refactor(composer): move Composer and Factory from mozart-core to mozart

Composer needs DownloadManager (from mozart-registry), but mozart-core
sits below mozart-registry in the dependency graph — adding the field
would create a dependency cycle. Moving Composer and create_composer to
the mozart CLI crate breaks the cycle and lets the root state container
hold a DownloadManager.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 362 insertions, 0 deletions

diff --git a/crates/mozart/src/factory.rs b/crates/mozart/src/factory.rs
new file mode 100644
index 0000000..67fc9a3
--- /dev/null
+++ b/crates/mozart/src/factory.rs
@@ -0,0 +1,362 @@
+//! Factory helpers for constructing Composer state.
+//!
+//! Ports the static factory methods from `Composer\Factory`. Today we
+//! cover [`create_config`] (effective global [`Config`]) and
+//! [`create_composer`] (the project-level [`Composer`] root, built from
+//! `composer.json` plus the on-disk `vendor/composer/installed.json`).
+//!
+//! Auth loading, htaccess creation, and the plugin/event-dispatcher
+//! wiring are intentionally omitted as they are out of scope for the
+//! current port.
+
+use crate::composer::Composer;
+use mozart_core::composer::{
+    AutoloadGenerator, InstallationManager, InstallationSource, LocalPackage, LocalRepository,
+    Locker, PackageReference, RepositoryManager,
+};
+use mozart_core::config::resolve_references;
+use mozart_core::factory::create_config;
+use mozart_core::package::read_from_file;
+use mozart_registry::download_manager::DownloadManager;
+
+/// Rust port of `Factory::createComposer()`.
+///
+/// Builds the project-level [`Composer`]:
+/// 1. Read `composer.json` from `composer_json` and load it into both
+///    the merged [`Config`] (overlaying [`create_config`]) and the
+///    untyped [`crate::package::RawPackageData`].
+/// 2. Resolve all `{$home}` / `{$vendor-dir}` placeholders via
+///    [`resolve_references`].
+/// 3. Resolve `vendor-dir` against `project_dir` if it is relative, so
+///    the installation manager hands back absolute paths
+///    (`Factory::createComposer` does the same via
+///    `Filesystem::isAbsolutePath`).
+/// 4. Wire up the [`InstallationManager`] and a [`RepositoryManager`]
+///    whose local repository is populated from
+///    `vendor/composer/installed.json` — the same role
+///    `Factory::addLocalRepository` plays in PHP.
+/// 5. Construct a fresh [`AutoloadGenerator`] with PHP defaults
+///    (`new AutoloadGenerator($eventDispatcher, $io)` in PHP, minus the
+///    not-yet-ported event dispatcher and IO dependencies).
+/// 6. Construct a [`Locker`] pointed at `composer.lock` next to the
+///    composer.json — same as `Factory::createComposer`'s
+///    `new Locker($io, new JsonFile($lockFile, …), $im, $contents)`,
+///    minus the IO/installation-manager/contents dependencies that
+///    only matter once we port `setLockData`.
+///
+/// The plugin manager, download manager, and event dispatcher that
+/// `Factory::createComposer` also wires up are not yet ported.
+pub fn create_composer(
+    project_dir: std::path::PathBuf,
+    composer_json: &std::path::Path,
+) -> anyhow::Result<Composer> {
+    let content = std::fs::read_to_string(composer_json)?;
+    let value: serde_json::Value = serde_json::from_str(&content)?;
+    let mut config = create_config()?;
+    if let Some(cfg_obj) = value.get("config").and_then(|v| v.as_object()) {
+        let overrides: std::collections::BTreeMap<String, serde_json::Value> = cfg_obj
+            .iter()
+            .map(|(k, v)| (k.clone(), v.clone()))
+            .collect();
+        config.merge(&overrides)?;
+    }
+    resolve_references(&mut config);
+
+    let package = read_from_file(composer_json)?;
+
+    // Mirrors `Factory::createComposer`'s `vendorDir` handling. The
+    // value out of `Config::get('vendor-dir')` already had `{$...}`
+    // placeholders substituted, but it may still be relative — resolve
+    // it against the project root so install paths are absolute.
+    let vendor_dir = if std::path::Path::new(&config.vendor_dir).is_absolute() {
+        std::path::PathBuf::from(&config.vendor_dir)
+    } else {
+        project_dir.join(&config.vendor_dir)
+    };
+
+    let (local_packages, dev_mode) = read_local_packages(&vendor_dir)?;
+    let repository_manager =
+        RepositoryManager::new(LocalRepository::with_dev_mode(local_packages, dev_mode));
+    let installation_manager = InstallationManager::new(vendor_dir.clone());
+    let download_manager = DownloadManager::new(vendor_dir.join(".cache").join("git"));
+    let autoload_generator = AutoloadGenerator::new();
+
+    // Mirrors `Factory::createComposer`'s lock-file path: the lockfile
+    // sits next to composer.json, with `.json` swapped for `.lock`.
