/**
 * MIT License
 *
 * Copyright (c) 2020 ManBang Group
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */

import Widget from './Widget'
import { ListView } from './basicWidget'
import Util from '../shared/Util'
import { RenderData, ThreshProvider } from '../types/type'
import threshApp from './ThreshApp'
import appContainer from './AppContainer'
import TimerManager from '../manager/TimerManager'
import UtilManager from '../manager/UtilManager'

export type PropChildrenVNodeType = VNode | VNode[]
const ChildrenKey: string = 'children'
type W = Widget<any, any>
type Key = string | number | void
type Ref = ((widget: W) => void) | void

export interface PropChildrenVNode {
    [childrenPropName: string]: PropChildrenVNodeType
}
interface NodeEvents {
    [eventName: string]: Function
}
interface VNodeUpdateInfo {
    updateNodeId: string, // flutter 端需要被更新的原子组件 node id
    invokeUpdateNodeId: string // js 端需要出发 update 的自定义组件 node id
}

export default class VNode {
    // 节点类型
    type: string
    // 节点属性
    props: any
    // 父节点
    parent: VNode | void
    // 子节点
    children: VNode[] = []
    // 原子节点属性上的子节点
    basicWidgetPropChildren: PropChildrenVNode = {}
    // 节点的 widget 实例
    widget: W
    // 节点实例构造器
    widgetBuilder: any
    // 是否原子节点
    isBasicWidget: boolean
    // 原子节点 children 属性对应的 name
    childrenMapedName: string = ChildrenKey
    // 原子节点 children 属性对应的类型是否为 array
    childrenIsArray: boolean = true
    // 节点 id
    nodeId: string
    // 节点为 NativeView 时的 viewId
    nativeViewId?: string
    // 节点上的事件
    events: NodeEvents = {}
    // 节点所属页面
    pageName?: string
    // 子节点中存在 Page 时保存 Page Node
    pageNode: VNode | void
    // 节点是否已挂载
    hasMount: boolean = false
    // context id
    contextId: string = appContainer.contextId as string

    isPageNode: boolean = false
    isNativeViewNode: boolean = false
    isInputNode: boolean = false

    key?: Key
    parentKey?: Key
    ref?: Ref
    updateInfo?: VNodeUpdateInfo
    shouldRender: boolean = true

    private _refHasMount: boolean = false

    static nodeIdIndex: number = 0
    static getNodeId(type: string): string {
        return `${type}#${++VNode.nodeIdIndex}`
    }
    static asyncEventTypes: string[] = [
        'onRefresh',
        'onLoadMore',
        'onStopBack',
    ]
    static eventTypes: string[] = [
        'onTap',
        'onLongTap',
        'onLongTapStart',
        'onLongTapEnd',
        'onPan',
        'onScroll',
        'onChange',
        'onLoad',
        'onLayout',
        'onFocus',
        'onBlur',
        'onActionsOpen',
        'onActionsClose',
        'willDragStatusChange',
        'onDragStatusChange',
        'onDragPositionChange',
        'onOpen',
        'onSubmitted',
        'onClicked',
        'onEnterClicked',
        'onRawKeyFocusChanged',
    	'dispatchKeyEvent',
        ...VNode.asyncEventTypes,
    ]
    static throttledEventTypes: string[] = ['onTap']

    constructor({
        type,
        props,
        widgetBuilder,
        isBasicWidget,
        childrenMapedName,
        childrenIsArray,
        parent,
        key,
        ref,
    }: {
        type: string,
        props: any,
        widgetBuilder: any,
        isBasicWidget: boolean,
        childrenMapedName: string
        childrenIsArray: boolean
        parent?: VNode | void,
        key?: Key,
        ref?: Ref,
    }) {
        this.type = type
        this.props = props
        this.widgetBuilder = widgetBuilder
        this.isBasicWidget = isBasicWidget
        this.childrenMapedName = childrenMapedName
        this.childrenIsArray = childrenIsArray
        this.parent = parent
        this.key = key
        this.ref = ref
        this.nodeId = VNode.getNodeId(type)

        if (isBasicWidget) {
            this.isPageNode = type === 'Page'
            this.isNativeViewNode = type === 'NativeView'
            this.isInputNode = type === 'Input'
        }

        if (this.isNativeViewNode) {
            this.nativeViewId = `${this.nodeId}#${this.props.type}#${Date.now()}`
        }

