package pt.ist.renderers.extensions;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Hashtable;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Properties;

import pt.ist.renderers.InputRenderer;
import pt.ist.renderers.components.HtmlActionLink;
import pt.ist.renderers.components.HtmlBlockContainer;
import pt.ist.renderers.components.HtmlComponent;
import pt.ist.renderers.components.HtmlContainer;
import pt.ist.renderers.components.HtmlHiddenField;
import pt.ist.renderers.components.HtmlSimpleValueComponent;
import pt.ist.renderers.components.HtmlTextInput;
import pt.ist.renderers.components.controllers.HtmlActionLinkController;
import pt.ist.renderers.components.controllers.HtmlController;
import pt.ist.renderers.components.converters.Converter;
import pt.ist.renderers.components.state.IViewState;
import pt.ist.renderers.contexts.PresentationContext;
import pt.ist.renderers.extensions.validators.MultiLanguageStringValidator;
import pt.ist.renderers.layouts.Layout;
import pt.ist.renderers.model.MetaObject;
import pt.ist.renderers.model.MetaSlot;
import pt.ist.renderers.model.MetaSlotKey;
import pt.ist.renderers.utils.RenderKit;
import pt.ist.renderers.utils.RenderUtils;
import pt.ist.renderers.validators.HtmlValidator;
import pt.utl.ist.fenix.tools.util.Pair;
import pt.utl.ist.fenix.tools.util.i18n.Language;
import pt.utl.ist.fenix.tools.util.i18n.MultiLanguageString;

/**
 * This renderer provides a generic way of editing slots that contain a
 * {@link MultiLanguageString}. The interface generated allows the user to
 * incrementally add more values in different languages. The user can also
 * remove some of the values already introduced.
 * <p>
 * Example: <div> <div> <input type="text"/> <select> <option
 * selected="selected" value="">-- Choose an option --</option> <option
 * value="eo">Esperanto</option> <option value="xx-klingon">Klingon</option>
 * <option value="xx-piglatin">Pig Latin</option> <option value="xx-elmer">Elmer
 * Fudd</option> </select> <a href="#">Remove</a> </div> <div> <input
 * type="text"/> <select> <option selected="selected" value="">-- Choose an
 * option --</option> <option value="eo">Esperanto</option> <option
 * value="xx-klingon">Klingon</option> <option value="xx-piglatin">Pig
 * Latin</option> <option value="xx-elmer">Elmer Fudd</option> </select> <a
 * href="#">Remove</a> </div> <a href="#">Add</a> </div>
 * 
 * @author cfgi
 */
public class MultiLanguageStringInputRenderer extends InputRenderer {

    private Integer size;

    private String eachClasses;

    private String inputClasses;

    public Integer getSize() {
	return this.size;
    }

    /**
     * Allows you to configure the size of the input fields for each language.
     * 
     * @property
     */
    public void setSize(Integer size) {
	this.size = size;
    }

    public String getEachClasses() {
	return this.eachClasses;
    }

    /**
     * The classes to apply to the div containing each language line.
     * 
     * @property
     */
    public void setEachClasses(String eachClasses) {
	this.eachClasses = eachClasses;
    }

    public String getInputClasses() {
	return this.inputClasses;
    }

    /**
     * The classes to apply to the input field.
     * 
     * @property
     */
    public void setInputClasses(String inputClasses) {
	this.inputClasses = inputClasses;
    }

    public static class LanguageBean implements Serializable {
	public Language language;
	public String value;

	public LanguageBean(Language language, String value) {
	    super();

	    this.language = language;
	    this.value = value;
	}

	public static String exportAsString(LanguageBean languageBean) {
	    StringBuilder builder = new StringBuilder();

	    if (languageBean != null) {
		builder.append(languageBean.language != null ? languageBean.language.toString() : "");
		builder.append(":");
		builder.append(languageBean.value != null ? languageBean.value : "");
	    }

	    return builder.toString();
	}

	public static String exportAsString(Collection<LanguageBean> languageBeans) {
	    StringBuilder builder = new StringBuilder();

	    if (languageBeans != null) {
		for (LanguageBean bean : languageBeans) {
		    String beanString = exportAsString(bean);
		    builder.append(beanString.replace("/", "//"));
		    builder.append("/");
		}
	    }

	    return builder.toString();
	}

	public static LanguageBean importFromString(String value) {
	    if (value == null || value.length() == 0) {
		return null;
	    }

	    int firstIndex = value.indexOf(":");
	    if (firstIndex == -1) {
		return null;
	    }

