/**
    *    Copyright 2009-2019 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.scripting;
  
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * @author Frank D. Martinez [mnesarco]
   */
  public class LanguageDriverRegistry {
  
    private final Map<Class<? extends LanguageDriver>, LanguageDriver> LANGUAGE_DRIVER_MAP = new HashMap<>();
  
    private Class<? extends LanguageDriver> defaultDriverClass;
  
    public void register(Class<? extends LanguageDriver> cls) {
      if (cls == null) {
        throw new IllegalArgumentException("null is not a valid Language Driver");
      }
      LANGUAGE_DRIVER_MAP.computeIfAbsent(cls, k -> {
        try {
          return k.getDeclaredConstructor().newInstance();
        } catch (Exception ex) {
          throw new ScriptingException("Failed to load language driver for " + cls.getName(), ex);
        }
      });
    }
  
    public void register(LanguageDriver instance) {
      if (instance == null) {
        throw new IllegalArgumentException("null is not a valid Language Driver");
      }
      Class<? extends LanguageDriver> cls = instance.getClass();
      if (!LANGUAGE_DRIVER_MAP.containsKey(cls)) {
        LANGUAGE_DRIVER_MAP.put(cls, instance);
      }
    }
  
    public LanguageDriver getDriver(Class<? extends LanguageDriver> cls) {
      return LANGUAGE_DRIVER_MAP.get(cls);
    }
  
    public LanguageDriver getDefaultDriver() {
      return getDriver(getDefaultDriverClass());
    }
  
    public Class<? extends LanguageDriver> getDefaultDriverClass() {
      return defaultDriverClass;
    }
  
    public void setDefaultDriverClass(Class<? extends LanguageDriver> defaultDriverClass) {
      register(defaultDriverClass);
      this.defaultDriverClass = defaultDriverClass;
    }
  
  }