    this.findVNodeInProps()
  }

        // 在 props 中查找所有的 vnode
        findVNodeInProps() {
            for (let key in this.props) {
                const item: any = this.props[key]
                if (item instanceof VNode && this.isBasicWidget) {
                    item.parent = this
                    this.basicWidgetPropChildren[key] = item
                }
                if (Array.isArray(item)) {
                    item.forEach((subItem: any) => {
                        if (subItem instanceof VNode) {
                            subItem.parent = this
                            if (key === ChildrenKey) this.appendChild(subItem)
                            else if (this.isBasicWidget) this.appendChildInArrayProps(subItem, key)
                        }
                    })
                }
            }
        }

        // 在 props 中查找事件
        findEventsInProps() {
            if (!this.isBasicWidget) return
            this.events = {}
            let eventId: number = 0
            VNode.eventTypes.forEach(key => {
                let prop: any = this.props[key]
                if (prop instanceof Function) {
                    const eventCacheId: string = `event/${++eventId}`
                    if (VNode.throttledEventTypes.includes(key)) prop = Util.throttle(prop)
                    this.events[eventCacheId] = prop
                    this.props[`_${key}Id`] = eventCacheId
                }
            })
        }

        // 触发组件实例 render
        doRender() {
            if (!this.shouldRender) return
            this.shouldRender = false
            if (!this.widget) {
                this.widget = new this.widgetBuilder(this.props)
                this.widget.__vNode__ = this
            }
            this.widget.props = this.props

            if (!this.isBasicWidget) {
                const node: VNode | void = this.widget.render()
                if (!node) throw new Error(`Widget's render method must return a widget. Error in: <${this.type} />`)
                node.parent = this
                this.children = [node]
            }
        }

        // 执行组件更新
        doUpdate(): VNode | void {
            if(!this.widget) {
            this.widget = new this.widgetBuilder(this.props)
            this.widget.__vNode__ = this
        }
        const newRenderNode: VNode | void = this.widget.render()
        if (!newRenderNode) throw new Error(`Widget's render method must return a widget. Error in: <${this.type} />`)
        return newRenderNode
    }

    // 新旧节点融合
    doMerge(oldNode: VNode) {
        this.contextId = oldNode.contextId
        this.hasMount = true
        this.nodeId = oldNode.nodeId
        this.nativeViewId = oldNode.nativeViewId
        this.widget = oldNode.widget
        this.widget.__vNode__ = this
    }

    // 将 vNode 转换为 flutter 可用的 json
    toRenderData(pageName: string, setStateful: boolean = true): RenderData {
        this.pageName = pageName
        if (this.pageNode) this.pageNode = void 0
        this.findEventsInProps()
        this.doRender()

        if (!this.isBasicWidget) {
            // 非原子组件，children 只有 1 个元素
            // flutter version 1.1.0 及以上，所有自定义组件都是 stateful
            // flutter version 1.1.0 以下，只有声明了 state 的自定义组件才是 stateful
            if (this.children.length) {
                const child: VNode = this.children[0]
                if (Util.isNil(child.key)) child.parentKey = this.key || this.parentKey
                return child.toRenderData(pageName, true)
            }
        } else {
            let childrenRenderData: any = {}
            this.mapChildren((vNode: VNode, key: string, fromArray: boolean) => {
                if (!fromArray) childrenRenderData[key] = vNode.toRenderData(pageName, false)
                else {
                    if (!childrenRenderData[key]) childrenRenderData[key] = []
                    childrenRenderData[key].push(vNode.toRenderData(pageName, false))
                }
                if (key === ChildrenKey && !this.childrenIsArray) {
                    childrenRenderData[this.childrenMapedName] = childrenRenderData[key][0]
                    delete childrenRenderData[key]
                }
            })

            if (this.isPageNode) {
                const rootNode: VNode = this.fetchRootNode()
                rootNode.pageNode = this
            }

            if (this.isNativeViewNode) {
                const params = this.props.params || {}
                if (!params.__viewId__) {
                    params.__viewId__ = this.nativeViewId
                    this.props.params = params
                }
            }

            return {
                name: this.type,
                widgetId: this.nodeId,
                isStateful: setStateful,
                pageName,
                props: this.execPropsProvider(Object.assign({}, this.props, childrenRenderData)),
                key: this.key || this.parentKey
            }
        }
    }

    private execPropsProvider(props: Object): Object {
        const propsProviders: ThreshProvider[] = threshApp.providers.propsProvider || []
        let index = propsProviders.length - 1
        while (index > -1) {
            const provider = propsProviders[index--]
            const tempProps = provider.propsProvider(props)
            if (tempProps) props = tempProps
        }
        return props
    }

