//  Job: Jay's Own Browser, a web browser written in Java by Jay Skeer
//  Copyright (C) 1996 Jay Skeer, Jay Prime Positive
//
//  This program is free software; you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation; either version 2 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
/** 
Base class for all HTML document subparts.
E.g. Heading, list, paragraph, etc.
*/
import java.io.*;
import HtmlToken;
import HtmlTokenStream;

public class HtmlComponent {
    /** The HTML type of this class, see HtmlComponent.BODY etc. */
    int id;
    /** a string with the actual key for this component, eg "body" */
    String id_string;
    /** The value of TEXT components, and hack to hold "begin", "end"
	or "only" marker for <...> expresions */
    String value;
    /** The name of a name=value pair */ 
    String name;

    /** Internal, pointer to next sibling component */
    HtmlComponent sib;
    /** Internal, pointer to first child component */
    HtmlComponent first_kid;
    /** Internal, pointer to last child component */
    HtmlComponent last_kid;
    /** The list of arguments==parameters to this <...> document */
    HtmlComponent arg;

    /** next sibling (either kid, or arg) component */
    public HtmlComponent sib() {
        return this.sib;
    }
    /** first child component */
    public HtmlComponent kid() {
        return this.first_kid;
    }
    /** last child component */
    public HtmlComponent last_kid() {
        return this.last_kid;
    }
    /** first argument==parameter component */
    public HtmlComponent arg() {
        return this.arg;
    }

    /** HTML is root of html document trees */
    public static final int HTML= 0;
    /** HEAD is title (and other parts?) */
    public static final int HEAD= 100;
    /** TITLE is title of this document */
    public static final int TITLE= 101;
    /** BODY is main part of document */
    public static final int BODY= 200;
    /** H1 is heading level 1 (highest level) */
    public static final int H1= 201;
    /** H2 is heading level 2 */
    public static final int H2= 202;
    /** H3 is heading level 3 (middle level) */
    public static final int H3= 203;
    /** H4 is heading level 4 */
    public static final int H4= 204;
    /** H5 is heading level 5 (lowest level) */
    public static final int H5= 205;
    /** PRE is a kind of paragraph format (fixed width font) */
    public static final int PRE= 206;
    /** TT is a kind of text format (fixed width font, fill ok) */
    public static final int TT= 207;
    /** STRONG is a kind of text format (bold i believe) */
    public static final int STRONG= 208;
    /** B is a kind of text format (bold i believe) */
    public static final int B= 209;
    /** HR is a horizontal rule line */
    public static final int HR= 210;
    /** P is a paragraph (a sequence) of TEXT */
    public static final int P= 220;
    /** TEXT is a (sequence of) characters */
    public static final int TEXT= 221;
    /** ANCHOR, a subtype of TEXT, is abstract super of HREF's and NAME's */
    public static final int ANCHOR= 222;
    /** AHREF is a reference to (another) HTML doc */
    public static final int AHREF= 223;
    /** ANAME is a name for a section (position) in an HTML doc */
    public static final int ANAME= 224;
    /** LIST is abstract supertype of UL, DL, etc. */
    public static final int LIST= 230;
    /** UL is a kind of list */
    public static final int UL= 231;
    /** DL is a kind of list */
    public static final int DL= 232;
    /** ITEM is a kind of list item marker */
    public static final int ITEM= 240;
    /** LI is a kind of list item marker */
    public static final int LI= 241;
    /** DD is a kind of list item marker */
    public static final int DD= 242;
    /** DT is a kind of list item marker */
    public static final int DT= 243;
    /** IMG is a image */
    public static final int IMG= 250;
    /** CENTER is centered text */
    public static final int CENTER= 260;
    /** OTHER is a html tag not recognized by this parser */
    public static final int OTHER= 999;
    /** ARG is a html name=value pair */
    public static final int ARG= 1000;

