cc.Class({
    extends: cc.Component,

    properties: {
        leftBtn: {
            default: null,
            type: cc.Node
        },
        rightBtn: {
            default: null,
            type: cc.Node
        },
        currentNode: {
            default: null,
            type: cc.Node
        },
        leftNode: {
            default: null,
            type: cc.Node
        },
        rightNode: {
            default: null,
            type: cc.Node
        },
        currentIdx: 2,
        scrolling: false
    },

    // LIFE-CYCLE CALLBACKS:

    onLoad() {
        let self = this;
        this.leftBtn.on('click', () => {
            if (!self.scrolling) {
                self.scrolling = true;
                self.moveRight();
            }
        });
        this.rightBtn.on('click', () => {
            if (!self.scrolling) {
                self.scrolling = true;
                this.moveLeft();
            }
        })
    },

    start() {
    },

    // update (dt) {},
    moveLeft: function () {
        let self = this;
        let moveFinish = cc.callFunc(function () {
            self.currentIdx ++;
            if (self.currentIdx > 4) {
                self.currentIdx = 0;
            }
            let nextIdx = self.currentIdx === 4 ? 0 : self.currentIdx + 1;
            let tmp = self.leftNode;
            self.leftNode = self.currentNode;
            self.currentNode = self.rightNode;
            self.rightNode = tmp;
            let url = 'textures/part5/0' + nextIdx;
            cc.loader.loadRes(url, cc.SpriteFrame, function (err, spriteFrame) {
                self.rightNode.getComponent(cc.Sprite).spriteFrame = spriteFrame;
            });
            self.scrolling = false;
        }, this, {});
        let moveCurrent = cc.moveTo(0.5, -561, 0);
        var seq = cc.sequence(moveCurrent, moveFinish);
        self.currentNode.runAction(seq);
        self.rightNode.runAction(cc.moveTo(0.5, 0, 0));
        self.leftNode.position = cc.v2(561, 0);
    },
    moveRight: function () {
        let self = this;
        let moveFinish = cc.callFunc(function () {
            self.currentIdx --;
            if (self.currentIdx < 0) {
                self.currentIdx = 4;
            }
            let nextIdx = self.currentIdx === 0 ? 4 : self.currentIdx - 1;
            self.rightNode.position = cc.v2(-561, 0);
            let tmp = self.rightNode;
            self.rightNode = self.currentNode;
            self.currentNode = self.leftNode;
            self.leftNode = tmp;
            let url = 'textures/part5/0' + nextIdx;
            cc.loader.loadRes(url, cc.SpriteFrame, function (err, spriteFrame) {
                self.leftNode.getComponent(cc.Sprite).spriteFrame = spriteFrame;
            });
            self.scrolling = false;
        }, this, {});
        let moveCurrent = cc.moveTo(0.5, 561, 0);
        var seq = cc.sequence(moveCurrent, moveFinish);
        self.currentNode.runAction(seq);
        self.leftNode.runAction(cc.moveTo(0.5, 0, 0));
    }
});