import { BasePluginConfig, EventHook } from '@embedpdf/core';
import { PdfPageObjectWithRotatedSize, Rect, Rotation } from '@embedpdf/models';
import { ViewportMetrics } from '@embedpdf/plugin-viewport';
import { VirtualItem } from './types/virtual-item';
export type ScrollBehavior = 'instant' | 'smooth' | 'auto';
export interface PageChangeState {
    isChanging: boolean;
    targetPage: number;
    fromPage: number;
    startTime: number;
}
export interface ScrollDocumentState {
    virtualItems: VirtualItem[];
    totalPages: number;
    currentPage: number;
    totalContentSize: {
        width: number;
        height: number;
    };
    strategy: ScrollStrategy;
    pageGap: number;
    visiblePages: number[];
    pageVisibilityMetrics: PageVisibilityMetrics[];
    renderedPageIndexes: number[];
    scrollOffset: {
        x: number;
        y: number;
    };
    startSpacing: number;
    endSpacing: number;
    pageChangeState: PageChangeState;
}
export interface ScrollState {
    defaultStrategy: ScrollStrategy;
    defaultPageGap: number;
    defaultBufferSize: number;
    documents: Record<string, ScrollDocumentState>;
}
export interface ScrollerLayout {
    startSpacing: number;
    endSpacing: number;
    totalWidth: number;
    totalHeight: number;
    pageGap: number;
    strategy: ScrollStrategy;
    items: VirtualItem[];
}
export declare enum ScrollStrategy {
    Vertical = "vertical",
    Horizontal = "horizontal"
}
export interface PageVisibilityMetrics {
    pageNumber: number;
    viewportX: number;
    viewportY: number;
    visiblePercentage: number;
    original: {
        pageX: number;
        pageY: number;
        visibleWidth: number;
        visibleHeight: number;
        scale: number;
    };
    scaled: {
        pageX: number;
        pageY: number;
        visibleWidth: number;
        visibleHeight: number;
        scale: number;
    };
}
export interface ScrollMetrics {
    currentPage: number;
    visiblePages: number[];
    pageVisibilityMetrics: PageVisibilityMetrics[];
    renderedPageIndexes: number[];
    scrollOffset: {
        x: number;
        y: number;
    };
    startSpacing: number;
    endSpacing: number;
}
export interface ScrollPluginConfig extends BasePluginConfig {
    defaultStrategy?: ScrollStrategy;
    defaultPageGap?: number;
    defaultBufferSize?: number;
}
export type LayoutChangePayload = Pick<ScrollDocumentState, 'virtualItems' | 'totalContentSize'>;
export interface ScrollToPageOptions {
    pageNumber: number;
    pageCoordinates?: {
        x: number;
        y: number;
    };
    behavior?: ScrollBehavior;
    /**
     * Horizontal alignment as a percentage (0-100).
     * 0 = target at left edge, 50 = centered, 100 = target at right edge.
     */
    alignX?: number;
    /**
     * Vertical alignment as a percentage (0-100).
     * 0 = target at top edge, 50 = centered, 100 = target at bottom edge.
     * Useful for mobile where UI overlays may cover part of the screen (e.g., alignY: 25 for top quarter).
     */
    alignY?: number;
}
export interface PageChangeEvent {
    documentId: string;
    pageNumber: number;
    totalPages: number;
}
export interface ScrollEvent {
    documentId: string;
    metrics: ScrollMetrics;
}
export interface LayoutChangeEvent {
    documentId: string;
    layout: LayoutChangePayload;
}
export interface PageChangeStateEvent {
    documentId: string;
    state: PageChangeState;
}
export interface LayoutReadyEvent {
    documentId: string;
    /** True only on the first layout ready after document load, false on subsequent (e.g., tab switches) */
    isInitial: boolean;
    pageNumber: number;
    totalPages: number;
}
export interface ScrollScope {
    getCurrentPage(): number;
    getTotalPages(): number;
    getPageChangeState(): PageChangeState;
    scrollToPage(options: ScrollToPageOptions): void;
    scrollToNextPage(behavior?: ScrollBehavior): void;
    scrollToPreviousPage(behavior?: ScrollBehavior): void;
    getSpreadPagesWithRotatedSize(): PdfPageObjectWithRotatedSize[][];
    getMetrics(viewport?: ViewportMetrics): ScrollMetrics;
    getLayout(): LayoutChangePayload;
    getRectPositionForPage(page: number, rect: Rect, scale?: number, rotation?: Rotation): Rect | null;
    setScrollStrategy(strategy: ScrollStrategy): void;
    onPageChange: EventHook<PageChangeEvent>;
    onScroll: EventHook<ScrollMetrics>;
    onLayoutChange: EventHook<LayoutChangePayload>;
}
export interface ScrollCapability {
    getCurrentPage(): number;
    getTotalPages(): number;
    getPageChangeState(): PageChangeState;
    scrollToPage(options: ScrollToPageOptions): void;
    scrollToNextPage(behavior?: ScrollBehavior): void;
    scrollToPreviousPage(behavior?: ScrollBehavior): void;
    getMetrics(viewport?: ViewportMetrics): ScrollMetrics;
    getLayout(): LayoutChangePayload;
    getRectPositionForPage(page: number, rect: Rect, scale?: number, rotation?: Rotation): Rect | null;
    forDocument(documentId: string): ScrollScope;
    setScrollStrategy(strategy: ScrollStrategy, documentId?: string): void;
    getPageGap(): number;
    onPageChange: EventHook<PageChangeEvent>;
    onScroll: EventHook<ScrollEvent>;
    onLayoutChange: EventHook<LayoutChangeEvent>;
    onLayoutReady: EventHook<LayoutReadyEvent>;
    onPageChangeState: EventHook<PageChangeStateEvent>;
    onStateChange: EventHook<ScrollDocumentState>;
}