    /** Given an id number, return an id_string */
    public static String idToIdString(int id) {
        switch (id) {
	  case HTML:    return "html";
	  case HEAD:    return "head";
	  case TITLE:   return "title";
	  case BODY:    return "body";
	  case H1:      return "h1";
	  case H2:      return "h2";
	  case H3:      return "h3";
	  case H4:      return "h4";
	  case H5:      return "h5";
	  case PRE:     return "pre";
	  case TT:      return "tt";
	  case STRONG:  return "strong";
	  case B:       return "b";
	  case HR:      return "hr";
	  case P:       return "p";
	  case TEXT:    return "text";
	  case ANCHOR:  return "a";
	  case AHREF:   return "a-href";
	  case ANAME:   return "a-name";
	  case LIST:    return "list-abstract";
	  case UL:      return "ul";
	  case DL:      return "dl";
	  case ITEM:    return "list-item-abstract";
	  case LI:      return "li";
	  case DD:      return "dd";
	  case DT:      return "dt";
	  case IMG:     return "img";
	  case CENTER:  return "center";
	  case OTHER:   return "other";
	  case ARG:     return "arg";
	  default:      return "error";
	}
    }
    
    /** Given an id_string, return an id number */
    public static int idStringToId(String id) {
             if (id.equalsIgnoreCase("HTML"))   return HTML;
	else if (id.equalsIgnoreCase("HEAD"))   return HEAD;
	else if (id.equalsIgnoreCase("TITLE"))  return TITLE;
	else if (id.equalsIgnoreCase("BODY"))   return BODY;
	else if (id.equalsIgnoreCase("H1"))     return H1;
	else if (id.equalsIgnoreCase("H2"))     return H2;
	else if (id.equalsIgnoreCase("H3"))     return H3;
	else if (id.equalsIgnoreCase("H4"))     return H4;
	else if (id.equalsIgnoreCase("H5"))     return H5;
	else if (id.equalsIgnoreCase("PRE"))    return PRE;
	else if (id.equalsIgnoreCase("TT"))     return TT;
	else if (id.equalsIgnoreCase("STRONG")) return STRONG;
	else if (id.equalsIgnoreCase("B"))      return B;
	else if (id.equalsIgnoreCase("HR"))     return HR;
	else if (id.equalsIgnoreCase("P"))      return P;
	else if (id.equalsIgnoreCase("TEXT"))   return TEXT;
	else if (id.equalsIgnoreCase("ANCHOR")) return ANCHOR;
	else if (id.equalsIgnoreCase("A"))      return ANCHOR;
	else if (id.equalsIgnoreCase("AHREF"))  return AHREF;
	else if (id.equalsIgnoreCase("ANAME"))  return ANAME;
	else if (id.equalsIgnoreCase("UL"))     return UL;
	else if (id.equalsIgnoreCase("DL"))     return DL;
	else if (id.equalsIgnoreCase("LI"))     return LI;
	else if (id.equalsIgnoreCase("DD"))     return DD;
	else if (id.equalsIgnoreCase("DT"))     return DT;
	else if (id.equalsIgnoreCase("IMG"))    return IMG;
	else if (id.equalsIgnoreCase("CENTER")) return CENTER;
	else if (id.equalsIgnoreCase("ARG"))    return ARG;
	else                                    return OTHER;
    }

    /** Creates a new HtmlComponent with the given id, and id_string */
    public HtmlComponent(int id, String id_string) {
	this.id= id;
	this.id_string= id_string;
	this.first_kid= null;
	this.last_kid= null;
	this.sib= null;
	this.arg= null;
	this.name= null;
	this.value= null;
    }

    /** Creates a new HtmlComponent with the given id */
    public HtmlComponent(int id) {
	this.id= id;
	this.id_string= HtmlComponent.idToIdString(id);
	this.first_kid= null;
	this.last_kid= null;
	this.sib= null;
	this.arg= null;
	this.name= null;
	this.value= null;
    }

    /** Creates a new HtmlComponent with the given id_string */
    public HtmlComponent(String id_string) {
	this.id= HtmlComponent.idStringToId(id_string);
	this.id_string= id_string;
	this.first_kid= null;
	this.last_kid= null;
	this.sib= null;
	this.arg= null;
	this.name= null;
	this.value= null;
    }
    
