/*
 * (C) Copyright 2006-2008 Nuxeo SA (http://nuxeo.com/) and others.
 *
 * 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.
 *
 * Contributors:
 *     bstefanescu
 *
 * $Id$
 */

package org.nuxeo.ecm.webengine.forms;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.RequestContext;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.fileupload.servlet.ServletRequestContext;
import org.apache.commons.lang.StringUtils;
import org.nuxeo.ecm.core.api.Blob;
import org.nuxeo.ecm.core.api.Blobs;
import org.nuxeo.ecm.core.api.DocumentModel;
import org.nuxeo.ecm.core.api.NuxeoException;
import org.nuxeo.ecm.core.api.PropertyException;
import org.nuxeo.ecm.core.api.VersioningOption;
import org.nuxeo.ecm.core.api.model.Property;
import org.nuxeo.ecm.core.api.model.impl.primitives.BlobProperty;
import org.nuxeo.ecm.core.schema.types.ListType;
import org.nuxeo.ecm.core.schema.types.Type;
import org.nuxeo.ecm.webengine.forms.validation.Form;
import org.nuxeo.ecm.webengine.forms.validation.FormManager;
import org.nuxeo.ecm.webengine.forms.validation.ValidationException;
import org.nuxeo.ecm.webengine.servlet.WebConst;

/**
 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
 */
public class FormData implements FormInstance {

    public static final String PROPERTY = "property";

    public static final String TITLE = "dc:title";

    public static final String DOCTYPE = "doctype";

    public static final String VERSIONING = "versioning";

    public static final String MAJOR = "major";

    public static final String MINOR = "minor";

    protected static ServletFileUpload fu = new ServletFileUpload(new DiskFileItemFactory());

    protected final HttpServletRequest request;

    protected boolean isMultipart = false;

    protected RequestContext ctx;

    // Multipart items cache
    protected Map<String, List<FileItem>> items;

    // parameter map cache - used in Multipart forms to convert to
    // ServletRequest#getParameterMap
    // format
    // protected Map<String, String[]> parameterMap;

    public FormData(HttpServletRequest request) {
        this.request = request;
        isMultipart = getIsMultipartContent();
        if (isMultipart) {
            ctx = new ServletRequestContext(request);
        }
    }

    protected String getString(FileItem item) {
        try {
            String enc = request.getCharacterEncoding();
            if (enc != null) {
                return item.getString(request.getCharacterEncoding());
            } else {
                return item.getString();
            }
        } catch (UnsupportedEncodingException e) {
            return item.getString();
        }
    }

    protected boolean getIsMultipartContent() {
        String method = request.getMethod().toLowerCase();
        if (!"post".equals(method) && !"put".equals(method)) {
            return false;
        }
        String contentType = request.getContentType();
        if (contentType == null) {
            return false;
        }
        return contentType.toLowerCase().startsWith(WebConst.MULTIPART);
    }

    public boolean isMultipartContent() {
        return isMultipart;
    }

    @SuppressWarnings("unchecked")
    public Map<String, String[]> getFormFields() {
        if (isMultipart) {
            return getMultiPartFormFields();
        } else {
            return request.getParameterMap();
        }
    }

    public Map<String, String[]> getMultiPartFormFields() {
        Map<String, List<FileItem>> items = getMultiPartItems();
        Map<String, String[]> result = new HashMap<String, String[]>();
        for (Map.Entry<String, List<FileItem>> entry : items.entrySet()) {
            List<FileItem> list = entry.getValue();
            String[] ar = new String[list.size()];
            for (int i = 0; i < ar.length; i++) {
                ar[i] = getString(list.get(i));
            }
            result.put(entry.getKey(), ar);
        }
        return result;
    }

    @SuppressWarnings("unchecked")
    public Map<String, List<FileItem>> getMultiPartItems() {
        if (items == null) {
            if (!isMultipart) {
                throw new IllegalStateException("Not in a multi part form request");
            }
            try {
                items = new HashMap<String, List<FileItem>>();
                ServletRequestContext ctx = new ServletRequestContext(request);
                List<FileItem> fileItems = new ServletFileUpload(new DiskFileItemFactory()).parseRequest(ctx);
                for (FileItem item : fileItems) {
                    String key = item.getFieldName();
                    List<FileItem> list = items.get(key);
                    if (list == null) {
                        list = new ArrayList<FileItem>();
                        items.put(key, list);
                    }
                    list.add(item);
                }
            } catch (FileUploadException e) {
                throw new NuxeoException("Failed to get uploaded files", e);
            }
        }
        return items;
    }

