
/**
 * Copyright (c) 2011-2019, James Zhan 詹波 (jfinal@126.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.tio.jfinal.plugin.activerecord.dialect;

import org.tio.jfinal.plugin.activerecord.*;
import org.tio.jfinal.plugin.activerecord.builder.KeepByteAndShortModelBuilder;
import org.tio.jfinal.plugin.activerecord.builder.KeepByteAndShortRecordBuilder;

import java.math.BigInteger;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.Function;
import java.util.regex.Pattern;

/**
 * Dialect.
 */
public abstract class Dialect {
	
	// 指示 Generator、ModelBuilder、RecordBuilder 是否保持住 Byte、Short 类型
	protected boolean keepByteAndShort = false;
	protected ModelBuilder modelBuilder = ModelBuilder.me;
	protected RecordBuilder recordBuilder = RecordBuilder.me;
	
	// Methods for common
	public abstract String forTableBuilderDoBuild(String tableName);
	public abstract String forPaginate(int pageNumber, int pageSize, StringBuilder findSql);
	
	// Methods for Model
	public abstract String forModelFindById(Table table, String columns);
	public abstract String forModelDeleteById(Table table);
	public abstract void forModelSave(Table table, Map<String, Object> attrs, StringBuilder sql, List<Object> paras);
	public abstract void forModelUpdate(Table table, Map<String, Object> attrs, Set<String> modifyFlag, StringBuilder sql, List<Object> paras);
	
	// Methods for DbPro. Do not delete the String[] pKeys parameter, the element of pKeys needs to trim()
	public abstract String forDbFindById(String tableName, String[] pKeys);
	public abstract String forDbDeleteById(String tableName, String[] pKeys);
	public abstract void forDbSave(String tableName, String[] pKeys, Record record, StringBuilder sql, List<Object> paras);
	public abstract void forDbUpdate(String tableName, String[] pKeys, Object[] ids, Record record, StringBuilder sql, List<Object> paras);
	
	public String forFindAll(String tableName) {
		return "select * from " + tableName;
	}
	
	/**
	 * 指示 Generator、ModelBuilder、RecordBuilder 是否保持住 Byte、Short 类型
	 */
	public Dialect setKeepByteAndShort(boolean keepByteAndShort) {
		this.keepByteAndShort = keepByteAndShort;
		/**
		 * 内部的 4 个 if 判断是为了避免替换掉用户通过 setModelBuilder(...)
		 * setRecordBuilder(...) 配置的自定义 builder
		 */
		if (keepByteAndShort) {
			if (modelBuilder.getClass() == ModelBuilder.class) {
				modelBuilder = KeepByteAndShortModelBuilder.me;
			}
			if (recordBuilder.getClass() == RecordBuilder.class) {
				recordBuilder = KeepByteAndShortRecordBuilder.me;
			}
		} else {
			if (modelBuilder.getClass() == KeepByteAndShortModelBuilder.class) {
				modelBuilder = ModelBuilder.me;
			}
			if (recordBuilder.getClass() == KeepByteAndShortRecordBuilder.class) {
				recordBuilder = RecordBuilder.me;
			}
		}
		return this;
	}
	
	/**
	 * 指示 MetaBuilder 生成的 ColumnMeta.javaType 是否保持住 Byte、Short 类型
	 * 进而 BaseModelBuilder 生成针对 Byte、Short 类型的获取方法： 
	 * getByte(String)、getShort(String)
	 */
	public boolean isKeepByteAndShort() {
		return keepByteAndShort;
	}
	
	/**
	 * 配置自定义 ModelBuilder
	 * 
	 * 通过继承扩展 ModelBuilder 可以对 JDBC 到 java 数据类型进行定制化转换
	 * 不同数据库从 JDBC 到 java 数据类型的映射关系有所不同
	 * 
	 * 此外，还可以通过改变 ModelBuilder.buildLabelNamesAndTypes()
	 * 方法逻辑，实现下划线字段名转驼峰变量名的功能
	 */
	public Dialect setModelBuilder(ModelBuilder modelBuilder) {
		this.modelBuilder = modelBuilder;
		return this;
	}
	
	/**
	 * 配置自定义 RecordBuilder
	 * 
	 * 通过继承扩展 RecordBuilder 可以对 JDBC 到 java 数据类型进行定制化转换
	 * 不同数据库从 JDBC 到 java 数据类型的映射关系有所不同
	 * 
	 * 此外，还可以通过改变 RecordBuilder.buildLabelNamesAndTypes()
	 * 方法逻辑，实现下划线字段名转驼峰变量名的功能
	 */
	public Dialect setRecordBuilder(RecordBuilder recordBuilder) {
		this.recordBuilder = recordBuilder;
		return this;
	}
	