	    String language = value.substring(0, firstIndex);
	    String message = value.substring(firstIndex + 1);

	    Language realLanguage = language.length() == 0 ? null : Language.valueOf(language);

	    return new LanguageBean(realLanguage, message);
	}

	public static Collection<LanguageBean> importAllFromString(String value) {
	    Collection<LanguageBean> allLanguageBeans = new ArrayList<LanguageBean>();

	    if (value == null || value.length() == 0) {
		return allLanguageBeans;
	    }

	    int startIndex = 0;
	    int lastIndex = 0;
	    int index;

	    while (lastIndex < value.length()) {
		index = value.indexOf("/", lastIndex);

		if (index == -1) {
		    return allLanguageBeans;
		}

		if (index < value.length() - 1 && value.charAt(index + 1) == '/') {
		    lastIndex = index + 2;
		    continue;
		}

		String part = value.substring(startIndex, index);
		allLanguageBeans.add(importFromString(part.replace("//", "/")));

		lastIndex = index + 1;
		startIndex = lastIndex;
	    }

	    return allLanguageBeans;
	}
    }

    protected HtmlSimpleValueComponent getInputComponent() {
	HtmlTextInput textInput = new HtmlTextInput();
	textInput.setSize(getSize() == null ? null : String.valueOf(getSize()));

	return textInput;
    }

    protected void configureInputComponent(HtmlSimpleValueComponent textInput) {
    }

    protected void configureLanguageContainer(HtmlContainer languageContainer, HtmlSimpleValueComponent input,
	    HtmlSimpleValueComponent languageComponent, HtmlActionLink removeLink) {
	languageContainer.addChild(input);
	languageContainer.addChild(languageComponent);
	languageContainer.addChild(removeLink);
    }

    protected Converter getConverter() {
	return new MultiLanguageStringConverter();
    }

    @Override
    protected Layout getLayout(Object object, Class type) {
	MetaObject metaObject = getInputContext().getMetaObject();

	if (metaObject != null && metaObject instanceof MetaSlot) {
	    MetaSlot metaSlot = (MetaSlot) metaObject;

	    if (!metaSlot.hasValidator()) {
		Class defaultValidator = MultiLanguageStringValidator.class;
		metaSlot.setValidators(Collections.singletonList(new Pair<Class<HtmlValidator>, Properties>(defaultValidator,
			new Properties())));
	    }
	}

	return new MultiLanguageStringInputLayout();
    }

    protected HtmlBlockContainer getTopContainer() {
	return new HtmlBlockContainer();
    }

    protected class MultiLanguageStringInputLayout extends Layout {
	private static final String STATE_MAP_NAME = "mlsMap";
	private static final String STATE_INDEX = "lastIndex";

	protected Map<Integer, LanguageBean> getLanguageMap(boolean create) {
	    Map<Integer, LanguageBean> map = (Map<Integer, LanguageBean>) getInputContext().getViewState().getLocalAttribute(
		    STATE_MAP_NAME);

	    if (map == null && create) {
		map = new Hashtable<Integer, LanguageBean>();
		getInputContext().getViewState().setLocalAttribute(STATE_MAP_NAME, map);
	    }

	    return map;
	}

	protected String getLocalName(String part) {
	    return getInputContext().getMetaObject().getKey() + "/" + part;
	}

	protected Integer updateLastIndex(Integer index) {
	    Integer lastIndex = (Integer) getInputContext().getViewState().getLocalAttribute(STATE_INDEX);

	    if (lastIndex == null || lastIndex < index) {
		lastIndex = index;
		getInputContext().getViewState().setLocalAttribute(STATE_INDEX, index);
	    }

	    return lastIndex;
	}

	@Override
	public HtmlComponent createComponent(Object object, Class type) {
	    MultiLanguageString mls = (MultiLanguageString) object;

