import { AllowedComponentProps, VNodeProps, ComponentCustomProps } from 'vue'

declare type LoadingStatus = 'loading' | 'no-more' | 'error' | 'idle'
declare type ScrollAlign = 'top' | 'center' | 'bottom'

declare interface ScrollToItemOptions {
    align?: ScrollAlign
    animated?: boolean
}

declare interface VirtualListItem<T = any> {
    data: T
    index: number
    height: number
    offset: number
}

declare interface ScrollEvent {
    detail: {
        scrollTop: number
        scrollLeft: number
        scrollHeight: number
        scrollWidth: number
        deltaX: number
        deltaY: number
    }
}

declare interface VirtualListProps<T = any> {
    /** 数据源 */
    data: T[]
    /** 预估的每项高度 */
    estimatedItemSize?: number
    /** 缓冲区大小（视窗外的渲染数量） */
    buffer?: number
    /** 滚动容器高度 */
    height?: string | number
    /** 唯一键字段名 */
    keyField?: string
    /** 是否显示顶部加载 */
    showTopLoading?: boolean
    /** 是否显示底部加载 */
    showBottomLoading?: boolean
    /** 顶部加载状态 */
    topStatus?: LoadingStatus
    /** 底部加载状态 */
    bottomStatus?: LoadingStatus
    /** 触发上拉加载的阈值 */
    lowerThreshold?: number
    /** 触发下拉刷新的阈值 */
    upperThreshold?: number
    /** 是否显示回到顶部按钮 */
    showBackToTop?: boolean
    /** 显示回到顶部按钮的阈值 */
    backToTopThreshold?: number
    /** 初始滚动位置 */
    initialScrollTop?: number
    /** 需要滚动到的项目ID */
    scrollIntoView?: string
    /** 是否保持滚动位置 */
    keepScrollPosition?: boolean
}

declare interface VirtualListEmits<T = any> {
    (e: 'scroll', event: ScrollEvent): void
    (e: 'scroll-to-lower'): void
    (e: 'scroll-to-upper'): void
    (e: 'item-click', item: T, index: number): void
    (e: 'item-long-press', item: T, index: number): void
    (e: 'top-load'): void
    (e: 'bottom-load'): void
    (e: 'update:scroll-into-view', value: string): void
}

declare interface VirtualListSlots<T = any> {
    default?: (props: {
        item: T,
        index: number
    }) => any

    topLoading?: (props: {
        status: LoadingStatus
    }) => any

    bottomLoading?: (props: {
        status: LoadingStatus
    }) => any

    backToTop?: () => any
}

declare interface VirtualListExposed<T = any> {
    // 滚动控制
    scrollToTop: () => void
    scrollToBottom: () => void
    scrollToItem: (index: number, options?: ScrollToItemOptions) => void
    scrollToIndex: (index: number, options?: ScrollToItemOptions) => void

    // 信息获取
    getVisibleRange: () => { start: number, end: number }
    getContainerHeight: () => number
    getScrollTop: () => number

    // 尺寸测量
    measureContainer: () => void
    getItemHeight: (item: T, index: number) => number

    // 数据操作
    updateData: (data: T[]) => void
    appendData: (data: T[]) => void
    prependData: (data: T[]) => void
    clearData: () => void

    // 状态控制
    startLoading: (type: 'top' | 'bottom') => void
    stopLoading: (type: 'top' | 'bottom') => void
    setLoadingStatus: (type: 'top' | 'bottom', status: LoadingStatus) => void
    refresh: () => void
}

declare interface _VirtualList {
    new(): {
        $props: AllowedComponentProps &
        VNodeProps &
        ComponentCustomProps &
        VirtualListProps

        $emit: VirtualListEmits
        $slots: VirtualListSlots

        // 暴露的方法
        scrollToTop: VirtualListExposed['scrollToTop']
        scrollToBottom: VirtualListExposed['scrollToBottom']
        scrollToItem: VirtualListExposed['scrollToItem']
        scrollToIndex: VirtualListExposed['scrollToIndex']
        getVisibleRange: VirtualListExposed['getVisibleRange']
        getContainerHeight: VirtualListExposed['getContainerHeight']
        getScrollTop: VirtualListExposed['getScrollTop']
        measureContainer: VirtualListExposed['measureContainer']
        getItemHeight: VirtualListExposed['getItemHeight']
        updateData: VirtualListExposed['updateData']
        appendData: VirtualListExposed['appendData']
        prependData: VirtualListExposed['prependData']
        clearData: VirtualListExposed['clearData']
        startLoading: VirtualListExposed['startLoading']
        stopLoading: VirtualListExposed['stopLoading']
        setLoadingStatus: VirtualListExposed['setLoadingStatus']
        refresh: VirtualListExposed['refresh']
    }
}

export declare const VirtualList: _VirtualList

// 默认导出
export default VirtualList

// 类型导出
export type {
    LoadingStatus,
    ScrollAlign,
    ScrollToItemOptions,
    VirtualListItem,
    ScrollEvent,
    VirtualListProps,
    VirtualListEmits,
    VirtualListSlots,
    VirtualListExposed
}