export type MediaType = 'image' | 'video' | 'gif' | 'audio';
/** Attribution for stock media (Unsplash/Pexels). Carried alongside the media
 * item so a host can append a credit line at publish/render time. */
export type StockAttribution = {
    name: string;
    source: 'unsplash' | 'pexels';
    kind: 'photo' | 'video';
    authorUrl?: string;
    mediaPageUrl?: string;
};
export type TimelineAspectRatio = '16:9' | '9:16' | '1:1';
export declare const FPS_OPTIONS: readonly [24, 25, 30, 50, 60];
export type TimelineFps = (typeof FPS_OPTIONS)[number];
export declare const FPS_DEFAULT: TimelineFps;
export type TimelineTrack = {
    id: string;
    name: string;
    muted: boolean;
    solo: boolean;
    hidden: boolean;
    locked: boolean;
    height: number;
};
export declare const TRACK_HEIGHT_MIN = 32;
export declare const TRACK_HEIGHT_MAX = 120;
export declare const TRACK_HEIGHT_DEFAULT = 56;
export declare const ZOOM_MIN = 5;
export declare const ZOOM_MAX = 400;
export declare const ZOOM_DEFAULT = 50;
/** Minimum clip length, in frames. */
export declare const CLIP_MIN_FRAMES = 1;
export type AnimPreset = 'fade' | 'slide-left' | 'slide-right' | 'slide-up' | 'slide-down' | 'scale' | 'zoom' | 'bounce' | 'pop' | 'spin' | 'blur' | 'wipe' | 'flip';
export type Easing = 'linear' | 'ease-in' | 'ease-out' | 'ease-in-out';
export declare const ANIM_PRESETS: readonly AnimPreset[];
export declare const EASINGS: readonly Easing[];
/** One side of a clip transition. */
export type ClipTransition = {
    preset: AnimPreset;
    /** Animation length in frames; clamped to the clip's duration. */
    durationF: number;
    easing: Easing;
};
/** Optional enter/exit transitions on a clip. Either side may be absent. */
export type ClipAnimation = {
    in?: ClipTransition;
    out?: ClipTransition;
};
/** Sensible default when a transition side is first enabled (~0.5s @30fps). */
export declare function defaultTransition(): ClipTransition;
export type ClipBase = {
    id: string;
    trackId: string;
    startF: number;
    durationF: number;
    groupId: string | null;
    locked: boolean;
    name: string;
    /** Optional enter/exit transitions, applied in the preview/compositor. */
    animation?: ClipAnimation;
};
export type MediaClipKind = 'video' | 'image' | 'audio';
export type MediaClip = ClipBase & {
    kind: MediaClipKind;
    url: string;
    assetId?: string;
    trimInF: number;
    sourceDurationF: number | null;
    volume: number;
    /** Linear gain ramps, in frames from the clip edges. */
    fadeInF: number;
    fadeOutF: number;
    linkId: string | null;
    audioDetached?: boolean;
    attribution?: StockAttribution;
};
export type TextClipStyle = {
    fontFamily: string;
    fontSizePct: number;
    fontWeight: 400 | 600 | 700;
    color: string;
    backgroundColor: string | null;
    backgroundOpacity: number;
    borderColor: string | null;
    borderWidthPct: number;
    align: 'left' | 'center' | 'right';
    xPct: number;
    yPct: number;
    paddingPct: number;
    borderRadiusPct: number;
    shadow: boolean;
    shadowColor: string;
    shadowBlurPct: number;
    shadowOffsetPct: number;
};
export type TextClip = ClipBase & {
    kind: 'text';
    text: string;
    style: TextClipStyle;
};
export type TimelineClip = MediaClip | TextClip;
export declare const MARKER_COLORS: readonly ["#ef4444", "#f59e0b", "#22c55e", "#06b6d4", "#8b5cf6", "#ec4899"];
export type TimelineMarker = {
    id: string;
    frame: number;
    color: string;
    label: string;
};
/** Project-level preview/composition background. `null` (on the project) means
 * transparent — no background. The default for new/migrated projects is solid
 * black, not null, so the historical look is preserved. */
export type ProjectBackground = {
    type: 'solid';
    color: string;
} | {
    type: 'gradient';
    from: string;
    to: string;
    angle: number;
};
/** Solid background presets (20). */
export declare const BACKGROUND_SOLID_PRESETS: readonly ["#000000", "#ffffff", "#18181b", "#27272a", "#3f3f46", "#1e293b", "#0f172a", "#0c4a6e", "#1e3a8a", "#312e81", "#4c1d95", "#831843", "#7f1d1d", "#7c2d12", "#713f12", "#14532d", "#064e3b", "#134e4a", "#164e63", "#52525b"];
/** Linear-gradient background presets (20). */
export declare const BACKGROUND_GRADIENT_PRESETS: {
    from: string;
    to: string;
    angle: number;
}[];
/** Default project background — explicit solid black (not transparent). */
export declare function defaultProjectBackground(): ProjectBackground;
export type TimelineRange = {
    inFrame: number;
    outFrame: number;
};
export type BinItem = {
    id: string;
    url: string;
    mediaType: MediaType;
    name: string;
    duration: number | null;
    assetId?: string;
    attribution?: StockAttribution;
};
export type TimelineProject = {
    schemaVersion: 2;
    id: string;
    /** Optional host-owned grouping key (workspace/user/etc.); the editor
     * never reads it. Kept for hosts that want to scope stored projects. */
    workspaceId: string;
    name: string;
    aspectRatio: TimelineAspectRatio;
    fps: TimelineFps;
    tracks: TimelineTrack[];
    clips: TimelineClip[];
    markers: TimelineMarker[];
    range: TimelineRange | null;
    bin: BinItem[];
    zoom: number;
    background: ProjectBackground | null;
    createdAt: number;
    updatedAt: number;
};
export declare function isMediaClip(clip: TimelineClip): clip is MediaClip;
export declare function isTextClip(clip: TimelineClip): clip is TextClip;
export declare function clipEndF(clip: TimelineClip): number;
export declare function frameToSec(frame: number, fps: number): number;
export declare function secToFrame(seconds: number, fps: number): number;
/** Whether a clip produces audio in the preview/render. */
export declare function clipHasAudio(clip: TimelineClip): clip is MediaClip;
export declare function clipKindForMediaType(mediaType: MediaType): MediaClipKind;
export declare function defaultTextClipStyle(): TextClipStyle;
export declare function createTrack(name: string): TimelineTrack;
export declare function createEmptyProject(name: string, options?: {
    fps?: TimelineFps;
    workspaceId?: string;
}): TimelineProject;