feat: implement global chord track

src/core/commands/global-region/CreateChordRegionCommand.ts

@@ -0,0 +1,68 @@
+import { KGCommand } from '../KGCommand';
+import { KGCore } from '../../KGCore';
+import { GlobalTrackType } from '../../global-track';
+import { KGChordRegion } from '../../region/KGChordRegion';
+import { generateUniqueId } from '../../../util/miscUtil';
+import { findGlobalTrackByType, findNonOverlappingNeighborBounds, getSongEndBeat } from '../../../util/globalTrackUtil';
+
+export class CreateChordRegionCommand extends KGCommand {
+  private readonly startBeat: number;
+  private readonly preferredLength: number;
+  private readonly symbol: string;
+  private readonly regionId: string;
+  private createdRegion: KGChordRegion | null = null;
+
+  constructor(startBeat: number, preferredLength: number, symbol: string = 'C', regionId?: string) {
+    super();
+    this.startBeat = startBeat;
+    this.preferredLength = preferredLength;
+    this.symbol = symbol;
+    this.regionId = regionId ?? generateUniqueId('KGChordRegion');
+  }
+
+  execute(): void {
+    const project = KGCore.instance().getCurrentProject();
+    const chordTrack = findGlobalTrackByType(project, GlobalTrackType.Chord);
+    if (!chordTrack) {
+      throw new Error('Chord global track not found');
+    }
+
+    const { maxEndBeat } = findNonOverlappingNeighborBounds(project, GlobalTrackType.Chord, null, this.startBeat);
+    const songEndBeat = getSongEndBeat(project);
+    const allowedEndBeat = Math.min(maxEndBeat, songEndBeat);
+    const targetEndBeat = Math.min(this.startBeat + this.preferredLength, allowedEndBeat);
+    const length = Math.max(1, targetEndBeat - this.startBeat);
+
+    this.createdRegion = new KGChordRegion(
+      this.regionId,
+      chordTrack.getId(),
+      chordTrack.getTrackIndex(),
+      this.symbol,
+      this.startBeat,
+      length
+    );
+
+    chordTrack.setRegions(
+      [...chordTrack.getRegions(), this.createdRegion]
+        .sort((left, right) => left.getStartFromBeat() - right.getStartFromBeat())
+    );
+  }
+
+  undo(): void {
+    const project = KGCore.instance().getCurrentProject();
+    const chordTrack = findGlobalTrackByType(project, GlobalTrackType.Chord);
+    if (!chordTrack) {
+      throw new Error('Chord global track not found during undo');
+    }
+
+    chordTrack.removeRegion(this.regionId);
+  }
+
+  getDescription(): string {
+    return `Create chord "${this.symbol}"`;
+  }
+
+  public getCreatedRegion(): KGChordRegion | null {
+    return this.createdRegion;
+  }
+}

src/core/commands/global-region/DeleteGlobalRegionCommand.ts

@@ -49,7 +49,7 @@ export class DeleteGlobalRegionCommand extends KGCommand {
   }
 
   getDescription(): string {
-    return `Delete marker "${this.deletedRegion?.getName() ?? this.regionId}"`;
+    return `Delete global region "${this.deletedRegion?.getName() ?? this.regionId}"`;
   }
 }
 
@@ -104,6 +104,6 @@ export class DeleteMultipleGlobalRegionsCommand extends KGCommand {
   }
 
   getDescription(): string {
-    return this.regionIds.length === 1 ? 'Delete marker' : `Delete ${this.regionIds.length} markers`;
+    return this.regionIds.length === 1 ? 'Delete global region' : `Delete ${this.regionIds.length} global regions`;
   }
 }