	    MetaSlotKey key = ((MetaSlot) getInputContext().getMetaObject()).getKey();
	    HtmlBlockContainer container = getTopContainer();

	    // hidden field with real value
	    HtmlHiddenField hiddenField = new HtmlHiddenField();
	    hiddenField.setTargetSlot(key);
	    hiddenField.setController(new MultiLanguageStringController());
	    hiddenField.setConverter(getConverter());
	    container.addChild(hiddenField);

	    // add link
	    HtmlActionLink addLink = new HtmlActionLink(RenderUtils.getResourceString("renderers.language.add"));
	    addLink.setName(getLocalName("add"));
	    container.addChild(addLink);

	    Map<Integer, LanguageBean> map = getLanguageMap(false);
	    if ((map == null || map.isEmpty()) && (mls != null && !mls.isEmpty())) {
		map = getLanguageMap(true);

		int index = 0;
		for (Language language : mls.getAllLanguages()) {
		    map.put(index++, new LanguageBean(language, mls.getContent(language)));
		}
	    }

	    HtmlActionLink firstRemoveLink = null;
	    HtmlActionLink secondRemoveLink = null;

	    if (map != null) {
		List<Map.Entry<Integer, LanguageBean>> list = new ArrayList<Map.Entry<Integer, LanguageBean>>(map.entrySet());
		Collections.sort(list, new Comparator<Map.Entry<Integer, LanguageBean>>() {

		    @Override
		    public int compare(Entry<Integer, LanguageBean> o1, Entry<Integer, LanguageBean> o2) {
			return o1.getKey().compareTo(o2.getKey());
		    }

		});

		for (Map.Entry<Integer, LanguageBean> entry : list) {
		    HtmlActionLink link = addLanguageInput(container, entry.getKey(), entry.getValue().value,
			    entry.getValue().language, list.size() > 1);

		    if (firstRemoveLink == null) {
			firstRemoveLink = link;
		    } else if (secondRemoveLink == null) {
			secondRemoveLink = link;
		    }
		}
	    } else {
		// default: present one entry without allowing to remove
		addLanguageInput(container, 0, "", null, false);
	    }

	    // setup controllers to avoid displaying the remove link when only
	    // one line is present
	    addLink.setController(new AddNewLanguageController(container, firstRemoveLink));
	    if (map != null && map.size() == 2) {
		((RemoveLanguageController) firstRemoveLink.getController()).setLink(secondRemoveLink);
		((RemoveLanguageController) secondRemoveLink.getController()).setLink(firstRemoveLink);
	    }

	    return container;
	}

	private HtmlActionLink addLanguageInput(HtmlContainer container, Integer index, String value, Language language,
		boolean allowRemove) {
	    // insert empty entry if not present
	    Map<Integer, LanguageBean> map = getLanguageMap(true);
	    if (!map.containsKey(index)) {
		map.put(index, new LanguageBean(null, null));
	    }

	    updateLastIndex(index);

	    // create component line
	    HtmlContainer inputContainer = new HtmlBlockContainer();
	    inputContainer.setClasses(getEachClasses());

	    HtmlSimpleValueComponent textInput = getInputComponent();
	    textInput.setClasses(getInputClasses());

	    textInput.setName(getLocalName("text/" + index));
	    textInput.setValue(value);

	    configureInputComponent(textInput);

	    PresentationContext context = getInputContext().createSubContext(getInputContext().getMetaObject());
	    context.setProperties(new Properties());

	    Language usedLanguage = language == null ? Language.getUserLanguage() : language;

