MVP autosave command

1 files changed, 135 insertions, 6 deletions

diff --git a/src/lib.rs b/src/lib.rs
index f359745..1126b55 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -39,11 +39,13 @@
  * - allow force
  */
 
-use std::path::PathBuf;
+use std::fs::Metadata;
+use std::path::{Path, PathBuf};
 
 use confy::ConfyError;
-use git2::{Error, Repository};
+use git2::{Oid, PushOptions, RemoteCallbacks, Repository};
 use serde::{Deserialize, Serialize};
+use thiserror::Error;
 use uuid::Uuid;
 
 #[derive(Default, Serialize, Deserialize)]
@@ -51,6 +53,14 @@ pub struct Config {
 	repositories: Vec<PathBuf>,
 }
 
+#[derive(Debug, Error)]
+pub enum TreeError {
+	#[error(transparent)]
+	Io(#[from] std::io::Error),
+	#[error(transparent)]
+	Git(#[from] git2::Error),
+}
+
 pub fn load_config() -> Result<Config, ConfyError> {
 	confy::load("git-autosave", "git-autosaved")
 }
@@ -59,14 +69,133 @@ pub fn save_config(config: &Config) -> Result<(), ConfyError> {
 	confy::store("git-autosave", "git-autosaved", config)
 }
 
-pub fn init(repository: &Repository, config: Option<&mut Config>) -> Result<(), Error> {
+pub fn init(repository: &Repository, config: Option<&mut Config>) -> Result<(), git2::Error> {
 	let id = Uuid::new_v4();
 	let workdir = repository.workdir();
-	repository.config()?.set_str("autosave.id", &id.to_string())?;
+	repository
+		.config()?
+		.set_str("autosave.id", &id.to_string())?;
 
-	if let Some(config) = config && let Some(workdir) = workdir {
+	if let Some(config) = config
+		&& let Some(workdir) = workdir
+	{
 		config.repositories.push(workdir.into());
 	}
-	
+
+	Ok(())
+}
+
+pub fn current_branch_ref(repository: &Repository) -> Result<String, git2::Error> {
+	let head = repository.head()?;
+	let ref_name = match head.kind() {
+		Some(git2::ReferenceType::Symbolic) => head.symbolic_target(),
+		_ => head.name(),
+	}
+	.ok_or(git2::Error::new(
+		git2::ErrorCode::Invalid,
+		git2::ErrorClass::Reference,
+		"The current branch's name is not valid UTF-8",
+	))?
+	.to_string();
+	Ok(ref_name)
+}
+
+pub fn current_branch(repository: &Repository) -> Result<String, git2::Error> {
+	let ref_name = current_branch_ref(repository)?;
+	let branch_name = ref_name
+		.strip_prefix("refs/heads/")
+		.unwrap_or(&ref_name)
+		.to_string();
+	Ok(branch_name)
+}
+
+pub fn filemode_for_dir_entry(metadata: &Metadata) -> i32 {
+	if metadata.is_dir() {
+		0o040000
+	} else if metadata.is_symlink() {
+		0o120000
+	} else if metadata.permissions().readonly() {
+		0o100644
+	} else {
+		0o100755
+	}
+}
+
+pub fn path_to_tree(repository: &Repository, path: &Path) -> Result<Oid, TreeError> {
+	let workdir = repository.workdir().expect("a non-bare repo");
+	if path.is_dir() {
+		let mut tree = repository.treebuilder(None)?;
+		for entry in path.read_dir()? {
+			let entry = entry?;
+			let full_path = entry.path();
+			let relative_path = full_path.strip_prefix(workdir).unwrap_or(path);
+			if repository.is_path_ignored(relative_path)? {
+				continue;
+			}
+
+			let filemode = filemode_for_dir_entry(&entry.metadata()?);
+			let oid = path_to_tree(repository, &entry.path())?;
+			let filename = entry.file_name();
+			tree.insert(filename, oid, filemode)?;
+		}
+		Ok(tree.write()?)
+	} else {
+		Ok(repository.blob_path(path)?)
+	}
+}
+
+pub fn workdir_to_tree(repository: &Repository) -> Result<Oid, TreeError> {
+	let Some(workdir) = repository.workdir() else {
+		return Err(TreeError::Git(git2::Error::new(
+			git2::ErrorCode::BareRepo,
+			git2::ErrorClass::Repository,
+			"git-autosave only supports worktrees",
+		)));
+	};
+
+	path_to_tree(repository, workdir)
+}
+
+pub fn commit_autosave(repository: &Repository) -> Result<Oid, TreeError> {
+	let config = repository.config()?;
+	let head = repository.head()?;
+	let uid = config.get_entry("autosave.id")?;
+	let uid = String::from_utf8_lossy(uid.value_bytes());
+	let branch = current_branch(repository)?;
+	let refname = &format!("refs/autosave/autosaves/{uid}/{branch}");
+	let signature = repository.signature()?;
+	let tree = repository.find_tree(workdir_to_tree(repository)?)?;
+	let parent = head.peel_to_commit()?;
+	let hostname = hostname::get();
+	let hostname = hostname
+		.map(|hostname| hostname.to_string_lossy().into_owned())
+		.map(|hostname| format!("Autosave: {hostname}"))
+		.unwrap_or_else(|_| "Autosave".to_string());
+
+	let commit = repository.commit(None, &signature, &signature, &hostname, &tree, &[&parent])?;
+	repository.reference(refname, commit, true, "Autosaved {branch}")?;
+
+	Ok(commit)
+}
+
+pub fn push_autosaves(
+	repository: &Repository,
+	callbacks: RemoteCallbacks<'_>,
+) -> Result<(), git2::Error> {
+	let remote = repository.branch_upstream_remote(&current_branch_ref(repository)?)?;
+	let mut remote = repository.find_remote(&String::from_utf8_lossy(&remote))?;
+	let refs = repository
+		.references()?
+		.filter_map(|reference| reference.ok())
+		.filter(|reference| {
+			reference
+				.name_bytes()
+				.starts_with(b"refs/autosave/autosaves")
+		})
+		.filter_map(|reference| reference.name().map(|n| n.to_string()))
+		.map(|reference| format!("+{reference}:{reference}"))
+		.collect::<Vec<_>>();
+	remote.push(&refs, Some(PushOptions::new().remote_callbacks(callbacks)))?;
+
 	Ok(())
 }