Added basic HTML generation and response handling.

[jrw.git] / src / jrw / sp / Formatter.java

package jrw.sp;

import jrw.util.*;
import java.util.*;

public class Formatter extends LazyPChannel {
    private final Element root;
    private final String header;
    private final List<Frame> stack = new ArrayList<>();
    private final Map<Namespace, String> ns = new IdentityHashMap<>();
    private boolean headed = false;

    class Frame {
	Element el;
	Iterator<Map.Entry<Name, String>> ai;
	Iterator<Node> ci;
	boolean sh;
	boolean h, e, t;

	Frame(Element el) {
	    this.el = el;
	    this.ai = el.attribs.entrySet().iterator();
	    this.ci = el.children.iterator();
	    this.sh = shorten(el);
	}
    }

    private void countns(Map<Namespace, Integer> freq, Set<Namespace> attrs, Element el) {
	for(Name anm : el.attribs.keySet()) {
	    if(anm.ns != null) {
		attrs.add(anm.ns);
		Integer f = freq.get(anm.ns);
		freq.put(anm.ns, ((f == null) ? 0 : f) + 1);
	    }
	}
	Integer f = freq.get(el.name.ns);
	freq.put(el.name.ns, ((f == null) ? 0 : f) + 1);
	for(Node ch : el.children) {
	    if(ch instanceof Element)
		countns(freq, attrs, (Element)ch);
	}
    }

    private void calcnsnames() {
	Map<Namespace, Integer> freq = new IdentityHashMap<>();
	Set<Namespace> attrs = new HashSet<>();
	countns(freq, attrs, root);
	if(freq.get(null) != null) {
	    ns.put(null, null);
	    freq.remove(null);
	} else if(!attrs.contains(root.name.ns)) {
	    ns.put(root.name.ns, null);
	    freq.remove(root.name.ns);
	}
	List<Namespace> order = new ArrayList<>(freq.keySet());
	Collection<String> ass = new HashSet<>();
	ass.add(null);
	Collections.sort(order, (x, y) -> (freq.get(y) - freq.get(x)));
	for(Namespace ns : order) {
	    String p = ns.prefabb;
	    if((p != null) && !ass.contains(p)) {
		this.ns.put(ns, p);
		ass.add(p);
	    } else {
		int i;
		if(p == null) {
		    p = "ns";
		    i = 1;
		} else {
		    i = 2;
		}
		while(ass.contains(p + i))
		    i++;
		this.ns.put(ns, p + i);
		ass.add(p + i);
	    }
	}
    }

    public Formatter(DocType doctype, Element root) {
	this.header = "<?xml version=\"1.0\" encoding=\"US-ASCII\"?>\n" + doctype.format() + "\n";
	this.root = root;
	calcnsnames();
	Frame rf = new Frame(root);
	Map<Name, String> ra = new HashMap<>(root.attribs);
	for(Map.Entry<Namespace, String> ent : this.ns.entrySet()) {
	    Namespace ns = ent.getKey();
	    String abb = ent.getValue();
	    if(ns == null)
		continue;
	    ra.put(new Name((abb == null) ? "xmlns" : ("xmlns:" + abb)), ns.uri);
	}
	rf.ai = ra.entrySet().iterator();
	stack.add(rf);
    }

    private String fmtname(Name nm) {
	String abb = ns.get(nm.ns);
	return((abb == null) ? nm.local : (abb + ":" + nm.local));
    }

    private String head(Element el) {
	return(String.format("<%s", fmtname(el.name)));
    }

    private String tail(Element el) {
	return(String.format("</%s>", fmtname(el.name)));
    }

    private String attrquote(String val) {
	char qc;
	if(val.indexOf('"') >= 0) {
	    qc = '\'';
	    val = val.replace("'", "&apos;");
	} else {
	    qc = '"';
	    val = val.replace("\"", "&quot;");
	}
	val = val.replace("&", "&amp;");
	val = val.replace("<", "&lt;");
	val = val.replace(">", "&gt;");
	return(qc + val + qc);
    }

    private String attr(Name nm, String value) {
	String anm = (nm.ns == null) ? nm.local : fmtname(nm);
	return(String.format(" %s=%s", anm, attrquote(value)));
    }

    private String quote(String text) {
	text = text.replace("&", "&amp;");
	text = text.replace("<", "&lt;");
	text = text.replace(">", "&gt;");
	return(text);
    }

    protected boolean shorten(Element el) {
	return(el.children.isEmpty());
    }

    protected boolean produce() {
	if(!headed) {
	    headed = true;
	    if(write(header))
		return(false);
	}
	if(stack.isEmpty())
	    return(true);
	Frame f = stack.get(stack.size() - 1);
	if(!f.h && (f.h = true) && write(head(f.el)))
	    return(false);
	while(f.ai.hasNext()) {
	    Map.Entry<Name, String> ent = f.ai.next();
	    if(write(attr(ent.getKey(), ent.getValue())))
		return(false);
	}
	if(!f.sh) {
	    if(!f.e && (f.e = true) && write(">"))
		return(false);
	    if(f.ci.hasNext()) {
		Node ch = f.ci.next();
		if(ch instanceof Text) {
		    write(quote(((Text)ch).text));
		} else if(ch instanceof Raw) {
		    write(((Raw)ch).text);
		} else {
		    stack.add(new Frame((Element)ch));
		}
		return(false);
	    }
	    if(!f.t && (f.t = true) && write(tail(f.el)))
		return(false);
	} else {
	    if(!f.e && (f.e = true) && write(" />"))
		return(false);
	}
	stack.remove(stack.size() - 1);
	return(false);
    }
}