package org.opendaylight.controller.sal.restconf.impl.test;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;

import javax.xml.stream.XMLStreamException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.opendaylight.yangtools.yang.data.api.CompositeNode;
import org.opendaylight.yangtools.yang.data.api.Node;
import org.opendaylight.yangtools.yang.data.api.SimpleNode;
import org.opendaylight.yangtools.yang.data.impl.XmlTreeBuilder;
import org.opendaylight.yangtools.yang.model.api.Module;
import org.opendaylight.yangtools.yang.model.api.SchemaContext;
import org.opendaylight.yangtools.yang.model.parser.api.YangModelParser;
import org.opendaylight.yangtools.yang.parser.impl.YangParserImpl;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Document;

final class TestUtils {

    private static final Logger logger = LoggerFactory.getLogger(TestUtils.class);

    private final static YangModelParser parser = new YangParserImpl();

    public static Set<Module> loadModules(String resourceDirectory) throws FileNotFoundException {
        final File testDir = new File(resourceDirectory);
        final String[] fileList = testDir.list();
        final List<File> testFiles = new ArrayList<File>();
        if (fileList == null) {
            throw new FileNotFoundException(resourceDirectory);
        }
        for (int i = 0; i < fileList.length; i++) {
            String fileName = fileList[i];
            if (new File(testDir, fileName).isDirectory() == false) {
                testFiles.add(new File(testDir, fileName));
            }
        }
        return parser.parseYangModels(testFiles);
    }

    public static SchemaContext loadSchemaContext(Set<Module> modules) {
        return parser.resolveSchemaContext(modules);
    }

    public static SchemaContext loadSchemaContext(String resourceDirectory) throws FileNotFoundException {
        return parser.resolveSchemaContext(loadModules(resourceDirectory));
    }

    public static Module findModule(Set<Module> modules, String moduleName) {
        Module result = null;
        for (Module module : modules) {
            if (module.getName().equals(moduleName)) {
                result = module;
                break;
            }
        }
        return result;
    }

    public static CompositeNode loadCompositeNode(InputStream xmlInputStream) throws FileNotFoundException {
        if (xmlInputStream == null) {
            throw new IllegalArgumentException();
        }
        Node<?> dataTree;
        try {
            dataTree = XmlTreeBuilder.buildDataTree(xmlInputStream);
        } catch (XMLStreamException e) {
            logger.error("Error during building data tree from XML", e);
            return null;
        }
        if (dataTree == null) {
            logger.error("data tree is null");
            return null;
        }
        if (dataTree instanceof SimpleNode) {
            logger.error("RPC XML was resolved as SimpleNode");
            return null;
        }
        return (CompositeNode) dataTree;
    }

    public static String getDocumentInPrintableForm(Document doc) {
        try {
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            TransformerFactory tf = TransformerFactory.newInstance();
            Transformer transformer = tf.newTransformer();
            transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
            transformer.setOutputProperty(OutputKeys.METHOD, "xml");
            transformer.setOutputProperty(OutputKeys.INDENT, "yes");
            transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
            transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");

            transformer.transform(new DOMSource(doc), new StreamResult(new OutputStreamWriter(out, "UTF-8")));
            byte[] charData = out.toByteArray();
            return new String(charData, "UTF-8");
        } catch (IOException | TransformerException e) {
            String msg = "Error during transformation of Document into String";
            logger.error(msg, e);
            return msg;
        }

    }

}