	    HtmlSimpleValueComponent languageComponent = (HtmlSimpleValueComponent) RenderKit.getInstance().render(context,
		    usedLanguage, Language.class);
	    languageComponent.setController(new UpdateLanguageController(textInput, index));
	    languageComponent.setTargetSlot(null);
	    languageComponent.setName(getLocalName("language/" + index));

	    HtmlActionLink removeLink = new HtmlActionLink(RenderUtils.getResourceString("renderers.language.remove"));
	    removeLink.setVisible(allowRemove);
	    removeLink.setName(getLocalName("remove/" + index));
	    removeLink.setController(new RemoveLanguageController(container, inputContainer, index));

	    configureLanguageContainer(inputContainer, textInput, languageComponent, removeLink);

	    container.getChildren().add(container.getChildren().size() - 2, inputContainer);

	    return removeLink;
	}

	private class MultiLanguageStringController extends HtmlController {
	    @Override
	    public void execute(IViewState viewState) {
		String value = null;
		Map<Integer, LanguageBean> map = getLanguageMap(false);

		if (map != null && map.size() > 0) {
		    value = LanguageBean.exportAsString(map.values());
		}

		HtmlSimpleValueComponent component = (HtmlSimpleValueComponent) getControlledComponent();
		component.setValue(value == null ? null : value.toString());
	    }
	}

	private class UpdateLanguageController extends HtmlController {
	    private final HtmlSimpleValueComponent input;
	    private final Integer index;

	    private UpdateLanguageController(HtmlSimpleValueComponent textInput, Integer index) {
		super();

		this.input = textInput;
		this.index = index;
	    }

	    @Override
	    public void execute(IViewState viewState) {
		Map<Integer, LanguageBean> map = getLanguageMap(true);

		HtmlSimpleValueComponent component = (HtmlSimpleValueComponent) getControlledComponent();

		String value = this.input.getValue();
		Language finalLanguage = component.getValue() == null || component.getValue().length() == 0 ? null : Language
			.valueOf(component.getValue());

		map.put(this.index, new LanguageBean(finalLanguage, value));
	    }
	}

	private class AddNewLanguageController extends HtmlActionLinkController {

	    private final HtmlBlockContainer container;
	    private final HtmlActionLink link;

	    public AddNewLanguageController(HtmlBlockContainer container, HtmlActionLink link) {
		this.container = container;
		this.link = link;
	    }

	    @Override
	    public void linkPressed(IViewState viewState, HtmlActionLink link) {
		viewState.setSkipValidation(true);

		Integer index = updateLastIndex(0);
		updateLastIndex(index++);

		if (this.link != null) {
		    this.link.setVisible(true);
		}

		addLanguageInput(this.container, index, "", null, true);
	    }

	}

	private class RemoveLanguageController extends HtmlActionLinkController {

	    private final HtmlContainer container;
	    private final HtmlContainer inputContainer;
	    private HtmlActionLink link;
	    private final Integer index;

	    public RemoveLanguageController(HtmlContainer container, HtmlContainer inputContainer, Integer index) {
		this.container = container;
		this.inputContainer = inputContainer;
		this.index = index;
	    }

	    public void setLink(HtmlActionLink link) {
		this.link = link;
	    }

	    @Override
	    public void linkPressed(IViewState viewState, HtmlActionLink link) {
		viewState.setSkipValidation(true);

		this.container.removeChild(this.inputContainer);
		if (this.link != null) {
		    this.link.setVisible(false);
		}

		Map<Integer, LanguageBean> map = getLanguageMap(true);
		map.remove(this.index);
	    }

	}

    }

    public static class MultiLanguageStringConverter extends Converter {

	@Override
	public Object convert(Class type, Object value) {
	    String text = (String) value;

	    MultiLanguageString mls = new MultiLanguageString();

	    Collection<LanguageBean> allLanguageBean = LanguageBean.importAllFromString(text);
	    for (LanguageBean bean : allLanguageBean) {
		if (bean.value != null && bean.value.trim().length() != 0) {
		    mls.setContent(bean.language, bean.value);
		}
	    }

	    return mls;
	}

    }

}