package org.apache.commons.ognl;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

import java.lang.reflect.Array;
import java.util.Map;

import static java.lang.String.format;

/**
 * Implementation of PropertyAccessor that uses numbers and dynamic subscripts as properties to index into Java arrays.
 */
public class ArrayPropertyAccessor
    extends ObjectPropertyAccessor
    implements PropertyAccessor
{

    @Override
    public Object getProperty( Map<String, Object> context, Object target, Object name )
        throws OgnlException
    {
        Object result = null;

        if ( name instanceof String )
        {
            if ( "length".equals( name ) )
            {
                result = Array.getLength( target );
            }
            else
            {
                result = super.getProperty( context, target, name );
            }
        }
        else
        {
            Object index = name;

            if ( index instanceof DynamicSubscript )
            {
                int len = Array.getLength( target );

                switch ( ( (DynamicSubscript) index ).getFlag() )
                {
                    case DynamicSubscript.ALL:
                        result = Array.newInstance( target.getClass().getComponentType(), len );
                        System.arraycopy( target, 0, result, 0, len );
                        break;
                    case DynamicSubscript.FIRST:
                        index = ( len > 0 ) ? 0 : -1;
                        break;
                    case DynamicSubscript.MID:
                        index = ( len > 0 ) ? ( len / 2 ) : -1;
                        break;
                    case DynamicSubscript.LAST:
                        index = ( len > 0 ) ? ( len - 1 ) : -1;
                        break;
                    default: break;
                }
            }
            if ( result == null )
            {
                if ( index instanceof Number )
                {
                    int i = ( (Number) index ).intValue();

                    result = ( i >= 0 ) ? Array.get( target, i ) : null;
                }
                else
                {
                    throw new NoSuchPropertyException( target, index );
                }
            }
        }
        return result;
    }

    @Override
    public void setProperty( Map<String, Object> context, Object target, Object name, Object value )
        throws OgnlException
    {
        boolean isNumber = ( name instanceof Number );

        if ( isNumber || ( name instanceof DynamicSubscript ) )
        {
            TypeConverter converter = ( (OgnlContext) context ).getTypeConverter();
            Object convertedValue;

            convertedValue = converter.convertValue( context, target, null, name.toString(), value,
                                                     target.getClass().getComponentType() );
            if ( isNumber )
            {
                int i = ( (Number) name ).intValue();

                if ( i >= 0 )
                {
                    Array.set( target, i, convertedValue );
                }
            }
            else
            {
                int len = Array.getLength( target );

                switch ( ( (DynamicSubscript) name ).getFlag() )
                {
                    case DynamicSubscript.ALL:
                        System.arraycopy( target, 0, convertedValue, 0, len );
                        return;
                    default:
                        break;
                }
            }
        }
        else
        {
            if ( name instanceof String )
            {
                super.setProperty( context, target, name, value );
            }
            else
            {
                throw new NoSuchPropertyException( target, name );
            }
        }
    }

    @Override
    public String getSourceAccessor( OgnlContext context, Object target, Object index )
    {
        String indexStr = getIndexString( context, index );

        context.setCurrentAccessor( target.getClass() );
        context.setCurrentType( target.getClass().getComponentType() );

        return format( "[%s]", indexStr );
    }

    @Override
    public String getSourceSetter( OgnlContext context, Object target, Object index )
    {
        String indexStr = getIndexString( context, index );

        Class<?> type = target.getClass().isArray() ? target.getClass().getComponentType() : target.getClass();

        context.setCurrentAccessor( target.getClass() );
        context.setCurrentType( target.getClass().getComponentType() );

        if ( type.isPrimitive() )
        {
            Class<?> wrapClass = OgnlRuntime.getPrimitiveWrapperClass( type );

            return format( "[%s]=((%s)org.apache.commons.ognl.OgnlOps.convertValue($3,%s.class, true)).%s", indexStr,
                           wrapClass.getName(), wrapClass.getName(), OgnlRuntime.getNumericValueGetter( wrapClass ) );
        }
        return format( "[%s]=org.apache.commons.ognl.OgnlOps.convertValue($3,%s.class)", indexStr, type.getName() );
    }

    private static String getIndexString( OgnlContext context, Object index )
    {
        String indexStr = index.toString();

        // need to convert to primitive for list index access

        // System.out.println("index class " + index.getClass() + " current type " + context.getCurrentType() +
        // " current object class " + context.getCurrentObject().getClass());

        if ( context.getCurrentType() != null && !context.getCurrentType().isPrimitive()
            && Number.class.isAssignableFrom( context.getCurrentType() ) )
        {
            indexStr += "." + OgnlRuntime.getNumericValueGetter( context.getCurrentType() );
        }
        else if ( context.getCurrentObject() != null && Number.class.isAssignableFrom(
            context.getCurrentObject().getClass() ) && !context.getCurrentType().isPrimitive() )
        {
            // means it needs to be cast first as well

            String toString =
                String.class.isInstance( index ) && context.getCurrentType() != Object.class ? "" : ".toString()";

            indexStr = format( "org.apache.commons.ognl.OgnlOps#getIntValue(%s%s)", indexStr, toString );
        }
        return indexStr;
    }
}