/*
 * 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.
 */
package org.apache.sling.scripting.javascript.wrapper;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import javax.jcr.Node;
import javax.jcr.NodeIterator;
import javax.jcr.Property;
import javax.jcr.PropertyIterator;
import javax.jcr.PropertyType;
import javax.jcr.RepositoryException;
import javax.jcr.Value;
import javax.jcr.ValueFormatException;
import javax.jcr.nodetype.NodeType;

import org.apache.sling.scripting.javascript.SlingWrapper;
import org.mozilla.javascript.Context;
import org.mozilla.javascript.NativeArray;
import org.mozilla.javascript.ScriptRuntime;
import org.mozilla.javascript.Scriptable;
import org.mozilla.javascript.Undefined;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A wrapper for JCR nodes that exposes all properties and child nodes as
 * properties of a Javascript object.
 */
@SuppressWarnings("serial")
public class ScriptableNode extends ScriptableBase implements SlingWrapper {

    public static final String CLASSNAME = "Node";
    private static final Class<?> [] WRAPPED_CLASSES = { Node.class };

    /** default log */
    private final Logger log = LoggerFactory.getLogger(getClass());

    /**
     * The wrapped JCR Node instance. Will be {@code null} if the
     * {@link #jsConstructor(Object)} method is not called, which particularly
     * is the case for the Node host object prototype.
     */
    private Node node;

    public void jsConstructor(Object res) {
        this.node = (Node) res;
    }

    @Override
    public String getClassName() {
        return CLASSNAME;
    }

    @Override
    public Class<?> [] getWrappedClasses() {
        return WRAPPED_CLASSES;
    }

    @Override
    protected Class<?> getStaticType() {
        return Node.class;
    }

    @Override
    protected Object getWrappedObject() {
        return node;
    }

    public Object jsFunction_addNode(String path, String primaryType) throws RepositoryException {
        Node n = null;
        if(primaryType == null || "undefined".equals(primaryType)) {
            n = node.addNode(path);
        } else {
            n = node.addNode(path, primaryType);
        }

        final Object result = ScriptRuntime.toObject(this, n);
        return result;
    }

    public Object jsFunction_getNode(String path) throws RepositoryException {
        return ScriptRuntime.toObject(this, node.getNode(path));
    }

    public Object jsFunction_getChildren() {
        try {
            return toScriptableItemMap(node.getNodes());
        } catch (RepositoryException re) {
            log.warn("Cannot get children of " + jsFunction_getPath(), re);
            return toScriptableItemMap(null);
        }
    }

    public Object jsFunction_getNodes(String namePattern) {
        try {
            NodeIterator iter = null;
            if(namePattern == null || "undefined".equals(namePattern)) {
                iter = node.getNodes();
            } else {
                iter = node.getNodes(namePattern);
            }
            return toScriptableItemMap(iter);
        } catch (RepositoryException re) {
            log.warn("Cannot get children of " + jsFunction_getPath() + " with pattern " + namePattern, re);
            return toScriptableItemMap(null);
        }
    }

    public Object jsFunction_getProperties() {
        try {
            return toScriptableItemMap(node.getProperties());
        } catch (RepositoryException re) {
            log.warn("Cannot get properties of " + jsFunction_getPath(), re);
            return toScriptableItemMap(null);
        }
    }

    public Object jsFunction_getPrimaryItem() {
        try {
            return ScriptRuntime.toObject(this, node.getPrimaryItem());
        } catch (RepositoryException re) {
            return Undefined.instance;
        }
    }

    public Object jsFunction_getProperty(String name) throws RepositoryException {
        Object[] args = { node.getProperty(name) };
        return ScriptRuntime.newObject(Context.getCurrentContext(), this,
            ScriptableProperty.CLASSNAME, args);
    }

    public String jsFunction_getUUID() {
        try {
            return node.getUUID();
        } catch (RepositoryException re) {
            return "";
        }
    }

    public int jsFunction_getIndex() {
        try {
            return node.getIndex();
        } catch (RepositoryException re) {
            return 1;
        }
    }

    public Iterator<?> jsFunction_getReferences() {
        try {
            return node.getReferences();
        } catch (RepositoryException re) {
            return Collections.EMPTY_LIST.iterator();
        }
    }

    public Object jsFunction_getPrimaryNodeType() {
        try {
            return node.getPrimaryNodeType();
        } catch (RepositoryException re) {
            return Undefined.instance;
        }
    }