+    let lock_file_path = composer_json
+        .parent()
+        .map(|p| p.to_path_buf())
+        .unwrap_or_else(|| project_dir.clone())
+        .join(
+            composer_json
+                .file_name()
+                .and_then(|n| n.to_str())
+                .map(|n| n.strip_suffix(".json").unwrap_or(n))
+                .map(|stem| format!("{stem}.lock"))
+                .unwrap_or_else(|| "composer.lock".to_string()),
+        );
+    let locker = Locker::new(lock_file_path);
+
+    Ok(Composer::new(
+        project_dir,
+        config,
+        package,
+        repository_manager,
+        installation_manager,
+        download_manager,
+        autoload_generator,
+        locker,
+    ))
+}
+
+/// Read `vendor/composer/installed.json` into the minimal shape the
+/// installation manager needs. Mirrors the relevant slice of
+/// `Composer\Repository\FilesystemRepository::initialize`: accept both
+/// the v2 object form (`{packages: [...]}`) and the legacy v1 array
+/// form. Returns an empty list when the file is missing — the same
+/// semantics as `FilesystemRepository::isFresh`.
+///
+/// We deliberately avoid pulling the full `InstalledPackages` reader from
+/// `mozart-registry` here to keep `mozart-core` at the bottom of the
+/// dependency graph; the parsing that's actually load-bearing for the
+/// install-path computation is just the package name + optional
+/// `target-dir`.
+fn read_local_packages(
+    vendor_dir: &std::path::Path,
+) -> anyhow::Result<(Vec<LocalPackage>, Option<bool>)> {
+    let path = vendor_dir.join("composer/installed.json");
+    if !path.exists() {
+        return Ok((Vec::new(), None));
+    }
+    let content = std::fs::read_to_string(&path)?;
+    let value: serde_json::Value = serde_json::from_str(&content)?;
+
+    let (entries, dev_mode): (&[serde_json::Value], Option<bool>) = match &value {
+        serde_json::Value::Object(obj) => {
+            let entries = match obj.get("packages") {
+                Some(serde_json::Value::Array(arr)) => arr.as_slice(),
+                _ => return Ok((Vec::new(), obj.get("dev").and_then(|v| v.as_bool()))),
+            };
+            (entries, obj.get("dev").and_then(|v| v.as_bool()))
+        }
+        serde_json::Value::Array(arr) => (arr.as_slice(), None),
+        _ => return Ok((Vec::new(), None)),
+    };
+
+    let mut out = Vec::with_capacity(entries.len());
+    for entry in entries {
+        let pretty_name = entry
+            .get("name")
+            .and_then(|v| v.as_str())
+            .unwrap_or("")
+            .to_string();
+        let pretty_version = entry
+            .get("version")
+            .and_then(|v| v.as_str())
+            .unwrap_or("")
+            .to_string();
+        let target_dir = entry
+            .get("target-dir")
+            .and_then(|v| v.as_str())
+            .map(|s| s.to_string());
+        let package_type = entry
+            .get("type")
+            .and_then(|v| v.as_str())
+            .map(|s| s.to_string());
+        let installation_source = entry
+            .get("installation-source")
+            .and_then(|v| v.as_str())
+            .and_then(InstallationSource::parse);
+        let source = read_package_reference(entry.get("source"));
+        let dist = read_package_reference(entry.get("dist"));
+        let extra = entry
+            .get("extra")
+            .cloned()
+            .unwrap_or(serde_json::Value::Null);
+        out.push(LocalPackage::new(
+            pretty_name,
+            pretty_version,
+            target_dir,
+            package_type,
+            installation_source,
+            source,
+            dist,
+            extra,
+        ));
+    }
+    Ok((out, dev_mode))
+}
+
+fn read_package_reference(value: Option<&serde_json::Value>) -> Option<PackageReference> {
+    let v = value?;
+    let kind = v.get("type").and_then(|x| x.as_str())?.to_string();
+    let url = v
+        .get("url")
+        .and_then(|x| x.as_str())
+        .unwrap_or("")
+        .to_string();
+    let reference = v
+        .get("reference")
+        .and_then(|x| x.as_str())
+        .map(|s| s.to_string());
+    let shasum = v
+        .get("shasum")
+        .and_then(|x| x.as_str())
+        .filter(|s| !s.is_empty())
+        .map(|s| s.to_string());
+    Some(PackageReference {
+        kind,
+        url,
+        reference,
+        shasum,
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::fs;
+    use std::path::Path;
+    use tempfile::tempdir;
+
+    fn write(path: &Path, content: &str) {
+        fs::create_dir_all(path.parent().unwrap()).unwrap();
+        fs::write(path, content).unwrap();
+    }
+
+    #[test]
+    fn install_path_is_vendor_dir_plus_pretty_name() {
+        let dir = tempdir().unwrap();
+        write(&dir.path().join("composer.json"), r#"{"name": "acme/app"}"#);
+        write(
+            &dir.path().join("vendor/composer/installed.json"),
+            r#"{"packages": [{"name": "Vendor/Pkg", "version": "1.0.0"}]}"#,
+        );
+
+        let composer = Composer::require(dir.path()).unwrap();
+        let pkg = composer
+            .repository_manager()
+            .local_repository()
+            .get_canonical_packages()
+            .next()
+            .unwrap();
+
+        let install_path = composer
+            .installation_manager()
+            .get_install_path(pkg)
+            .unwrap();
+
+        // Mirrors `LibraryInstaller::getInstallPath`:
+        // `vendorDir + '/' + prettyName`. `pretty-name` is preserved
+        // case (Composer/Repository/FilesystemRepository keeps the original).