    /** Adds (another) child component to this component */
    public void add(HtmlComponent new_kid) {
        if (null != new_kid.sib) {
	    /* error */
	    new_kid.sib= null;
	}
	if (null == this.last_kid) {
	    this.first_kid= new_kid;
	} else {
	    this.last_kid.sib= new_kid;
	}
	this.last_kid= new_kid;
    }

    /** Adds (another) argument component to this component */
    public void addArg(HtmlComponent new_arg) {
        if (null != new_arg.sib) {
	    /* error */
	}
        new_arg.sib= this.arg;
	this.arg= new_arg;
    }

    public String kidsToString() {
	String rv= new String();
	HtmlComponent k= this.kid();
	while (null != k) {
	    rv= rv + k.toString();
	    k= k.sib();
	}
	return rv;
    }

    public String argsToString() {
	String rv= null;
	HtmlComponent k= this.arg;
	while (null != k) {
	    if (null == rv) {
		rv= k.toString();
	    } else {
		rv= k.toString() + " " + rv;
	    }
	    k= k.sib;
	}
	if (null == rv) {
	    rv= new String();
	}
	return rv;
    }

    /** returns value of name=value arg pair of this component */
    public String getArgValue(String name) {
	HtmlComponent a= this.arg();
	while (null != a) {
	    if (a.ARG != a.id) {
		return new String();
	    } else if (a.name.equalsIgnoreCase(name)) {
		return a.value;
	    } else {
		a= a.sib();
	    }
	}
	return new String(); /* none found */
    }

    /** debugging interest only -- produce a string which captures the
	formating structure of the HtmlComponent */
    public String toString() {
	switch (this.id) {
	    case HtmlComponent.HTML:
	    case HtmlComponent.HEAD:
	    case HtmlComponent.TITLE:
	    case HtmlComponent.BODY:
	    case HtmlComponent.H1:
	    case HtmlComponent.H2:
	    case HtmlComponent.H3:
	    case HtmlComponent.H4:
	    case HtmlComponent.H5:
	    case HtmlComponent.PRE:
	    case HtmlComponent.TT:
	    case HtmlComponent.STRONG:
	    case HtmlComponent.CENTER:
	    case HtmlComponent.B:
	    case HtmlComponent.HR:
	    case HtmlComponent.DL:
	    case HtmlComponent.UL:
	    case HtmlComponent.LI:
	    case HtmlComponent.DD:
	    case HtmlComponent.DT:
	        return "[" + HtmlComponent.idToIdString(this.id) +
		    ((null!=this.value)?(" " + this.value):(""))+
		    ((null!=this.kid())?(" "+this.kidsToString()):(""))+
                    "]";
	    case HtmlComponent.P:
	        return "[P" +
		    ((null!=this.kid())?(" "+this.kidsToString()):(""))+
                    "]";
	    case HtmlComponent.TEXT:
	        return "[\"" + this.id_string + "\"]"; // hack!
	    case HtmlComponent.ANCHOR:
	    case HtmlComponent.AHREF:
	    case HtmlComponent.ANAME:
	    case HtmlComponent.IMG:
	        return "[" + HtmlComponent.idToIdString(this.id) +
		    ((null!=this.value)?(" " + this.value):(""))+
		    ((null!=this.arg())?(" ("+this.argsToString()+")"):(""))+
		    ((null!=this.kid())?(" "+this.kidsToString()):(""))+
                    "]";
	    case HtmlComponent.ARG:
	        return "{" + this.name + "}={" + this.value + "}";
	    case HtmlComponent.OTHER:
		return "[OTHER" +
		    ((null!=this.id_string)?(" \""+this.id_string+"\""):(""))+
		    ((null!=this.value)?(" " + this.value):(""))+
		    ((null!=this.arg())?(" ("+this.argsToString()+")"):(""))+
		    ((null!=this.kid())?(" "+this.kidsToString()):(""))+
                    "]";
	    default:
		return "[-error-]";
	}
    }
}