    public NodeType[] jsFunction_getMixinNodeTypes() {
        try {
            return node.getMixinNodeTypes();
        } catch (RepositoryException re) {
            return new NodeType[0];
        }
    }

    public Object jsFunction_getDefinition() {
        try {
            return node.getDefinition();
        } catch (RepositoryException re) {
            return Undefined.instance;
        }
    }

    public boolean jsFunction_getCheckedOut() {
        try {
            return node.isCheckedOut();
        } catch (RepositoryException re) {
            return false;
        }
    }

    public Object jsFunction_getVersionHistory() {
        try {
            return ScriptRuntime.toObject(this, node.getVersionHistory());
        } catch (RepositoryException re) {
            return Undefined.instance;
        }
    }

    public Object jsFunction_getBaseVersion() {
        try {
            return ScriptRuntime.toObject(this, node.getBaseVersion());
        } catch (RepositoryException re) {
            return Undefined.instance;
        }
    }

    public Object jsFunction_getLock() {
        try {
            return node.getLock();
        } catch (RepositoryException re) {
            return Undefined.instance;
        }
    }

    public boolean jsFunction_getLocked() {
        try {
            return node.isLocked();
        } catch (RepositoryException re) {
            return false;
        }
    }

    public Object jsFunction_getSession() {
        try {
            return node.getSession();
        } catch (RepositoryException re) {
            return Undefined.instance;
        }
    }

    public String jsFunction_getPath() {
        try {
            return node.getPath();
        } catch (RepositoryException e) {
            return node.toString();
        }
    }

    public String jsFunction_getName() {
        try {
            return node.getName();
        } catch (RepositoryException e) {
            return node.toString();
        }
    }

    public Object jsFunction_getParent() {
        try {
            return ScriptRuntime.toObject(this, node.getParent());
        } catch (RepositoryException re) {
            return Undefined.instance;
        }
    }

    public int jsFunction_getDepth() {
        try {
            return node.getDepth();
        } catch (RepositoryException re) {
            return -1;
        }
    }

    public boolean jsFunction_getNew() {
        return node.isNew();
    }

    public boolean jsFunction_getModified() {
        return node.isModified();
    }

    public void jsFunction_remove() throws RepositoryException {
        node.remove();
    }

    public boolean jsFunction_hasNode(String path) throws RepositoryException {
        return node.hasNode(path);
    }

    /**
     * Gets the value of a (Javascript) property or child node. If there is a single single-value
     * JCR property of this node, return its string value. If there are multiple properties
     * of the same name or child nodes of the same name, return an array.
     */
    @Override
    public Object get(String name, Scriptable start) {

        // builtin javascript properties (jsFunction_ etc.) have priority
        final Object fromSuperclass = super.get(name, start);
        if(fromSuperclass != Scriptable.NOT_FOUND) {
            return fromSuperclass;
        }

        if(node == null) {
            return Undefined.instance;
        }

        final List<Scriptable> items = new ArrayList<Scriptable>();

        // Add all matching nodes to result
        try {
            NodeIterator it = node.getNodes(name);
            while (it.hasNext()) {
                items.add(ScriptRuntime.toObject(this, it.nextNode()));
            }
        } catch (RepositoryException e) {
            log.debug("RepositoryException while collecting Node children",e);
        }

        // Add all matching properties to result
        boolean isMulti = false;
        try {
            PropertyIterator it = node.getProperties(name);
            while (it.hasNext()) {
                Property prop = it.nextProperty();
                if (prop.getDefinition().isMultiple()) {
                    isMulti = true;
                    Value[] values = prop.getValues();
                    for (int i = 0; i < values.length; i++) {
                        items.add(wrap(values[i]));
                    }
                } else {
                    items.add(wrap(prop.getValue()));
                }
            }
        } catch (RepositoryException e) {
            log.debug("RepositoryException while collecting Node properties", e);
        }

        if (items.size()==0) {
            return getNative(name, start);

        } else if (items.size()==1 && !isMulti) {
            return items.iterator().next();

        } else {
            NativeArray result = new NativeArray(items.toArray());
            ScriptRuntime.setObjectProtoAndParent(result, this);
            return result;
        }
    }

    /** Wrap JCR Values in a simple way */
    private Scriptable wrap(Value value) throws ValueFormatException,
            IllegalStateException, RepositoryException {

        Object javaObject;
        if (value.getType() == PropertyType.REFERENCE) {
            String nodeUuid = value.getString();
            javaObject = node.getSession().getNodeByUUID(nodeUuid);

