fix: MIDI Rearrange — selected item triggers dedicated tool flow

- midiExtractor.js: extractSelectedMIDIContext with note name conversion - aiGateway.js: REARRANGE_TOOL_SPEC + buildRearrangeMessage - dawCommandDispatcher.js: register REARRANGE_MIDI_MELODY command - app.jsx: handleAISend detects selected MIDI item → rearrange flow - rearrangeMidiMelody handler places A/B track below source track
2026-07-28 10:54:35 +07:00
parent 421535ca0e
commit 2eb327056d
6 changed files with 285 additions and 0 deletions
@@ -0,0 +1,60 @@
+const SonicMidiExtractor = (function() {
+  const NOTE_NAMES = ['C','C#','D','D#','E','F','F#','G','G#','A','A#','B'];
+
+  function midiPitchToNoteName(pitch) {
+    const note = NOTE_NAMES[pitch % 12];
+    const octave = Math.floor(pitch / 12) - 1;
+    return note + octave;
+  }
+
+  function extractSelectedMIDIContext(tracks, selectedItemId, bpm) {
+    let targetItem = null;
+    let targetTrack = null;
+
+    for (const track of tracks) {
+      const items = track.midiItems || [];
+      const item = items.find(i => i.id === selectedItemId);
+      if (item) { targetItem = item; targetTrack = track; break; }
+    }
+
+    if (!targetItem) {
+      throw new Error('Please select a MIDI Item on the Timeline before requesting a Rearrangement!');
+    }
+
+    const notes = targetItem.notes || [];
+    if (notes.length === 0) {
+      throw new Error('Selected MIDI item has no notes to rearrange.');
+    }
+
+    const compactNotes = notes.map(n => ({
+      pitch: n.pitch,
+      note_name: midiPitchToNoteName(n.pitch),
+      start_beat: parseFloat((n.start_beat || 0).toFixed(2)),
+      duration_beats: parseFloat((n.duration_beats || 1).toFixed(2)),
+      velocity: parseFloat((n.velocity || 0.8).toFixed(2))
+    }));
+
+    const totalDurationBeats = compactNotes.reduce((max, n) => Math.max(max, n.start_beat + n.duration_beats), 0);
+
+    return {
+      track_name: targetTrack.name,
+      track_id: targetTrack.id,
+      item_id: targetItem.id,
+      item_name: targetItem.name,
+      duration_bars: targetItem.length_bars || Math.ceil(totalDurationBeats / 4),
+      total_beats: Math.ceil(totalDurationBeats),
+      bpm: parseInt(bpm || '120'),
+      total_notes: compactNotes.length,
+      notes: compactNotes,
+      instrument: targetTrack.synth_engine ? {
+        soundfont_id: targetTrack.synth_engine.soundfont_id || '',
+        soundfont_bank: targetTrack.synth_engine.soundfont_bank ?? 0,
+        soundfont_program: targetTrack.synth_engine.soundfont_program ?? 0
+      } : null
+    };
+  }
+
+  return { extractSelectedMIDIContext, midiPitchToNoteName };
+})();
+
+window.SonicMidiExtractor = SonicMidiExtractor;