"""tools/build_trees.py 单元测试。

覆盖纯函数（完整性校验、待建清单发现、SRT 查找）与编排集成（Task 3 追加）。
"""

from __future__ import annotations

import sys
from pathlib import Path

PROJECT_ROOT = Path(__file__).resolve().parent.parent.parent
if str(PROJECT_ROOT) not in sys.path:
    sys.path.insert(0, str(PROJECT_ROOT))

from app.tree.index import IndexMeta, L1Card, L1Node, TreeIndex  # noqa: E402
from tools.build_trees import (  # noqa: E402
    _discover_pending,
    _find_srt_entries,
    _tree_is_complete,
)


def _write_valid_tree(tree_path: Path) -> None:
    """写入一棵最小合法树。"""
    l1 = L1Node(
        id="vid_L1_000",
        card=L1Card("场景", "室内", ["实体"], ["动作"], ["关键词"], [], "线性"),
        time_range=(0.0, 10.0),
        children=[],
    )
    index = TreeIndex(metadata=IndexMeta("/v.mp4", "video"), roots=[l1])
    tree_path.parent.mkdir(parents=True, exist_ok=True)
    index.save_json(str(tree_path))


class TestTreeIsComplete:
    """_tree_is_complete 测试。"""

    def test_valid_tree(self, tmp_path: Path) -> None:
        """合法 tree.json 判定完整。"""
        tree_path = tmp_path / "vid" / "tree.json"
        _write_valid_tree(tree_path)
        assert _tree_is_complete(tree_path) is True

    def test_missing_file(self, tmp_path: Path) -> None:
        """文件不存在判定不完整。"""
        assert _tree_is_complete(tmp_path / "nope" / "tree.json") is False

    def test_corrupt_json(self, tmp_path: Path) -> None:
        """损坏 JSON 判定不完整（不抛异常）。"""
        p = tmp_path / "vid" / "tree.json"
        p.parent.mkdir(parents=True)
        p.write_text("{broken", encoding="utf-8")
        assert _tree_is_complete(p) is False


class TestDiscoverPending:
    """_discover_pending 测试。"""

    def _touch_videos(self, videos_dir: Path, names: list[str]) -> None:
        videos_dir.mkdir(parents=True, exist_ok=True)
        for n in names:
            (videos_dir / n).write_bytes(b"")

    def test_all_pending_when_fresh(self, tmp_path: Path) -> None:
        """无进度无产物时全部待建，按名排序。"""
        videos = tmp_path / "videos"
        self._touch_videos(videos, ["b.mp4", "a.mkv", "c.txt"])
        pending = _discover_pending(videos, tmp_path / "out", set())
        assert [p.name for p in pending] == ["a.mkv", "b.mp4"]  # 非视频扩展名被忽略

    def test_skips_finished_and_complete(self, tmp_path: Path) -> None:
        """progress 已记录或 tree.json 完整的视频被跳过。"""
        videos = tmp_path / "videos"
        out = tmp_path / "out"
        self._touch_videos(videos, ["a.mp4", "b.mp4", "c.mp4"])
        _write_valid_tree(out / "b" / "tree.json")  # b 已有完整树
        pending = _discover_pending(videos, out, {"a"})  # a 在 progress 中
        assert [p.name for p in pending] == ["c.mp4"]

    def test_incomplete_tree_not_skipped(self, tmp_path: Path) -> None:
        """tree.json 损坏的视频仍待建（重建覆盖）。"""
        videos = tmp_path / "videos"
        out = tmp_path / "out"
        self._touch_videos(videos, ["a.mp4"])
        (out / "a").mkdir(parents=True)
        (out / "a" / "tree.json").write_text("{broken", encoding="utf-8")
        pending = _discover_pending(videos, out, set())
        assert [p.name for p in pending] == ["a.mp4"]


class TestFindSrtEntries:
    """_find_srt_entries 测试。"""

    def test_found(self, tmp_path: Path) -> None:
        """同名 .srt 存在时解析返回条目。"""
        srt = tmp_path / "vid.srt"
        srt.write_text(
            "1\n00:00:01,000 --> 00:00:03,000\nhello world\n\n",
            encoding="utf-8",
        )
        entries = _find_srt_entries(tmp_path / "vid.mp4", tmp_path)
        assert entries is not None
        assert len(entries) == 1

    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