+        assert_eq!(install_path, dir.path().join("vendor").join("Vendor/Pkg"));
+    }
+
+    #[test]
+    fn install_path_appends_target_dir() {
+        let dir = tempdir().unwrap();
+        write(&dir.path().join("composer.json"), r#"{"name": "acme/app"}"#);
+        write(
+            &dir.path().join("vendor/composer/installed.json"),
+            r#"{"packages": [{"name": "vendor/pkg", "target-dir": "src/lib"}]}"#,
+        );
+
+        let composer = Composer::require(dir.path()).unwrap();
+        let pkg = composer
+            .repository_manager()
+            .local_repository()
+            .get_canonical_packages()
+            .next()
+            .unwrap();
+
+        let install_path = composer
+            .installation_manager()
+            .get_install_path(pkg)
+            .unwrap();
+
+        assert_eq!(install_path, dir.path().join("vendor/vendor/pkg/src/lib"));
+    }
+
+    #[test]
+    fn local_repository_is_empty_when_installed_json_missing() {
+        let dir = tempdir().unwrap();
+        write(&dir.path().join("composer.json"), r#"{"name": "acme/app"}"#);
+
+        let composer = Composer::require(dir.path()).unwrap();
+        let count = composer
+            .repository_manager()
+            .local_repository()
+            .get_canonical_packages()
+            .count();
+        assert_eq!(count, 0);
+    }
+
+    #[test]
+    fn local_repository_accepts_v1_array_form() {
+        // Older Composer 1.x / fixture format: bare array of packages.
+        // FilesystemRepository::initialize accepts this; our minimal
+        // reader must too.
+        let dir = tempdir().unwrap();
+        write(&dir.path().join("composer.json"), r#"{"name": "acme/app"}"#);
+        write(
+            &dir.path().join("vendor/composer/installed.json"),
+            r#"[{"name": "a/a"}, {"name": "b/b"}]"#,
+        );
+
+        let composer = Composer::require(dir.path()).unwrap();
+        let names: Vec<&str> = composer
+            .repository_manager()
+            .local_repository()
+            .get_canonical_packages()
+            .map(|p| p.pretty_name())
+            .collect();
+        assert_eq!(names, vec!["a/a", "b/b"]);
+    }
+
+    #[test]
+    fn package_returns_root_composer_json() {
+        let dir = tempdir().unwrap();
+        write(
+            &dir.path().join("composer.json"),
+            r#"{"name": "acme/app", "require": {"vendor/pkg": "^1.0"}}"#,
+        );
+
+        let composer = Composer::require(dir.path()).unwrap();
+        assert_eq!(composer.package().name, "acme/app");
+        assert_eq!(
+            composer
+                .package()
+                .require
+                .get("vendor/pkg")
+                .map(String::as_str),
+            Some("^1.0"),
+        );
+    }
+
+    #[test]
+    fn install_path_uses_configured_vendor_dir() {
+        let dir = tempdir().unwrap();
+        write(
+            &dir.path().join("composer.json"),
+            r#"{"name": "acme/app", "config": {"vendor-dir": "deps"}}"#,
+        );
+        write(
+            &dir.path().join("deps/composer/installed.json"),
+            r#"{"packages": [{"name": "vendor/pkg"}]}"#,
+        );
+
+        let composer = Composer::require(dir.path()).unwrap();
+        let pkg = composer
+            .repository_manager()
+            .local_repository()
+            .get_canonical_packages()
+            .next()
+            .unwrap();
+
+        let install_path = composer
+            .installation_manager()
+            .get_install_path(pkg)
+            .unwrap();
+        assert_eq!(install_path, dir.path().join("deps/vendor/pkg"));
+    }
+}