        } else {
            javaObject = toJavaObject(value);
        }

        return ScriptRuntime.toObject(this, javaObject);
    }

    /**
     * Converts a JCR Value to a corresponding Java Object
     *
     * @param value the JCR Value to convert
     * @return the Java Object
     * @throws RepositoryException if the value cannot be converted
     */
    private static Object toJavaObject(Value value) throws RepositoryException {
        switch (value.getType()) {
            case PropertyType.DECIMAL:
                return value.getDecimal();
            case PropertyType.BINARY:
                return new LazyInputStream(value);
            case PropertyType.BOOLEAN:
                return value.getBoolean();
            case PropertyType.DATE:
                return value.getDate();
            case PropertyType.DOUBLE:
                return value.getDouble();
            case PropertyType.LONG:
                return value.getLong();
            case PropertyType.NAME: // fall through
            case PropertyType.PATH: // fall through
            case PropertyType.REFERENCE: // fall through
            case PropertyType.STRING: // fall through
            case PropertyType.UNDEFINED: // not actually expected
            default: // not actually expected
                return value.getString();
        }
    }

    @Override
    public Object[] getIds() {
        Collection<String> ids = new ArrayList<String>();
        if(node != null) {
            try {
                PropertyIterator pit = node.getProperties();
                while (pit.hasNext()) {
                    ids.add(pit.nextProperty().getName());
                }
            } catch (RepositoryException e) {
                //do nothing, just do not list properties
            }
            try {
                NodeIterator nit = node.getNodes();
                while (nit.hasNext()) {
                    ids.add(nit.nextNode().getName());
                }
            } catch (RepositoryException e) {
                //do nothing, just do not list child nodes
            }
        }
        return ids.toArray();
    }

    @SuppressWarnings("unchecked")
    @Override
    public Object getDefaultValue(Class typeHint) {
        return toString();
    }

    @Override
    public boolean has(String name, Scriptable start) {
        if (node != null) {
            try {
                // TODO should this take into account our jsFunction_ members?
                return node.hasProperty(name) || node.hasNode(name);
            } catch (RepositoryException e) {
                // does not matter
            }
        }

        return false;
    }

    @Override
    public String toString() {
        if (node != null) {
            try {
                return node.getPath();
            } catch (RepositoryException e) {
                return node.toString();
            }
        }

        return String.valueOf((Object) null);
    }

    // ---------- Wrapper interface --------------------------------------------

    // returns the wrapped node
    @Override
    public Object unwrap() {
        return node;
    }

    //---------- Helper -------------------------------------------------------

    private Object toScriptableItemMap(Iterator<?> iter) {
        Object[] args = (iter != null) ? new Object[] { iter } : null;
        return ScriptRuntime.newObject(Context.getCurrentContext(), this,
            ScriptableItemMap.CLASSNAME, args);
    }

    /**
     * Lazily acquired InputStream which only accesses the JCR Value InputStream if
     * data is to be read from the stream.
     */
    private static class LazyInputStream extends InputStream {

        /** The JCR Value from which the input stream is requested on demand */
        private final Value value;

        /** The inputstream created on demand, null if not used */
        private InputStream delegatee;

        public LazyInputStream(Value value) {
            this.value = value;
        }

        /**
         * Closes the input stream if acquired otherwise does nothing.
         */
        @Override
        public void close() throws IOException {
            if (delegatee != null) {
                delegatee.close();
            }
        }

        @Override
        public int available() throws IOException {
            return getStream().available();
        }

        @Override
        public int read() throws IOException {
            return getStream().read();
        }

        @Override
        public int read(byte[] b) throws IOException {
            return getStream().read(b);
        }

        @Override
        public int read(byte[] b, int off, int len) throws IOException {
            return getStream().read(b, off, len);
        }

        @Override
        public long skip(long n) throws IOException {
            return getStream().skip(n);
        }

        @Override
        public boolean markSupported() {
            try {
                return getStream().markSupported();
            } catch (IOException ioe) {
                // ignore
            }
            return false;
        }

        @Override
        public synchronized void mark(int readlimit) {
            try {
                getStream().mark(readlimit);
            } catch (IOException ioe) {
                // ignore
            }
        }

        @Override
        public synchronized void reset() throws IOException {
            getStream().reset();
        }

        /** Actually retrieves the input stream from the underlying JCR Value */
        private InputStream getStream() throws IOException {
            if (delegatee == null) {
                try {
                    delegatee = value.getStream();
                } catch (RepositoryException re) {
                    throw (IOException) new IOException(re.getMessage()).initCause(re);
                }
            }
            return delegatee;
        }

    }
}