const MIN_DISTANCE = 10;
export default {
    showWatch(newVal, oldVal, ownerInstance, instance, self) {
        var state = self.state
        var $el = ownerInstance.$el || ownerInstance.$vm && ownerInstance.$vm.$el
        if (!$el) return
        this.getDom(instance, ownerInstance, self)
        if (newVal && newVal !== 'none') {
            this.openState(newVal, instance, ownerInstance, self)
            return
        }

        if (state.left) {
            this.openState('none', instance, ownerInstance, self)
        }
        this.resetTouchStatus(instance, self)
    },

    /**
     * 开始触摸操作
     * @param {Object} e
     * @param {Object} ins
     */
    touchstart(e, ownerInstance, self) {
        let instance = e.instance;
        let disabled = instance.getDataset().disabled
        let state = self.state;
        this.getDom(instance, ownerInstance, self)
        // fix by mehaotian, TODO 兼容 app-vue 获取dataset为字符串 , h5 获取 为 undefined 的问题,待框架修复
        disabled = this.getDisabledType(disabled)
        if (disabled) return
        // 开始触摸时移除动画类
        instance.requestAnimationFrame(function () {
            instance.removeClass('ani');
            ownerInstance.callMethod('closeSwipe');
        })

        // 记录上次的位置
        state.x = state.left || 0
        // 计算滑动开始位置
        this.stopTouchStart(e, ownerInstance, self)
    },

    /**
     * 开始滑动操作
     * @param {Object} e
     * @param {Object} ownerInstance
     */
    touchmove(e, ownerInstance, self) {
        let instance = e.instance;
        // 删除之后已经那不到实例了
        if (!instance) return;
        let disabled = instance.getDataset().disabled
        let state = self.state
        // fix by mehaotian, TODO 兼容 app-vue 获取dataset为字符串 , h5 获取 为 undefined 的问题,待框架修复
        disabled = this.getDisabledType(disabled)
        if (disabled) return
        // 是否可以滑动页面
        this.stopTouchMove(e, self);
        if (state.direction !== 'horizontal') {
            return;
        }
        if (e.preventDefault) {
            // 阻止页面滚动
            e.preventDefault()
        }
        let x = state.x + state.deltaX
        this.move(x, instance, ownerInstance, self)
    },

    /**
     * 结束触摸操作
     * @param {Object} e
     * @param {Object} ownerInstance
     */
    touchend(e, ownerInstance, self) {
        let instance = e.instance;
        let disabled = instance.getDataset().disabled
        let state = self.state
        // fix by mehaotian, TODO 兼容 app-vue 获取dataset为字符串 , h5 获取 为 undefined 的问题,待框架修复
        disabled = this.getDisabledType(disabled)

        if (disabled) return
        // 滑动过程中触摸结束,通过阙值判断是开启还是关闭
        // fixed by mehaotian 定时器解决点击按钮，touchend 触发比 click 事件时机早的问题 ，主要是 ios13
        this.moveDirection(state.left, instance, ownerInstance, self)

    },

    /**
     * 设置移动距离
     * @param {Object} value
     * @param {Object} instance
     * @param {Object} ownerInstance
     */
    move(value, instance, ownerInstance, self) {
        value = value || 0
        let state = self.state
        let leftWidth = state.leftWidth
        let rightWidth = state.rightWidth
        // 获取可滑动范围
        state.left = this.range(value, -rightWidth, leftWidth);
        instance.requestAnimationFrame(function () {
            instance.setStyle({
                transform: 'translateX(' + state.left + 'px)',
                '-webkit-transform': 'translateX(' + state.left + 'px)'
            })
        })

