refactor(downloader): turn DownloadManager into downloader registry

Reshape DownloadManager from a hard-coded VCS match into a registry of
DownloaderInterface instances keyed by source type, mirroring
Composer's DownloadManager — with prefer-source/dist preferences, an
IO handle, and a files cache. ArchiveManager now resolves dist
sources through a shared DownloadManager instead of calling
download_dist directly, and Composer::require / try_load take an IO
so it flows through the factory wiring.

1 files changed, 85 insertions, 50 deletions

diff --git a/crates/mozart-core/src/downloader/download_manager.rs b/crates/mozart-core/src/downloader/download_manager.rs
index c83bc64..68ae20e 100644
--- a/crates/mozart-core/src/downloader/download_manager.rs
+++ b/crates/mozart-core/src/downloader/download_manager.rs
@@ -1,40 +1,49 @@
-//! `DownloadManager` — pick the right [`VcsDownloader`] for a given
-//! [`LocalPackage`]. Mirrors `Composer\Downloader\DownloadManager`.
-
 use crate::composer::{InstallationSource, LocalPackage};
-use crate::downloader::{GitDownloader, HgDownloader, SvnDownloader, VcsDownloader};
-use crate::vcs::process::ProcessExecutor;
-use crate::vcs::util::git::GitUtil;
-use crate::vcs::util::hg::HgUtil;
-use crate::vcs::util::svn::SvnUtil;
-use std::path::PathBuf;
+use crate::console::IoInterface;
+use crate::downloader::{DownloaderInterface, VcsDownloader};
+use crate::repository::cache::Cache;
+use crate::repository::downloader::{DownloadProgress, download_dist};
+use crate::util::Filesystem;
 
-/// Selects a `VcsDownloader` for a package based on its installation source
-/// and source type. Mirrors `DownloadManager::getDownloaderForPackage`:
-///
-/// - `metapackage` → `None`.
-/// - `installation-source: dist` → `None` (Composer would return a
-///   `FileDownloader`-family object that does not implement
-///   `ChangeReportInterface` / `DvcsDownloaderInterface`, so the status
-///   command's `instanceof` checks all become no-ops; returning `None`
-///   directly is the equivalent in our trait-object world).
-/// - `installation-source: source` → the matching VCS downloader by
-///   `source.type` (`git` / `hg` / `svn`).
+/// ref: \Composer\Downloader\DownloadManager
 pub struct DownloadManager {
-    git_cache_dir: PathBuf,
+    #[allow(unused)]
+    io: std::sync::Arc<std::sync::Mutex<Box<dyn IoInterface>>>,
+    prefer_dist: bool,
+    prefer_source: bool,
+    #[allow(unused)]
+    package_preferences: Vec<(String, InstallationSource)>,
+    #[allow(unused)]
+    filesystem: Filesystem,
+    downloaders: indexmap::IndexMap<String, Box<dyn DownloaderInterface>>,
+    files_cache: Cache, // TODO: remove
 }
 
 impl DownloadManager {
-    /// `git_cache_dir`: where `GitUtil` should keep mirror clones (e.g.
-    /// `<vendor>/.cache/git`).
-    pub fn new(git_cache_dir: PathBuf) -> Self {
-        Self { git_cache_dir }
+    pub fn new(
+        io: std::sync::Arc<std::sync::Mutex<Box<dyn IoInterface>>>,
+        prefer_source: bool,
+        filesystem: Filesystem,
+        files_cache: Cache,
+    ) -> Self {
+        Self {
+            io,
+            prefer_dist: false,
+            prefer_source,
+            package_preferences: Vec::new(),
+            filesystem,
+            downloaders: indexmap::IndexMap::new(),
+            files_cache,
+        }
     }
 
