5 files changed, 115 insertions, 7 deletions

diff --git a/apps/web/src/core/managers/audio-manager.ts b/apps/web/src/core/managers/audio-manager.ts
index 3a83be48..457e49d6 100644
--- a/apps/web/src/core/managers/audio-manager.ts
+++ b/apps/web/src/core/managers/audio-manager.ts
@@ -125,7 +125,8 @@ export class AudioManager {
 
 	private getPlaybackTime(): number {
 		if (!this.audioContext) return this.playbackStartTime;
-		const elapsed = this.audioContext.currentTime - this.playbackStartContextTime;
+		const elapsed =
+			this.audioContext.currentTime - this.playbackStartContextTime;
 		return this.playbackStartTime + elapsed;
 	}
 
@@ -176,7 +177,11 @@ export class AudioManager {
 			if (clip.startTime > windowEnd) continue;
 
 			this.activeClipIds.add(clip.id);
-			void this.runClipIterator({ clip, startTime: currentTime, sessionId: this.playbackSessionId });
+			void this.runClipIterator({
+				clip,
+				startTime: currentTime,
+				sessionId: this.playbackSessionId,
+			});
 		}
 	}
 
@@ -239,8 +244,7 @@ export class AudioManager {
 			node.connect(this.masterGain ?? audioContext.destination);
 
 			const startTimestamp =
-				this.playbackStartContextTime +
-				(timelineTime - this.playbackStartTime);
+				this.playbackStartContextTime + (timelineTime - this.playbackStartTime);
 
 			if (startTimestamp >= audioContext.currentTime) {
 				node.start(startTimestamp);
diff --git a/apps/web/src/core/managers/commands.ts b/apps/web/src/core/managers/commands.ts
index d996a30e..46ee643a 100644
--- a/apps/web/src/core/managers/commands.ts
+++ b/apps/web/src/core/managers/commands.ts
@@ -11,6 +11,11 @@ export class CommandManager {
 		return command;
 	}
 
+	push({ command }: { command: Command }): void {
+		this.history.push(command);
+		this.redoStack = [];
+	}
+
 	undo(): void {
 		if (this.history.length === 0) return;
 		const command = this.history.pop();
diff --git a/apps/web/src/core/managers/project-manager.ts b/apps/web/src/core/managers/project-manager.ts
index c7497ef0..2608b8c0 100644
--- a/apps/web/src/core/managers/project-manager.ts
+++ b/apps/web/src/core/managers/project-manager.ts
@@ -27,6 +27,8 @@ import {
 	type MigrationProgress,
 } from "@/services/storage/migrations";
 import { DEFAULT_TIMELINE_VIEW_STATE } from "@/constants/timeline-constants";
+import { loadFonts } from "@/lib/fonts/google-fonts";
+import { collectFontFamilies } from "@/lib/timeline/element-utils";
 
 export interface MigrationState {
 	isMigrating: boolean;
@@ -146,6 +148,9 @@ export class ProjectManager {
 
 			await this.editor.media.loadProjectMedia({ projectId: id });
 
+			const allTracks = (project.scenes ?? []).flatMap((scene) => scene.tracks);
+			await loadFonts({ families: collectFontFamilies({ tracks: allTracks }) });
+
 			if (!project.metadata.thumbnail) {
 				const didUpdateThumbnail = await this.updateThumbnailFromTimeline();
 				if (didUpdateThumbnail) {
diff --git a/apps/web/src/core/managers/scenes-manager.ts b/apps/web/src/core/managers/scenes-manager.ts
index 8c761f9b..c844f448 100644
--- a/apps/web/src/core/managers/scenes-manager.ts
+++ b/apps/web/src/core/managers/scenes-manager.ts
@@ -7,14 +7,20 @@ import {
 	canDeleteScene,
 	findCurrentScene,
 } from "@/lib/scenes";
-import { getFrameTime, isBookmarkAtTime } from "@/lib/timeline/bookmarks";
+import {
+	getBookmarkAtTime,
+	getFrameTime,
+	isBookmarkAtTime,
+} from "@/lib/timeline/bookmarks";
 import { ensureMainTrack } from "@/lib/timeline/track-utils";
 import {
 	CreateSceneCommand,
 	DeleteSceneCommand,
+	MoveBookmarkCommand,
 	RemoveBookmarkCommand,
 	RenameSceneCommand,
 	ToggleBookmarkCommand,
+	UpdateBookmarkCommand,
 } from "@/lib/commands/scene";
 
 export class ScenesManager {
@@ -125,6 +131,45 @@ export class ScenesManager {
 		this.editor.command.execute({ command });
 	}
 
