package frontend.ast.exp;

import frontend.ast.Node;
import frontend.ast.SyntaxType;
import frontend.ast.token.TokenNode;
import frontend.lexer.TokenStream;
import frontend.lexer.TokenType;
import midend.symbol.SymbolManager;
import midend.symbol.Symbol;
import midend.symbol.ArraySymbol;
import error.Errors;
import error.Error;
import error.ErrorType;

public class LVal extends Node {
    public LVal(TokenStream ts) {
        super(SyntaxType.LVAL_EXP, ts);
    }

    public void parse(Errors errors) {
        addChild(new TokenNode(this.ts)); // idenfr
        if (getCurrToken().getType() == TokenType.LBRACK) {
            addChild(new TokenNode(this.ts)); // lbrack
            Exp exp = new Exp(this.ts);
            exp.parse(errors);
            addChild(exp);
            if (getCurrToken().getType() == TokenType.RBRACK) {
                addChild(new TokenNode(this.ts)); // rbrack
            } else {
                errors.addError(new Error(this.ts.peek(-1).getLine(), ErrorType.k));
            }
        }
    }

    public int getType() {
        if (getChildren().size() == 1) {
            TokenNode idenfr = (TokenNode) getChild(0);
            Symbol symbol = SymbolManager.getSymbol(idenfr.getName());
            if (symbol instanceof ArraySymbol) {
                return 1;
            }
            return 0;
        } else {
            return 0;
        }
    }

    public int getValue() {
        TokenNode idenfr = (TokenNode) getChild(0); //idenfr一定是个常量，可在符号表找到且有值
        if (getChildren().size() == 1) {
            Symbol symbol = SymbolManager.getSymbol(idenfr.getName());
            return symbol.getValue(0);
        } else {
            int index = ((Exp) getChild(2)).getValue();
            Symbol symbol = SymbolManager.getSymbol(idenfr.getName());
            return symbol.getValue(index);
        }
    }
}