1 files changed, 123 insertions, 0 deletions
diff --git a/src/model/repo.rs b/src/model/repo.rs
new file mode 100644
index 0000000..557efb4
--- /dev/null
+++ b/src/model/repo.rs
@@ -0,0 +1,123 @@
+//! Definition of an iris [repo][Repository].
+
+use crate::{error, Result};
+
+use log::{debug, trace};
+use std::{path::PathBuf, sync::OnceLock};
+use url::Url;
+
+/// A handle to a locally stored git repository.
+pub struct Repository {
+	/// The remote url that the git repository is located at.
+	pub url: Url,
+	/// The path on disk that the this repository is/will be located at.
+	pub path: PathBuf,
+	/// The git2 lib handle to the repo
+	inner: OnceLock<git2::Repository>,
+}
+
+impl Repository {
+	/// Creates a new handle to a local git repository.
+	pub const fn new(url: Url, path: PathBuf) -> Self {
+		Self {
+			url,
+			path,
+			inner: OnceLock::new(),
+		}
+	}
+
+	/// Gets the handle to the local repository
+	fn repo(&self) -> Result<&git2::Repository> {
+		// we only need to initalize once
+		if let Some(repo) = self.inner.get() {
+			return Ok(repo);
+		}
+
+		trace!("loading repo");
+
+		// repository not loaded, try loading it
+		let repo = if self.path.exists() {
+			// repo exists on file system, just open it
+			git2::Repository::open(&self.path)?
+		} else {
+			// repo needs to be cloned
+			git2::Repository::clone(self.url.as_str(), &self.path)?
+		};
+
+		// save and return repo
+		Ok(self.inner.get_or_init(|| repo))
+	}
+
+	/// Gets the current remote in the git repository
+	fn remote(&self) -> Result<git2::Remote> {
+		let repo = self.repo()?;
+		let remote_name = "origin";
+		let mut remote = repo.find_remote(remote_name)?;
+
+		// make sure that out remote is connected before
+		// we do anything with it. otherwise things will
+		// fail!
+		if !remote.connected() {
+			trace!("connecting to remote");
+			remote.connect(git2::Direction::Fetch)?;
+		}
+
+		Ok(remote)
+	}
+
+	/// Fetches the latest commits in the provided branch.
+	pub fn fetch(&self, branch: &str) -> Result<()> {
+		let mut remote = self.remote()?;
+		trace!("fetching '{branch}");
+		remote.fetch(&[branch], None, None)?;
+		Ok(())
+	}
+
+	/// Returns the default branch of the git repositroy.
+	pub fn default_branch(&self) -> Result<String> {
+		let remote = self.remote()?;
+		let buf = remote.default_branch()?;
+		let name = buf
+			.as_str()
+			.and_then(|s| s.strip_prefix("refs/heads/"))
+			.map(String::from)
+			.ok_or_else(|| error::error!("cannot get default branch"))?;
+		debug!("default branch is '{name}'");
+		Ok(name)
+	}
+
+	/// Returns the latest fetched commit in `branch`.
+	pub fn latest_commit(&self, branch: &str) -> Result<String> {
+		let repo = self.repo()?;
+		let refr_name = format!("refs/remotes/origin/{branch}");
+		let refr = repo.find_reference(&refr_name)?;
+		let commit = refr.peel_to_commit()?;
+		let oid = commit.id().to_string();
+		Ok(oid)
+	}
+
+	/// Checks out the local repository to the given commit and detaches
+	/// HEAD to that commit.
+	pub fn checkout(&self, commit: &str) -> Result<()> {
+		let repo = self.repo()?;
+		trace!("checkout to '{commit}'");
+		let oid = git2::Oid::from_str(commit)?;
+		let commit = repo.find_commit(oid)?;
+		repo.reset(commit.as_object(), git2::ResetType::Hard, None)?;
+		Ok(())
+	}
+}
+
+impl std::fmt::Debug for Repository {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		write!(f, "_")
+	}
+}
+
+impl PartialEq for Repository {
+    fn eq(&self, other: &Self) -> bool {
+        self.url.eq(&other.url) && self.path.eq(&other.path)
+    }
+}
+
+impl Eq for Repository {}