"""基础单元测试：覆盖不依赖外部工具/模型的纯函数。

运行：.venv/bin/python -m pytest tests/ -v
或：.venv/bin/python tests/test_core.py
"""
import hashlib
import os
import tempfile
import unittest

from analysis.hashing import compute_md5
from analysis.motion_filter import merge_motion_windows
from analysis.fall_detector import _find_fall_windows
from analysis.activity_tagger import _merge_labeled_samples
from analysis.ollama_client import _parse_label


class TestHashing(unittest.TestCase):
    def test_compute_md5_matches_hashlib(self):
        with tempfile.NamedTemporaryFile(delete=False) as f:
            f.write(b"hello world" * 1000)
            path = f.name
        try:
            expected = hashlib.md5(b"hello world" * 1000).hexdigest()
            self.assertEqual(compute_md5(path), expected)
        finally:
            os.unlink(path)

    def test_compute_md5_empty_file(self):
        with tempfile.NamedTemporaryFile(delete=False) as f:
            path = f.name
        try:
            self.assertEqual(compute_md5(path), hashlib.md5(b"").hexdigest())
        finally:
            os.unlink(path)


class TestMergeMotionWindows(unittest.TestCase):
    def test_single_window(self):
        flags = [(0.0, True), (0.5, True), (1.0, True)]
        self.assertEqual(merge_motion_windows(flags), [[0.0, 1.0]])

    def test_merge_nearby_windows(self):
        # 两段活动间隔 1.0s < MERGE_GAP 1.5s，应合并
        flags = [(0.0, True), (0.5, True), (2.0, True), (2.5, True)]
        result = merge_motion_windows(flags)
        self.assertEqual(len(result), 1)
        self.assertEqual(result[0], [0.0, 2.5])

    def test_separate_windows(self):
        # 第一段 0-0.5s 活动，中间 1.0-3.5s 无活动（间隔3s > MERGE_GAP 1.5s），第二段 4.0-4.5s 活动
        flags = [(0.0, True), (0.5, True), (1.0, False), (2.0, False),
                 (3.0, False), (3.5, False), (4.0, True), (4.5, True)]
        result = merge_motion_windows(flags)
        self.assertEqual(len(result), 2)

    def test_filter_short_windows(self):
        # 0.3s < MIN_DURATION 0.5s，应被过滤
        flags = [(0.0, True), (0.3, True)]
        self.assertEqual(merge_motion_windows(flags), [])

    def test_empty_input(self):
        self.assertEqual(merge_motion_windows([]), [])


class TestFallDetection(unittest.TestCase):
    def test_upright_to_prone_fast(self):
        # 直立(0s) → 1秒后横躺(1s) → 持续到3s，应检测为摔倒
        states = [(0.0, "upright"), (1.0, "prone"), (2.0, "prone"), (3.0, "prone")]
        windows = _find_fall_windows(states)
        self.assertEqual(len(windows), 1)
        self.assertEqual(windows[0], (1.0, 3.0))

    def test_slow_prone_not_fall(self):
        # 直立(0s) → 3秒后才横躺(3s) > TRANSITION_MAX 1.5s，不是摔倒
        states = [(0.0, "upright"), (3.0, "prone"), (4.0, "prone")]
        self.assertEqual(_find_fall_windows(states), [])

    def test_prone_without_prior_upright(self):
        # 视频开头就是横躺，没有直立前置，不算摔倒
        states = [(0.0, "prone"), (1.0, "prone"), (2.0, "prone")]
        self.assertEqual(_find_fall_windows(states), [])

    def test_prone_too_short(self):
        # 横躺只持续 0.5s < SUSTAIN_MIN 1.0s，不算摔倒
        states = [(0.0, "upright"), (0.5, "prone"), (1.0, "upright")]
        self.assertEqual(_find_fall_windows(states), [])

    def test_unknown_states_ignored(self):
        states = [(0.0, "upright"), (0.5, "unknown"), (1.0, "prone"),
                  (2.0, "prone"), (3.0, "prone")]
        windows = _find_fall_windows(states)
        self.assertEqual(len(windows), 1)


class TestActivityMerge(unittest.TestCase):
    def test_merge_same_label(self):
        samples = [(0.0, "走动", "raw1"), (2.0, "走动", "raw2")]
        segments = _merge_labeled_samples(samples)
        self.assertEqual(len(segments), 1)
        self.assertEqual(segments[0]["label"], "走动")
        self.assertEqual(segments[0]["start"], 0.0)
        self.assertEqual(segments[0]["end"], 2.0)

    def test_different_labels_separate(self):
        samples = [(0.0, "走动", "raw1"), (5.0, "坐下", "raw2")]
        segments = _merge_labeled_samples(samples)
        self.assertEqual(len(segments), 2)

    def test_gap_too_large_separates(self):
        # 间隔 5.0s > MERGE_GAP 3.0s，即使同标签也分开
        samples = [(0.0, "走动", "raw1"), (5.0, "走动", "raw2")]
        segments = _merge_labeled_samples(samples)
        self.assertEqual(len(segments), 2)


class TestOllamaParse(unittest.TestCase):
    def test_exact_label(self):
        self.assertEqual(_parse_label("走动"), "走动")

    def test_label_with_punctuation(self):
        self.assertEqual(_parse_label("走动。"), "走动")

    def test_label_in_sentence(self):
        self.assertEqual(_parse_label("这个人在坐下休息"), "坐下")

    def test_unknown_fallback(self):
        self.assertEqual(_parse_label("xyz 不存在的标签"), "其他")

    def test_empty_string(self):
        self.assertEqual(_parse_label(""), "其他")


if __name__ == "__main__":
    unittest.main()