-    pub fn get_downloader_for_package(
-        &self,
-        package: &LocalPackage,
-    ) -> Option<Box<dyn VcsDownloader>> {
+    pub fn set_downloader(&mut self, r#type: String, downloader: Box<dyn DownloaderInterface>) {
+        assert!(r#type.chars().all(|c| c.is_ascii_lowercase()));
+
+        self.downloaders.insert(r#type, downloader);
+    }
+
+    pub fn get_downloader_for_package(&self, package: &LocalPackage) -> Option<&dyn VcsDownloader> {
         if package.package_type() == Some("metapackage") {
             return None;
         }
@@ -42,32 +51,58 @@ impl DownloadManager {
             InstallationSource::Dist => None,
             InstallationSource::Source => {
                 let kind = package.source()?.kind.as_str();
-                match kind {
-                    "git" => {
-                        let git_util =
-                            GitUtil::new(ProcessExecutor::new(), self.git_cache_dir.clone());
-                        Some(Box::new(GitDownloader::new(git_util)))
-                    }
-                    "hg" => {
-                        let hg_util = HgUtil::new(ProcessExecutor::new());
-                        Some(Box::new(HgDownloader::new(hg_util)))
-                    }
-                    "svn" => {
-                        let svn_util = SvnUtil::new(ProcessExecutor::new());
-                        Some(Box::new(SvnDownloader::new(svn_util)))
-                    }
-                    _ => None,
-                }
+                self.downloaders
+                    .get(kind)
+                    .and_then(|d| d.as_vcs_downloader())
             }
         }
     }
+
+    /// Makes downloader prefer source installation over the dist.
+    pub fn set_prefer_source(&mut self, prefer_source: bool) {
+        self.prefer_source = prefer_source;
+    }
+
+    /// Makes downloader prefer dist installation over the source.
+    pub fn set_prefer_dist(&mut self, prefer_dist: bool) {
+        self.prefer_dist = prefer_dist;
+    }
+
+    pub async fn download_legacy(
+        &self,
+        url: &str,
+        expected_shasum: Option<&str>,
+        progress: Option<&mut DownloadProgress>,
+    ) -> anyhow::Result<Vec<u8>> {
+        download_dist(url, expected_shasum, progress, &self.files_cache).await
+    }
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
     use crate::composer::PackageReference;
+    use crate::console::Console;
+    use crate::downloader::GitDownloader;
+    use crate::vcs::process::ProcessExecutor;
     use serde_json::Value;
+    use std::path::PathBuf;
+    use std::sync::{Arc, Mutex};
+
+    fn make_dm() -> DownloadManager {
+        let io: Arc<Mutex<Box<dyn IoInterface>>> = Arc::new(Mutex::new(Box::new(Console::new(
+            0, true, false, true, true,
+        ))
+            as Box<dyn IoInterface>));
+        let cache_dir = PathBuf::from("/tmp/mz-test-cache");
+        let cache = Cache::new(cache_dir.clone(), false);
+        let mut dm = DownloadManager::new(io, false, Filesystem::new(), cache);
+        dm.set_downloader(
+            "git".to_owned(),
+            Box::new(GitDownloader::new(ProcessExecutor::new(), cache_dir)),
+        );
+        dm
+    }
 
     fn pkg(
         installation_source: Option<InstallationSource>,
@@ -93,7 +128,7 @@ mod tests {
 
     #[test]
     fn metapackage_returns_none() {
-        let dm = DownloadManager::new(PathBuf::from("/tmp/mz-test-cache"));
+        let dm = make_dm();
         let mut p = pkg(Some(InstallationSource::Source), Some("git"));
         // override type
         p = LocalPackage::new(
@@ -111,28 +146,28 @@ mod tests {
 
     #[test]
     fn dist_install_returns_none() {
-        let dm = DownloadManager::new(PathBuf::from("/tmp/mz-test-cache"));
+        let dm = make_dm();
         let p = pkg(Some(InstallationSource::Dist), Some("git"));
         assert!(dm.get_downloader_for_package(&p).is_none());
     }
 
     #[test]
     fn source_install_with_git_returns_some() {
-        let dm = DownloadManager::new(PathBuf::from("/tmp/mz-test-cache"));
+        let dm = make_dm();
         let p = pkg(Some(InstallationSource::Source), Some("git"));
         assert!(dm.get_downloader_for_package(&p).is_some());
     }
 
     #[test]
     fn unknown_source_kind_returns_none() {
-        let dm = DownloadManager::new(PathBuf::from("/tmp/mz-test-cache"));
+        let dm = make_dm();
         let p = pkg(Some(InstallationSource::Source), Some("perforce"));
         assert!(dm.get_downloader_for_package(&p).is_none());
     }
 
     #[test]
     fn missing_installation_source_returns_none() {
-        let dm = DownloadManager::new(PathBuf::from("/tmp/mz-test-cache"));
+        let dm = make_dm();
         let p = pkg(None, Some("git"));
         assert!(dm.get_downloader_for_package(&p).is_none());
     }