studio.raptor.sqlparser.visitor.functions.Insert Maven / Gradle / Ivy

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/*
 * Copyright 1999-2017 Alibaba Group Holding Ltd.
 *
 * 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 studio.raptor.sqlparser.visitor.functions;

import static studio.raptor.sqlparser.visitor.SQLEvalVisitor.EVAL_VALUE;

import studio.raptor.sqlparser.ast.SQLExpr;
import studio.raptor.sqlparser.ast.expr.SQLMethodInvokeExpr;
import studio.raptor.sqlparser.visitor.SQLEvalVisitor;

public class Insert implements Function {

  public final static Insert instance = new Insert();

  public Object eval(SQLEvalVisitor visitor, SQLMethodInvokeExpr x) {
    if (x.getParameters().size() != 4) {
      return SQLEvalVisitor.EVAL_ERROR;
    }

    SQLExpr param0 = x.getParameters().get(0);
    SQLExpr param1 = x.getParameters().get(1);
    SQLExpr param2 = x.getParameters().get(2);
    SQLExpr param3 = x.getParameters().get(3);
    param0.accept(visitor);
    param1.accept(visitor);
    param2.accept(visitor);
    param3.accept(visitor);

    Object param0Value = param0.getAttributes().get(EVAL_VALUE);
    Object param1Value = param1.getAttributes().get(EVAL_VALUE);
    Object param2Value = param2.getAttributes().get(EVAL_VALUE);
    Object param3Value = param3.getAttributes().get(EVAL_VALUE);

    if (!(param0Value instanceof String)) {
      return SQLEvalVisitor.EVAL_ERROR;
    }
    if (!(param1Value instanceof Number)) {
      return SQLEvalVisitor.EVAL_ERROR;
    }
    if (!(param2Value instanceof Number)) {
      return SQLEvalVisitor.EVAL_ERROR;
    }
    if (!(param3Value instanceof String)) {
      return SQLEvalVisitor.EVAL_ERROR;
    }

    String str = (String) param0Value;
    int pos = ((Number) param1Value).intValue();
    int len = ((Number) param2Value).intValue();
    String newstr = (String) param3Value;

    if (pos <= 0) {
      return str;
    }

    if (pos == 1) {
      if (len > str.length()) {
        return newstr;
      }
      return newstr + str.substring(len);
    }

    String first = str.substring(0, pos - 1);
    if (pos + len - 1 > str.length()) {
      return first + newstr;
    }

    return first + newstr + str.substring(pos + len - 1);
  }
}