/*
 * Copyright 2004 The Apache Software Foundation.
 *
 * 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:
 *     Anahide Tchertchian
 *     Florent Guillaume
 */
package org.nuxeo.ecm.platform.ui.web.component.file;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.el.ELException;
import javax.el.ValueExpression;
import javax.faces.FacesException;
import javax.faces.application.Application;
import javax.faces.application.FacesMessage;
import javax.faces.component.EditableValueHolder;
import javax.faces.component.NamingContainer;
import javax.faces.component.UIComponent;
import javax.faces.component.UIInput;
import javax.faces.component.html.HtmlInputText;
import javax.faces.context.FacesContext;
import javax.faces.context.ResponseWriter;
import javax.faces.convert.ConverterException;
import javax.faces.event.ValueChangeEvent;
import javax.faces.validator.ValidatorException;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.nuxeo.ecm.core.api.Blob;
import org.nuxeo.ecm.platform.ui.web.application.NuxeoResponseStateManagerImpl;
import org.nuxeo.ecm.platform.ui.web.util.ComponentUtils;
import org.nuxeo.runtime.api.Framework;

import com.sun.faces.util.MessageFactory;

/**
 * UIInput file that handles complex validation.
 * <p>
 * Attribute value is the file to be uploaded. Its submitted value as well as filename are handled by sub components.
 * Rendering and validation of subcomponents are handled here.
 */
public class UIInputFile extends UIInput implements NamingContainer {

    public static final String COMPONENT_TYPE = UIInputFile.class.getName();

    public static final String COMPONENT_FAMILY = "javax.faces.Input";

    protected static final String CHOICE_FACET_NAME = "choice";

    protected static final String UPLOAD_FACET_NAME = "upload";

    protected static final String DEFAULT_DOWNLOAD_FACET_NAME = "default_download";

    protected static final String DOWNLOAD_FACET_NAME = "download";

    protected static final String EDIT_FILENAME_FACET_NAME = "edit_filename";

    protected static final Log log = LogFactory.getLog(UIInputFile.class);

    protected final JSFBlobUploaderService uploaderService;

    // value for filename, will disappear when it's part of the blob
    protected String filename;

    // used to decide whether filename can be edited
    protected Boolean editFilename;

    protected String onchange;

    protected String onclick;

    protected String onselect;

    public UIInputFile() {
        // initiate sub components
        FacesContext faces = FacesContext.getCurrentInstance();
        Application app = faces.getApplication();
        ComponentUtils.initiateSubComponent(this, DEFAULT_DOWNLOAD_FACET_NAME,
                app.createComponent(UIOutputFile.COMPONENT_TYPE));
        ComponentUtils.initiateSubComponent(this, EDIT_FILENAME_FACET_NAME,
                app.createComponent(HtmlInputText.COMPONENT_TYPE));
        uploaderService = Framework.getService(JSFBlobUploaderService.class);
        for (JSFBlobUploader uploader : uploaderService.getJSFBlobUploaders()) {
            uploader.hookSubComponent(this);
        }
    }

    // component will render itself
    @Override
    public String getRendererType() {
        return null;
    }

    // getters and setters

    /**
     * Override value so that an {@link InputFileInfo} structure is given instead of the "value" attribute resolution.
     */
    @Override
    public Object getValue() {
        Object localValue = getLocalValue();
        if (localValue != null) {
            return localValue;
        } else {
            Blob blob = null;
            Object originalValue = super.getValue();
            String mimeType = null;
            if (originalValue instanceof Blob) {
                blob = (Blob) originalValue;
                mimeType = blob.getMimeType();
            }
            List<String> choices = getAvailableChoices(blob, false);
            String choice = choices.get(0);
            return new InputFileInfo(choice, blob, getFilename(), mimeType);
        }
    }

    public String getFilename() {
        if (filename != null) {
            return filename;
        }
        ValueExpression ve = getValueExpression("filename");
        if (ve != null) {
            try {
                return (String) ve.getValue(getFacesContext().getELContext());
            } catch (ELException e) {
                throw new FacesException(e);
            }
        } else {
            return null;
        }
    }

    public void setFilename(String filename) {
        this.filename = filename;
    }

    public Boolean getEditFilename() {
        if (editFilename != null) {
            return editFilename;
        }
        ValueExpression ve = getValueExpression("editFilename");
        if (ve != null) {
            try {
                return !Boolean.FALSE.equals(ve.getValue(getFacesContext().getELContext()));
            } catch (ELException e) {
                throw new FacesException(e);
            }
        } else {
            // default value
            return false;
        }
    }

