Add a resolver reporter (#225)

Closes https://github.com/astral-sh/puffin/issues/223.

crates/puffin-cli/src/commands/pip_compile.rs

@@ -18,6 +18,7 @@ use puffin_dispatch::BuildDispatch;
 use puffin_interpreter::Virtualenv;
 use puffin_resolver::{Manifest, PreReleaseMode, ResolutionMode};
 
+use crate::commands::reporters::ResolverReporter;
 use crate::commands::{elapsed, ExitStatus};
 use crate::index_urls::IndexUrls;
 use crate::printer::Printer;
@@ -110,7 +111,8 @@ pub(crate) async fn pip_compile(
         &tags,
         &client,
         &build_dispatch,
-    );
+    )
+    .with_reporter(ResolverReporter::from(printer));
     let resolution = match resolver.resolve().await {
         Err(puffin_resolver::ResolveError::PubGrub(pubgrub::error::PubGrubError::NoSolution(
             mut derivation_tree,

crates/puffin-cli/src/commands/reporters.rs

@@ -1,4 +1,5 @@
 use indicatif::{ProgressBar, ProgressStyle};
+use std::time::Duration;
 
 use pep440_rs::Version;
 use puffin_package::package_name::PackageName;
@@ -29,7 +30,7 @@ impl WheelFinderReporter {
     }
 }
 
-impl puffin_resolver::Reporter for WheelFinderReporter {
+impl puffin_resolver::WheelFinderReporter for WheelFinderReporter {
     fn on_progress(&self, package: &puffin_resolver::PinnedPackage) {
         self.progress
             .set_message(format!("{}=={}", package.name(), package.version()));
@@ -145,3 +146,32 @@ impl puffin_installer::InstallReporter for InstallReporter {
         self.progress.finish_and_clear();
     }
 }
+
+#[derive(Debug)]
+pub(crate) struct ResolverReporter {
+    progress: ProgressBar,
+}
+
+impl From<Printer> for ResolverReporter {
+    fn from(printer: Printer) -> Self {
+        let progress = ProgressBar::with_draw_target(None, printer.target());
+        progress.set_message("Resolving dependencies...");
+        progress.enable_steady_tick(Duration::from_millis(200));
+        progress.set_style(
+            ProgressStyle::with_template("{spinner:.white} {wide_msg:.dim}")
+                .unwrap()
+                .tick_strings(&["⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"]),
+        );
+        Self { progress }
+    }
+}
+
+impl puffin_resolver::ResolverReporter for ResolverReporter {
+    fn on_progress(&self, name: &PackageName, version: &Version) {
+        self.progress.set_message(format!("{name}=={version}"));
+    }
+
+    fn on_complete(&self) {
+        self.progress.finish_and_clear();
+    }
+}

crates/puffin-resolver/src/lib.rs

@@ -3,9 +3,9 @@ pub use manifest::Manifest;
 pub use prerelease_mode::PreReleaseMode;
 pub use resolution::{Graph, PinnedPackage};
 pub use resolution_mode::ResolutionMode;
-pub use resolver::Resolver;
+pub use resolver::{Reporter as ResolverReporter, Resolver};
 pub use source_distribution::BuiltSourceDistributionCache;
-pub use wheel_finder::{Reporter, WheelFinder};
+pub use wheel_finder::{Reporter as WheelFinderReporter, WheelFinder};
 
 mod candidate_selector;
 mod distribution;

crates/puffin-resolver/src/resolver.rs

@@ -50,6 +50,7 @@ pub struct Resolver<'a, Context: BuildContext + Sync> {
     selector: CandidateSelector,
     index: Arc<Index>,
     build_context: &'a Context,
+    reporter: Option<Box<dyn Reporter>>,
 }
 
 #[derive(Debug, Default)]
@@ -92,6 +93,16 @@ impl<'a, Context: BuildContext + Sync> Resolver<'a, Context> {
             tags,
             client,
             build_context,
+            reporter: None,
+        }
+    }
+
+    /// Set the [`Reporter`] to use for this installer.
+    #[must_use]
+    pub fn with_reporter(self, reporter: impl Reporter + 'static) -> Self {
+        Self {
+            reporter: Some(Box::new(reporter)),
+            ..self
         }
     }
 
@@ -121,6 +132,8 @@ impl<'a, Context: BuildContext + Sync> Resolver<'a, Context> {
             }
         };
 
+        self.on_complete();
+
         Ok(resolution)
     }
 
@@ -210,6 +223,8 @@ impl<'a, Context: BuildContext + Sync> Resolver<'a, Context> {
                 Some(version) => version,
             };
 
+            self.on_progress(&next, &version);
+
             if added_dependencies
                 .entry(next.clone())
                 .or_default()
@@ -620,6 +635,28 @@ impl<'a, Context: BuildContext + Sync> Resolver<'a, Context> {
             }),
         }
     }
+
+    fn on_progress(&self, package: &PubGrubPackage, version: &PubGrubVersion) {
+        if let Some(reporter) = self.reporter.as_ref() {
+            if let PubGrubPackage::Package(package_name, _) = package {
+                reporter.on_progress(package_name, version.into());
+            }
+        }
+    }
+
+    fn on_complete(&self) {
+        if let Some(reporter) = self.reporter.as_ref() {
+            reporter.on_complete();
+        }
+    }
+}
+
+pub trait Reporter: Send + Sync {
+    /// Callback to invoke when a dependency is resolved.
+    fn on_progress(&self, name: &PackageName, version: &pep440_rs::Version);
+
+    /// Callback to invoke when the resolution is complete.
+    fn on_complete(&self);
 }
 
 /// Fetch the metadata for an item