From 7af033987173d7b78e93088f1873ad90fea289bd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fe=CC=81lix=20Saparelli?= <felix@passcod.name>
Date: Sun, 10 Oct 2021 17:55:50 +1300
Subject: [PATCH] Detect project origins (if any)

---
 lib/examples/project-origins.rs |  18 +++++
 lib/src/project.rs              | 115 +++++++++++++++++++++++++++++++-
 2 files changed, 131 insertions(+), 2 deletions(-)
 create mode 100644 lib/examples/project-origins.rs

diff --git a/lib/examples/project-origins.rs b/lib/examples/project-origins.rs
new file mode 100644
index 0000000..ffbd187
--- /dev/null
+++ b/lib/examples/project-origins.rs
@@ -0,0 +1,18 @@
+use std::env::args;
+
+use miette::{IntoDiagnostic, Result};
+use watchexec::project::origins;
+
+// Run with: `cargo run --example project-origins [PATH]`
+#[tokio::main]
+async fn main() -> Result<()> {
+	tracing_subscriber::fmt::init();
+
+	let path =
+		dunce::canonicalize(args().nth(1).unwrap_or_else(|| ".".to_string())).into_diagnostic()?;
+	for origin in origins(&path).await {
+		println!("{}", origin.display());
+	}
+
+	Ok(())
+}
diff --git a/lib/src/project.rs b/lib/src/project.rs
index 482849e..8ca6a11 100644
--- a/lib/src/project.rs
+++ b/lib/src/project.rs
@@ -1,12 +1,90 @@
 //! Detect project type and origin.
 
 use std::{
+	fs::Metadata,
 	io::Error,
 	path::{Path, PathBuf},
 };
 
-pub async fn origins(path: impl AsRef<Path>) -> Result<Vec<PathBuf>, Error> {
-	todo!()
+use futures::{future::ready as is_true, stream::FuturesUnordered, StreamExt};
+use tokio::fs::metadata;
+use tracing::trace;
+
+pub async fn origins(path: impl AsRef<Path>) -> Vec<PathBuf> {
+	let mut origins = Vec::new();
+
+	async fn check_origin(path: &Path) -> bool {
+		let dirtests: FuturesUnordered<_> = vec![
+			dir_exists(path.join("_darcs")),
+			dir_exists(path.join(".bzr")),
+			dir_exists(path.join(".fossil-settings")),
+			dir_exists(path.join(".git")),
+			dir_exists(path.join(".github")),
+			dir_exists(path.join(".hg")),
+		]
+		.into_iter()
+		.collect();
+
+		let filetests: FuturesUnordered<_> = vec![
+			file_exists(path.join(".asf.yaml")),
+			file_exists(path.join(".bzrignore")),
+			file_exists(path.join(".codecov.yml")),
+			file_exists(path.join(".ctags")),
+			file_exists(path.join(".editorconfig")),
+			file_exists(path.join(".gitattributes")),
+			file_exists(path.join(".gitmodules")),
+			file_exists(path.join(".hgignore")),
+			file_exists(path.join(".hgtags")),
+			file_exists(path.join(".perltidyrc")),
+			file_exists(path.join(".travis.yml")),
+			file_exists(path.join("appveyor.yml")),
+			file_exists(path.join("build.gradle")),
+			file_exists(path.join("build.properties")),
+			file_exists(path.join("build.xml")),
+			file_exists(path.join("Cargo.toml")),
+			file_exists(path.join("cgmanifest.json")),
+			file_exists(path.join("CMakeLists.txt")),
+			file_exists(path.join("composer.json")),
+			file_exists(path.join("COPYING")),
+			file_exists(path.join("docker-compose.yml")),
+			file_exists(path.join("Dockerfile")),
+			file_exists(path.join("Gemfile")),
+			file_exists(path.join("LICENSE.txt")),
+			file_exists(path.join("LICENSE")),
+			file_exists(path.join("Makefile.am")),
+			file_exists(path.join("Makefile.pl")),
+			file_exists(path.join("Makefile.PL")),
+			file_exists(path.join("Makefile")),
+			file_exists(path.join("mix.exs")),
+			file_exists(path.join("moonshine-dependencies.xml")),
+			file_exists(path.join("package.json")),
+			file_exists(path.join("pom.xml")),
+			file_exists(path.join("project.clj")),
+			file_exists(path.join("README.md")),
+			file_exists(path.join("README")),
+			file_exists(path.join("requirements.txt")),
+			file_exists(path.join("v.mod")),
+		]
+		.into_iter()
+		.collect();
+
+		dirtests.any(is_true).await || filetests.any(is_true).await
+	}
+
+	let mut current = path.as_ref();
+	if check_origin(path.as_ref()).await {
+		origins.push(current.to_owned());
+	}
+
+	while let Some(parent) = current.parent() {
+		current = parent;
+		if check_origin(current).await {
+			origins.push(current.to_owned());
+			continue;
+		}
+	}
+
+	origins
 }
 
 /// Returns all project types detected at this given origin.
@@ -33,3 +111,36 @@ pub enum ProjectType {
 	Pip,
 	RubyGem,
 }
+
+#[inline]
+async fn exists(path: &Path) -> Option<Metadata> {
+	metadata(path).await.ok()
+}
+
+#[inline]
+async fn file_exists(path: PathBuf) -> bool {
+	let res = exists(&path)
+		.await
+		.map(|meta| meta.is_file())
+		.unwrap_or(false);
+
+	if res {
+		trace!(?path, "file exists");
+	}
+
+	res
+}
+
+#[inline]
+async fn dir_exists(path: PathBuf) -> bool {
+	let res = exists(&path)
+		.await
+		.map(|meta| meta.is_dir())
+		.unwrap_or(false);
+
+	if res {
+		trace!(?path, "dir exists");
+	}
+
+	res
+}