package liquibase.database.core;

import liquibase.Scope;
import liquibase.database.DatabaseConnection;
import liquibase.exception.DatabaseException;
import liquibase.logging.Logger;
/**
 * 通过继承PostgresDatabase实现kingbase8数据库方言
 */
public class Kingbase8Database extends PostgresDatabase {
    public static final String PRODUCT_NAME = "KingbaseES";

    private static final int DEFAULT_TCP_PORT_NUMBER = 54321;//PGSQL为5432
    private static final Logger LOG = Scope.getCurrentScope().getLog(Kingbase8Database.class);
    @Override
    public String getShortName() {
        return "kingbase8";
    }
    @Override
    protected String getDefaultDatabaseProductName() {
        return PRODUCT_NAME;
    }
    @Override
    public Integer getDefaultPort() {
        return DEFAULT_TCP_PORT_NUMBER;
    }    
    @Override
    public boolean isCorrectDatabaseImplementation(DatabaseConnection conn) throws DatabaseException {
        if (!PRODUCT_NAME.equalsIgnoreCase(conn.getDatabaseProductName())) {
            return false;
        }
        //getDatabaseMajorVersion()返回的是12应该是Kingbase封装的postgre版本
        int majorVersion = conn.getDatabaseMajorVersion();
        int minorVersion = conn.getDatabaseMinorVersion();
        if (majorVersion < 12) {
            LOG.warning(
                String.format(
                    "Your Kingbase8 software version (%d.%d) seems to indicate that your software is " +
                    "older than %d.%d. This means that you might encounter strange behaviour and " + 
                    "incorrect error messages.", majorVersion, minorVersion, 12, 1));
        }
        return true;
    }
    @Override
    public String getDefaultDriver(String url) {
    	if (url.startsWith("jdbc:kingbase8:")) {
            return "com.kingbase8.Driver";
        }
        return null;
    }
    /**
     * Should the database use "serial" datatypes vs. "generated by default as identity"
     */
    public boolean useSerialDatatypes() {
    	//postgre10以上版本默认使用 "generated by default as identity"
    	//如果需要使用"serial" datatypes，则都返回true
    	return true;
    }
}
/** 
 * 使用Postgres驱动连接Kingbase8数据库
 * 如果没有洁癖（缺省端口一定要改成54321）或者序列创建不影响的话可以直接使用liquibase的PostgresDatabase
 */
public class PostgresKingbaseDatabase extends PostgresDatabase {
    private static final int DEFAULT_TCP_PORT_NUMBER = 54321;//PGSQL为5432
    @Override
    public Integer getDefaultPort() {
        return DEFAULT_TCP_PORT_NUMBER;
    } 
    /**
     * Should the database use "serial" datatypes vs. "generated by default as identity"
     */
    public boolean useSerialDatatypes() {    	
    	return true;
    }
    @Override
    public int getPriority() {
    	//提高优先级以便优先于liquibase自带的PostgresDatabase
        return PRIORITY_DATABASE;
    }
}