1 files changed, 167 insertions, 0 deletions
diff --git a/crates/rebel/src/recipe.rs b/crates/rebel/src/recipe.rs
new file mode 100644
index 0000000..28cc84c
--- /dev/null
+++ b/crates/rebel/src/recipe.rs
@@ -0,0 +1,167 @@
+use std::{collections::HashMap, ffi::OsStr, fs::File, path::Path};
+
+use serde::{de::DeserializeOwned, Deserialize};
+use walkdir::WalkDir;
+
+use rebel_common::error::*;
+use rebel_resolve::task::{TaskDef, TaskMeta};
+
+#[derive(Clone, Debug, Deserialize, Default)]
+pub struct RecipeMeta {
+	pub name: Option<String>,
+	pub version: Option<String>,
+}
+
+#[derive(Debug, Deserialize)]
+struct Recipe {
+	#[serde(default)]
+	pub meta: RecipeMeta,
+	pub tasks: HashMap<String, TaskDef>,
+}
+
+#[derive(Debug, Deserialize)]
+struct Subrecipe {
+	pub tasks: HashMap<String, TaskDef>,
+}
+
+fn read_yaml<T: DeserializeOwned>(path: &Path) -> Result<T> {
+	let f = File::open(path).context("IO error")?;
+
+	let value: T = serde_yaml::from_reader(f)
+		.map_err(Error::new)
+		.context("YAML error")?;
+
+	Ok(value)
+}
+
+const RECIPE_NAME: &str = "build";
+const RECIPE_PREFIX: &str = "build.";
+
+fn recipe_name(path: &Path) -> Option<&str> {
+	if path.extension() != Some("yml".as_ref()) {
+		return None;
+	}
+
+	let stem = path.file_stem()?.to_str()?;
+	if stem == RECIPE_NAME {
+		return Some("");
+	}
+	stem.strip_prefix(RECIPE_PREFIX)
+}
+
+fn handle_recipe_tasks(
+	tasks: &mut HashMap<String, HashMap<String, Vec<TaskDef>>>,
+	recipe_tasks: HashMap<String, TaskDef>,
+	meta: &TaskMeta,
+) {
+	let task_map = match tasks.get_mut(&meta.recipe) {
+		Some(task_map) => task_map,
+		None => tasks.entry(meta.recipe.clone()).or_default(),
+	};
+
+	for (label, mut task) in recipe_tasks {
+		task.meta = meta.clone();
+		task_map.entry(label).or_default().push(task);
+	}
+}
+
+fn read_recipe_tasks(
+	path: &Path,
+	basename: &str,
+	tasks: &mut HashMap<String, HashMap<String, Vec<TaskDef>>>,
+) -> Result<RecipeMeta> {
+	let recipe_def = read_yaml::<Recipe>(path)?;
+
+	let name = recipe_def
+		.meta
+		.name
+		.as_deref()
+		.unwrap_or(basename)
+		.to_string();
+
+	let meta = TaskMeta {
+		basename: basename.to_string(),
+		recipename: "".to_string(),
+		recipe: basename.to_string(),
+		name,
+		version: recipe_def.meta.version.clone(),
+	};
+
+	handle_recipe_tasks(tasks, recipe_def.tasks, &meta);
+
+	Ok(recipe_def.meta)
+}
+
+fn read_subrecipe_tasks(
+	path: &Path,
+	basename: &str,
+	recipename: &str,
+	recipe_meta: &RecipeMeta,
+	tasks: &mut HashMap<String, HashMap<String, Vec<TaskDef>>>,
+) -> Result<()> {
+	let recipe = format!("{basename}/{recipename}");
+	let recipe_def = read_yaml::<Subrecipe>(path)?;
+
+	let name = recipe_meta.name.as_deref().unwrap_or(basename).to_string();
+
+	let meta = TaskMeta {
+		basename: basename.to_string(),
+		recipename: recipename.to_string(),
+		recipe: recipe.clone(),
+		name,
+		version: recipe_meta.version.clone(),
+	};
+
+	handle_recipe_tasks(tasks, recipe_def.tasks, &meta);
+
+	Ok(())
+}
+
+pub fn read_recipes<P: AsRef<Path>>(
+	path: P,
+) -> Result<HashMap<String, HashMap<String, Vec<TaskDef>>>> {
+	let mut tasks = HashMap::<String, HashMap<String, Vec<TaskDef>>>::new();
+	let mut recipe_metas = HashMap::<String, RecipeMeta>::new();
+
+	for entry in WalkDir::new(path)
+		.sort_by(|a, b| {
+			// Files are sorted first by stem, then by extension, so that
+			// recipe.yml will always be read before recipe.NAME.yml
+			let stem_cmp = a.path().file_stem().cmp(&b.path().file_stem());
+			let ext_cmp = a.path().extension().cmp(&b.path().extension());
+			stem_cmp.then(ext_cmp)
+		})
+		.into_iter()
+		.filter_map(|e| e.ok())
+	{
+		let path = entry.path();
+		if !path.is_file() {
+			continue;
+		}
+
+		let Some(recipename) = recipe_name(path) else {
+			continue;
+		};
+		let Some(basename) = path
+			.parent()
+			.and_then(Path::file_name)
+			.and_then(OsStr::to_str)
+		else {
+			continue;
+		};
+
+		if recipename.is_empty() {
+			recipe_metas.insert(
+				basename.to_string(),
+				read_recipe_tasks(path, basename, &mut tasks)?,
+			);
+		} else {
+			let Some(recipe_meta) = recipe_metas.get(basename) else {
+				continue;
+			};
+			read_subrecipe_tasks(path, basename, recipename, recipe_meta, &mut tasks)?;
+		}
+	}
+
+	Ok(tasks)
+}