    @SuppressWarnings("unchecked")
    public Collection<String> getKeys() {
        if (isMultipart) {
            return getMultiPartItems().keySet();
        } else {
            return ((Map<String, String[]>) request.getParameterMap()).keySet();
        }
    }

    public Blob getBlob(String key) {
        FileItem item = getFileItem(key);
        return item == null ? null : getBlob(item);
    }

    public Blob[] getBlobs(String key) {
        List<FileItem> list = getFileItems(key);
        Blob[] ar = null;
        if (list != null) {
            ar = new Blob[list.size()];
            for (int i = 0, len = list.size(); i < len; i++) {
                ar[i] = getBlob(list.get(i));
            }
        }
        return ar;
    }

    /**
     * XXX TODO implement it
     */
    public Map<String, Blob[]> getBlobFields() {
        throw new UnsupportedOperationException("Not yet implemented");
    }

    public Blob getFirstBlob() {
        Map<String, List<FileItem>> items = getMultiPartItems();
        for (List<FileItem> list : items.values()) {
            for (FileItem item : list) {
                if (!item.isFormField()) {
                    return getBlob(item);
                }
            }
        }
        return null;
    }

    protected Blob getBlob(FileItem item) {
        try {
            InputStream in;
            if (item.isInMemory()) {
                in = new ByteArrayInputStream(item.get());
            } else {
                in = item.getInputStream();
            }
            String ctype = item.getContentType();
            Blob blob = Blobs.createBlob(in, ctype == null ? "application/octet-stream" : ctype);
            blob.setFilename(item.getName());
            in.close();
            return blob;
        } catch (IOException e) {
            throw new NuxeoException("Failed to get blob data", e);
        }
    }

    public final FileItem getFileItem(String key) {
        Map<String, List<FileItem>> items = getMultiPartItems();
        List<FileItem> list = items.get(key);
        if (list != null && !list.isEmpty()) {
            return list.get(0);
        }
        return null;
    }

    public final List<FileItem> getFileItems(String key) {
        return getMultiPartItems().get(key);
    }

    public String getMultiPartFormProperty(String key) {
        FileItem item = getFileItem(key);
        return item == null ? null : getString(item);
    }

    public String[] getMultiPartFormListProperty(String key) {
        List<FileItem> list = getFileItems(key);
        String[] ar = null;
        if (list != null) {
            ar = new String[list.size()];
            for (int i = 0, len = list.size(); i < len; i++) {
                ar[i] = getString(list.get(i));
            }
        }
        return ar;
    }

    /**
     * @param key
     * @return an array of strings or an array of blobs
     */
    public Object[] getMultiPartFormItems(String key) {
        return getMultiPartFormItems(getFileItems(key));
    }

    public Object[] getMultiPartFormItems(List<FileItem> list) {
        Object[] ar = null;
        if (list != null) {
            if (list.isEmpty()) {
                return null;
            }
            FileItem item0 = list.get(0);
            if (item0.isFormField()) {
                ar = new String[list.size()];
                ar[0] = getString(item0);
                for (int i = 1, len = list.size(); i < len; i++) {
                    ar[i] = getString(list.get(i));
                }
            } else {
                List<Blob> blobs = new ArrayList<Blob>();
                for (FileItem item : list) {
                    if (!StringUtils.isBlank(item.getName())) {
                        blobs.add(getBlob(item));
                    }
                }
                ar = blobs.toArray(new Blob[blobs.size()]);
            }
        }
        return ar;
    }

    public final Object getFileItemValue(FileItem item) {
        if (item.isFormField()) {
            return getString(item);
        } else {
            return getBlob(item);
        }
    }

    public String getFormProperty(String key) {
        String[] value = request.getParameterValues(key);
        if (value != null && value.length > 0) {
            return value[0];
        }
        return null;
    }

    public String[] getFormListProperty(String key) {
        return request.getParameterValues(key);
    }

    public String getString(String key) {
        if (isMultipart) {
            return getMultiPartFormProperty(key);
        } else {
            return getFormProperty(key);
        }
    }

    public String[] getList(String key) {
        if (isMultipart) {
            return getMultiPartFormListProperty(key);
        } else {
            return getFormListProperty(key);
        }
    }

    public Object[] get(String key) {
        if (isMultipart) {
            return getMultiPartFormItems(key);
        } else {
            return getFormListProperty(key);
        }
    }

    public void fillDocument(DocumentModel doc) {
        try {
            if (isMultipart) {
                fillDocumentFromMultiPartForm(doc);
            } else {
                fillDocumentFromForm(doc);
            }
        } catch (PropertyException e) {
            e.addInfo("Failed to fill document properties from request properties");
            throw e;
        }
    }

