package com.huojutech.sharding.algorithm;

import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import groovy.util.logging.Slf4j;
import io.shardingsphere.core.api.algorithm.sharding.ListShardingValue;
import io.shardingsphere.core.api.algorithm.sharding.PreciseShardingValue;
import io.shardingsphere.core.api.algorithm.sharding.RangeShardingValue;
import io.shardingsphere.core.api.algorithm.sharding.ShardingValue;
import io.shardingsphere.core.api.algorithm.sharding.standard.RangeShardingAlgorithm;

@Slf4j
public class RangeTableShardingAlgorithm implements RangeShardingAlgorithm<String> {
    
    
    public Collection<String> doSharding(Collection<String> availableTargetNames,
            Collection<ShardingValue> shardingValues) {
        
        Collection<Object> orderCodeValues = getShardingValue(shardingValues, "order_code");
        Collection<Object> dateValues = getShardingValue(shardingValues, "gmt_create");
        List<String> shardingSuffix = new ArrayList<>();
        
        /**例如：根据user_id + order_id 双分片键来进行分表*/
        //Set<List<Integer>> valueResult = Sets.cartesianProduct(userIdValues, orderIdValues);
        for (Object orderCode : orderCodeValues) {
            long code = Long.parseLong(((String)orderCode).substring(16, 20));
            
            for (Object date : dateValues) {                
                Timestamp timestamp = (Timestamp)date;
                Calendar calendar = Calendar.getInstance();
                calendar.setTimeInMillis(timestamp.getTime());
                int year = calendar.get(Calendar.YEAR);
                String suffix = year + "_" + (code&0x001);
                
                availableTargetNames.forEach(x -> {
                    if (x.endsWith(suffix)) {
                        shardingSuffix.add(x);
                    }
                });
            }
        }
                
        return shardingSuffix;
    }

    private Collection<Object> getShardingValue(Collection<ShardingValue> shardingValues, final String key) {
        Collection<Object> valueSet = new ArrayList<>();
        Iterator<ShardingValue> iterator = shardingValues.iterator();
        while (iterator.hasNext()) {
            ShardingValue next = iterator.next();
            if (next instanceof ListShardingValue) {
                ListShardingValue value = (ListShardingValue) next;
                /**例如：根据user_id + order_id 双分片键来进行分表*/
                if (value.getColumnName().equals(key)) {
                    return value.getValues();
                }
            }
        }
        return valueSet;
    }

    public String doSharding(Collection<String> availableTargetNames, PreciseShardingValue<String> shardingValue) {
        long code = Long.parseLong((shardingValue.getValue()).substring(16, 20));
        long year = Long.parseLong((shardingValue.getValue()).substring(0, 4));
        String suffix = year + "_" + (code&0x001);
        
        for (String tableName : availableTargetNames) {
            if (tableName.endsWith(suffix)) {
                return tableName;
            }
        }
        return null;
    }

    @Override
    public Collection<String> doSharding(Collection<String> availableTargetNames,
            RangeShardingValue<String> shardingValue) {
        
        
        return null;
    }

}