Add RankLLM legacy CLI wrappers (#366)

* Add packaged rank-llm entrypoint baseline

* Fix ruff formatting in CLI packaging test

* Add RankLLM legacy CLI wrappers

* Restore legacy wrapper behavior

Author: ronakice

src/rank_llm/cli/legacy.py

@@ -0,0 +1,71 @@
+from __future__ import annotations
+
+import argparse
+from collections.abc import Sequence
+from enum import Enum
+
+
+def translate_legacy_argv(
+    argv: Sequence[str],
+    *,
+    mapping: dict[str, str] | None = None,
+    drop_flags: set[str] | None = None,
+) -> list[str]:
+    translated: list[str] = []
+    mapping = mapping or {}
+    drop_flags = drop_flags or set()
+    skip_next = False
+
+    for token in argv:
+        if skip_next:
+            skip_next = False
+            continue
+        if not token.startswith("--"):
+            translated.append(token)
+            continue
+
+        if "=" in token:
+            flag, value = token.split("=", 1)
+            normalized = flag[2:]
+            if normalized in drop_flags:
+                continue
+            mapped_flag = mapping.get(normalized, normalized.replace("_", "-"))
+            translated.append(f"--{mapped_flag}={value}")
+            continue
+
+        normalized = token[2:]
+        if normalized in drop_flags:
+            skip_next = True
+            continue
+        mapped_flag = mapping.get(normalized, normalized.replace("_", "-"))
+        translated.append(f"--{mapped_flag}")
+
+    return translated
+
+
+def namespace_to_legacy_argv(
+    args: argparse.Namespace,
+    *,
+    mapping: dict[str, str] | None = None,
+    drop_flags: set[str] | None = None,
+) -> list[str]:
+    argv: list[str] = []
+    mapping = mapping or {}
+    drop_flags = drop_flags or set()
+
+    for key, value in vars(args).items():
+        if key in drop_flags or value is None or value is False:
+            continue
+        flag = mapping.get(key, key.replace("_", "-"))
+        if value is True:
+            argv.append(f"--{flag}")
+            continue
+        if isinstance(value, list):
+            if value:
+                argv.append(f"--{flag}")
+                argv.extend(str(item) for item in value)
+            continue
+        if isinstance(value, Enum):
+            value = value.value
+        argv.extend([f"--{flag}", str(value)])
+    return argv

src/rank_llm/scripts/generate_retrieve_results_json_cache.py

@@ -46,11 +46,11 @@
         --topk 20
 """
 
-import argparse
 import json
 import os
 import sys
 from collections import defaultdict
+from collections.abc import Sequence
 
 from rank_llm._optional import missing_extra_error
 
@@ -62,6 +62,8 @@
     get_topics = None
 from tqdm import tqdm
 
+from rank_llm.cli.legacy import namespace_to_legacy_argv, translate_legacy_argv
+from rank_llm.cli.main import main as cli_main
 from rank_llm.retrieve import TOPICS
 
 sys.path.append(os.getcwd())
@@ -183,24 +185,16 @@ def write_output_file(output_file_path, data):
         json.dump(data, file)
 
 
-def main():
-    parser = argparse.ArgumentParser()
-    parser.add_argument("--trec_file", required=True)
-    parser.add_argument("--collection_file", required=True)
-    parser.add_argument("--query_file", required=True)
-    parser.add_argument("--output_file", required=True)
-    parser.add_argument("--output_trec_file", type=str, default=None)
-    parser.add_argument("--topk", type=int, default=20)
-    args = parser.parse_args()
-
-    results = generate_retrieve_results(
-        args.trec_file,
-        args.collection_file,
-        args.query_file,
-        args.topk,
-        args.output_trec_file,
-    )
-    write_output_file(args.output_file, results)
+def main(args: Sequence[str] | object | None = None) -> int:
+    if hasattr(args, "__dict__"):
+        argv = namespace_to_legacy_argv(args)
+    elif args is None:
+        argv = sys.argv[1:]
+    else:
+        argv = list(args)
+
+    translated = translate_legacy_argv(argv)
+    return cli_main(["retrieve-cache", *translated])
 
 
 if __name__ == "__main__":