1 files changed, 48 insertions, 0 deletions
diff --git a/crates/mozart-registry/src/version_selector.rs b/crates/mozart-registry/src/version_selector.rs
new file mode 100644
index 0000000..7aa409e
--- /dev/null
+++ b/crates/mozart-registry/src/version_selector.rs
@@ -0,0 +1,48 @@
+use crate::cache::Cache;
+use crate::packagist::{self, PackagistVersion};
+use crate::version;
+use mozart_core::package::Stability;
+
+/// Mirrors `Composer\Package\Version\VersionSelector`.
+pub struct VersionSelector {
+    preferred_stability: Stability,
+    repo_cache: Cache,
+}
+
+impl VersionSelector {
+    pub fn new(preferred_stability: Stability, repo_cache: Cache) -> Self {
+        Self {
+            preferred_stability,
+            repo_cache,
+        }
+    }
+
+    /// Fetch versions from Packagist and pick the best candidate.
+    /// Mirrors `VersionSelector::findBestCandidate()`.
+    pub async fn find_best_candidate(
+        &self,
+        package_name: &str,
+    ) -> anyhow::Result<Option<PackagistVersion>> {
+        let versions = packagist::fetch_package_versions(package_name, &self.repo_cache).await?;
+        Ok(version::find_best_candidate(&versions, self.preferred_stability).cloned())
+    }
+
+    /// Generate a recommended constraint string from a concrete version.
+    /// Mirrors `VersionSelector::findRecommendedRequireVersion()`.
+    pub fn find_recommended_require_version_string(
+        &self,
+        pkg: &PackagistVersion,
+        fixed: bool,
+    ) -> String {
+        if fixed {
+            pkg.version.clone()
+        } else {
+            let stability = version::stability_of(&pkg.version_normalized);
+            version::find_recommended_require_version(
+                &pkg.version,
+                &pkg.version_normalized,
+                stability,
+            )
+        }
+    }
+}