feat: add asset pool with severity tagging and rotation

tests/test_asset_pool.py

@@ -0,0 +1,112 @@
+from pathlib import Path
+
+from server.asset_pool import AssetPool
+
+
+def _make_pool(tmp_path: Path, max_images: int = 10, max_audio: int = 5) -> AssetPool:
+    return AssetPool(
+        base_dir=str(tmp_path),
+        max_images=max_images,
+        max_audio=max_audio,
+    )
+
+
+def _fake_image(tmp_path: Path, pool: AssetPool, severity: float) -> str:
+    content = b"fake png data"
+    return pool.add_image(content, severity=severity)
+
+
+def _fake_audio(tmp_path: Path, pool: AssetPool, severity: float) -> str:
+    content = b"fake wav data"
+    return pool.add_audio(content, severity=severity)
+
+
+class TestAssetPoolInit:
+    def test_creates_directories(self, tmp_path):
+        """Pool creates img/ and audio/ subdirectories."""
+        pool = _make_pool(tmp_path)
+        assert (tmp_path / "img").is_dir()
+        assert (tmp_path / "audio").is_dir()
+
+    def test_empty_pool(self, tmp_path):
+        """New pool has no assets."""
+        pool = _make_pool(tmp_path)
+        assert pool.image_count == 0
+        assert pool.audio_count == 0
+
+
+class TestAddAssets:
+    def test_add_image(self, tmp_path):
+        """Adding an image increments count and returns a URL path."""
+        pool = _make_pool(tmp_path)
+        url = _fake_image(tmp_path, pool, severity=1.0)
+        assert pool.image_count == 1
+        assert url.startswith("/assets/img/")
+        assert url.endswith(".png")
+
+    def test_add_audio(self, tmp_path):
+        """Adding audio increments count and returns a URL path."""
+        pool = _make_pool(tmp_path)
+        url = _fake_audio(tmp_path, pool, severity=1.0)
+        assert pool.audio_count == 1
+        assert url.startswith("/assets/audio/")
+        assert url.endswith(".wav")
+
+    def test_file_exists_on_disk(self, tmp_path):
+        """Added assets exist as real files."""
+        pool = _make_pool(tmp_path)
+        url = _fake_image(tmp_path, pool, severity=1.0)
+        filename = url.split("/")[-1]
+        assert (tmp_path / "img" / filename).exists()
+
+
+class TestSelectAssets:
+    def test_select_image_by_severity(self, tmp_path):
+        """Selects an image closest to target severity."""
+        pool = _make_pool(tmp_path)
+        _fake_image(tmp_path, pool, severity=0.5)
+        _fake_image(tmp_path, pool, severity=2.0)
+        _fake_image(tmp_path, pool, severity=4.0)
+        url = pool.select_image(target_severity=1.8)
+        assert url is not None
+
+    def test_select_audio_by_severity(self, tmp_path):
+        """Selects an audio clip closest to target severity."""
+        pool = _make_pool(tmp_path)
+        _fake_audio(tmp_path, pool, severity=0.5)
+        _fake_audio(tmp_path, pool, severity=3.0)
+        url = pool.select_audio(target_severity=2.5)
+        assert url is not None
+
+    def test_select_from_empty_returns_none(self, tmp_path):
+        """Selecting from empty pool returns None."""
+        pool = _make_pool(tmp_path)
+        assert pool.select_image(target_severity=1.0) is None
+        assert pool.select_audio(target_severity=1.0) is None
+
+
+class TestRotation:
+    def test_image_rotation(self, tmp_path):
+        """Oldest images are removed when pool exceeds max."""
+        pool = _make_pool(tmp_path, max_images=3)
+        for i in range(5):
+            _fake_image(tmp_path, pool, severity=float(i))
+        assert pool.image_count == 3
+
+    def test_audio_rotation(self, tmp_path):
+        """Oldest audio clips are removed when pool exceeds max."""
+        pool = _make_pool(tmp_path, max_audio=2)
+        for i in range(4):
+            _fake_audio(tmp_path, pool, severity=float(i))
+        assert pool.audio_count == 2
+
+
+class TestStatus:
+    def test_status_dict(self, tmp_path):
+        """Status returns pool sizes."""
+        pool = _make_pool(tmp_path)
+        _fake_image(tmp_path, pool, severity=1.0)
+        _fake_audio(tmp_path, pool, severity=1.0)
+        status = pool.get_status()
+        assert status["image_pool_size"] == 1
+        assert status["audio_pool_size"] == 1