/*
    *    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.io.PrintStream;
  import java.sql.Connection;
  import java.sql.SQLException;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  import org.apache.ibatis.migration.Change;
  import org.apache.ibatis.migration.ConnectionProvider;
  import org.apache.ibatis.migration.MigrationException;
  import org.apache.ibatis.migration.MigrationLoader;
  import org.apache.ibatis.migration.options.DatabaseOperationOption;
  import org.apache.ibatis.migration.utils.Util;
  
  public final class StatusOperation extends DatabaseOperation {
  
    private int applied;
    private int pending;
    private int missing;
  
    private List<Change> changes;
  
    public StatusOperation operate(ConnectionProvider connectionProvider, MigrationLoader migrationsLoader,
        DatabaseOperationOption option, PrintStream printStream) {
      if (option == null) {
        option = new DatabaseOperationOption();
      }
      println(printStream, "ID             Applied At          Description");
      println(printStream, Util.horizontalLine("", 80));
      changes = new ArrayList<>();
      List<Change> migrations = migrationsLoader.getMigrations();
      String skippedOrMissing = null;
      try (Connection con = connectionProvider.getConnection()) {
        if (changelogExists(con, option)) {
          List<Change> changelog = getChangelog(con, option);
          skippedOrMissing = checkSkippedOrMissing(changelog, migrations);
  
          Set<Change> changelogAndMigrations = new HashSet<>(changelog);
          changelogAndMigrations.addAll(migrations);
  
          for (Change change : changelogAndMigrations) {
            if (!migrations.contains(change)) {
              change = new MissingScript(change);
              missing++;
            } else if (change.getAppliedTimestamp() != null) {
              applied++;
            } else {
              pending++;
            }
            changes.add(change);
          }
        } else {
          changes.addAll(migrations);
          pending = migrations.size();
        }
      } catch (SQLException e) {
        throw new MigrationException("Error getting connection. Cause: " + e, e);
      }
  
      Collections.sort(changes);
      for (Change change : changes) {
        println(printStream, change.toString());
      }
      println(printStream);
  
      if (skippedOrMissing != null && !skippedOrMissing.isEmpty()) {
        println(printStream, skippedOrMissing);
      }
  
      return this;
    }
  
    public int getAppliedCount() {
      return applied;
    }
  
    public int getPendingCount() {
      return pending;
    }
  
   public int getMissingCount() {
     return missing;
   }
 
   public List<Change> getCurrentStatus() {
     return changes;
   }
 
   class MissingScript extends Change {
     public MissingScript(Change change) {
       super(change);
     }
 
     @Override
     public String toString() {
       return super.toString() + " <=== MISSING!";
     }
   }
 }