src/core/commands/global-region/GlobalChordCommands.test.ts

@@ -0,0 +1,107 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { KGCore } from '../../KGCore';
+import { KGProject } from '../../KGProject';
+import { GlobalTrackType } from '../../global-track';
+import { KGChordRegion } from '../../region/KGChordRegion';
+import { CreateChordRegionCommand } from './CreateChordRegionCommand';
+import { InsertChordRegionAtBeatCommand } from './InsertChordRegionAtBeatCommand';
+import { MoveGlobalRegionCommand } from './MoveGlobalRegionCommand';
+import { ResizeGlobalRegionCommand } from './ResizeGlobalRegionCommand';
+import { UpdateChordRegionCommand } from './UpdateChordRegionCommand';
+
+describe('global chord region commands', () => {
+  beforeEach(() => {
+    const project = new KGProject('Chords', 8, 0, 120);
+    const mockCore = KGCore.instance() as unknown as {
+      getCurrentProject: ReturnType<typeof vi.fn>;
+      getSelectedItems: ReturnType<typeof vi.fn>;
+      removeSelectedItem?: ReturnType<typeof vi.fn>;
+    };
+
+    mockCore.getCurrentProject.mockReturnValue(project);
+    mockCore.getSelectedItems.mockReturnValue([]);
+    if (!mockCore.removeSelectedItem) {
+      mockCore.removeSelectedItem = vi.fn();
+    } else {
+      mockCore.removeSelectedItem.mockReset();
+    }
+  });
+
+  const getChordTrack = () => {
+    const chordTrack = KGCore.instance().getCurrentProject().getGlobalTracks()
+      .find(track => track.getType() === GlobalTrackType.Chord);
+
+    if (!chordTrack) {
+      throw new Error('Chord track missing in test setup');
+    }
+
+    return chordTrack;
+  };
+
+  it('creates a chord region with a default one-bar length clamped by the next region', () => {
+    const chordTrack = getChordTrack();
+    chordTrack.addRegion(new KGChordRegion('existing', chordTrack.getId(), chordTrack.getTrackIndex(), 'Fmaj7', 6, 2));
+
+    const command = new CreateChordRegionCommand(4, 4, 'Cmaj7');
+    command.execute();
+
+    const created = command.getCreatedRegion();
+    expect(created?.getStartFromBeat()).toBe(4);
+    expect(created?.getLength()).toBe(2);
+  });
+
+  it('moves and resizes chord regions with beat snapping and no overlap', () => {
+    const chordTrack = getChordTrack();
+    const region = new KGChordRegion('middle', chordTrack.getId(), chordTrack.getTrackIndex(), 'Dm7', 4, 2);
+    chordTrack.setRegions([
+      new KGChordRegion('left', chordTrack.getId(), chordTrack.getTrackIndex(), 'C', 0, 4),
+      region,
+      new KGChordRegion('right', chordTrack.getId(), chordTrack.getTrackIndex(), 'G7', 10, 2),
+    ]);
+
+    const moveCommand = new MoveGlobalRegionCommand('middle', 9);
+    moveCommand.execute();
+    expect(region.getStartFromBeat()).toBe(8);
+
+    const resizeCommand = new ResizeGlobalRegionCommand('middle', 'end', 12);
+    resizeCommand.execute();
+    expect(region.getLength()).toBe(2);
+
+    const resizeMinCommand = new ResizeGlobalRegionCommand('middle', 'start', 9);
+    resizeMinCommand.execute();
+    expect(region.getStartFromBeat()).toBe(9);
+    expect(region.getLength()).toBe(1);
+  });
+
+  it('updates chord symbols with undo support', () => {
+    const chordTrack = getChordTrack();
+    const region = new KGChordRegion('chord', chordTrack.getId(), chordTrack.getTrackIndex(), 'C', 0, 4);
+    chordTrack.setRegions([region]);
+
+    const command = new UpdateChordRegionCommand('chord', 'Bm7b5');
+    command.execute();
+    expect(region.getSymbol()).toBe('Bm7b5');
+
+    command.undo();
+    expect(region.getSymbol()).toBe('C');
+  });
+
+  it('inserts a new chord inside an existing region and shortens the original', () => {
+    const chordTrack = getChordTrack();
+    const region = new KGChordRegion('chord', chordTrack.getId(), chordTrack.getTrackIndex(), 'Am', 0, 8);
+    chordTrack.setRegions([region]);
+
+    const command = new InsertChordRegionAtBeatCommand(3, 'C');
+    command.execute();
+
+    const created = command.getCreatedRegion();
+    expect(created).not.toBeNull();
+    expect(region.getLength()).toBe(3);
+    expect(created?.getStartFromBeat()).toBe(3);
+    expect(created?.getLength()).toBe(5);
+
+    command.undo();
+    expect(chordTrack.getRegions()).toHaveLength(1);
+    expect(region.getLength()).toBe(8);
+  });
+});

