feat: separate preset banks per channel (guitar/bass)

- Channel enum (GUITAR, BASS) with channel field on Preset dataclass - Channel-prefixed storage: {root}/{channel}/bank_{bank}/preset_{program}.json - PresetManager channel awareness: set_channel(), current_channel property - Per-channel state persistence (channel_state.json per channel dir) - Legacy migration: flat bank_* dirs auto-migrate to guitar/ on first boot - All CRUD methods accept optional channel parameter - API endpoints accept channel param on GET/PUT/DELETE /api/presets - /api/channel GET/POST for channel switching - 10 new channel tests (independence, switching, migration, scoping) - Factory presets install to specified channel
2026-06-12 23:22:47 -04:00
parent 0a21297f77
commit bfe1434f75
10 changed files with 1100 additions and 352 deletions
@@ -27,7 +27,7 @@ from src.presets.manager import (
    _preset_from_dict,
    _preset_to_dict,
 )
-from src.presets.types import FXBlock, FXType, MIDIMapping, Preset
+from src.presets.types import Channel, FXBlock, FXType, MIDIMapping, Preset


 # ── Fixtures ────────────────────────────────────────────────────────────────
@@ -152,7 +152,7 @@ class TestSaveLoad:

    def test_save_creates_json_file(self, manager: PresetManager, sample_preset: Preset, preset_dir: Path):
        manager.save(sample_preset)
-        path = preset_dir / "bank_0" / "preset_0.json"
+        path = preset_dir / "guitar" / "bank_0" / "preset_0.json"
        assert path.exists()
        content = path.read_text(encoding="utf-8")
        assert "Crunch Rhythm" in content
@@ -513,8 +513,152 @@ class TestEdgeCases:
        assert manager.current_program == 1

