Set repository mtime to GitHub `updated_at` time

CGit reads the repository modification time from the following
locations, in order from top to bottom:

1. agefile
2. repo.git/refs/heads/{default_branch | "master"}
3. repo.git/packed-refs

(https://git.zx2c4.com/cgit/tree/ui-repolist.c?id=bd6f5683f6cde4212364354b3139c1d521f40f39#n35)

Update the `/refs/heads/{default_branch}` file mtime when cloning and
updating the repo to match the GitHub `updated_at` time.

This ensures that when mirroring old repositories, they don't appear at
the top of the CGit repository index list when sorting by age.

1 files changed, 33 insertions, 3 deletions

diff --git a/src/main.rs b/src/main.rs
index 9689d3c..bae2da8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,6 @@
 use anyhow::{self, Context};
+use chrono::DateTime;
+use filetime;
 use sqlx;
 use tokio;
 
@@ -10,9 +12,9 @@ use std::path::{Path, PathBuf};
 
 #[tokio::main]
 async fn main() {
-    let repos = github::fetch_repos("teddywing").await.unwrap();
-
-    dbg!(&repos);
+    // let repos = github::fetch_repos("teddywing").await.unwrap();
+    //
+    // dbg!(&repos);
 
     // git::mirror(
     //     "https://github.com/teddywing/google-calendar-rsvp.git",
@@ -22,6 +24,8 @@ async fn main() {
     // git::update(
     //     Path::new("/tmp/grsvp"),
     // ).unwrap();
+
+    run().await.unwrap();
 }
 
 async fn run() -> anyhow::Result<()> {
@@ -129,6 +133,8 @@ fn mirror<P: AsRef<Path>>(
             ))?;
     }
 
+    update_mtime(&clone_path, &repo)?;
+
     Ok(())
 }
 
@@ -145,5 +151,29 @@ fn update<P: AsRef<Path>>(
         git::update_description(&repo_path, remote_description)?;
     }
 
+    update_mtime(&repo_path, &updated_repo)?;
+
+    Ok(())
+}
+
+fn update_mtime<P: AsRef<Path>>(
+    repo_path: P,
+    repo: &github::Repo,
+) -> anyhow::Result<()> {
+    let default_branch_ref = repo_path
+        .as_ref()
+        .join("refs/heads")
+        .join(&repo.default_branch);
+
+    let update_time = filetime::FileTime::from_system_time(
+        DateTime::parse_from_rfc3339(&repo.updated_at)?.into()
+    );
+
+    filetime::set_file_times(&default_branch_ref, update_time, update_time)
+        .with_context(|| format!(
+            "unable to set mtime on '{}'",
+            &default_branch_ref.display(),
+        ))?;
+
     Ok(())
 }