    // 在当前 vnode 上查找目标节点
    fetch(targetNodeId: string): VNode {
        if (this.nodeId === targetNodeId) return this
        let targetVNode: VNode
        this.mapChildren((vNode: VNode) => {
            if (vNode.nodeId === targetNodeId) {
                targetVNode = vNode
                return false
            }
            targetVNode = vNode.fetch(targetNodeId)
            return !targetVNode
        })
        return targetVNode
    }

    // 查找距离当前节点向上最近的可更新的原子节点
    fetchNearlyCanUpdateBasicNode(): VNode {
        const node: VNode = this.fetchNearlyCustomNode()
        let firstChildNode: VNode = node.children[0]
        while (firstChildNode && !firstChildNode.isBasicWidget) {
            firstChildNode = firstChildNode.children[0]
        }
        return firstChildNode
    }
    // 查找距离当前节点向上最近的非原子节点
    fetchNearlyCustomNode(): VNode {
        if (!this.isBasicWidget) return this
        const parent: VNode | void = this.parent
        if (parent) return parent.fetchNearlyCustomNode()
        return this
    }
    // 查找距离当前节点向下最近的原子节点
    fetchNearlyBasicNode(): VNode {
        if (this.isBasicWidget) return this
        return this.children[0].fetchNearlyBasicNode()
    }
    // 查找根节点
    fetchRootNode(): VNode {
        if (!this.parent) return this
        const parent: VNode | void = this.parent
        if (parent) return parent.fetchRootNode()
        return this
    }
    // 查找页面名
    fetchNodePageName(): string {
        if (this.pageName) return this.pageName
        if (this.parent) return this.parent.fetchNodePageName()
        return ''
    }

    // 毕竟两个节点的 type & key 是否相等
    isSameAs(otherNode: VNode) {
        return this.type === otherNode.type && this.key === otherNode.key
    }

    // 触发组件上的事件
    async invokeEvent(targetNodeId: string, eventId: string, eventType: string, params: any) {
        const targetNode: VNode = this.fetch(targetNodeId)
        if (!targetNode) return
        const eventFn: Function = targetNode.events[eventId]
        if (!eventFn) return
        if (!eventType || !VNode.asyncEventTypes.includes(eventType)) eventFn(params)
        else {
            try {
                await eventFn(params)
            } finally {
                // Hack fix
                // 异步操作完成后的32毫秒再发送停止异步操作的通知
                // 异步操作中可能含有setState，从而保证停止通知在setState后再发送
                TimerManager.setTimeout(() => {
                    this.stopAsyncEvent(targetNode, eventType)
                }, 32)
            }
        }
    }

    // 停止异步事件
    stopAsyncEvent(node: VNode, eventType: string) {
        if (!node || !eventType || !VNode.asyncEventTypes.includes(eventType)) return
        if (node.type === 'ListView') {
            (node.widget as unknown as ListView).stopAsyncOperate(eventType === 'onRefresh' ? 'refresh' : 'loadMore')
        }
    }

    // 触发组件生命周期方法
    invokeLifeCycle(lifeStep: string) {
        if (!this.widget || !LifeCycle.isExist(lifeStep)) return

        const lifeStepIsDidUnmount = lifeStep === LifeCycle.widgetDidUnmount

        // 当生命周期不是卸载时，从子组件向父组件依次触发
        if (!lifeStepIsDidUnmount) {
            this._invokeChildrenLifeCycle(lifeStep)
        }

        if (!this.hasMount && lifeStep === LifeCycle.widgetDidUpdate) {
            this.hasMount = true
            this._invokeMountRef()
            this.widget.widgetDidMount()
        } else {
            this.hasMount = !lifeStepIsDidUnmount
            this._invokeMountRef()
            this.widget[lifeStep]()
        }