    @SuppressWarnings("unchecked")
    public void fillDocumentFromForm(DocumentModel doc) throws PropertyException {
        Map<String, String[]> map = request.getParameterMap();
        for (Map.Entry<String, String[]> entry : map.entrySet()) {
            String key = entry.getKey();
            if (key.indexOf(':') > -1) { // an XPATH property
                Property p;
                try {
                    p = doc.getProperty(key);
                } catch (PropertyException e) {
                    continue; // not a valid property
                }
                String[] ar = entry.getValue();
                fillDocumentProperty(p, key, ar);
            }
        }
    }

    public void fillDocumentFromMultiPartForm(DocumentModel doc) throws PropertyException {
        Map<String, List<FileItem>> map = getMultiPartItems();
        for (Map.Entry<String, List<FileItem>> entry : map.entrySet()) {
            String key = entry.getKey();
            if (key.indexOf(':') > -1) { // an XPATH property
                Property p;
                try {
                    p = doc.getProperty(key);
                } catch (PropertyException e) {
                    continue; // not a valid property
                }
                List<FileItem> list = entry.getValue();
                if (list.isEmpty()) {
                    fillDocumentProperty(p, key, null);
                } else {
                    Object[] ar = getMultiPartFormItems(list);
                    fillDocumentProperty(p, key, ar);
                }
            }
        }
    }

    static void fillDocumentProperty(Property p, String key, Object[] ar) throws PropertyException {
        if (ar == null || ar.length == 0) {
            p.remove();
        } else if (p.isScalar()) {
            p.setValue(ar[0]);
        } else if (p.isList()) {
            if (!p.isContainer()) { // an array
                p.setValue(ar);
            } else {
                Type elType = ((ListType) p.getType()).getFieldType();
                if (elType.isSimpleType()) {
                    p.setValue(ar);
                } else if ("content".equals(elType.getName())) {
                    // list of blobs
                    List<Blob> blobs = new ArrayList<Blob>();
                    if (ar.getClass().getComponentType() == String.class) { // transform
                                                                            // strings
                                                                            // to
                                                                            // blobs
                        for (Object obj : ar) {
                            blobs.add(Blobs.createBlob(obj.toString()));
                        }
                    } else {
                        for (Object obj : ar) {
                            blobs.add((Blob) obj);
                        }
                    }
                    p.setValue(blobs);
                } else {
                    // complex properties will be ignored
                    // throw new
                    // WebException("Cannot create complex lists properties from HTML forms");
                }
            }
        } else if (p.isComplex()) {
            if (p.getClass() == BlobProperty.class) {
                // should be a file upload
                Blob blob = null;
                if (ar[0].getClass() == String.class) {
                    blob = Blobs.createBlob(ar[0].toString());
                } else {
                    blob = (Blob) ar[0];
                }
                p.setValue(blob);
            } else {
                // complex properties will be ignored
                // throw new WebException(
                // "Cannot set complex properties from HTML forms. You need to set each sub-scalar property
                // explicitely");
            }
        }
    }

    public VersioningOption getVersioningOption() {
        String val = getString(VERSIONING);
        if (val != null) {
            return val.equals(MAJOR) ? VersioningOption.MAJOR : val.equals(MINOR) ? VersioningOption.MINOR : null;
        }
        return null;
    }

    public String getDocumentType() {
        return getString(DOCTYPE);
    }

    public String getDocumentTitle() {
        return getString(TITLE);
    }

    public <T extends Form> T validate(Class<T> type) throws ValidationException {
        T proxy = FormManager.newProxy(type);
        try {
            proxy.load(this, proxy);
            return proxy;
        } catch (ValidationException e) {
            e.setForm(proxy);
            throw e;
        }
    }

}