src/core/commands/global-region/InsertChordRegionAtBeatCommand.ts

@@ -0,0 +1,86 @@
+import { KGCommand } from '../KGCommand';
+import { KGCore } from '../../KGCore';
+import { GlobalTrackType } from '../../global-track';
+import { KGChordRegion } from '../../region/KGChordRegion';
+import { generateUniqueId } from '../../../util/miscUtil';
+import { findChordRegionAtBeat, findGlobalTrackByType } from '../../../util/globalTrackUtil';
+
+export class InsertChordRegionAtBeatCommand extends KGCommand {
+  private readonly insertBeat: number;
+  private readonly symbol: string;
+  private readonly regionId: string;
+  private createdRegion: KGChordRegion | null = null;
+  private targetRegionId: string | null = null;
+  private originalTargetLength = 0;
+
+  constructor(insertBeat: number, symbol: string = 'C', regionId?: string) {
+    super();
+    this.insertBeat = insertBeat;
+    this.symbol = symbol;
+    this.regionId = regionId ?? generateUniqueId('KGChordRegion');
+  }
+
+  execute(): void {
+    const project = KGCore.instance().getCurrentProject();
+    const chordTrack = findGlobalTrackByType(project, GlobalTrackType.Chord);
+    if (!chordTrack) {
+      throw new Error('Chord global track not found');
+    }
+
+    const occupiedRegion = findChordRegionAtBeat(project, this.insertBeat);
+    if (!occupiedRegion) {
+      throw new Error(`No chord region found at beat ${this.insertBeat}`);
+    }
+
+    const regionStart = occupiedRegion.getStartFromBeat();
+    const regionEnd = regionStart + occupiedRegion.getLength();
+    if (this.insertBeat <= regionStart || this.insertBeat >= regionEnd) {
+      throw new Error(`Cannot insert chord at beat ${this.insertBeat} without shrinking region below minimum length`);
+    }
+
+    this.targetRegionId = occupiedRegion.getId();
+    this.originalTargetLength = occupiedRegion.getLength();
+    occupiedRegion.setLength(this.insertBeat - regionStart);
+
+    this.createdRegion = new KGChordRegion(
+      this.regionId,
+      chordTrack.getId(),
+      chordTrack.getTrackIndex(),
+      this.symbol,
+      this.insertBeat,
+      regionEnd - this.insertBeat
+    );
+
+    chordTrack.setRegions(
+      [...chordTrack.getRegions(), this.createdRegion]
+        .sort((left, right) => left.getStartFromBeat() - right.getStartFromBeat())
+    );
+  }
+
+  undo(): void {
+    const project = KGCore.instance().getCurrentProject();
+    const chordTrack = findGlobalTrackByType(project, GlobalTrackType.Chord);
+    if (!chordTrack || !this.targetRegionId || !this.createdRegion) {
+      throw new Error('Cannot undo inserted chord region');
+    }
+
+    chordTrack.removeRegion(this.createdRegion.getId());
+    const targetRegion = chordTrack.getRegions().find((region): region is KGChordRegion => (
+      region instanceof KGChordRegion && region.getId() === this.targetRegionId
+    ));
+    if (!targetRegion) {
+      throw new Error(`Chord region ${this.targetRegionId} not found during undo`);
+    }
+
+    targetRegion.setLength(this.originalTargetLength);
+    chordTrack.setRegions([...chordTrack.getRegions()].sort((left, right) => left.getStartFromBeat() - right.getStartFromBeat()));
+  }
+
+  getDescription(): string {
+    return `Insert chord "${this.symbol}"`;
+  }
+
+  public getCreatedRegion(): KGChordRegion | null {
+    return this.createdRegion;
+  }
+}

src/core/commands/global-region/MoveGlobalRegionCommand.ts

@@ -2,7 +2,7 @@ import { KGCommand } from '../KGCommand';
 import { KGCore } from '../../KGCore';
 import { KGGlobalRegion } from '../../region/KGGlobalRegion';
 import { GlobalTrackType } from '../../global-track';
-import { findGlobalTrackContainingRegion, findMarkerNeighborBounds } from '../../../util/globalTrackUtil';
+import { findGlobalTrackContainingRegion, findNonOverlappingNeighborBounds } from '../../../util/globalTrackUtil';
 
 export class MoveGlobalRegionCommand extends KGCommand {
   private readonly regionId: string;
@@ -26,12 +26,17 @@ export class MoveGlobalRegionCommand extends KGCommand {
     this.targetRegion = result.region;
     this.originalStartBeat = result.region.getStartFromBeat();
 
-    if (result.track.getType() !== GlobalTrackType.Marker) {
+    if (result.track.getType() !== GlobalTrackType.Marker && result.track.getType() !== GlobalTrackType.Chord) {
       result.region.setStartFromBeat(this.desiredStartBeat);
       return;
     }
 
-    const { minStartBeat, maxEndBeat } = findMarkerNeighborBounds(project, this.regionId, this.desiredStartBeat);
+    const { minStartBeat, maxEndBeat } = findNonOverlappingNeighborBounds(
+      project,
+      result.track.getType() as GlobalTrackType.Marker | GlobalTrackType.Chord,
+      this.regionId,
+      this.desiredStartBeat
+    );
     const maxStartBeat = Math.max(minStartBeat, maxEndBeat - result.region.getLength());
     const clampedStartBeat = Math.max(minStartBeat, Math.min(this.desiredStartBeat, maxStartBeat));
     result.region.setStartFromBeat(clampedStartBeat);

src/core/commands/global-region/ResizeGlobalRegionCommand.ts

@@ -1,7 +1,7 @@
 import { KGCommand } from '../KGCommand';
 import { KGCore } from '../../KGCore';
 import { GlobalTrackType } from '../../global-track';
-import { findGlobalTrackContainingRegion, findMarkerNeighborBounds, getSongEndBeat } from '../../../util/globalTrackUtil';
+import { findGlobalTrackContainingRegion, findNonOverlappingNeighborBounds, getSongEndBeat } from '../../../util/globalTrackUtil';
 import { KGGlobalRegion } from '../../region/KGGlobalRegion';
 
 export type GlobalRegionResizeEdge = 'start' | 'end';
@@ -32,12 +32,17 @@ export class ResizeGlobalRegionCommand extends KGCommand {
     this.originalStartBeat = result.region.getStartFromBeat();
     this.originalLength = result.region.getLength();
 
