added update command

2 files changed, 89 insertions, 4 deletions

diff --git a/src/action.rs b/src/action.rs
index a9c2563..d873fc9 100644
--- a/src/action.rs
+++ b/src/action.rs
@@ -1,5 +1,5 @@
 use crate::config::{self, ConfigCommand, TEMP_CONFIG_PATH, create_config};
-use crate::util::{dir_size, get_editor, open_in_editor, yn_prompt};
+use crate::util::{dir_size, get_editor, open_in_editor, pull_repo, yn_prompt};
 use git2::Repository;
 use std::fs;
 use std::path::PathBuf;
@@ -65,7 +65,7 @@ impl Action {
     pub fn execute(self) -> Result<(), String> {
         match self {
             Action::Add { url } => add(url.as_str()),
-            Action::Update => Ok(update()),
+            Action::Update => update(),
             Action::Upgrade { packages } => Ok(upgrade(packages)),
             Action::Autoremove => Ok(autoremove()),
             Action::Remove { packages } => remove(packages),
@@ -126,8 +126,51 @@ fn add(url: &str) -> Result<(), String> {
     Ok(())
 }
 
-fn update() {
-    println!("updating");
+fn update() -> Result<(), String> {
+    if !nix::unistd::geteuid().is_root() {
+        return Err("update must be run as root".to_string());
+    }
+
+    let package_paths: Vec<(String, PathBuf)> = fs::read_dir(BASE_CONFIG_PATH)
+        .map_err(|e| format!("failed to iterate package directory: {}", e))?
+        .map(|p| {
+            let entry = p.map_err(|e| e.to_string())?;
+            let path = entry.path();
+
+            let pkgname = path
+                .file_stem()
+                .ok_or_else(|| format!("invalid filename: {:?}", path))?
+                .to_string_lossy()
+                .into_owned();
+
+            let path = PathBuf::from(BASE_REPO_PATH).join(&pkgname);
+
+            if !path.exists() {
+                Err(format!("no installed package: {}", pkgname))
+            } else {
+                Ok((pkgname, path))
+            }
+        })
+        .collect::<Result<_, _>>()?;
+
+    println!(
+        "Packages to update ({}): {}\n",
+        package_paths.len(),
+        package_paths
+            .iter()
+            .map(|(p, _)| p.as_str())
+            .collect::<Vec<_>>()
+            .join(", ")
+    );
+
+    if yn_prompt("Proceed with update?") {
+        for (name, path) in package_paths {
+            pull_repo(&path).map_err(|e| format!("failed to update repo: {e}"))?;
+            println!("Updated {}", name);
+        }
+    }
+
+    Ok(())
 }
 
 fn upgrade(packages: Vec<String>) {
diff --git a/src/util.rs b/src/util.rs
index 6f04573..0958764 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -1,3 +1,4 @@
+use git2::{Cred, FetchOptions, RemoteCallbacks, Repository, build::CheckoutBuilder};
 use std::env;
 use std::fs;
 use std::io;
@@ -40,6 +41,47 @@ pub fn open_in_editor(editor: &str, file: &str) -> Result<(), String> {
     Ok(())
 }
 
+pub fn pull_repo(path: &Path) -> Result<(), git2::Error> {
+    let repo = Repository::open(path)?;
+
+    let head = repo.head()?;
+    let branch = head
+        .shorthand()
+        .ok_or_else(|| git2::Error::from_str("Could not determine current branch"))?;
+
+    let mut callbacks = RemoteCallbacks::new();
+    callbacks.credentials(|_url, username_from_url, _allowed| {
+        Cred::ssh_key_from_agent(username_from_url.unwrap())
+    });
+
+    let mut fetch_options = FetchOptions::new();
+    fetch_options.remote_callbacks(callbacks);
+
+    let mut remote = repo.find_remote("origin")?;
+    remote.fetch(&[branch], Some(&mut fetch_options), None)?;
+
+    let fetch_head = repo.find_reference("FETCH_HEAD")?;
+    let fetch_commit = repo.reference_to_annotated_commit(&fetch_head)?;
+
+    let (analysis, _pref) = repo.merge_analysis(&[&fetch_commit])?;
+
+    if analysis.is_fast_forward() {
+        println!("Fast-forwarding...");
+
+        let refname = format!("refs/heads/{}", branch);
+        let mut reference = repo.find_reference(&refname)?;
+        reference.set_target(fetch_commit.id(), "Fast-Forward")?;
+        repo.set_head(&refname)?;
+        repo.checkout_head(Some(CheckoutBuilder::default().force()))?;
+    } else if analysis.is_up_to_date() {
+        println!("Already up to date.");
+    } else {
+        println!("Non fast-forward merge required (manual merge needed).");
+    }
+
+    Ok(())
+}
+
 pub fn yn_prompt(prompt: &str) -> bool {
     print!("{} [y/n]: ", prompt);
     io::stdout().flush().unwrap();