feat(tools): batch tree build orchestration with shared API semaphore

tests/unit/test_build_trees.py

@@ -5,9 +5,14 @@
 
 from __future__ import annotations
 
+import argparse
+import asyncio
+import json
 import sys
 from pathlib import Path
 
+import pytest
+
 PROJECT_ROOT = Path(__file__).resolve().parent.parent.parent
 if str(PROJECT_ROOT) not in sys.path:
     sys.path.insert(0, str(PROJECT_ROOT))
@@ -17,6 +22,8 @@ from tools.build_trees import (  # noqa: E402
     _discover_pending,
     _find_srt_entries,
     _tree_is_complete,
+    load_progress,
+    main_async,
 )
 
 
@@ -106,3 +113,121 @@ class TestFindSrtEntries:
     def test_missing_returns_none(self, tmp_path: Path) -> None:
         """无同名 .srt 返回 None。"""
         assert _find_srt_entries(tmp_path / "vid.mp4", tmp_path) is None
+
+
+# ── 编排集成（桩 builder，无真实视频/LLM）──────────────────────
+
+
+class _StubBuilder:
+    """记录并发与注入信号量的桩 builder。"""
+
+    instances: list[_StubBuilder] = []
+    inflight = 0
+    max_inflight = 0
+
+    def __init__(self, vlm, llm, config, *, api_semaphore=None) -> None:
+        """记录注入的 api_semaphore 并登记实例。"""
+        self.api_semaphore = api_semaphore
+        _StubBuilder.instances.append(self)
+
+    async def build_async(self, video_path: str, srt_entries=None) -> TreeIndex:
+        """模拟建树：短暂 sleep 并统计并发峰值，返回最小合法树。"""
+        _StubBuilder.inflight += 1
+        _StubBuilder.max_inflight = max(_StubBuilder.max_inflight, _StubBuilder.inflight)
+        await asyncio.sleep(0.02)
+        _StubBuilder.inflight -= 1
+
+        l1 = L1Node(
+            id="x_L1_000",
+            card=L1Card("s", "室内", [], [], [], [], "线性"),
+            time_range=(0.0, 1.0),
+            children=[],
+        )
+        return TreeIndex(metadata=IndexMeta(video_path, "video"), roots=[l1])
+
+
+@pytest.fixture()
+def batch_env(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> dict:
+    """5 个假视频 + 桩 builder + 隔离的 progress 路径。"""
+    import tools.build_trees as bt
+
+    _StubBuilder.instances = []
+    _StubBuilder.inflight = 0
+    _StubBuilder.max_inflight = 0
+    monkeypatch.setattr(bt, "VideoTreeBuilder", _StubBuilder)
+    monkeypatch.setattr(bt, "_build_clients", lambda api_concurrency: (None, None))
+
+    videos = tmp_path / "videos"
+    videos.mkdir()
+    for i in range(5):
+        (videos / f"v{i}.mp4").write_bytes(b"")
+
+    return {
+        "videos": videos,
+        "out": tmp_path / "out",
+        "progress": tmp_path / "build_progress.json",
+    }
+
+
+def _make_args(env: dict, video_concurrency: int = 2, limit: int = 0) -> argparse.Namespace:
+    """构造 main_async 所需的 CLI 参数命名空间。"""
+    return argparse.Namespace(
+        videos_dir=str(env["videos"]),
+        out_dir=str(env["out"]),
+        srt_dir=str(env["videos"]),
+        video_concurrency=video_concurrency,
+        limit=limit,
+        progress_path=str(env["progress"]),
+    )
+
+
+class TestOrchestration:
+    """main_async 编排行为（桩 builder）。"""
+
+    @pytest.mark.asyncio
+    async def test_video_concurrency_capped(self, batch_env: dict) -> None:
+        """同时在建视频数不得超过 video_concurrency。"""
+        await main_async(_make_args(batch_env, video_concurrency=2))
+        assert _StubBuilder.max_inflight <= 2
+        assert len(_StubBuilder.instances) == 5
+
+    @pytest.mark.asyncio
+    async def test_shared_api_semaphore(self, batch_env: dict) -> None:
+        """全部 builder 实例共享同一个 API Semaphore 对象。"""
+        await main_async(_make_args(batch_env))
+        sems = {id(b.api_semaphore) for b in _StubBuilder.instances}
+        assert len(sems) == 1
+        assert _StubBuilder.instances[0].api_semaphore is not None
+
+    @pytest.mark.asyncio
+    async def test_trees_saved_and_progress_recorded(self, batch_env: dict) -> None:
+        """每个视频产出 tree.json 且 progress 记录全部完成。"""
+        await main_async(_make_args(batch_env))
+        for i in range(5):
+            assert (batch_env["out"] / f"v{i}" / "tree.json").exists()
+
+        assert load_progress(batch_env["progress"]) == {f"v{i}" for i in range(5)}
+
+    @pytest.mark.asyncio
+    async def test_resume_skips_finished(self, batch_env: dict) -> None:
+        """第二次运行跳过全部已完成视频。"""
+        await main_async(_make_args(batch_env))
+        n_first = len(_StubBuilder.instances)
+        await main_async(_make_args(batch_env))
+        assert len(_StubBuilder.instances) == n_first  # 无新建
+
+    @pytest.mark.asyncio
+    async def test_partial_completion_resume(self, batch_env: dict) -> None:
+        """部分完成后重跑只建剩余视频（模拟中断后恢复）。"""
+        batch_env["progress"].write_text(
+            json.dumps({"finished_video_ids": ["v0", "v1"]}),
+            encoding="utf-8",
+        )
+        await main_async(_make_args(batch_env))
+        assert len(_StubBuilder.instances) == 3  # 仅 v2/v3/v4
+
+    @pytest.mark.asyncio
+    async def test_limit(self, batch_env: dict) -> None:
+        """--limit 2 只建前两个（烟测入口）。"""
+        await main_async(_make_args(batch_env, limit=2))
+        assert len(_StubBuilder.instances) == 2