    },

    /**
     * 获取元素信息
     * @param {Object} instance
     * @param {Object} ownerInstance
     */
    getDom(instance, ownerInstance, self) {
        var state = self.state
        var $el = ownerInstance.$el || ownerInstance.$vm && ownerInstance.$vm.$el
        var leftDom = $el.querySelector('.button-group--left')
        var rightDom = $el.querySelector('.button-group--right')

        state.leftWidth = leftDom.offsetWidth || 0
        state.rightWidth = rightDom.offsetWidth || 0
        state.threshold = instance.getDataset().threshold
    },

    getDisabledType(value) {
        return (typeof (value) === 'string' ? JSON.parse(value) : value) || false;
    },

    /**
     * 获取范围
     * @param {Object} num
     * @param {Object} min
     * @param {Object} max
     */
    range(num, min, max) {
        return Math.min(Math.max(num, min), max);
    },


    /**
     * 移动方向判断
     * @param {Object} left
     * @param {Object} value
     * @param {Object} ownerInstance
     * @param {Object} ins
     */
    moveDirection(left, ins, ownerInstance, self) {
        var state = self.state
        var threshold = state.threshold
        var position = state.position
        var isopen = state.isopen || 'none'
        var leftWidth = state.leftWidth
        var rightWidth = state.rightWidth
        if (state.deltaX === 0) {
            this.openState('none', ins, ownerInstance, self)
            return
        }
        if ((isopen === 'none' && rightWidth > 0 && -left > threshold) || (isopen !== 'none' && rightWidth > 0 &&
            rightWidth +
            left < threshold)) {
            // right
            this.openState('right', ins, ownerInstance, self)
        } else if ((isopen === 'none' && leftWidth > 0 && left > threshold) || (isopen !== 'none' && leftWidth > 0 &&
            leftWidth - left < threshold)) {
            // left
            this.openState('left', ins, ownerInstance, self)
        } else {
            // default
            this.openState('none', ins, ownerInstance, self)
        }
    },


    /**
     * 开启状态
     * @param {Boolean} type
     * @param {Object} ins
     * @param {Object} ownerInstance
     */
    openState(type, ins, ownerInstance, self) {
        let state = self.state
        let leftWidth = state.leftWidth
        let rightWidth = state.rightWidth
        let left = ''
        state.isopen = state.isopen ? state.isopen : 'none'
        switch (type) {
            case "left":
                left = leftWidth
                break
            case "right":
                left = -rightWidth
                break
            default:
                left = 0
        }

        // && !state.throttle

        if (state.isopen !== type) {
            state.throttle = true
            ownerInstance.callMethod('change', {
                open: type
            })

        }

        state.isopen = type
        // 添加动画类
        ins.requestAnimationFrame(() => {
            ins.addClass('ani');
            this.move(left, ins, ownerInstance, self)
        })
    },


    getDirection(x, y) {
        if (x > y && x > MIN_DISTANCE) {
            return 'horizontal';
        }
        if (y > x && y > MIN_DISTANCE) {
            return 'vertical';
        }
        return '';
    },

    /**
     * 重置滑动状态
     * @param {Object} event
     */
    resetTouchStatus(instance, self) {
        let state = self.state;
        state.direction = '';
        state.deltaX = 0;
        state.deltaY = 0;
        state.offsetX = 0;
        state.offsetY = 0;
    },

    /**
     * 设置滑动开始位置
     * @param {Object} event
     */
    stopTouchStart(event, ownerInstance, self) {
        let instance = event.instance;
        let state = self.state
        this.resetTouchStatus(instance, self);
        var touch = event.touches[0];
        state.startX = touch.clientX;
        state.startY = touch.clientY;
    },

    /**
     * 滑动中，是否禁止打开
     * @param {Object} event
     */
    stopTouchMove(event, self) {
        let instance = event.instance;
        let state = self.state;
        let touch = event.touches[0];

        state.deltaX = touch.clientX - state.startX;
        state.deltaY = touch.clientY - state.startY;
        state.offsetY = Math.abs(state.deltaY);
        state.offsetX = Math.abs(state.deltaX);
        state.direction = state.direction || this.getDirection(state.offsetX, state.offsetY);
    }
}