import java.io.*;
import java.util.*;
import syntaxTree.*;
import globalEnv.*;

public class StatementParser {

    private static StreamTokenizer in;
    private static char lParen = '(';
    private static char rParen = ')';
    
	public static void main(String args[]) throws IOException {
	   if (args.length < 1) throw new IOException("Supply a filename on command line");
	   FileReader fileIn = new FileReader(args[0]);
	   echoFile(fileIn);
	   fileIn = new FileReader(args[0]);
	   in = new StreamTokenizer(fileIn);
	   in.ordinaryChar('/');
	   in.ordinaryChar('-');
	   
	   try { parseStatements();}
	   catch (IOException e) { System.out.println(e);}}
	
	private static void echoFile(FileReader fileIn) throws IOException {
	   int b;
	   while ((b = fileIn.read()) != -1)
	     System.out.write(b);
	   System.out.println();
	   System.out.println();
	   fileIn.close();}
	   
	private static void parseStatements() throws IOException {
		BinNonTermNd root;
		int i = 1;
		while (in.nextToken() != StreamTokenizer.TT_EOF) {
			in.pushBack();
			System.out.println("Processing statement " + i++ + "...");
			root = parseStatement();
			root.printTree();
			System.out.println("Value is: " + root.evaluate());
			System.out.println();}
		System.out.println("The symbols and their final values are:");
		Enumeration e = GlobalEnv.theSymbols();
		while (e.hasMoreElements()) {
			String name = (String)e.nextElement();
			System.out.println(name + " = " + GlobalEnv.valueInEnv(name));}}
				   
	private static AbstractNode parseExpression() throws IOException {
//		System.out.println("Expression called");
		AbstractNode root = parseTerm();
		in.nextToken();
		char op;
		while ((in.ttype == '+') || (in.ttype == '-')) {
			op = (char)in.ttype;
//			System.out.println(String.valueOf(op));
		 	BinNonTermNd temp = new BinNonTermNd();
		 	temp.setLeft(root);
		 	temp.setRight(parseTerm());
		 	temp.setOp(op);
		 	root = temp;
		    in.nextToken();}
		in.pushBack();
//		System.out.println("Expression finished");
		return root;}
		
	private static NumericTermNode parseUnsignedNumber() throws IOException {
//		System.out.println("Number called");
		in.nextToken();
		if (in.ttype != StreamTokenizer.TT_NUMBER)
			throw new IOException("Number expected");
		return new NumericTermNode(in.nval);}
}