#!/usr/bin/env node
const fs=require("fs");


function print(/*arguments*/){
	process.stdout.write.apply(process.stdout,arguments);
}

function pad(s,w,c){
	s=s+"";
	if(s.length>=Math.abs(w))return s;
	if(w<0)return s+Array(-w-s.length+1).join(c?c:" ");
	else return Array(w-s.length+1).join(c?c:" ")+s;
}


function readopmap(fname){
	let table=String(fs.readFileSync(fname)).split("\n");
	let i;
	for(i=0;i<table.length;i++){
		if(/Oper.*Prec.*Assoc/.test(table[i]))break;
	}
	let header=table[i];
	table=table.slice(i+1);
	for(i=0;i<table.length;i++){
		if(table[i].length==0)break;
	}
	table=table.slice(0,i);

	let opsidx=header.indexOf("Oper"),
	    precidx=header.indexOf("Prec"),
	    associdx=header.indexOf("Assoc");

	let opmap={};

	for(let row of table){
		let ops=row.slice(opsidx,precidx).trim().split(" "),
		    prec=parseInt(row.slice(precidx,associdx).trim(),10),
		    assoc=row.slice(associdx).replace(/ *([^ ]+).*/,"$1");
		for(let op of ops){
			opmap[op]={prec,assoc};
		}
	}
	return opmap;
}

function outputfunc(_ /*opmap,name,gen,padw,dolen,rettype,defval,checkend*/){
	let opmap=_.opmap, name=_.name, gen=_.gen,
	    padw=_.padw, dolen=_.dolen, rettype=_.rettype,
	    defval=_.defval, checkend=_.checkend;
	print("\n"+rettype+" "+name+"(const char *op"+(dolen?",const int len":"")+"){\n");
	if(dolen)print("\tif(len<=0)return "+defval+";\n");
	print("\tswitch(op[0]){\n");

	let firstchars={};
	for(let k in opmap){
		if(firstchars[k[0]])firstchars[k[0]].push(k);
		else firstchars[k[0]]=[k];
	}
	let arr=[];
	for(k in firstchars){
		arr.push([k,firstchars[k].sort(function(a,b){
			return b.length-a.length;
		})]);
	}
	arr=arr.sort();
	for(let tup of arr){
		let k=tup[0],ops=tup[1];
		print("\t\tcase '"+k+"': return ");
		let expr="";
		for(let op of ops){
			let cond;
			if(dolen){
				cond="len=="+op.length;
				for(j=1;j<op.length;j++)cond+="&&op["+j+"]=='"+op[j]+"'";
			} else {
				cond="";
				for(j=1;j<op.length;j++)cond+="op["+j+"]=='"+op[j]+"'&&";
				if(checkend)cond+="!op["+j+"]";
				else cond=cond.slice(0,-2);
				if(cond=="")cond="true";
			}
			expr+=cond+"?"+pad(gen(op,opmap[op]),padw)+":";
		}
		expr+=defval;
		expr=expr.replace(/true\?([^:]*):[^)]*/,"$1");
		print(expr+";\n");
	}

	print("\t\tdefault: return "+defval+";\n");
	print("\t}\n");
	print("}\n");
}


const opmap=readopmap("LANGUAGE.txt");
const assocenum={
	"Prefix": "AS_PREFIX", "Suffix": "AS_SUFFIX",
	"Left": "AS_LEFT", "Right": "AS_RIGHT",
	"Nonassociative": "AS_NONASSOC"
};

print("#include <stddef.h>\n\n");
print("#include \"opfuncs.h\"\n");
print("#include \"parser.h\"\n");

function alsolen(_){
	outputfunc(_);
	_.name+="_len";
	_.dolen=true;
	outputfunc(_);
}

alsolen({
	opmap:opmap,
	name:"precedence",
	gen:(op,o)=>o.prec,
	padw:2,
	dolen:false,
	rettype:"int",
	defval:"-1",
	checkend:true
});

alsolen({
	opmap:opmap,
	name:"associativity",
	gen:(op,o)=>assocenum[o.assoc],
	padw:-11,
	dolen:false,
	rettype:"int",
	defval:"-1",
	checkend:true
});

outputfunc({
	opmap:opmap,
	name:"parseoplength",
	gen:(op,o)=>op.length,
	padw:1,
	dolen:false,
	rettype:"int",
	defval:"-1",
	checkend:false
});

outputfunc({
	opmap:opmap,
	name:"opconststring_len",
	gen:(op,o)=>'"'+op+'"',
	padw:3,
	dolen:true,
	rettype:"const char*",
	defval:"NULL",
	checkend:true
});