/*
    *    Copyright 2009-2023 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.scripting.xmltags;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.StringJoiner;
  
  import ognl.OgnlContext;
  import ognl.OgnlRuntime;
  import ognl.PropertyAccessor;
  
  import org.apache.ibatis.reflection.MetaObject;
  import org.apache.ibatis.session.Configuration;
  
  /**
   * @author Clinton Begin
   */
  public class DynamicContext {
  
    public static final String PARAMETER_OBJECT_KEY = "_parameter";
    public static final String DATABASE_ID_KEY = "_databaseId";
  
    static {
      OgnlRuntime.setPropertyAccessor(ContextMap.class, new ContextAccessor());
    }
  
    private final ContextMap bindings;
    private final StringJoiner sqlBuilder = new StringJoiner(" ");
    private int uniqueNumber;
  
    public DynamicContext(Configuration configuration, Object parameterObject) {
      if (parameterObject != null && !(parameterObject instanceof Map)) {
        MetaObject metaObject = configuration.newMetaObject(parameterObject);
        boolean existsTypeHandler = configuration.getTypeHandlerRegistry().hasTypeHandler(parameterObject.getClass());
        bindings = new ContextMap(metaObject, existsTypeHandler);
      } else {
        bindings = new ContextMap(null, false);
      }
      bindings.put(PARAMETER_OBJECT_KEY, parameterObject);
      bindings.put(DATABASE_ID_KEY, configuration.getDatabaseId());
    }
  
    public Map<String, Object> getBindings() {
      return bindings;
    }
  
    public void bind(String name, Object value) {
      bindings.put(name, value);
    }
  
    public void appendSql(String sql) {
      sqlBuilder.add(sql);
    }
  
    public String getSql() {
      return sqlBuilder.toString().trim();
    }
  
    public int getUniqueNumber() {
      return uniqueNumber++;
    }
  
    static class ContextMap extends HashMap<String, Object> {
      private static final long serialVersionUID = 2977601501966151582L;
      private final MetaObject parameterMetaObject;
      private final boolean fallbackParameterObject;
  
      public ContextMap(MetaObject parameterMetaObject, boolean fallbackParameterObject) {
        this.parameterMetaObject = parameterMetaObject;
        this.fallbackParameterObject = fallbackParameterObject;
      }
  
      @Override
      public Object get(Object key) {
        String strKey = (String) key;
        if (super.containsKey(strKey)) {
          return super.get(strKey);
        }
  
        if (parameterMetaObject == null) {
          return null;
        }
  
        if (fallbackParameterObject && !parameterMetaObject.hasGetter(strKey)) {
          return parameterMetaObject.getOriginalObject();
       }
       // issue #61 do not modify the context when reading
       return parameterMetaObject.getValue(strKey);
     }
   }
 
   static class ContextAccessor implements PropertyAccessor {
 
     @Override
     public Object getProperty(OgnlContext context, Object target, Object name) {
       Map map = (Map) target;
 
       Object result = map.get(name);
       if (map.containsKey(name) || result != null) {
         return result;
       }
 
       Object parameterObject = map.get(PARAMETER_OBJECT_KEY);
       if (parameterObject instanceof Map) {
         return ((Map) parameterObject).get(name);
       }
 
       return null;
     }
 
     @Override
     public void setProperty(OgnlContext context, Object target, Object name, Object value) {
       Map<Object, Object> map = (Map<Object, Object>) target;
       map.put(name, value);
     }
 
     @Override
     public String getSourceAccessor(OgnlContext arg0, Object arg1, Object arg2) {
       return null;
     }
 
     @Override
     public String getSourceSetter(OgnlContext arg0, Object arg1, Object arg2) {
       return null;
     }
   }
 }