textutil.js

const Ksanapos=require("./ksanapos");
const tt=require("./tokentypes");
const TokenTypes=tt.TokenTypes;

const isPunc=function(c){
	const c2tt=this.tokenizer.code2TokenType;
	return (c2tt[c]===TokenTypes.PUNC || c2tt[c]===TokenTypes.SPACE);
}
const openbracket=function(s){
	return s=='「'||s=='《'||s=='『'||s=='（'||s=='〔'||s=='【'||s=='〈';
}
const trimRight=function(str,chcount,tailing) {
	if (!str) return "";
	var c=chcount,dis=0,t,s=str,code;
	t=this.koffset(s,c,tailing);
	dis+=t;
	return str.substr(0,dis);
}


const trimLeft=function(str,chcount,tailing) {
	if (!str) return "";
	var c=chcount,dis=0,t,s=str;
	t=this.koffset(s,c,tailing);
	dis+=t;
	return str.substr(dis);
}

//linetpos: tpos of input text
//output linetpos, only works for no breaks, 
const layoutText=function(text,startkpos,breaks,linetpos){
	var page=0,prevpage=0,lines=[],linetext="",ltpos=[];
	var linebreaks=[],pagebreaks=[],kpos=startkpos,nbreak=0;
	var nextkpos;//kpos of next line start

	for (var i=0;i<text.length;i++) {
		nextkpos=advanceLineChar.call(this,startkpos,i+1);
		page=this.pageOf(kpos)-1;
		if (prevpage!==page) {
			while (lines.length>0&&!lines[lines.length-1].trim()) { 
				linebreaks.pop();
				lines.pop(); //remove extra tailing blank lines
				ltpos.length&&ltpos.pop();
			}
			pagebreaks.push(kpos); //show page break on screen
		}
		if (breaks) {
			var breakcount=0,t=text[i],consumed=0;
			//one text line might consist more than one p
			while (nbreak<breaks.length&&nextkpos>breaks[nbreak]) {
				breakcount++;
				const leftpart=trimRight.call(this,text[i],breaks[nbreak]-kpos,true);
				lines.push(linetext+leftpart.substr(consumed));
				consumed=leftpart.length;
				linetext="";
				nbreak++;
			} 
			
			if (!breakcount) {
				const delimiter=this.tokenizer.isConcatable(text[i])?"":" ";
				linetext+=delimiter+text[i];
			} else {
				linetext=text[i].substr(consumed);//remaining
			}
		} else {
			lines.push(text[i].replace(/\r?\n/g," "));
			linetpos&&ltpos.push(linetpos[i]);
			linebreaks.push(kpos);				
		}
		prevpage=page;
		kpos=nextkpos;
	}
	if (breaks) {
		linebreaks=breaks;
		linebreaks.unshift(startkpos);
		lines.push(linetext);
	}

	linetpos&&ltpos.push(linetpos[linetpos.length-1]);//termintor
	return {linebreaks:linebreaks,pagebreaks:pagebreaks,lines:lines,linetpos:ltpos};
}
const extractKPos=function(text){
	var out={},pat=this.addressPattern,articleOf=this.articleOf.bind(this);
	text.replace(this.addressRegex,function(m,m1){
		const range=Ksanapos.parse(m1,pat);
		if (typeof range!=="undefined") {
			var f=articleOf(range);
			if (!f.articlename) return;
			if (!out[f.articlename]) out[f.articlename]=[];
			out[f.articlename].push(range);
		}
	});
	return out;
}
/*
  add advline to kpos and return new kpos 
  advline can be more than maxChar
	crossing vol is not allowed
*/

const advanceLineChar=function(kpos,advline,linetext){
	const pat=this.addressPattern;
	kpos+=advline*pat.maxchar;
	
	if (linetext) {
		var arr=Ksanapos.unpack(kpos,pat);
		arr[3]=this.kcount(linetext);
		return Ksanapos.makeKPos(arr,pat);
	} else {
		return kpos;
	}
}
const parseRange=function(range,pat){
	if (typeof pat=="undefined") pat=this.addressPattern;
	if (typeof range=="string") {
		range=Ksanapos.parse(range,pat);
	}
	const r=Ksanapos.breakRange(range,pat);
	
	const startarr=Ksanapos.unpack(r.start,pat);
	var endarr=Ksanapos.unpack(r.end,pat);
	return {startarr:startarr,endarr:endarr,start:r.start,end:r.end,range:range};
}

const kPosUnpack=function(kpos,pat){
	pat=pat||this.addressPattern;
	const startarr=Ksanapos.unpack(kpos,pat);
	return startarr;
}

const bookOf=function(address){
	const r=parseRange(address,this.addressPattern);
	const arr=kPosUnpack.call(this,r.start);
	return arr[0];
}
const pageOf=function(address){
	const r=parseRange(address,this.addressPattern);
	const arr=kPosUnpack.call(this,r.start);
	return arr[1];
}
const bookLineOf=function(address){ //line counting from this book
	const r=parseRange(address,this.addressPattern);
	const arr=kPosUnpack.call(this,r.start);
	return arr[1]*this.addressPattern.maxline+arr[2];
}
const lineOf=function(address){
	const r=parseRange(address,this.addressPattern);
	const arr=kPosUnpack.call(this,r.start);
	return arr[2];
}
const charOf=function(address){
	const r=parseRange(address,this.addressPattern);
	const arr=kPosUnpack.call(this,r.start);
	return arr[3];
}
const pageStart=function(address){//return address of begining of page
	const r=parseRange(address,this.addressPattern);
	const arr=kPosUnpack.call(this,r.start);
	const pat=this.addressPattern;
	arr[2]=0;
	arr[3]=0;
	return Ksanapos.makeKPos(arr,pat);
}
const getParagraphBreaks=function(fields){
	var out=[];

	if (fields.head) {
		const headpos=fields.head.pos.map(function(p){
			const r=this.parseRange(p);
			return r.start;
		}.bind(this));
		out=out.concat(headpos);
	}
	if (fields.p) out=out.concat(fields.p.pos);
	out.sort();
	return out;
}
module.exports={trimLeft:trimLeft,trimRight:trimRight,parseRange:parseRange,
	bookOf:bookOf,pageOf:pageOf,lineOf:lineOf,charOf:charOf,pageStart:pageStart,
	bookLineOf:bookLineOf,	layoutText:layoutText,isPunc:isPunc,
	extractKPos:extractKPos,advanceLineChar:advanceLineChar,getParagraphBreaks:getParagraphBreaks};