/*
    *    Copyright 2010-2023 the original author or authors.
    *
    *    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
    *
    *       https://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.apache.ibatis.migration.operations;
  
  import java.math.BigDecimal;
  import java.sql.Connection;
  import java.sql.PreparedStatement;
  import java.sql.ResultSet;
  import java.sql.SQLException;
  import java.sql.Statement;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.ibatis.migration.Change;
  import org.apache.ibatis.migration.options.DatabaseOperationOption;
  
  public class ChangelogOperation {
    private final Connection con;
    private final DatabaseOperationOption option;
  
    public ChangelogOperation(Connection con, DatabaseOperationOption option) {
      this.con = con;
      this.option = option;
    }
  
    public boolean tableExists() {
      try (Statement stmt = con.createStatement();
          ResultSet rs = stmt.executeQuery("select count(1) from " + option.getChangelogTable())) {
        return rs.next();
      } catch (SQLException e) {
        return false;
      }
    }
  
    public List<Change> selectAll() throws SQLException {
      List<Change> changes = new ArrayList<>();
      try (
          PreparedStatement stmt = con
              .prepareStatement("select ID, APPLIED_AT, DESCRIPTION from " + option.getChangelogTable() + " order by ID");
          ResultSet rs = stmt.executeQuery()) {
        while (rs.next()) {
          changes.add(new Change(rs.getBigDecimal(1), rs.getString(2), rs.getString(3)));
        }
        return changes;
      }
    }
  
    public void insert(Change change) throws SQLException {
      try (PreparedStatement stmt = con.prepareStatement(
          "insert into " + option.getChangelogTable() + " (ID, APPLIED_AT, DESCRIPTION) values (?,?,?)")) {
        stmt.setBigDecimal(1, change.getId());
        stmt.setString(2, change.getAppliedTimestamp());
        stmt.setString(3, change.getDescription());
        stmt.execute();
        con.commit();
      }
    }
  
    public void deleteById(BigDecimal id) throws SQLException {
      try (PreparedStatement stmt = con.prepareStatement("delete from " + option.getChangelogTable() + " where ID = ?")) {
        stmt.setBigDecimal(1, id);
        stmt.execute();
        con.commit();
      }
    }
  }