", write_tree(".".to_owned()));
+
+    if let Ok(head) = data::get_head() {
+        commit += format!("parent {}\n", head).as_str();
+    }
+
     commit += "\n";
     commit += format!("{}\n", message).as_str();
 
diff --git a/src/data.rs b/src/data.rs
index 336e9a3..e520303 100644
--- a/src/data.rs
+++ b/src/data.rs
@@ -45,3 +45,8 @@ pub fn get_object(hash: String, expected: String) -> String {
 pub fn set_head(oid: String) {
     fs::write(format!("{}/HEAD", RGIT_DIR), oid).expect("Failed to updated HEAD");
 }
+
+pub fn get_head() -> Result<String, Box<dyn std::error::Error + 'static>> {
+    let oid = fs::read_to_string(format!("{}/HEAD", RGIT_DIR))?;
+    return Ok(oid);
+}