package pt.ist.renderers.components;

import java.io.IOException;
import java.io.Serializable;
import java.io.Writer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.regex.Pattern;

import javax.servlet.jsp.PageContext;

import pt.ist.renderers.components.tags.HtmlTag;
import pt.ist.renderers.utils.RenderUtils;

import org.apache.commons.collections.Predicate;

public abstract class HtmlComponent implements Serializable {

    public enum TextDirection {
	RIGTH_TO_LEFT, LEFT_TO_RIGHT;

	public String toString() {
	    if (this == RIGTH_TO_LEFT) {
		return "rtl";
	    } else {
		return "ltr";
	    }
	}
    };

    private boolean visible;
    private boolean indented;

    // %coreattrs
    private String id;
    private String classes;
    private String style;
    private String title;

    // %i18n
    private String language;
    private TextDirection direction;

    // %event
    private String onClick;
    private String onDblClick;
    private String onMouseDown;
    private String onMouseUp;
    private String onMouseOver;
    private String onMouseMove;
    private String onMouseOut;
    private String onKeyPress;
    private String onKeyDown;
    private String onKeyUp;

    // custom
    private Map<String, String> custom;

    public HtmlComponent() {
	this.custom = new HashMap<String, String>();
	this.visible = true;
	this.indented = true;
    }

    public String getClasses() {
	return classes;
    }

    public void addClass(String newClass) {
	this.classes = classes == null ? newClass : classes + " " + newClass;
    }

    public void setClasses(String classes) {
	this.classes = classes;
    }

    public String getId() {
	return id;
    }

    /**
     * Sets the id of the component. If the given id is not a valid id then it
     * will be transformed to obey SGML rules. As such {@link #getId()} may
     * return a value that is not equal to the one given to this method.
     * 
     * @param id
     *            the desired id
     */
    public void setId(String id) {
	this.id = getValidIdOrName(id);
    }

    public String getStyle() {
	return style;
    }

    public void setStyle(String style) {
	this.style = style;
    }

    public String getTitle() {
	return title;
    }

    public void setTitle(String title) {
	this.title = title;
    }

    public TextDirection getDirection() {
	return this.direction;
    }

    public void setDirection(TextDirection direction) {
	this.direction = direction;
    }

    public String getLanguage() {
	return this.language;
    }

    public void setLanguage(String language) {
	this.language = language;
    }

    public boolean isVisible() {
	return visible;
    }

    public void setVisible(boolean visible) {
	this.visible = visible;
    }

    public boolean isIndented() {
	return this.indented;
    }

    public void setIndented(boolean idented) {
	this.indented = idented;
    }

    public String getOnClick() {
	return this.onClick;
    }

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

    public String getOnDblClick() {
	return this.onDblClick;
    }

    public void setOnDblClick(String ondblclick) {
	this.onDblClick = ondblclick;
    }

    public String getOnKeyDown() {
	return this.onKeyDown;
    }

    public void setOnKeyDown(String onkeydown) {
	this.onKeyDown = onkeydown;
    }

    public String getOnKeyPress() {
	return this.onKeyPress;
    }

    public void setOnKeyPress(String onkeypress) {
	this.onKeyPress = onkeypress;
    }

    public String getOnKeyUp() {
	return this.onKeyUp;
    }

    public void setOnKeyUp(String onkeyup) {
	this.onKeyUp = onkeyup;
    }

    public String getOnMouseDown() {
	return this.onMouseDown;
    }

    public void setOnMouseDown(String onmousedown) {
	this.onMouseDown = onmousedown;
    }

    public String getOnMouseMove() {
	return this.onMouseMove;
    }

    public void setOnMouseMove(String onmousemove) {
	this.onMouseMove = onmousemove;
    }

    public String getOnMouseOut() {
	return this.onMouseOut;
    }

    public void setOnMouseOut(String onmouseout) {
	this.onMouseOut = onmouseout;
    }

    public String getOnMouseOver() {
	return this.onMouseOver;
    }

    public void setOnMouseOver(String onmouseover) {
	this.onMouseOver = onmouseover;
    }

    public String getOnMouseUp() {
	return this.onMouseUp;
    }

    public void setOnMouseUp(String onmouseup) {
	this.onMouseUp = onmouseup;
    }

    public String getAttribute(String name) {
	return this.custom.get(name);
    }

    public void setAttribute(String name, String value) {
	this.custom.put(name, value);
    }

    public List<HtmlComponent> getChildren() {
	return new ArrayList<HtmlComponent>();
    }