    public void setEditFilename(Boolean editFilename) {
        this.editFilename = editFilename;
    }

    public InputFileInfo getFileInfoValue() {
        return (InputFileInfo) getValue();
    }

    public InputFileInfo getFileInfoLocalValue() {
        return (InputFileInfo) getLocalValue();
    }

    public InputFileInfo getFileInfoSubmittedValue() {
        return (InputFileInfo) getSubmittedValue();
    }

    protected String getStringValue(String name, String defaultValue) {
        ValueExpression ve = getValueExpression(name);
        if (ve != null) {
            try {
                return (String) ve.getValue(getFacesContext().getELContext());
            } catch (ELException e) {
                throw new FacesException(e);
            }
        } else {
            return defaultValue;
        }
    }

    public String getOnchange() {
        if (onchange != null) {
            return onchange;
        }
        return getStringValue("onchange", null);
    }

    public void setOnchange(String onchange) {
        this.onchange = onchange;
    }

    public String getOnclick() {
        if (onclick != null) {
            return onclick;
        }
        return getStringValue("onclick", null);
    }

    public void setOnclick(String onclick) {
        this.onclick = onclick;
    }

    public String getOnselect() {
        if (onselect != null) {
            return onselect;
        }
        return getStringValue("onselect", null);
    }

    public void setOnselect(String onselect) {
        this.onselect = onselect;
    }

    // handle submitted values

    @Override
    public void decode(FacesContext context) {
        if (context == null) {
            throw new IllegalArgumentException();
        }

        // Force validity back to "true"
        setValid(true);

        // decode the radio button, other input components will decode
        // themselves
        Map<String, String> requestMap = context.getExternalContext().getRequestParameterMap();
        String radioClientId = getClientId(context) + NamingContainer.SEPARATOR_CHAR + CHOICE_FACET_NAME;
        String choice = requestMap.get(radioClientId);
        // other submitted values will be handled at validation time
        InputFileInfo submitted = new InputFileInfo(choice, null, null, null);
        setSubmittedValue(submitted);
    }

    /**
     * Process validation. Sub components are already validated.
     */
    @Override
    public void validate(FacesContext context) {
        if (context == null) {
            throw new IllegalArgumentException();
        }

        // Submitted value == null means "the component was not submitted
        // at all"; validation should not continue
        InputFileInfo submitted = getFileInfoSubmittedValue();
        if (submitted == null) {
            return;
        }

        InputFileInfo previous = getFileInfoValue();

        // validate choice
        String choice;
        try {
            choice = submitted.getConvertedChoice();
        } catch (ConverterException ce) {
            ComponentUtils.addErrorMessage(context, this, ce.getMessage());
            setValid(false);
            return;
        }
        if (choice == null) {
            ComponentUtils.addErrorMessage(context, this, "error.inputFile.choiceRequired");
            setValid(false);
            return;
        }
        submitted.setChoice(choice);
        String previousChoice = previous.getConvertedChoice();
        boolean temp = InputFileChoice.isUploadOrKeepTemp(previousChoice);
        List<String> choices = getAvailableChoices(previous.getBlob(), temp);
        if (!choices.contains(choice)) {
            ComponentUtils.addErrorMessage(context, this, "error.inputFile.invalidChoice");
            setValid(false);
            return;
        }

        // validate choice in respect to other submitted values
        if (InputFileChoice.KEEP_TEMP.equals(choice)) {
            // re-submit stored values
            if (isLocalValueSet()) {
                submitted.setBlob(previous.getConvertedBlob());
                submitted.setFilename(previous.getConvertedFilename());
            }
            if (getEditFilename()) {
                validateFilename(context, submitted);
            }
        } else if (InputFileChoice.KEEP.equals(choice)) {
            // re-submit stored values
            submitted.setBlob(previous.getConvertedBlob());
            submitted.setFilename(previous.getConvertedFilename());
            if (getEditFilename()) {
                validateFilename(context, submitted);
            }
        } else if (InputFileChoice.isUpload(choice)) {
            try {
                uploaderService.getJSFBlobUploader(choice).validateUpload(this, context, submitted);
                if (isValid()) {
                    submitted.setChoice(InputFileChoice.KEEP_TEMP);
                }
            } catch (ValidatorException e) {
                // set file to null: blob is null but file is not required
                submitted.setBlob(null);
                submitted.setFilename(null);
                submitted.setChoice(InputFileChoice.NONE);
            }
        } else if (InputFileChoice.DELETE.equals(choice) || InputFileChoice.NONE.equals(choice)) {
            submitted.setBlob(null);
            submitted.setFilename(null);
        }

