/**
    *    Copyright 2009-2015 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
    *
    *       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.apache.ibatis.jdbc;
  
  import java.io.BufferedReader;
  import java.io.PrintWriter;
  import java.io.Reader;
  import java.io.UnsupportedEncodingException;
  import java.sql.Connection;
  import java.sql.ResultSet;
  import java.sql.ResultSetMetaData;
  import java.sql.SQLException;
  import java.sql.Statement;
  
  /**
   * @author Clinton Begin
   */
  public class ScriptRunner {
  
    private static final String LINE_SEPARATOR = System.getProperty("line.separator", "\n");
  
    private static final String DEFAULT_DELIMITER = ";";
  
    private Connection connection;
  
    private boolean stopOnError;
    private boolean autoCommit;
    private boolean sendFullScript;
    private boolean removeCRs;
    private boolean escapeProcessing = true;
  
    private PrintWriter logWriter = new PrintWriter(System.out);
    private PrintWriter errorLogWriter = new PrintWriter(System.err);
  
    private String delimiter = DEFAULT_DELIMITER;
    private boolean fullLineDelimiter = false;
  
    public ScriptRunner(Connection connection) {
      this.connection = connection;
    }
  
    public void setStopOnError(boolean stopOnError) {
      this.stopOnError = stopOnError;
    }
  
    public void setAutoCommit(boolean autoCommit) {
      this.autoCommit = autoCommit;
    }
  
    public void setSendFullScript(boolean sendFullScript) {
      this.sendFullScript = sendFullScript;
    }
  
    public void setRemoveCRs(boolean removeCRs) {
      this.removeCRs = removeCRs;
    }
  
    /**
     * @since 3.1.1
     */
    public void setEscapeProcessing(boolean escapeProcessing) {
      this.escapeProcessing = escapeProcessing;
    }
  
    public void setLogWriter(PrintWriter logWriter) {
      this.logWriter = logWriter;
    }
  
    public void setErrorLogWriter(PrintWriter errorLogWriter) {
      this.errorLogWriter = errorLogWriter;
    }
  
    public void setDelimiter(String delimiter) {
      this.delimiter = delimiter;
    }
  
    public void setFullLineDelimiter(boolean fullLineDelimiter) {
      this.fullLineDelimiter = fullLineDelimiter;
    }
  
    public void runScript(Reader reader) {
      setAutoCommit();
  
      try {
        if (sendFullScript) {
          executeFullScript(reader);
       } else {
         executeLineByLine(reader);
       }
     } finally {
       rollbackConnection();
     }
   }
 
   private void executeFullScript(Reader reader) {
     StringBuilder script = new StringBuilder();
     try {
       BufferedReader lineReader = new BufferedReader(reader);
       String line;
       while ((line = lineReader.readLine()) != null) {
         script.append(line);
         script.append(LINE_SEPARATOR);
       }
       String command = script.toString();
       println(command);
       executeStatement(command);
       commitConnection();
     } catch (Exception e) {
       String message = "Error executing: " + script + ".  Cause: " + e;
       printlnError(message);
       throw new RuntimeSqlException(message, e);
     }
   }
 
   private void executeLineByLine(Reader reader) {
     StringBuilder command = new StringBuilder();
     try {
       BufferedReader lineReader = new BufferedReader(reader);
       String line;
       while ((line = lineReader.readLine()) != null) {
         command = handleLine(command, line);
       }
       commitConnection();
       checkForMissingLineTerminator(command);
     } catch (Exception e) {
       String message = "Error executing: " + command + ".  Cause: " + e;
       printlnError(message);
       throw new RuntimeSqlException(message, e);
     }
   }
 
   public void closeConnection() {
     try {
       connection.close();
     } catch (Exception e) {
       // ignore
     }
   }
 
   private void setAutoCommit() {
     try {
       if (autoCommit != connection.getAutoCommit()) {
         connection.setAutoCommit(autoCommit);
       }
     } catch (Throwable t) {
       throw new RuntimeSqlException("Could not set AutoCommit to " + autoCommit + ". Cause: " + t, t);
     }
   }
 
