package be.jeffcheasey88.peeratcode.parser;

import java.util.function.BiConsumer;
import java.util.function.Function;

public class TokenValidator{
	
	public static int MAX_VALIDATE = 0;
	public static int TOKENS = 0;
	
	private Token[] elements;
	private int index;
	private int validated;
	
	private Bag bag;
	
	private TokenValidator(Bag bag){
		this.bag = bag;
	}
	
	public TokenValidator(Token[] elements){
		this.elements = elements;
		this.bag = new Bag();
	}
	
	public boolean hasNext(){
		return validated < elements.length;
	}
	
	public boolean validate(Function<Token, Boolean> action){
		if(validated >= this.elements.length) return false;
		if(action.apply(this.elements[validated])){
			if(validated+1 > MAX_VALIDATE){
				MAX_VALIDATE = validated+1;
				TOKENS = elements.length;
			}
			this.validated++;
			return true;
		}
		return false;
	}
	
	public boolean validate(Function<Token, Boolean> action, BiConsumer<Bag, Token> filler){
		if(validate(action)){
			filler.accept(bag, elements[validated-1]);
			return true;
		}
		return false;
	}
	
	public TokenValidator branch(){
		TokenValidator branch = new TokenValidator(bag);
		branch.elements = this.elements;
		branch.index = Math.max(0, this.validated-1);
		branch.validated = this.validated;
		return branch;
	}
	
	public void merge(TokenValidator branch){
		this.index = branch.index;
		this.validated = branch.validated;
		this.bag = branch.bag;
	}
	
	public void setBag(Bag bag){
		this.bag = bag;
	}
	
	public Bag getBag(){
		return this.bag;
	}
	
//	private Token[] elements;
//	private int index;
//	private int validated;
//	
//	private Bag bag;
//	
//	public TokenValidator(Token[] tokens){
//		this.elements = tokens;
//		this.validated = -1;
//		this.bag = new Bag();
//	}
//	
//	@Override
//	public boolean hasNext(){
//		return index < elements.length;
//	}
//
//	@Override
//	public Token next(){
//		return elements[index++];
//	}
//	
//	public boolean validate(Function<Token, Boolean> action){
//		if(index >= this.elements.length) return false;
//		if(action.apply(this.elements[index])){
//			System.out.println("validate "+elements[index]);
//			this.validated = index;
//			next();
//			return true;
//		}
//		return false;
//	}
//	
//	public boolean validate(Function<Token, Boolean> action, BiConsumer<Bag, Token> filler){
//		if(validate(action)){
//			filler.accept(bag, elements[index-1]);
//			return true;
//		}
//		return false;
//	}
//	
//	public void rollbackValidate(){
//		this.index = validated+1;
//	}
//	
//	public TokenValidator pullValidated(){
//		Token[] validated = new Token[this.validated+1];
//		System.arraycopy(this.elements, 0, validated, 0, validated.length);
//		TokenValidator tk = new TokenValidator(validated);
//		tk.bag = bag;
//		return tk;
//	}
//	
//	public void pushValidated(){
//		Token[] validated = new Token[this.elements.length-(this.validated+1)];
//		System.arraycopy(this.elements, this.validated+1, validated, 0, validated.length);
//		this.elements = validated;
//		this.index = 0;
//		this.validated = -1;
//	}
//	
//	public TokenValidator branch(){
//		pushValidated();
//		TokenValidator branch = new TokenValidator(this.elements);
//		branch.bag = this.bag;
//		return branch;
//	}
//	
//	public void merge(TokenValidator branch){
//		branch.pushValidated();
//		this.elements = branch.elements;
//		this.index = 0;
//		this.validated = -1;
//	}
//	
//	public Token[] toArray(){
//		return this.elements;
//	}
//	
//	public void setBag(Bag bag){
//		this.bag = bag;
//	}
//	
//	public Bag getBag(){
//		return this.bag;
//	}
//	
}