        // will need this to call declared validators
        super.validateValue(context, submitted);

        // If our value is valid, store the new value, erase the
        // "submitted" value, and emit a ValueChangeEvent if appropriate
        if (isValid()) {
            setValue(submitted);
            setSubmittedValue(null);
            if (compareValues(previous, submitted)) {
                queueEvent(new ValueChangeEvent(this, previous, submitted));
            }
        }
    }

    public void validateFilename(FacesContext context, InputFileInfo submitted) {
        // validate filename
        UIComponent filenameFacet = getFacet(EDIT_FILENAME_FACET_NAME);
        if (filenameFacet instanceof EditableValueHolder) {
            EditableValueHolder filenameComp = (EditableValueHolder) filenameFacet;
            submitted.setFilename(filenameComp.getLocalValue());
            String filename;
            try {
                filename = submitted.getConvertedFilename();
            } catch (ConverterException ce) {
                ComponentUtils.addErrorMessage(context, this, ce.getMessage());
                setValid(false);
                return;
            }
            submitted.setFilename(filename);
        }
    }

    public void updateFilename(FacesContext context, String newFilename) {
        // set filename by hand after validation
        ValueExpression ve = getValueExpression("filename");
        if (ve != null) {
            ve.setValue(context.getELContext(), newFilename);
        }
    }

    @Override
    public void updateModel(FacesContext context) {
        if (context == null) {
            throw new IllegalArgumentException();
        }

        if (!isValid() || !isLocalValueSet()) {
            return;
        }
        ValueExpression ve = getValueExpression("value");
        if (ve == null) {
            return;
        }
        try {
            InputFileInfo local = getFileInfoLocalValue();
            String choice = local.getConvertedChoice();
            // set blob and filename
            if (InputFileChoice.DELETE.equals(choice)) {
                // set filename first to avoid error in case it maps the blob filename
                ValueExpression vef = getValueExpression("filename");
                if (vef != null) {
                    vef.setValue(context.getELContext(), local.getConvertedFilename());
                }
                ve.setValue(context.getELContext(), local.getConvertedBlob());
                setValue(null);
                setLocalValueSet(false);
            } else if (InputFileChoice.isUploadOrKeepTemp(choice)) {
                // set blob first to avoid error in case the filename maps the blob filename
                ve.setValue(context.getELContext(), local.getConvertedBlob());
                setValue(null);
                setLocalValueSet(false);
                ValueExpression vef = getValueExpression("filename");
                if (vef != null) {
                    vef.setValue(context.getELContext(), local.getConvertedFilename());
                }
            } else if (InputFileChoice.KEEP.equals(choice)) {
                // reset local value
                setValue(null);
                setLocalValueSet(false);
                if (getEditFilename()) {
                    // set filename
                    ValueExpression vef = getValueExpression("filename");
                    if (vef != null) {
                        vef.setValue(context.getELContext(), local.getConvertedFilename());
                    }
                }
            }
            return;
        } catch (ELException e) {
            String messageStr = e.getMessage();
            Throwable result = e.getCause();
            while (result != null && result instanceof ELException) {
                messageStr = result.getMessage();
                result = result.getCause();
            }
            FacesMessage message;
            if (messageStr == null) {
                message = MessageFactory.getMessage(context, UPDATE_MESSAGE_ID, MessageFactory.getLabel(context, this));
            } else {
                message = new FacesMessage(FacesMessage.SEVERITY_ERROR, messageStr, messageStr);
            }
            context.addMessage(getClientId(context), message);
            setValid(false);
        } catch (IllegalArgumentException | ConverterException e) {
            FacesMessage message = MessageFactory.getMessage(context, UPDATE_MESSAGE_ID,
                    MessageFactory.getLabel(context, this));
            context.addMessage(getClientId(context), message);
            setValid(false);
        }
    }