   private void commitConnection() {
     try {
       if (!connection.getAutoCommit()) {
         connection.commit();
       }
     } catch (Throwable t) {
       throw new RuntimeSqlException("Could not commit transaction. Cause: " + t, t);
     }
   }
 
   private void rollbackConnection() {
     try {
       if (!connection.getAutoCommit()) {
         connection.rollback();
       }
     } catch (Throwable t) {
       // ignore
     }
   }
 
   private void checkForMissingLineTerminator(StringBuilder command) {
     if (command != null && command.toString().trim().length() > 0) {
       throw new RuntimeSqlException("Line missing end-of-line terminator (" + delimiter + ") => " + command);
     }
   }
 
   private StringBuilder handleLine(StringBuilder command, String line) throws SQLException, UnsupportedEncodingException {
     String trimmedLine = line.trim();
     if (lineIsComment(trimmedLine)) {
         final String cleanedString = trimmedLine.substring(2).trim().replaceFirst("//", "");
         if(cleanedString.toUpperCase().startsWith("@DELIMITER")) {
             delimiter = cleanedString.substring(11,12);
             return command;
         }
       println(trimmedLine);
     } else if (commandReadyToExecute(trimmedLine)) {
       command.append(line.substring(0, line.lastIndexOf(delimiter)));
       command.append(LINE_SEPARATOR);
       println(command);
       executeStatement(command.toString());
       command.setLength(0);
     } else if (trimmedLine.length() > 0) {
       command.append(line);
       command.append(LINE_SEPARATOR);
     }
     return command;
   }
 
   private boolean lineIsComment(String trimmedLine) {
     return trimmedLine.startsWith("//") || trimmedLine.startsWith("--");
   }
 
   private boolean commandReadyToExecute(String trimmedLine) {
     // issue #561 remove anything after the delimiter
     return !fullLineDelimiter && trimmedLine.contains(delimiter) || fullLineDelimiter && trimmedLine.equals(delimiter);
   }
 
   private void executeStatement(String command) throws SQLException {
     boolean hasResults = false;
     Statement statement = connection.createStatement();
     statement.setEscapeProcessing(escapeProcessing);
     String sql = command;
     if (removeCRs) {
       sql = sql.replaceAll("\r\n", "\n");
     }
     if (stopOnError) {
       hasResults = statement.execute(sql);
     } else {
       try {
         hasResults = statement.execute(sql);
       } catch (SQLException e) {
         String message = "Error executing: " + command + ".  Cause: " + e;
         printlnError(message);
       }
     }
     printResults(statement, hasResults);
     try {
       statement.close();
     } catch (Exception e) {
       // Ignore to workaround a bug in some connection pools
     }
   }
 
   private void printResults(Statement statement, boolean hasResults) {
     try {
       if (hasResults) {
         ResultSet rs = statement.getResultSet();
         if (rs != null) {
           ResultSetMetaData md = rs.getMetaData();
           int cols = md.getColumnCount();
           for (int i = 0; i < cols; i++) {
             String name = md.getColumnLabel(i + 1);
             print(name + "\t");
           }
           println("");
           while (rs.next()) {
             for (int i = 0; i < cols; i++) {
               String value = rs.getString(i + 1);
               print(value + "\t");
             }
             println("");
           }
         }
       }
     } catch (SQLException e) {
       printlnError("Error printing results: " + e.getMessage());
     }
   }
 
   private void print(Object o) {
     if (logWriter != null) {
       logWriter.print(o);
       logWriter.flush();
     }
   }
 
   private void println(Object o) {
     if (logWriter != null) {
       logWriter.println(o);
       logWriter.flush();
     }
   }
 
   private void printlnError(Object o) {
     if (errorLogWriter != null) {
       errorLogWriter.println(o);
       errorLogWriter.flush();
     }
   }
 
 }