package pt.ist.renderers.components;

import java.util.ArrayList;
import java.util.Hashtable;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.servlet.jsp.PageContext;

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

public class HtmlLink extends HtmlComponent {

    private String text;

    private String target;
    private String url;
    private String module;
    private String anchor;
    private String contentType;
    private String charSet;
    private boolean moduleRelative;
    private boolean contextRelative;
    private boolean escapeAmpersand;

    private HtmlComponent body;

    private Map<String, String[]> parameters;

    public HtmlLink() {
	super();

	parameters = new Hashtable<String, String[]>();
	setModuleRelative(true);
	setEscapeAmpersand(true);
    }

    public String getTarget() {
	return this.target;
    }

    public void setTarget(String target) {
	this.target = target;
    }

    public String getAnchor() {
	return anchor;
    }

    public void setAnchor(String anchor) {
	this.anchor = anchor;
    }

    public String getCharSet() {
	return charSet;
    }

    public void setCharSet(String charSet) {
	this.charSet = charSet;
    }

    public String getContentType() {
	return contentType;
    }

    public void setContentType(String contentType) {
	this.contentType = contentType;
    }

    public String getUrl() {
	return url;
    }

    public void setUrl(String url) {
	String realUrl = null;

	// parse parameters from url if the url has the form
	// 'url?param=value&other=otherValue'
	if (url != null) {
	    int indexOfQuestion = url.indexOf('?');
	    int indexOfAnchor = url.indexOf('#');

	    if (indexOfAnchor != -1) {
		setAnchor(url.substring(indexOfAnchor + 1));
	    }

	    if (indexOfQuestion != -1) {
		realUrl = url.substring(0, indexOfQuestion);

		if (indexOfQuestion < url.length()) {
		    String parameters = indexOfAnchor != -1 ? url.substring(indexOfQuestion + 1, indexOfAnchor) : url
			    .substring(indexOfQuestion + 1);
		    String[] parameresParts = getParameters(parameters);

		    for (int i = 0; i < parameresParts.length; i++) {
			String part = parameresParts[i];

			int equalPos = part.indexOf('=');
			if (equalPos == -1) {
			    addParameter(part, "");
			} else {
			    String name = part.substring(0, equalPos);

			    String value;
			    if (part.length() == equalPos + 1) {
				value = "";
			    } else {
				value = part.substring(equalPos + 1);
			    }

			    addParameter(name, value);
			}
		    }
		}
	    }
	}

	this.url = HtmlText.escape(realUrl != null ? realUrl : url);

    }

    private String[] getParameters(String parameters) {
	String[] parameresParts = parameters.split("&amp;");
	if (parameresParts.length < 2) {
	    parameresParts = parameters.split("&");
	}
	return parameresParts;
    }

    public String getModule() {
	return this.module;
    }

    public void setModule(String module) {
	this.module = module;
    }

    public String getParameter(String name) {
	String[] values = this.parameters.get(name);

	if (values != null && values.length > 0) {
	    return values[0];
	} else {
	    return null;
	}
    }

    public String[] getParameterValues(String name) {
	String[] values = this.parameters.get(name);
	return values == null ? new String[0] : values;
    }

    public void setParameter(String name, String value) {
	setParameter(name, new String[] { value });
    }

    public void setParameter(String name, Object value) {
	if (value != null) {
	    setParameter(name, value.toString());
	}
    }

    public void setParameter(String name, String[] value) {
	this.parameters.put(name, value);
    }

    public void addParameter(String name, Object value) {
	String[] values = this.parameters.get(name);

	if (values == null) {
	    setParameter(name, value);
	} else {
	    if (value != null) {
		String[] newValues = new String[values.length + 1];
		System.arraycopy(values, 0, newValues, 0, values.length);

		newValues[values.length] = value.toString();
		setParameter(name, newValues);
	    }
	}
    }

    public Map<String, String[]> getParameters() {
	return this.parameters;
    }

    public HtmlComponent getBody() {
	return body;
    }

    public void setBody(HtmlComponent body) {
	this.body = body;
    }

    public String getText() {
	return text;
    }

    public void setText(String text) {
	this.text = text;
    }

    public boolean isContextRelative() {
	return this.contextRelative;
    }

    public void setContextRelative(boolean contextRelative) {
	this.contextRelative = contextRelative;