    public void draw(Writer writer) throws IOException {
	HtmlTag tag = getOwnTag(null);
	tag.writeTag(writer);
    }

    public void draw(PageContext context) throws IOException {
	HtmlTag tag = getOwnTag(context);
	tag.writeTag(context);
    }

    public HtmlTag getOwnTag(PageContext context) {
	HtmlTag tag = new HtmlTag("div"); // generic container

	tag.setAttribute("id", getId());
	tag.setAttribute("class", getClasses());
	tag.setAttribute("style", getStyle());
	tag.setAttribute("title", getTitle());

	tag.setAttribute("lang", getLanguage());

	if (getDirection() != null) {
	    tag.setAttribute("dir", getDirection().toString());
	}

	tag.setAttribute("onclick", getOnClick());
	tag.setAttribute("ondblclick", getOnDblClick());
	tag.setAttribute("onmousedown", getOnMouseDown());
	tag.setAttribute("onmouseup", getOnMouseUp());
	tag.setAttribute("onmouseover", getOnMouseOver());
	tag.setAttribute("onmousemove", getOnMouseMove());
	tag.setAttribute("onmouseout", getOnMouseOut());
	tag.setAttribute("onkeypress", getOnKeyPress());
	tag.setAttribute("onkeydown", getOnKeyDown());
	tag.setAttribute("onkeyup", getOnKeyUp());

	tag.setVisible(isVisible());
	tag.setIndented(isIndented());

	for (Entry<String, String> entry : this.custom.entrySet()) {
	    tag.setAttribute(entry.getKey(), entry.getValue());
	}

	return tag;
    }

    public HtmlComponent getChild(Predicate predicate) {
	for (HtmlComponent child : getChildren()) {
	    if (predicate.evaluate(child)) {
		return child;
	    } else {
		HtmlComponent foundComponent = child.getChild(predicate);
		if (foundComponent != null) {
		    return foundComponent;
		}
	    }
	}

	return null;
    }

    public List<HtmlComponent> getChildren(Predicate predicate) {
	List<HtmlComponent> results = new ArrayList<HtmlComponent>();

	for (HtmlComponent child : getChildren()) {
	    if (predicate.evaluate(child)) {
		results.add(child);
	    }

	    results.addAll(child.getChildren(predicate));
	}

	return results;
    }

    public HtmlComponent getChildWithId(final String id) {
	return getChild(new Predicate() {

	    public boolean evaluate(Object component) {
		return ((HtmlComponent) component).getId().equals(id);
	    }

	});
    }

    public static HtmlComponent getComponent(HtmlComponent component, Predicate predicate) {
	if (component == null) {
	    return null;
	}

	if (predicate.evaluate(component)) {
	    return component;
	}

	return component.getChild(predicate);
    }

    public static List<HtmlComponent> getComponents(HtmlComponent component, Predicate predicate) {
	if (component == null) {
	    return new ArrayList<HtmlComponent>();
	}

	if (predicate.evaluate(component)) {
	    List<HtmlComponent> results = new ArrayList<HtmlComponent>();
	    results.add(component);

	    return results;
	} else {
	    return component.getChildren(predicate);
	}
    }

    public void register() {
	RenderUtils.registerComponent(getId(), this);
    }

    public void register(String id) {
	RenderUtils.registerComponent(id, this);
    }

    //
    //
    //

    private static Pattern ACCEPTABLE_ID_START_CHAR = Pattern.compile("[A-Za-z]");
    private static Pattern ACCEPTABLE_ID_CHAR = Pattern.compile("[A-Za-z0-9_:.-]");

    public static String getValidIdOrName(String desired) {
	if (desired == null) {
	    return null;
	}

	// ID and NAME tokens must begin with a letter ([A-Za-z]) and may be
	// followed by any number of letters, digits ([0-9]), hyphens ("-"),
	// underscores ("_"), colons (":"), and periods (".").

	StringBuilder name = new StringBuilder();

	int position = 0;
	for (Character c : desired.toCharArray()) {
	    if (position == 0) {
		if (!ACCEPTABLE_ID_START_CHAR.matcher(c.toString()).matches()) {
		    name.append("i"); // ensure that it starts with a letter
		}
	    }

	    if (ACCEPTABLE_ID_CHAR.matcher(c.toString()).matches()) {
		name.append(c);
	    } else {
		name.append('_'); // an acceptable character
	    }

	    position++;
	}

	return name.toString();
    }
}