    def test_corrupted_json_raises(self, manager: PresetManager, preset_dir: Path):
-        path = preset_dir / "bank_0" / "preset_0.json"
+        path = preset_dir / "guitar" / "bank_0" / "preset_0.json"
        path.parent.mkdir(parents=True)
        path.write_text("not valid json", encoding="utf-8")
        with pytest.raises(json.JSONDecodeError):
-            manager.load(0, 0)
+            manager.load(0, 0)
+
+
+# ── Channel independence ────────────────────────────────────────────────
+
+
+class TestChannelIndependence:
+    """Guitar and bass channels each have their own preset bank namespace."""
+
+    def test_channel_serialization_round_trip(self):
+        """Channel field survives to_dict / from_dict."""
+        p = Preset(name="GTR Lead", channel=Channel.GUITAR, bank=0, program=0)
+        d = _preset_to_dict(p)
+        assert d["channel"] == "guitar"
+        restored = _preset_from_dict(d)
+        assert restored.channel == Channel.GUITAR
+
+        p2 = Preset(name="Bass Slap", channel=Channel.BASS, bank=0, program=0)
+        d2 = _preset_to_dict(p2)
+        assert d2["channel"] == "bass"
+        restored2 = _preset_from_dict(d2)
+        assert restored2.channel == Channel.BASS
+
+    def test_channel_defaults_to_guitar(self):
+        """Presets without explicit channel default to guitar."""
+        p = Preset(name="Default", bank=0, program=0)
+        assert p.channel == Channel.GUITAR
+
+    def test_guitar_and_bass_independent_banks(self, manager: PresetManager):
+        """Guitar and bass presets in the same (bank, program) don't collide."""
+        gtr = Preset(name="GTR Crunch", channel=Channel.GUITAR, bank=0, program=0)
+        bass = Preset(name="Bass Slap", channel=Channel.BASS, bank=0, program=0)
+
+        # Save guitar via current channel (defaults to guitar)
+        manager.save(gtr)
+        # Save bass explicitly
+        manager.save(bass, channel=Channel.BASS)
+
+        # Load guitar
+        loaded_gtr = manager.load(0, 0, Channel.GUITAR)
+        assert loaded_gtr.name == "GTR Crunch"
+        assert loaded_gtr.channel == Channel.GUITAR
+
+        # Load bass
+        loaded_bass = manager.load(0, 0, Channel.BASS)
+        assert loaded_bass.name == "Bass Slap"
+        assert loaded_bass.channel == Channel.BASS
+
+    def test_channel_switch_restores_preset(self, manager: PresetManager):
+        """Switching channels restores the last active state for that channel."""
+        manager.save(Preset(name="GTR Lead", channel=Channel.GUITAR, bank=0, program=0))
+        manager.save(Preset(name="GTR Clean", channel=Channel.GUITAR, bank=0, program=1))
+        manager.save(Preset(name="Bass Slap", channel=Channel.BASS, bank=1, program=2))
+
+        # Select guitar preset (bank=0, program=1)
+        manager.select(0, 1, Channel.GUITAR)
+
+        # Select bass preset so its channel state is saved
+        manager.select(1, 2, Channel.BASS)
+
+        # Switch to guitar — should go to (0, 1)
+        manager.set_channel(Channel.GUITAR)
+        assert manager.current_channel == Channel.GUITAR
+        assert manager.current_bank == 0
+        assert manager.current_program == 1
+
+        # Switch back to bass — should restore (1, 2)
+        manager.set_channel(Channel.BASS)
+        assert manager.current_channel == Channel.BASS
+        assert manager.current_bank == 1
+        assert manager.current_program == 2
+
+    def test_set_same_channel_noop(self, manager: PresetManager):
+        """set_channel to the same channel preserves current position."""
+        manager.save(Preset(name="Only", channel=Channel.GUITAR, bank=0, program=2))
+        manager.select(0, 2, Channel.GUITAR)
+        result = manager.set_channel(Channel.GUITAR)
+        assert result.name == "Only"
+        assert manager.current_bank == 0
+        assert manager.current_program == 2
+
+    def test_current_channel_property(self, manager: PresetManager):
+        """current_channel returns the active channel."""
+        assert manager.current_channel == Channel.GUITAR
+        manager.set_channel(Channel.BASS)
+        assert manager.current_channel == Channel.BASS
+        manager.set_channel(Channel.GUITAR)
+        assert manager.current_channel == Channel.GUITAR
+
+    def test_list_banks_channel_scoped(self, manager: PresetManager):
+        """list_banks only returns banks for the specified channel."""
+        manager.save(Preset(name="GTR_A", channel=Channel.GUITAR, bank=0, program=0))
+        manager.save(Preset(name="BASS_A", channel=Channel.BASS, bank=5, program=0))
+
+        gtr_banks = manager.list_banks(Channel.GUITAR)
+        assert len(gtr_banks) == 1
+        assert gtr_banks[0].number == 0
+
+        bass_banks = manager.list_banks(Channel.BASS)
+        assert len(bass_banks) == 1
+        assert bass_banks[0].number == 5
+
+    def test_migrate_legacy_presets(self, tmp_path: Path):
+        """Legacy flat bank_* dirs are migrated to guitar/ on first boot."""
+        # Create legacy layout: bank_0/preset_0.json at root
+        legacy_bank = tmp_path / "bank_0"
+        legacy_bank.mkdir()
+        (legacy_bank / "preset_0.json").write_text(
+            json.dumps({"name": "Legacy Tone", "bank": 0, "program": 0}),
+            encoding="utf-8",
+        )
+
+        # Create PresetManager — should migrate
+        pm = PresetManager(preset_dir=str(tmp_path), audio_pipeline=None)
+
+        # Old location should be gone
+        assert not (tmp_path / "bank_0").exists()
+
+        # New location should exist
+        guitar_path = tmp_path / "guitar" / "bank_0" / "preset_0.json"
+        assert guitar_path.exists()
+
+        # Preset should be loadable from guitar channel
+        preset = pm.load(0, 0, Channel.GUITAR)
+        assert preset.name == "Legacy Tone"
+
+    def test_migration_skips_when_already_migrated(self, tmp_path: Path):
+        """Migration doesn't run if guitar/ dir already exists."""
+        guitar_dir = tmp_path / "guitar"
+        guitar_dir.mkdir(parents=True)
+        (guitar_dir / "bank_0").mkdir()
+        (guitar_dir / "bank_0" / "preset_0.json").write_text(
+            json.dumps({"name": "Already Migrated", "channel": "guitar", "bank": 0, "program": 0}),
+            encoding="utf-8",
+        )
+
+        pm = PresetManager(preset_dir=str(tmp_path), audio_pipeline=None)
+        preset = pm.load(0, 0, Channel.GUITAR)
+        assert preset.name == "Already Migrated"
+
+    def test_fresh_install_no_migration(self, tmp_path: Path):
+        """Fresh install with no files doesn't raise or create guitar dir."""
+        pm = PresetManager(preset_dir=str(tmp_path), audio_pipeline=None)
+        assert not (tmp_path / "guitar").exists()
+        assert pm.list_banks() == []