package com.iplatform.gather;

import com.walker.store.support.DatabaseStore;

/**
 * 单表数据采集调度器默认实现。后续该对象会废弃，没太大意义，因为通常都不会只采集一个表。
 * @author shikeying
 * @date 2016年2月22日
 *
 */
public abstract class SingleTableGatherScheduler extends GatherScheduler{

    private String tableName;

    private String createTableSql;

    private String loadSql;

    private int index = 0;

    private int pageSize = 64;

    public SingleTableGatherScheduler(int id, String name, DatabaseStore store){
        super(id, name, store);
    }

    public void setTableName(String tableName) {
        this.tableName = tableName;
    }

    public void setCreateTableSql(String createTableSql) {
        this.createTableSql = createTableSql;
    }

    public void setLoadSql(String loadSql) {
        this.loadSql = loadSql;
    }

    public void setPageSize(int pageSize) {
        this.pageSize = pageSize;
    }

    @Override
    protected Object[] getRunParameters(Object previousInvokeResult) {
        // 从原始表加载数据，这里主要是给出加载的条件。
        Object[] params = new Object[2];
        String querySql = null;
        if(this.getInvokeCount() == 0){
            logger.debug("第一次执行：getRunParameters");
            querySql = this.loadSql + getPageSQLInfo(index, pageSize);
            params[0] = 0;
            index += pageSize;

        } else if(previousInvokeResult != null){
            logger.debug("第" + this.getInvokeCount() + "次调用，前一次存在数据");
            querySql = this.loadSql + getPageSQLInfo(index, pageSize);
            params[0] = index;
            index += pageSize;

        } else {
            logger.debug("第" + this.getInvokeCount() + "次调用，前一次未获得数据");
            querySql = this.loadSql + getPageSQLInfo(index, pageSize);
            if(index - pageSize >= 0){
                index -= pageSize;
                params[0] = index;
                index += pageSize;
            } else {
                params[0] = 0;
                index += pageSize;
            }
        }
        logger.debug("-----> SQL = " + querySql + ", index = " + params[0]);

//		params[0] = index;
        params[1] = pageSize;
        return new Object[]{tableName, createTableSql, null, new Object[]{querySql, params}};
    }

    /**
     * 子类提供分页查询的SQL代码，如：MySQL = limit ?, ?、ORACLE等
     * @param index
     * @param pageSize
     * @return
     */
    protected abstract String getPageSQLInfo(int index, int pageSize);
}