import { _decorator, Component, Node, Prefab, EventTouch, SystemEventType, Vec3, CCBoolean, tween, EventHandler, Layout, UITransform, Label } from 'cc';
import { DEV } from 'cc/env';
import { GeometryUtils } from '../../core/utils/GeometryUtils';
const { ccclass, property } = _decorator;

@ccclass('ListPanel')
export class ListPanel extends Component {

    @property({ type: Prefab, tooltip: "页面Item预制体" })
    itemPrefab: Prefab = null;

    @property({ type: Node, tooltip: "页面节点，触摸检测" })
    panelNode: Node = null;

    @property({ type: Node, tooltip: "页面Content节点" })
    panelContent: Node = null;

    @property({ type: Label, tooltip: "文本页签" })
    txtPage: Label = null;

    @property({ tooltip: "是否为虚拟列表" })
    isVirtualList: boolean = true;
    @property({ tooltip: "是否为循环列表" })
    isLoopPanel: boolean = false;
    // @property({
    //     type: [Node],
    //     tooltip: "页面子节点",
    //     visible() { return this.isVirtualList; }
    // })
    // panelChildNodes: Node[] = [];

    //渲染事件（渲染器）
    @property({
        type: EventHandler,
        tooltip: DEV && '渲染事件（渲染器）',
    })
    public renderEvent: EventHandler = new EventHandler();

    private _numItems: number = 5;
    set numItems(val: number) {
        this._numItems = val;
        if (this.renderEvent) {
            for (let i = 0; i < this.panelContent.children.length; i++) {
                let item = this.panelContent.children[i];
                EventHandler.emitEvents([this.renderEvent], item, i % this._numItems);
            }
        }
        this.txtPage.string = `${this._index + 1}/${this._numItems}`;
    }
    get numItems() {
        return this._numItems;
    }

    private panelItemWidth: number = 540;
    private _index: number = 0;
    private _panelTotalIndex: number = 0;
    private _panelIndex: number = 0;
    private leftPadding = 20;
    private rightPadding = 20;
    private spacingX = 20;
    private get deltaMoveDis() {
        return this.panelItemWidth + this.spacingX;
    }

    private contentUt: UITransform;
    private initPoint: Vec3 = Vec3.ZERO;
    private startPoint: Vec3 = Vec3.ZERO;
    private curPoint: Vec3 = Vec3.ZERO;
    //private moveDis: number = 0;

    onLoad() {
        this.contentUt = this.panelContent.getComponent(UITransform);
        this.panelNode.on(SystemEventType.TOUCH_START, this.onTouchStart, this);
    }

    start() {
        this.curPoint = new Vec3(this.panelContent.position.x, this.panelContent.position.y, 0);
        this.panelContent.getComponent(Layout).enabled = false;
        this.txtPage.string = `${this._index + 1}/${this._numItems}`;
    }

    private onTouchStart(e: EventTouch) {
        this.initPoint = this.startPoint = GeometryUtils.V2ToV3(e.getUILocation());
        this.panelNode.on(SystemEventType.TOUCH_MOVE, this.onTouchMove, this);
        this.panelNode.on(SystemEventType.TOUCH_END, this.onTouchEnd, this);
        this.panelNode.on(SystemEventType.TOUCH_CANCEL, this.onTouchEnd, this);
    }

    private onTouchMove(e: EventTouch) {
        let touches = e.getAllTouches();
        if (touches.length == 1) {
            let point = GeometryUtils.V2ToV3(e.getUILocation());
            let offsetX = point.x - this.startPoint.x;
            this.moving(new Vec3(offsetX, 0, 0));
            this.startPoint = point;
        }
    }

    private onTouchEnd(e: EventTouch) {
        let point = GeometryUtils.V2ToV3(e.getUILocation());
        let disVec = point.subtract(this.initPoint);
        let dis = disVec.length();
        //console.log("Dis: " + disVec);
        if (dis > this.panelItemWidth * 0.55) {
            if (disVec.x <= 0) {
                if (this._index < this._numItems - 1 || this.isLoopPanel) {
                    this._panelTotalIndex++;
                    this.movePanel(true);
                } else {
                    this.moveRevert();
                    console.log("到了最右边");
                }
            } else {
                if (this._index > 0 || this.isLoopPanel) {
                    this._panelTotalIndex--;
                    this.movePanel(false);
                } else {
                    this.moveRevert();
                    console.log("到了最左边");
                }
            }
        } else {
            this.moveRevert();
            console.log("翻页失败");
        }
        //this.panelContent.setPosition(this.curPoint);
        this.startPoint = Vec3.ZERO;
        this.panelNode.off(SystemEventType.TOUCH_MOVE, this.onTouchMove, this);
        this.panelNode.off(SystemEventType.TOUCH_END, this.onTouchEnd, this);
        this.panelNode.off(SystemEventType.TOUCH_CANCEL, this.onTouchEnd, this);
    }