    // rendering methods

    protected List<String> getAvailableChoices(Object value, boolean temp) {
        List<String> choices = new ArrayList<String>(3);
        boolean hasFile = value != null;
        boolean isRequired = isRequired();
        if (hasFile) {
            choices.add(temp ? InputFileChoice.KEEP_TEMP : InputFileChoice.KEEP);
        } else if (!isRequired) {
            choices.add(InputFileChoice.NONE);
        }
        for (JSFBlobUploader uploader : uploaderService.getJSFBlobUploaders()) {
            choices.add(uploader.getChoice());
        }
        if (hasFile && !isRequired) {
            choices.add(InputFileChoice.DELETE);
        }
        return choices;
    }

    public Blob getCurrentBlob() {
        Blob blob = null;
        InputFileInfo submittedFileInfo = getFileInfoSubmittedValue();
        if (submittedFileInfo != null) {
            String choice = submittedFileInfo.getConvertedChoice();
            if (InputFileChoice.isKeepOrKeepTemp(choice)) {
                // rebuild other info from current value
                InputFileInfo fileInfo = getFileInfoValue();
                blob = fileInfo.getConvertedBlob();
            } else {
                blob = submittedFileInfo.getConvertedBlob();
            }
        } else {
            InputFileInfo fileInfo = getFileInfoValue();
            blob = fileInfo.getConvertedBlob();
        }
        return blob;
    }

    public String getCurrentFilename() {
        String filename = null;
        InputFileInfo submittedFileInfo = getFileInfoSubmittedValue();
        if (submittedFileInfo != null) {
            String choice = submittedFileInfo.getConvertedChoice();
            if (InputFileChoice.isKeepOrKeepTemp(choice)) {
                // rebuild it in case it's supposed to be kept
                InputFileInfo fileInfo = getFileInfoValue();
                filename = fileInfo.getConvertedFilename();
            } else {
                filename = submittedFileInfo.getConvertedFilename();
            }
        } else {
            InputFileInfo fileInfo = getFileInfoValue();
            filename = fileInfo.getConvertedFilename();
        }
        return filename;
    }

    @Override
    public void encodeBegin(FacesContext context) throws IOException {

        notifyPreviousErrors(context);

        // not ours to close
        @SuppressWarnings("resource")
        ResponseWriter writer = context.getResponseWriter();
        Blob blob = null;
        try {
            blob = getCurrentBlob();
        } catch (ConverterException e) {
            // can happen -> ignore, don't break rendering
        }
        String filename = null;
        try {
            filename = getCurrentFilename();
        } catch (ConverterException e) {
            // can happen -> ignore, don't break rendering
        }
        InputFileInfo fileInfo = getFileInfoSubmittedValue();
        if (fileInfo == null) {
            fileInfo = getFileInfoValue();
        }
        String currentChoice = fileInfo.getConvertedChoice();
        boolean temp = InputFileChoice.KEEP_TEMP.equals(currentChoice);
        List<String> choices = getAvailableChoices(blob, temp);

