/*
  *  Copyright (C) 2022 github.com/REAndroid
  *
  *  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 com.reandroid.xml;

import android.content.res.XmlResourceParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlSerializer;

import java.io.IOException;

public class XmlParserToSerializer {
    private final XmlSerializer serializer;
    private final XmlResourceParser parser;
    public XmlParserToSerializer(XmlResourceParser parser, XmlSerializer serializer){
        this.parser = parser;
        this.serializer = serializer;
    }
    public void write() throws IOException, XmlPullParserException {
        XmlResourceParser parser = this.parser;
        int event = parser.next();
        while (nextEvent(event)){
            event = parser.next();
        }
        close();
    }
    private void close(){
        parser.close();
    }
    private boolean nextEvent(int event) throws IOException, XmlPullParserException {
        boolean hasNext = true;
        switch (event){
            case XmlResourceParser.START_DOCUMENT:
                onStartDocument();
                break;
            case XmlResourceParser.START_TAG:
                onStartTag();
                break;
            case XmlResourceParser.TEXT:
                onText();
                break;
            case XmlResourceParser.COMMENT:
                onComment();
                break;
            case XmlResourceParser.END_TAG:
                onEndTag();
                break;
            case XmlResourceParser.END_DOCUMENT:
                onEndDocument();
                hasNext = false;
                break;
        }
        return hasNext;
    }

    private void onStartDocument() throws IOException{
        serializer.startDocument("utf-8", null);
    }
    private void onStartTag() throws IOException, XmlPullParserException {
        XmlResourceParser parser = this.parser;
        XmlSerializer serializer = this.serializer;
        serializer.setFeature("http://xmlpull.org/v1/doc/features.html#indent-output", true);
        int nsCount = parser.getNamespaceCount(parser.getDepth());
        for(int i=0; i<nsCount; i++){
            String prefix = parser.getNamespacePrefix(i);
            String namespace = parser.getNamespaceUri(i);
            serializer.setPrefix(prefix, namespace);
        }
        serializer.startTag(parser.getNamespace(), parser.getName());
        int attrCount = parser.getAttributeCount();
        for(int i=0; i<attrCount; i++){
            serializer.attribute(parser.getAttributeNamespace(i),
                    parser.getAttributeName(i),
                    parser.getAttributeValue(i));
        }
    }
    private void onText() throws IOException{
        serializer.text(parser.getText());
    }
    private void onComment() throws IOException{
        serializer.comment(parser.getText());
    }
    private void onEndTag() throws IOException{
        serializer.endTag(parser.getNamespace(), parser.getName());
    }
    private void onEndDocument() throws IOException{
        serializer.endDocument();
    }
}