	@SuppressWarnings("rawtypes")
	public <T> List<T> buildModelList(ResultSet rs, Class<? extends Model> modelClass) throws SQLException, ReflectiveOperationException {
		return modelBuilder.build(rs, modelClass);
	}
	
	@SuppressWarnings("rawtypes")
	public <T> void eachModel(ResultSet rs, Class<? extends Model> modelClass, Function<T, Boolean> func) throws SQLException, ReflectiveOperationException {
		modelBuilder.build(rs, modelClass, func);
	}
	
	public List<Record> buildRecordList(Config config, ResultSet rs) throws SQLException {
		return recordBuilder.build(config, rs);
	}
	
	public void eachRecord(Config config, ResultSet rs, Function<Record, Boolean> func) throws SQLException {
		recordBuilder.build(config, rs, func);
	}
	
	/**
	 * 用于获取 Model.save() 以后自动生成的主键值，可通过覆盖此方法实现更精细的控制
	 * 目前只有 PostgreSqlDialect，覆盖过此方法
	 */
	public void getModelGeneratedKey(Model<?> model, PreparedStatement pst, Table table) throws SQLException {
		String[] pKeys = table.getPrimaryKey();
		ResultSet rs = pst.getGeneratedKeys();
		for (String pKey : pKeys) {
			if (model.get(pKey) == null || isOracle()) {
				if (rs.next()) {
					Class<?> colType = table.getColumnType(pKey);
					if (colType != null) {	// 支持没有主键的用法，有人将 model 改造成了支持无主键:济南-费小哥
						if (colType == Integer.class || colType == int.class) {
							model.set(pKey, rs.getInt(1));
						} else if (colType == Long.class || colType == long.class) {
							model.set(pKey, rs.getLong(1));
						} else if (colType == BigInteger.class) {
							processGeneratedBigIntegerKey(model, pKey, rs.getObject(1));
						} else {
							model.set(pKey, rs.getObject(1));	// It returns Long for int colType for mysql
						}
					}
				}
			}
		}
		rs.close();
	}
	
	/**
	 * mysql 数据库的  bigint unsigned 对应的 java 类型为 BigInteger
	 * 但是 rs.getObject(1) 返回值为 Long 型，造成 model.save() 以后
	 * model.getId() 时的类型转换异常 
	 */
	protected void processGeneratedBigIntegerKey(Model<?> model, String pKey, Object v) {
		if (v instanceof BigInteger) {
			model.set(pKey, (BigInteger)v);
		} else if (v instanceof Number) {
			Number n = (Number)v;
			model.set(pKey, BigInteger.valueOf(n.longValue()));
		} else {
			model.set(pKey, v);
		}
	}
	
	/**
	 * 用于获取 Db.save(tableName, record) 以后自动生成的主键值，可通过覆盖此方法实现更精细的控制
	 * 目前只有 PostgreSqlDialect，覆盖过此方法
	 */
	public void getRecordGeneratedKey(PreparedStatement pst, Record record, String[] pKeys) throws SQLException {
		ResultSet rs = pst.getGeneratedKeys();
		for (String pKey : pKeys) {
			if (record.get(pKey) == null || isOracle()) {
				if (rs.next()) {
					record.set(pKey, rs.getObject(1));	// It returns Long for int colType for mysql
				}
			}
		}
		rs.close();
	}
	
	public boolean isOracle() {
		return false;
	}
	
	public boolean isTakeOverDbPaginate() {
		return false;
	}
	
	public Page<Record> takeOverDbPaginate(Connection conn, int pageNumber, int pageSize, Boolean isGroupBySql, String totalRowSql, StringBuilder findSql, Object... paras) throws SQLException {
		throw new RuntimeException("You should implements this method in " + getClass().getName());
	}
	
	public boolean isTakeOverModelPaginate() {
		return false;
	}
	
	@SuppressWarnings("rawtypes")
	public Page takeOverModelPaginate(Connection conn, Class<? extends Model> modelClass, int pageNumber, int pageSize, Boolean isGroupBySql, String totalRowSql, StringBuilder findSql, Object... paras) throws Exception {
		throw new RuntimeException("You should implements this method in " + getClass().getName());
	}
	
	public void fillStatement(PreparedStatement pst, List<Object> paras) throws SQLException {
		for (int i=0, size=paras.size(); i<size; i++) {
			pst.setObject(i + 1, paras.get(i));
		}
	}
	
	public void fillStatement(PreparedStatement pst, Object... paras) throws SQLException {
		for (int i=0; i<paras.length; i++) {
			pst.setObject(i + 1, paras[i]);
		}
	}
	
	public String getDefaultPrimaryKey() {
		return "id";
	}
	
	public boolean isPrimaryKey(String colName, String[] pKeys) {
		for (String pKey : pKeys) {
			if (colName.equalsIgnoreCase(pKey)) {
				return true;
			}
		}
		return false;
	}
	