+	async updateBookmark({
+		time,
+		updates,
+	}: {
+		time: number;
+		updates: Partial<{ note: string; color: string; duration: number }>;
+	}): Promise<void> {
+		const command = new UpdateBookmarkCommand(time, updates);
+		this.editor.command.execute({ command });
+	}
+
+	async moveBookmark({
+		fromTime,
+		toTime,
+	}: {
+		fromTime: number;
+		toTime: number;
+	}): Promise<void> {
+		const command = new MoveBookmarkCommand(fromTime, toTime);
+		this.editor.command.execute({ command });
+	}
+
+	getBookmarkAtTime({ time }: { time: number }) {
+		const activeScene = this.active;
+		const activeProject = this.editor.project.getActive();
+
+		if (!activeScene || !activeProject) return null;
+
+		const frameTime = getFrameTime({
+			time,
+			fps: activeProject.settings.fps,
+		});
+
+		return getBookmarkAtTime({
+			bookmarks: activeScene.bookmarks,
+			frameTime,
+		});
+	}
+
 	async loadProjectScenes({ projectId }: { projectId: string }): Promise<void> {
 		try {
 			const result = await storageService.loadProject({ id: projectId });
diff --git a/apps/web/src/core/managers/timeline-manager.ts b/apps/web/src/core/managers/timeline-manager.ts
index ad9f7792..c8ac5a79 100644
--- a/apps/web/src/core/managers/timeline-manager.ts
+++ b/apps/web/src/core/managers/timeline-manager.ts
@@ -23,12 +23,14 @@ import {
 	PasteCommand,
 	UpdateElementStartTimeCommand,
 	MoveElementCommand,
+	TracksSnapshotCommand,
 } from "@/lib/commands/timeline";
-import { BatchCommand } from "@/lib/commands";
+import { BatchCommand, PreviewTracker } from "@/lib/commands";
 import type { InsertElementParams } from "@/lib/commands/timeline/element/insert-element";
 
 export class TimelineManager {
 	private listeners = new Set<() => void>();
+	private previewTracker = new PreviewTracker<TimelineTrack[]>();
 
 	constructor(private editor: EditorCore) {}
 
@@ -214,7 +216,8 @@ export class TimelineManager {
 			({ trackId, elementId, updates: elementUpdates }) =>
 				new UpdateElementCommand(trackId, elementId, elementUpdates),
 		);
-		const command = commands.length === 1 ? commands[0] : new BatchCommand(commands);
+		const command =
+			commands.length === 1 ? commands[0] : new BatchCommand(commands);
 		if (pushHistory) {
 			this.editor.command.execute({ command });
 		} else {
@@ -222,6 +225,52 @@ export class TimelineManager {
 		}
 	}
 
+	isPreviewActive(): boolean {
+		return this.previewTracker.isActive();
+	}
+
+	previewElements({
+		updates,
+	}: {
+		updates: Array<{
+			trackId: string;
+			elementId: string;
+			updates: Partial<Record<string, unknown>>;
+		}>;
+	}): void {
+		const tracks = this.getTracks();
+		this.previewTracker.begin({ state: tracks });
+
+		let updatedTracks = tracks;
+		for (const { trackId, elementId, updates: elementUpdates } of updates) {
+			updatedTracks = updatedTracks.map((track) => {
+				if (track.id !== trackId) return track;
+				const newElements = track.elements.map((element) =>
+					element.id === elementId
+						? { ...element, ...elementUpdates }
+						: element,
+				);
+				return { ...track, elements: newElements } as TimelineTrack;
+			});
+		}
+		this.updateTracks(updatedTracks);
+	}
+
+	commitPreview(): void {
+		const snapshot = this.previewTracker.end();
+		if (snapshot === null) return;
+		const currentTracks = this.getTracks();
+		const command = new TracksSnapshotCommand(snapshot, currentTracks);
+		this.editor.command.push({ command });
+	}
+
+	discardPreview(): void {
+		const snapshot = this.previewTracker.end();
+		if (snapshot !== null) {
+			this.updateTracks(snapshot);
+		}
+	}
+
 	duplicateElements({
 		elements,
 	}: {