import { ComputedRef, Ref } from 'vue';
export type ScrollDirection = 'vertical' | 'horizontal';
export type ScrollAlign = 'start' | 'center' | 'end' | 'nearest';
export type KeyValue = string | number;
export type KeyFieldResolver<TItem = unknown> = (item: TItem, index: number) => KeyValue;
export type KeyFieldValue<TItem = unknown> = string | KeyFieldResolver<TItem>;
export type ItemSizeResolver<TItem = unknown> = (item: TItem, index: number) => number;
export type ItemSizeValue<TItem = unknown> = number | null | ItemSizeResolver<TItem>;
export type StringKeyOf<T> = Extract<keyof T, string>;
/**
 * Default key-field shape for generic option helpers.
 * Keep valid object field names plus resolver functions, instead of freezing to `'id'`.
 */
export type DefaultKeyField<TItem> = TItem extends object ? StringKeyOf<TItem> | KeyFieldResolver<TItem> : string;
export type ValidKeyField<TItem, TKeyField extends KeyFieldValue<TItem>> = TItem extends object ? TKeyField extends KeyFieldResolver<TItem> ? TKeyField : TKeyField extends StringKeyOf<TItem> ? TKeyField : never : string;
export type NumericFieldKey<TItem> = TItem extends object ? Extract<{
    [K in StringKeyOf<TItem>]-?: Exclude<TItem[K], undefined> extends number ? K : never;
}[StringKeyOf<TItem>], string> : string;
export type ValidSizeField<TItem, TSizeField extends string> = TItem extends object ? [NumericFieldKey<TItem>] extends [never] ? string : TSizeField extends NumericFieldKey<TItem> ? TSizeField : never : string;
export type ItemKey<TItem, TKeyField extends KeyFieldValue<TItem> = 'id'> = TItem extends object ? TKeyField extends KeyFieldResolver<TItem> ? Extract<ReturnType<TKeyField>, KeyValue> : Extract<TKeyField extends keyof TItem ? TItem[TKeyField] : never, KeyValue> : number;
export type ClassValue = string | Record<string, boolean> | Array<string | Record<string, boolean>>;
export interface ScrollToOptions {
    align?: ScrollAlign;
    smooth?: boolean;
    offset?: number;
}
export interface ScrollState {
    start: number;
    end: number;
}
export interface ViewNonReactive<TKey = KeyValue> {
    id: number;
    index: number;
    used: boolean;
    key: TKey;
    type: unknown;
}
export interface View<TItem = unknown, TKey = KeyValue> {
    item: TItem;
    position: number;
    offset: number;
    nr: ViewNonReactive<TKey>;
}
/**
 * Public pooled-view shape exposed by `useDynamicScroller`.
 * It flattens common render fields while still exposing measured metadata.
 */
export interface DynamicScrollerView<TItem = unknown, TKey = KeyValue> {
    item: TItem;
    itemWithSize: ItemWithSize<TItem, TKey>;
    size: number | undefined;
    position: number;
    offset: number;
    id: number;
    index: number;
    used: boolean;
    key: TKey;
    type: unknown;
}
export interface CacheSnapshot {
    keys: KeyValue[];
    sizes: Array<number | null>;
}
export interface SizeEntry {
    accumulator: number;
    size?: number;
}
export interface Sizes {
    [key: number]: SizeEntry;
}
export interface VScrollData {
    active: boolean;
    sizes: Record<KeyValue, number>;
    keyField: KeyFieldValue<any>;
    simpleArray: boolean;
}
export interface ItemWithSize<TItem = unknown, TKey = KeyValue> {
    item: TItem;
    id: TKey;
    size: number | undefined;
}
export interface RecycleScrollerSlotProps<TItem = unknown> {
    item: TItem;
    index: number;
    active: boolean;
}
export interface DynamicScrollerSlotProps<TItem = unknown, TKey = KeyValue> extends RecycleScrollerSlotProps<TItem> {
    itemWithSize: ItemWithSize<TItem, TKey>;
}
export interface RecycleScrollerExposed<TItem = unknown, TKey = KeyValue> {
    el: Ref<HTMLElement | undefined>;
    visiblePool: ComputedRef<Array<View<TItem, TKey>>>;
    startSpacerSize: Ref<number>;
    endSpacerSize: Ref<number>;
    scrollToItem: (index: number, options?: ScrollToOptions) => void;
    scrollToPosition: (position: number, options?: ScrollToOptions) => void;
    getScroll: () => ScrollState;
    findItemIndex: (offset: number) => number;
    getItemOffset: (index: number) => number;
    getItemSize: (index: number) => number;
    cacheSnapshot: ComputedRef<CacheSnapshot>;
    restoreCache: (snapshot: CacheSnapshot | null | undefined) => boolean;
    updateVisibleItems: (itemsChanged: boolean, checkPositionDiff?: boolean) => {
        continuous: boolean;
    };
}
export interface DynamicScrollerExposed<TItem = unknown> {
    startSpacerSize: Ref<number>;
    endSpacerSize: Ref<number>;
    scrollToItem: (index: number, options?: ScrollToOptions) => void;
    scrollToPosition: (position: number, options?: ScrollToOptions) => void;
    findItemIndex: (offset: number) => number;
    getItemOffset: (index: number) => number;
    scrollToBottom: () => void;
    getItemSize: (item: TItem, index?: number) => number;
    cacheSnapshot: ComputedRef<CacheSnapshot>;
    restoreCache: (snapshot: CacheSnapshot | null | undefined) => boolean;
    forceUpdate: (clear?: boolean) => void;
}
export interface WindowScrollerExposed<TItem = unknown, TKey = KeyValue> {
    el: Ref<HTMLElement | undefined>;
    startSpacerSize: Ref<number>;
    endSpacerSize: Ref<number>;
    scrollToItem: (index: number, options?: ScrollToOptions) => void;
    scrollToPosition: (position: number, options?: ScrollToOptions) => void;
    getScroll: () => ScrollState;
    findItemIndex: (offset: number) => number;
    getItemOffset: (index: number) => number;
    getItemSize: (index: number) => number;
    cacheSnapshot: ComputedRef<CacheSnapshot>;
    restoreCache: (snapshot: CacheSnapshot | null | undefined) => boolean;
    updateVisibleItems: (itemsChanged: boolean, checkPositionDiff?: boolean) => {
        continuous: boolean;
    };
}
export interface PluginOptions {
    installComponents?: boolean;
    componentsPrefix?: string;
}