        // 当组件卸载时，didUnmount从父组件向子组件触发
        if (lifeStepIsDidUnmount) {
            this._invokeChildrenLifeCycle(lifeStep)
        }
    }

    private _invokeChildrenLifeCycle(lifeStep: string) {
        this.mapChildren((vNode: VNode) => {
            vNode.invokeLifeCycle(lifeStep)
        })
    }

    private _invokeMountRef() {
        if (!this.ref) return
        if (this.hasMount && !this._refHasMount) {
            this.ref(this.widget)
            this._refHasMount = true
        }
        else if (!this.hasMount && this._refHasMount) {
            this.ref(undefined)
            this._refHasMount = false
        }
    }

    // 向数组尾部添加子节点
    appendChild(child: VNode, target: VNode[] = this.children) {
        if (target.includes(child)) this.removeChild(child)
        target.push(child)
    }
    // 移除数组中的某个节点
    removeChild(child: VNode, target: VNode[] = this.children) {
        const removeIndex: number = target.indexOf(child)
        if (removeIndex > -1) target.splice(removeIndex, 1)
    }
    // 向 basicWidgetPropChildren 中的某个数组属性添加子节点
    appendChildInArrayProps(child: VNode, propName: string) {
        this.appendChild(child, this.getTargetChildrenArrayInPropChildren(propName))
    }

    // 遍历当前节点或目标中的所有子节点
    private mapChildren(
        cb: (vNode: VNode, key: string, fromArray: boolean) => boolean | void,
        mapTarget?: PropChildrenVNode | VNode[]
    ) {
        if (!mapTarget) {
            for (let i = 0; i < this.children.length; i++) {
                const item: VNode = this.children[i]
                if (item instanceof VNode && cb(item, ChildrenKey, true) === false) return
            }
            for (let key in this.basicWidgetPropChildren) {
                const item: PropChildrenVNodeType = this.basicWidgetPropChildren[key]
                if (!Array.isArray(item)) {
                    if (item instanceof VNode && cb(item, key, false) === false) return
                } else {
                    for (let i = 0; i < item.length; i++) {
                        if (item[i] instanceof VNode && cb(item[i], key, true) === false) return
                    }
                }
            }
        } else {
            if (Util.isArray(mapTarget)) {
                for (let i = 0; i < (mapTarget as VNode[]).length; i++) {
                    const item: VNode = mapTarget[i]
                    if (item instanceof VNode && cb(item, '', true) === false) return
                }
            } else {
                for (let key in mapTarget) {
                    const item: PropChildrenVNodeType = mapTarget[key]
                    if (!Array.isArray(item)) {
                        if (item instanceof VNode && cb(item, key, false) === false) return
                    } else {
                        for (let i = 0; i < item.length; i++) {
                            if (item[i] instanceof VNode && cb(item[i], key, true) === false) return
                        }
                    }
                }
            }
        }
    }

    // 获取 basicWidgetPropChildren 中的某个数组属性
    private getTargetChildrenArrayInPropChildren(propName: string): VNode[] {
        if (!this.basicWidgetPropChildren[propName]) this.basicWidgetPropChildren[propName] = []
        return this.basicWidgetPropChildren[propName] as VNode[]
    }
}

/**
 * 生命周期类
 */
export class LifeCycle {
  private static lifes: string[] = [
    'widgetDidMount',
    'widgetDidUpdate',
    'widgetDidUnmount',
/// Called when the current route has been pushed.
/// 当前的页面被push显示到用户面前 viewWillAppear.
    'pageDidPush',
/// Called when the current route has been popped off.
/// 当前的页面被pop viewWillDisappear. 
    'pageDidPop', 
/// Called when the top route has been popped off, and the current route
/// shows up.
/// 上面的页面被pop后当前页面被显示时 viewWillAppear.
    'pageDidPopNext', 
/// Called when a new route has been pushed, and the current route is no
/// longer visible.
/// 从当前页面push到另一个页面 viewWillDisappear.
    'pageDidPushNext',
  ]

    static widgetDidMount: string = LifeCycle.lifes[0]
    static widgetDidUpdate: string = LifeCycle.lifes[1]
    static widgetDidUnmount: string = LifeCycle.lifes[2]

    static pageDidPush: string = LifeCycle.lifes[3]
    static pageDidPop: string = LifeCycle.lifes[4]
    static pageDidPopNext: string = LifeCycle.lifes[5]
    static pageDidPushNext: string = LifeCycle.lifes[6]

    static isExist(lifeStep: string): boolean {
        return LifeCycle.lifes.indexOf(lifeStep) > -1
    }
}