	/**
	 * 一、forDbXxx 系列方法中若有如下两种情况之一，则需要调用此方法对 pKeys 数组进行 trim():
	 * 1：方法中调用了 isPrimaryKey(...)：为了防止在主键相同情况下，由于前后空串造成 isPrimaryKey 返回 false
	 * 2：为了防止 tableName、colName 与数据库保留字冲突的，添加了包裹字符的：为了防止串包裹区内存在空串
	 *   如 mysql 使用的 "`" 字符以及 PostgreSql 使用的 "\"" 字符
	 * 不满足以上两个条件之一的 forDbXxx 系列方法也可以使用 trimPrimaryKeys(...) 方法让 sql 更加美观，但不是必须
	 * 
	 * 二、forModelXxx 由于在映射时已经trim()，故不再需要调用此方法
	 */
	public void trimPrimaryKeys(String[] pKeys) {
		for (int i=0; i<pKeys.length; i++) {
			pKeys[i] = pKeys[i].trim();
		}
	}
	
	protected static class Holder {
		// "order\\s+by\\s+[^,\\s]+(\\s+asc|\\s+desc)?(\\s*,\\s*[^,\\s]+(\\s+asc|\\s+desc)?)*";
		private static final Pattern ORDER_BY_PATTERN = Pattern.compile(
			"order\\s+by\\s+[^,\\s]+(\\s+asc|\\s+desc)?(\\s*,\\s*[^,\\s]+(\\s+asc|\\s+desc)?)*",
			Pattern.CASE_INSENSITIVE | Pattern.MULTILINE);
	}
	
	public String replaceOrderBy(String sql) {
		return Holder.ORDER_BY_PATTERN.matcher(sql).replaceAll("");
	}
	
	/**
	 * fillStatement 时处理日期类型
	 */
	protected void fillStatementHandleDateType(PreparedStatement pst, List<Object> paras) throws SQLException {
		for (int i=0, size=paras.size(); i<size; i++) {
			Object value = paras.get(i);
			if (value instanceof java.util.Date) {
				if (value instanceof java.sql.Date) {
					pst.setDate(i + 1, (java.sql.Date)value);
				} else if (value instanceof java.sql.Timestamp) {
					pst.setTimestamp(i + 1, (java.sql.Timestamp)value);
				} else {
					// Oracle、SqlServer 中的 TIMESTAMP、DATE 支持 new Date() 给值
					java.util.Date d = (java.util.Date)value;
					pst.setTimestamp(i + 1, new java.sql.Timestamp(d.getTime()));
				}
			} else {
				pst.setObject(i + 1, value);
			}
		}
	}
	
	/**
	 * fillStatement 时处理日期类型
	 */
	protected void fillStatementHandleDateType(PreparedStatement pst, Object... paras) throws SQLException {
		for (int i=0; i<paras.length; i++) {
			Object value = paras[i];
			if (value instanceof java.util.Date) {
				if (value instanceof java.sql.Date) {
					pst.setDate(i + 1, (java.sql.Date)value);
				} else if (value instanceof java.sql.Timestamp) {
					pst.setTimestamp(i + 1, (java.sql.Timestamp)value);
				} else {
					// Oracle、SqlServer 中的 TIMESTAMP、DATE 支持 new Date() 给值
					java.util.Date d = (java.util.Date)value;
					pst.setTimestamp(i + 1, new java.sql.Timestamp(d.getTime()));
				}
			} else {
				pst.setObject(i + 1, value);
			}
		}
	}
	
	/**
	 * 为分页方法生成查询 totalRow 值的 sql
	 * @param select sql 语句的 select 部分
	 * @param sqlExceptSelect sql 语句除了 select 以外的部分
	 * @param ext 扩展参数，在 Model 调用时传入 Model 对象，在 DbPro 调用时传入 null
	 */
	public String forPaginateTotalRow(String select, String sqlExceptSelect, Object ext) {
		return "select count(*) " + replaceOrderBy(sqlExceptSelect);
	}
}