        String radioClientId = getClientId(context) + NamingContainer.SEPARATOR_CHAR + CHOICE_FACET_NAME;
        writer.startElement("table", this);
        writer.writeAttribute("class", "dataInput", null);
        writer.startElement("tbody", this);
        writer.writeAttribute("class", getAttributes().get("styleClass"), null);
        for (String radioChoice : choices) {
            String id = radioClientId + radioChoice;
            writer.startElement("tr", this);
            writer.startElement("td", this);
            writer.writeAttribute("class", "radioColumn", null);
            Map<String, String> props = new HashMap<String, String>();
            props.put("type", "radio");
            props.put("name", radioClientId);
            props.put("id", id);
            props.put("value", radioChoice);
            if (radioChoice.equals(currentChoice)) {
                props.put("checked", "checked");
            }
            String onchange = getOnchange();
            if (onchange != null) {
                props.put("onchange", onchange);
            }
            String onclick = getOnclick();
            if (onclick != null) {
                props.put("onclick", onclick);
            }
            String onselect = getOnselect();
            if (onselect != null) {
                props.put("onselect", onselect);
            }
            StringBuffer htmlBuffer = new StringBuffer();
            htmlBuffer.append("<input");
            for (Map.Entry<String, String> prop : props.entrySet()) {
                htmlBuffer.append(String.format(" %s=\"%s\"", prop.getKey(), prop.getValue()));
            }
            htmlBuffer.append(" />");
            writer.write(htmlBuffer.toString());
            writer.endElement("td");
            writer.startElement("td", this);
            writer.writeAttribute("class", "fieldColumn", null);
            String html = "<label for=\"%s\" style=\"float:left\">%s</label>";
            String label = (String) ComponentUtils.getAttributeValue(this, radioChoice + "Label", null);
            if (label == null) {
                label = ComponentUtils.translate(context, "label.inputFile." + radioChoice + "Choice");
            }
            writer.write(String.format(html, id, label));
            writer.write(ComponentUtils.WHITE_SPACE_CHARACTER);
            if (InputFileChoice.isKeepOrKeepTemp(radioChoice)) {
                UIComponent downloadFacet = getFacet(DOWNLOAD_FACET_NAME);
                if (downloadFacet != null) {
                    // redefined in template
                    ComponentUtils.encodeComponent(context, downloadFacet);
                } else {
                    downloadFacet = getFacet(DEFAULT_DOWNLOAD_FACET_NAME);
                    if (downloadFacet != null) {
                        UIOutputFile downloadComp = (UIOutputFile) downloadFacet;
                        downloadComp.setQueryParent(true);
                        ComponentUtils.copyValues(this, downloadComp, new String[] { "downloadLabel", "iconRendered" });
                        ComponentUtils.copyLinkValues(this, downloadComp);
                        ComponentUtils.encodeComponent(context, downloadComp);
                    }
                }
                if (getEditFilename()) {
                    writer.write("<br />");
                    UIComponent filenameFacet = getFacet(EDIT_FILENAME_FACET_NAME);
                    if (filenameFacet instanceof HtmlInputText) {
                        HtmlInputText filenameComp = (HtmlInputText) filenameFacet;
                        filenameComp.setValue(filename);
                        filenameComp.setLocalValueSet(false);
                        String onClick = "document.getElementById('%s').checked='checked'";
                        filenameComp.setOnclick(String.format(onClick, id));
                        writer.write(ComponentUtils.WHITE_SPACE_CHARACTER);
                        html = "<label for=\"%s\">%s</label>";
                        label = (String) ComponentUtils.getAttributeValue(this, "editFilenameLabel", null);
                        if (label == null) {
                            label = ComponentUtils.translate(context, "label.inputFile.editFilename");
                        }
                        writer.write(String.format(html, filenameComp.getId(), label));
                        writer.write(ComponentUtils.WHITE_SPACE_CHARACTER);
                        ComponentUtils.encodeComponent(context, filenameComp);
                    }
                }
            } else if (InputFileChoice.isUpload(radioChoice)) {
                String onClick = String.format("document.getElementById('%s').checked='checked'", id);
                uploaderService.getJSFBlobUploader(radioChoice).encodeBeginUpload(this, context, onClick);
            }
            writer.endElement("td");
            writer.endElement("tr");
        }
        writer.endElement("tbody");
        writer.endElement("table");
        writer.flush();
    }

    /**
     * @since 6.1.1
     */
    private void notifyPreviousErrors(FacesContext context) {
        final Object hasError = context.getAttributes().get(NuxeoResponseStateManagerImpl.MULTIPART_SIZE_ERROR_FLAG);
        final String componentId = (String) context.getAttributes().get(
                NuxeoResponseStateManagerImpl.MULTIPART_SIZE_ERROR_COMPONENT_ID);
        if (Boolean.TRUE.equals(hasError)) {
            if (StringUtils.isBlank(componentId)) {
                ComponentUtils.addErrorMessage(context, this, "error.inputFile.maxRequestSize",
                        new Object[] { Framework.getProperty("nuxeo.jsf.maxRequestSize") });
            } else if (componentId.equals(getFacet(UPLOAD_FACET_NAME).getClientId())) {
                ComponentUtils.addErrorMessage(context, this, "error.inputFile.maxSize",
                        new Object[] { Framework.getProperty("nuxeo.jsf.maxFileSize") });
            }
        }
    }

    // state holder

    @Override
    public Object saveState(FacesContext context) {
        Object[] values = new Object[6];
        values[0] = super.saveState(context);
        values[1] = filename;
        values[2] = editFilename;
        values[3] = onchange;
        values[4] = onclick;
        values[5] = onselect;
        return values;
    }

    @Override
    public void restoreState(FacesContext context, Object state) {
        Object[] values = (Object[]) state;
        super.restoreState(context, values[0]);
        filename = (String) values[1];
        editFilename = (Boolean) values[2];
        onchange = (String) values[3];
        onclick = (String) values[4];
        onselect = (String) values[5];
    }

}