	if (!contextRelative) {
	    setModuleRelative(false);
	}
    }

    public boolean isModuleRelative() {
	return this.moduleRelative;
    }

    public void setModuleRelative(boolean moduleRelative) {
	this.moduleRelative = moduleRelative;

	if (moduleRelative) {
	    setContextRelative(true);
	}
    }

    public boolean isEscapeAmpersand() {
	return escapeAmpersand;
    }

    public void setEscapeAmpersand(boolean escapeAmpersand) {
	this.escapeAmpersand = escapeAmpersand;
    }

    @Override
    public List<HtmlComponent> getChildren() {
	ArrayList<HtmlComponent> children = new ArrayList<HtmlComponent>(super.getChildren());

	if (getBody() != null) {
	    children.add(getBody());
	}

	return children;
    }

    @Override
    public HtmlTag getOwnTag(PageContext context) {
	HtmlTag tag = super.getOwnTag(context);

	tag.setName("a");

	tag.setAttribute("href", calculateUrl());
	tag.setAttribute("charset", getCharSet());
	tag.setAttribute("type", getContentType());
	tag.setAttribute("target", getTarget());

	if (getText() != null) {
	    tag.addChild(new HtmlTag(null, getText()));
	}

	if (getBody() != null) {
	    tag.addChild(getBody().getOwnTag(context));
	}

	return tag;
    }

    public String calculateUrl() {
	StringBuilder buffer = new StringBuilder();

	if (getModule() != null) {
	    buffer.append(RenderUtils.getContextRelativePath(getModule()));
	} else if (isModuleRelative()) {
	    buffer.append(RenderUtils.getModuleRelativePath(""));
	} else if (isContextRelative()) {
	    buffer.append(RenderUtils.getContextRelativePath(""));
	}

	if (getUrl() != null) {
	    buffer.append(getUrl());

	    if (!getParameters().isEmpty()) {
		if (getUrl().indexOf('?') == -1) {
		    buffer.append("?");
		} else {
		    buffer.append(getParametersSeparator());
		}

		Set<String> keys = getParameters().keySet();
		int count = keys.size();

		for (String key : keys) {
		    String[] values = getParameters().get(key);
		    for (int i = 0; i < values.length; i++) {
			if (i > 0) {
			    buffer.append(getParametersSeparator());
			}

			buffer.append(key);
			if (values[i] != null && values[i].length()>0) {
			    buffer.append("=");

			    buffer.append(values[i]);
			}
			// try {
			// buffer.append(URLEncoder.encode(values[i],
			// "ISO-8859-1"));
			// } catch (UnsupportedEncodingException e) {
			// e.printStackTrace();
			// }
		    }

		    count--;
		    if (count > 0) {
			buffer.append(getParametersSeparator());
		    }
		}
	    }
	}

	if (getAnchor() != null) {
	    buffer.append("#");
	    buffer.append(getAnchor());
	}

	// allways make a link
	if (buffer.length() == 0) {
	    buffer.append("#");
	}

	return buffer.toString();
    }

    private String getParametersSeparator() {
	return isEscapeAmpersand() ? "&amp;" : "&";
    }

    /**
     * Predefined values for the {@link HtmlLink#setTarget(String) target}
     * attribute.
     */
    public static final class Target {
	/**
	 * The user agent should load the designated document in a new, unnamed
	 * window.
	 */
	public static final String BLANK = "_blank";

	/**
	 * The user agent should load the document in the same frame as the
	 * element that refers to this target.
	 */
	public static final String SELF = "_self";

	/**
	 * The user agent should load the document into the immediate FRAMESET
	 * parent of the current frame. This value is equivalent to _self if the
	 * current frame has no parent.
	 */
	public static final String PARENT = "_parent";

	/**
	 * The user agent should load the document into the full, original
	 * window (thus canceling all other frames). This value is equivalent to
	 * _self if the current frame has no parent.
	 */
	public static final String TOP = "_top";
    };

}