/*
 * Copyright (c) 2009-2013 Panxiaobo
 * 
 * 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 pxb.android.axml;

import java.io.IOException;
import java.util.Stack;

import static pxb.android.axml.AxmlParser.*;

/**
 * a class to read android axml
 *
 * @author <a href="mailto:pxb1988@gmail.com">Panxiaobo</a>
 */
public class AxmlReader {
    public static final NodeVisitor EMPTY_VISITOR = new NodeVisitor() {

        @Override
        public NodeVisitor child(String ns, String name) {
            return this;
        }

    };
    final AxmlParser parser;

    public AxmlReader(byte[] data) {
        super();
        this.parser = new AxmlParser(data);
    }

    public void accept(final AxmlVisitor av) throws IOException {
        Stack<NodeVisitor> nvs = new Stack<NodeVisitor>();
        NodeVisitor tos = av;
        while (true) {
            int type = parser.next();
            switch (type) {
                case START_TAG:
                    nvs.push(tos);
                    tos = tos.child(parser.getNamespaceUri(), parser.getName());
                    if (tos != null) {
                        if (tos != EMPTY_VISITOR) {
                            tos.line(parser.getLineNumber());
                            for (int i = 0; i < parser.getAttrCount(); i++) {
                                tos.attr(parser.getAttrNs(i), parser.getAttrName(i), parser.getAttrResId(i),
                                        parser.getAttrType(i), parser.getAttrValue(i));
                            }
                        }
                    } else {
                        tos = EMPTY_VISITOR;
                    }
                    break;
                case END_TAG:
                    tos.end();
                    tos = nvs.pop();
                    break;
                case START_NS:
                    av.ns(parser.getNamespacePrefix(), parser.getNamespaceUri(), parser.getLineNumber());
                    break;
                case END_NS:
                    break;
                case TEXT:
                    tos.text(parser.getLineNumber(), parser.getText());
                    break;
                case END_FILE:
                    return;
            }
        }
    }
}
