Restructure as Codex plugin

skills/last30days/scripts/lib/fanout.py

@@ -0,0 +1,85 @@
+"""Parallel multi-entity fan-out for the --competitors flag.
+
+The orchestrator accepts a `main_runner()` for the topic and a
+`competitor_runner(entity)` for each peer. It parallelizes their execution
+via a `ThreadPoolExecutor` and collects per-entity Reports. Per-entity
+failures are logged and dropped; the run survives as long as the main topic
+plus at least one competitor succeed.
+
+This module owns no business logic about pipeline arguments — the caller
+(scripts/last30days.py main) builds the closures with the appropriate
+config, depth, and overrides for each entity.
+"""
+
+from __future__ import annotations
+
+import sys
+from concurrent.futures import ThreadPoolExecutor, as_completed
+from typing import Callable
+
+from . import schema
+
+# Sub-runs hit the same upstream APIs as the main topic. Cap parallelism so a
+# 6-way fan-out does not stampede a single backend's rate limit.
+MAX_PARALLEL_SUBRUNS = 6
+
+
+def _log(msg: str) -> None:
+    print(f"[Fanout] {msg}", file=sys.stderr)
+
+
+def run_competitor_fanout(
+    *,
+    main_topic: str,
+    main_runner: Callable[[], schema.Report],
+    competitors: list[str],
+    competitor_runner: Callable[[str], schema.Report],
+) -> list[tuple[str, schema.Report]]:
+    """Run main + competitor pipelines in parallel; return surviving reports.
+
+    Args:
+        main_topic: Display label for the user's primary topic.
+        main_runner: Zero-arg callable returning the main topic's Report.
+        competitors: Ordered list of competitor entity names.
+        competitor_runner: Callable(entity_name) -> Report for each peer.
+
+    Returns:
+        Ordered list of (entity_name, Report) tuples for runs that succeeded.
+        Empty list if every run raised; the caller decides how to surface
+        partial-failure modes.
+    """
+    if not competitors:
+        report = main_runner()
+        return [(main_topic, report)]
+
+    workers = min(len(competitors) + 1, MAX_PARALLEL_SUBRUNS)
+
+    def _run_one(label: str, fn: Callable[[], schema.Report]) -> tuple[str, schema.Report | None, Exception | None]:
+        try:
+            return label, fn(), None
+        except Exception as exc:
+            return label, None, exc
+
+    submissions: list[tuple[str, Callable[[], schema.Report]]] = [
+        (main_topic, main_runner),
+    ]
+    for entity in competitors:
+        submissions.append((entity, lambda e=entity: competitor_runner(e)))
+
+    with ThreadPoolExecutor(max_workers=workers) as executor:
+        futures = {
+            executor.submit(_run_one, label, fn): label
+            for label, fn in submissions
+        }
+        results: dict[str, schema.Report] = {}
+        for future in as_completed(futures):
+            label, report, exc = future.result()
+            if exc is not None:
+                _log(f"Sub-run failed for {label!r}: {type(exc).__name__}: {exc}")
+                continue
+            assert report is not None
+            results[label] = report
+
+    # Preserve the original submission order rather than completion order so
+    # the comparison render is deterministic across runs.
+    return [(label, results[label]) for label, _ in submissions if label in results]