    private moveRevert() {
        console.log("panelPos: ", this.panelContent.position);
        console.log("panel init Pos: ", this.curPoint);
        tween(this.panelContent).to(0.15, { position: this.curPoint }).start();
    }

    private movePanel(isMoveRight: boolean) {
        isMoveRight ? this._index++ : this._index--;
        isMoveRight ? this._panelIndex++ : this._panelIndex--;
        if (this.isLoopPanel) {
            if (this._index < 0) this._index = this._numItems - 1;
            if (this._index > this._numItems - 1) this._index = 0;
        }
        let isRight = 0;
        console.log("PanelIndex: " + this._panelIndex + " Data Index: " + this._index);
        this._panelIndex == 2 && (isRight = 1);
        this._panelIndex == 0 && (isRight = -1);
        let targetPos = new Vec3(-this.deltaMoveDis * this._panelTotalIndex, 0, 0);
        //this.curPoint = targetPos;
        tween(this.panelContent).to(0.15, { position: targetPos }).call(() => {
            if (!this.isLoopPanel) {    //非循环列表 会到达顶部
                if (isRight == 1) {
                    if (this._index < this._numItems - 1) {
                        let firstItem = this.panelContent.children[0];
                        let lastPosX = this.panelContent.children[2].position.x;
                        if (this.panelContent.children[2].position.x + this.panelItemWidth > this.contentUt.width)
                            this.contentUt.width += this.panelItemWidth + this.spacingX;
                        firstItem.setSiblingIndex(2);
                        firstItem.setPosition(new Vec3(lastPosX + this.panelItemWidth + this.spacingX, 0, 0));
                        this._panelIndex = 1;
                    }
                } else if (isRight == -1) {
                    if (this._index > 0) {
                        let lastItem = this.panelContent.children[2];
                        let firstPosX = this.panelContent.children[0].position.x;
                        lastItem.setSiblingIndex(0);
                        lastItem.setPosition(new Vec3(firstPosX - this.panelItemWidth - this.spacingX, 0, 0));
                        this._panelIndex = 1;
                    }
                }
            } else {    //循环列表
                //TODO
                if (isRight == 1) {
                    let firstItem = this.panelContent.children[0];
                    let lastPosX = this.panelContent.children[2].position.x;
                    if (this.panelContent.children[2].position.x + this.panelItemWidth > this.contentUt.width)
                        this.contentUt.width += this.panelItemWidth + this.spacingX;
                    firstItem.setSiblingIndex(2);
                    firstItem.setPosition(new Vec3(lastPosX + this.panelItemWidth + this.spacingX, 0, 0));
                    this._panelIndex = 1;
                } else if (isRight == -1) {
                    let lastItem = this.panelContent.children[2];
                    let firstPosX = this.panelContent.children[0].position.x;
                    lastItem.setSiblingIndex(0);
                    lastItem.setPosition(new Vec3(firstPosX - this.panelItemWidth - this.spacingX, 0, 0));
                    this._panelIndex = 1;
                }
            }
            this.curPoint = targetPos;
            this.txtPage.string = `${this._index + 1}/${this._numItems}`;
        }).start();
    }

    private moving(offset: Vec3) {
        this.startPoint = Vec3.ZERO;
        offset.x *= 0.5;
        offset.y *= 0.5;
        this.panelContent.setPosition(new Vec3(this.panelContent.position.x + offset.x, this.panelContent.position.y + offset.y, 0));
    }

    private onClickLeft() {
        if (this._index > 0 || this.isLoopPanel) {
            this._panelTotalIndex--;
            this.movePanel(false);
        } else {
            this.moveRevert();
            console.log("到了最左边");
        }
    }

    private onClickRight() {
        if (this._index < this._numItems - 1 || this.isLoopPanel) {
            this._panelTotalIndex++;
            this.movePanel(true);
        } else {
            this.moveRevert();
            console.log("到了最右边");
        }
    }
}