/*
 * 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
 *
 *   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.bcel.classfile;

import java.io.DataInput;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.Arrays;
import java.util.Iterator;
import java.util.stream.Stream;

import org.apache.bcel.Const;
import org.apache.bcel.util.Args;

// The new table is used when generic types are about...

//LocalVariableTable_attribute {
//       u2 attribute_name_index;
//       u4 attribute_length;
//       u2 local_variable_table_length;
//       {  u2 start_pc;
//          u2 length;
//          u2 name_index;
//          u2 descriptor_index;
//          u2 index;
//       } local_variable_table[local_variable_table_length];
//     }

//LocalVariableTypeTable_attribute {
//    u2 attribute_name_index;
//    u4 attribute_length;
//    u2 local_variable_type_table_length;
//    {
//      u2 start_pc;
//      u2 length;
//      u2 name_index;
//      u2 signature_index;
//      u2 index;
//    } localVariableTypeTable[local_variable_type_table_length];
//  }
// J5TODO: Needs some testing !

/**
 * Represents the LocalVariableTypeTable attribute.
 *
 * @since 6.0
 */
public class LocalVariableTypeTable extends Attribute implements Iterable<LocalVariable> {

    private static final LocalVariable[] EMPTY_ARRAY = {};

    private LocalVariable[] localVariableTypeTable; // variables

    LocalVariableTypeTable(final int nameIdx, final int len, final DataInput input, final ConstantPool cpool) throws IOException {
        this(nameIdx, len, (LocalVariable[]) null, cpool);
        final int localVariableTypeTableLength = input.readUnsignedShort();
        localVariableTypeTable = new LocalVariable[localVariableTypeTableLength];
        for (int i = 0; i < localVariableTypeTableLength; i++) {
            localVariableTypeTable[i] = new LocalVariable(input, cpool);
        }
    }

    public LocalVariableTypeTable(final int nameIndex, final int length, final LocalVariable[] localVariableTypeTable, final ConstantPool constantPool) {
        super(Const.ATTR_LOCAL_VARIABLE_TYPE_TABLE, nameIndex, length, constantPool);
        this.localVariableTypeTable = localVariableTypeTable != null ? localVariableTypeTable : LocalVariable.EMPTY_ARRAY;
        Args.requireU2(this.localVariableTypeTable.length, "localVariableTypeTable.length");
    }

    public LocalVariableTypeTable(final LocalVariableTypeTable c) {
        this(c.getNameIndex(), c.getLength(), c.getLocalVariableTypeTable(), c.getConstantPool());
    }

    @Override
    public void accept(final Visitor v) {
        v.visitLocalVariableTypeTable(this);
    }

    /**
     * @return deep copy of this attribute.
     */
    @Override
    public Attribute copy(final ConstantPool constantPool) {
        final LocalVariableTypeTable c = (LocalVariableTypeTable) clone();
        c.localVariableTypeTable = new LocalVariable[localVariableTypeTable.length];
        Arrays.setAll(c.localVariableTypeTable, i -> localVariableTypeTable[i].copy());
        c.setConstantPool(constantPool);
        return c;
    }

    @Override
    public final void dump(final DataOutputStream file) throws IOException {
        super.dump(file);
        file.writeShort(localVariableTypeTable.length);
        for (final LocalVariable variable : localVariableTypeTable) {
            variable.dump(file);
        }
    }

    public final LocalVariable getLocalVariable(final int index) {
        for (final LocalVariable variable : localVariableTypeTable) {
            if (variable.getIndex() == index) {
                return variable;
            }
        }
        return null;
    }

    public final LocalVariable[] getLocalVariableTypeTable() {
        return localVariableTypeTable;
    }

    public final int getTableLength() {
        return localVariableTypeTable == null ? 0 : localVariableTypeTable.length;
    }

    @Override
    public Iterator<LocalVariable> iterator() {
        return Stream.of(localVariableTypeTable).iterator();
    }

    public final void setLocalVariableTable(final LocalVariable[] localVariableTable) {
        this.localVariableTypeTable = localVariableTable != null ? localVariableTable : EMPTY_ARRAY;
    }

    /**
     * @return String representation.
     */
    @Override
    public final String toString() {
        final StringBuilder buf = new StringBuilder();
        for (int i = 0; i < localVariableTypeTable.length; i++) {
            buf.append(localVariableTypeTable[i].toStringShared(true));
            if (i < localVariableTypeTable.length - 1) {
                buf.append('\n');
            }
        }
        return buf.toString();
    }
}
