ScriptCommand.java

/*
 *    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.commands;

import java.io.IOException;
import java.io.Reader;
import java.math.BigDecimal;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;

import org.apache.ibatis.migration.Change;
import org.apache.ibatis.migration.MigrationException;
import org.apache.ibatis.migration.hook.MigrationHook;
import org.apache.ibatis.migration.hook.ScriptHookContext;
import org.apache.ibatis.migration.operations.DatabaseOperation;
import org.apache.ibatis.migration.operations.StatusOperation;
import org.apache.ibatis.migration.options.SelectedOptions;

public final class ScriptCommand extends BaseCommand {

  public ScriptCommand(SelectedOptions options) {
    super(options);
  }

  @Override
  public void execute(String... sparams) {
    try {
      if (sparams == null || sparams.length < 1 || sparams[0] == null) {
        throw new MigrationException("The script command requires a range of versions from v1 - v2.");
      }
      StringTokenizer parser = new StringTokenizer(sparams[0]);
      int tokenCount = parser.countTokens();
      boolean scriptPending = false;
      boolean scriptPendingUndo = false;

      String firstToken = parser.nextToken();

      if (tokenCount == 1 && firstToken.equals("pending")) {
        scriptPending = true;
      } else if (tokenCount == 1 && firstToken.equals("pending_undo")) {
        scriptPendingUndo = true;
      } else if (!scriptPending && !scriptPendingUndo && tokenCount != 2) {
        throw new MigrationException("The script command requires a range of versions from v1 - v2.");
      }

      BigDecimal v1 = scriptPending || scriptPendingUndo ? null : new BigDecimal(firstToken);
      BigDecimal v2 = scriptPending || scriptPendingUndo ? null : new BigDecimal(parser.nextToken());

      boolean undo;
      undo = scriptPendingUndo;
      if (!scriptPending && !scriptPendingUndo) {
        int comparison = v1.compareTo(v2);
        if (comparison == 0) {
          throw new MigrationException(
              "The script command requires two different versions. Use 0 to include the first version.");
        }
        undo = comparison > 0;
      }

      Map<String, Object> hookBindings = new HashMap<>();
      MigrationHook hook = createScriptHook();
      List<Change> migrations = scriptPending || scriptPendingUndo ? new StatusOperation()
          .operate(getConnectionProvider(), getMigrationLoader(), getDatabaseOperationOption(), null).getCurrentStatus()
          : getMigrationLoader().getMigrations();
      Collections.sort(migrations);
      if (undo) {
        Collections.reverse(migrations);
      }
      int count = 0;
      for (int i = 0; i < migrations.size(); i++) {
        Change change = migrations.get(i);
        if (shouldRun(change, v1, v2, scriptPending || scriptPendingUndo)) {
          if (count == 0 && hook != null) {
            hookBindings.put(MigrationHook.HOOK_CONTEXT, new ScriptHookContext(null, undo));
            hook.before(hookBindings);
            printStream.println();
          }
          if (hook != null) {
            hookBindings.put(MigrationHook.HOOK_CONTEXT, new ScriptHookContext(new Change(change), undo));
            hook.beforeEach(hookBindings);
            printStream.println();
          }
          printStream.println("-- " + change.getFilename());
          try (Reader migrationReader = getMigrationLoader().getScriptReader(change, undo)) {
            char[] cbuf = new char[1024];
            int l;
            while ((l = migrationReader.read(cbuf)) > -1) {
              printStream.print(l == cbuf.length ? cbuf : Arrays.copyOf(cbuf, l));
            }
          }
          count++;
          printStream.println();
          printStream.println();
          if (!undo) {
            printStream.println(generateVersionInsert(change));
          } else if (i + 1 < migrations.size() || !DESC_CREATE_CHANGELOG.equals(change.getDescription())) {
            printStream.println(generateVersionDelete(change));
          }
          printStream.println();
          if (hook != null) {
            hookBindings.put(MigrationHook.HOOK_CONTEXT, new ScriptHookContext(new Change(change), undo));
            hook.afterEach(hookBindings);
            printStream.println();
          }
        }
      }
      if (count > 0 && hook != null) {
        hookBindings.put(MigrationHook.HOOK_CONTEXT, new ScriptHookContext(null, undo));
        hook.after(hookBindings);
        printStream.println();
      }
    } catch (IOException e) {
      throw new MigrationException("Error generating script. Cause: " + e, e);
    }
  }

  private String generateVersionInsert(Change change) {
    return "INSERT INTO " + changelogTable() + " (ID, APPLIED_AT, DESCRIPTION) " + "VALUES (" + change.getId() + ", '"
        + DatabaseOperation.generateAppliedTimeStampAsString() + "', '" + change.getDescription().replace('\'', ' ')
        + "')" + getDelimiter();
  }

  private String generateVersionDelete(Change change) {
    return "DELETE FROM " + changelogTable() + " WHERE ID = " + change.getId() + getDelimiter();
  }

  private boolean shouldRun(Change change, BigDecimal v1, BigDecimal v2, boolean pendingOnly) {
    if (pendingOnly) {
      return change.getAppliedTimestamp() == null;
    }
    BigDecimal id = change.getId();
    if (v1.compareTo(v2) > 0) {
      return id.compareTo(v2) > 0 && id.compareTo(v1) <= 0;
    }
    return id.compareTo(v1) > 0 && id.compareTo(v2) <= 0;
  }

  // Issue 699
  private String getDelimiter() {
    StringBuilder delimiter = new StringBuilder();
    if (environment().isFullLineDelimiter()) {
      delimiter.append('\n');
    }
    delimiter.append(environment().getDelimiter());
    return delimiter.toString();
  }

  private MigrationHook createScriptHook() {
    String before = environment().getHookBeforeScript();
    String beforeEach = environment().getHookBeforeEachScript();
    String afterEach = environment().getHookAfterEachScript();
    String after = environment().getHookAfterScript();
    if (before == null && beforeEach == null && afterEach == null && after == null) {
      return null;
    }
    return createFileMigrationHook(before, beforeEach, afterEach, after);
  }
}