Refactor into modular molecular workloads

scimesh/cli.py

@@ -0,0 +1,37 @@
+"""Command-line entry point for SciMesh."""
+
+from __future__ import annotations
+
+import argparse
+import sys
+
+from scimesh.core.registry import WorkloadRegistry
+from scimesh.workloads import register_workloads
+
+
+def build_parser() -> argparse.ArgumentParser:
+    """Build the top-level parser from the registered workloads."""
+    parser = argparse.ArgumentParser(
+        prog="scimesh",
+        description="Run local scientific workloads on molecular datasets.",
+    )
+    subparsers = parser.add_subparsers(dest="workload", required=True)
+    registry = WorkloadRegistry()
+    register_workloads(registry)
+    registry.add_subparsers(subparsers)
+    return parser
+
+
+def main(argv: list[str] | None = None) -> int:
+    """Run a selected workload and return its exit status."""
+    parser = build_parser()
+    args = parser.parse_args(argv)
+    try:
+        return args.handler(args)
+    except (OSError, ValueError) as error:
+        print(f"Error: {error}", file=sys.stderr)
+        return 1
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())