package com.zy.common.model;

import com.alibaba.fastjson.JSON;
import com.core.exception.CoolException;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * <strong>立库货架实体类</strong>
 * Created by vincent on 2020/6/11
 */
public class Shelves {

    // 货架排数量
    public final int size;

    // 货架组数量
    public final int group;

    // 偏移量[default:0]
    public final int offset;

    // 货架实例节点集合
    public List<List<Integer>> nodes;

    public Shelves(int size, int group) {
        this(size, group, 0);
    }

    /**
     * @param size 货架单排总数
     * @param group 货架组数量
     * @param offset 序列号偏移量
     */
    public Shelves(int size, int group, int offset) {
        this.size = size;
        this.group = group;
        this.offset = offset;
        init();
    }

    /**
     * 初始化方法【私有】
     */
    private void init(){
        if (group == 0 || size%group != 0) {
            throw new RuntimeException("shelves init fail!");
        }
        nodes = new ArrayList<>();
        for (int g = 1; g <= this.group; g++){
            int unit = size/group;
            List<Integer> node = new ArrayList<>();
            for (int i = (g-1)*unit+1+offset ; i <= g*unit+offset; i++){
                node.add(i);
            }
            nodes.add(node);
        }
    }

    /**
     * 开始计算 =======>>>
     *
     *          货架命中规则如下：
     *              安装位置：   [1]  [2]  |  [3]  [4]  --------  [5] [6]  |  [7] [8]
     *                  命中顺序：      1 -> 5 -> 4 -> 8 -> 2 -> 6 -> 3 -> 7 -> 1 ...
     *
     *          1.该规则适不限制货架数量，总数与组别在构造器中设置
     *          2.如有序列号起始问题，用偏移量规避即可
     *
     * @param curSeq 当前货架号
     * @return 规则命中货架号
     */
    public int start(int curSeq){
        Iterator<List<Integer>> iterator = nodes.iterator();
        while (iterator.hasNext()){
            List<Integer> node = iterator.next();
            if (node.contains(curSeq)) {
                int idx = node.indexOf(curSeq);
                // 是否为末尾货架
                if (iterator.hasNext()) {
                    return iterator.next().get(idx);
                } else {
                    List<Integer> first = nodes.get(0);
                    int val = first.get(idx);
                    int res = size / group + 1 + offset - val;
                    // 反向命中货架时不再是对立下标（相对于巷道）
                    if (res < val) {
                        // 轮询所有货架后重新开始定位
                        if (val - res - offset == 1) {
                            return first.get(0);
                        }
                        res = res + 1;
                    }
                    return res + offset;
                }
            }
        }
        return -1;
    }

    public Integer get(Integer curRow) {
        for (List<Integer> node : nodes){
            if (node.contains(curRow)) {
                return nodes.indexOf(node) + 1;
            }
        }
        throw new CoolException("货排检索系统报错， node:" + JSON.toJSONString(nodes) + ", curRow:" + curRow);
    }

    public static void main(String[] args) throws InterruptedException {
        Shelves shelves = new Shelves(8,2);
        System.out.println(shelves.nodes.toString());
        int start = 1;
        while (true) {
            System.out.println(start);
            start = shelves.start(start);
            Thread.sleep(500L);
        }
    }

}