-    if (result.track.getType() !== GlobalTrackType.Marker) {
+    if (result.track.getType() !== GlobalTrackType.Marker && result.track.getType() !== GlobalTrackType.Chord) {
       return;
     }
 
     const originalEndBeat = this.originalStartBeat + this.originalLength;
-    const { minStartBeat, maxEndBeat } = findMarkerNeighborBounds(project, this.regionId, this.originalStartBeat);
+    const { minStartBeat, maxEndBeat } = findNonOverlappingNeighborBounds(
+      project,
+      result.track.getType() as GlobalTrackType.Marker | GlobalTrackType.Chord,
+      this.regionId,
+      this.originalStartBeat
+    );
     const songEndBeat = getSongEndBeat(project);
     const absoluteMaxEndBeat = Math.min(maxEndBeat, songEndBeat);
 

src/core/commands/global-region/UpdateChordRegionCommand.ts

@@ -0,0 +1,39 @@
+import { KGCommand } from '../KGCommand';
+import { KGCore } from '../../KGCore';
+import { findGlobalTrackContainingRegion } from '../../../util/globalTrackUtil';
+import { KGChordRegion } from '../../region/KGChordRegion';
+
+export class UpdateChordRegionCommand extends KGCommand {
+  private readonly regionId: string;
+  private readonly nextSymbol: string;
+  private previousSymbol: string | null = null;
+
+  constructor(regionId: string, nextSymbol: string) {
+    super();
+    this.regionId = regionId;
+    this.nextSymbol = nextSymbol;
+  }
+
+  execute(): void {
+    const result = findGlobalTrackContainingRegion(KGCore.instance().getCurrentProject(), this.regionId);
+    if (!result || !(result.region instanceof KGChordRegion)) {
+      throw new Error(`Chord region with ID ${this.regionId} not found`);
+    }
+
+    this.previousSymbol = result.region.getSymbol();
+    result.region.setSymbol(this.nextSymbol);
+  }
+
+  undo(): void {
+    const result = findGlobalTrackContainingRegion(KGCore.instance().getCurrentProject(), this.regionId);
+    if (!result || !(result.region instanceof KGChordRegion) || this.previousSymbol === null) {
+      throw new Error(`Chord region with ID ${this.regionId} not found during undo`);
+    }
+
+    result.region.setSymbol(this.previousSymbol);
+  }
+
+  getDescription(): string {
+    return `Change chord to "${this.nextSymbol}"`;
+  }
+}

src/core/commands/index.ts

@@ -36,6 +36,8 @@ export { MergeMidiRegionsCommand } from './region/MergeMidiRegionsCommand';
 
 // Global region commands
 export { CreateGlobalMarkerRegionCommand } from './global-region/CreateGlobalMarkerRegionCommand';
+export { CreateChordRegionCommand } from './global-region/CreateChordRegionCommand';
+export { InsertChordRegionAtBeatCommand } from './global-region/InsertChordRegionAtBeatCommand';
 export { CreateKeySignatureRegionCommand } from './global-region/CreateKeySignatureRegionCommand';
 export { CreateTempoRegionCommand } from './global-region/CreateTempoRegionCommand';
 export { MoveGlobalRegionCommand } from './global-region/MoveGlobalRegionCommand';
@@ -44,6 +46,7 @@ export { ResizeKeySignatureRegionCommand } from './global-region/ResizeKeySignat
 export { ResizeTempoRegionCommand } from './global-region/ResizeTempoRegionCommand';
 export { DeleteGlobalRegionCommand, DeleteMultipleGlobalRegionsCommand } from './global-region/DeleteGlobalRegionCommand';
 export { UpdateGlobalRegionTextCommand } from './global-region/UpdateGlobalRegionTextCommand';
+export { UpdateChordRegionCommand } from './global-region/UpdateChordRegionCommand';
 export { DeleteKeySignatureRegionCommand, DeleteMultipleKeySignatureRegionsCommand } from './global-region/DeleteKeySignatureRegionCommand';
 export { UpdateKeySignatureRegionCommand } from './global-region/UpdateKeySignatureRegionCommand';
 export { DeleteTempoRegionCommand, DeleteMultipleTempoRegionsCommand } from './global-region/DeleteTempoRegionCommand';