package visitor.identification;

import ast.definition.Definition;
import ast.definition.classes.FuncDefinition;
import ast.definition.classes.VarDefinition;
import ast.expression.classes.Variable;
import ast.statement.classes.IfElse;
import ast.statement.classes.WhileLoop;
import ast.type.classes.ErrorType;
import ast.type.classes.FunctionType;
import visitor.AbstractVisitor;

public class IdentificationVisitor extends AbstractVisitor<Void, Void> {

    private SymbolTable st = new SymbolTable();

    //DEFINITIONS

    @Override
    public Void visit(FuncDefinition ast, Void param) {
        if (!st.insert(ast))
            new ErrorType(ast.getLine(), ast.getColumn(), "Function \"" + ast.getName() + "\" already defined");
        else {
            st.set();
            super.visit(ast, param);
            st.reset();
        }
        return null;
    }

    @Override
    public Void visit(VarDefinition ast, Void param) {
        if (!st.insert(ast))
            new ErrorType(ast.getLine(), ast.getColumn(), "Variable \"" + ast.getName() + "\" already defined");
        else {
            super.visit(ast, param);
        }
        return null;
    }

    // TYPE

    @Override
    public Void visit(FunctionType ast, Void param) {
        ast.getParameters().forEach(parameter -> {
            if (!st.insert(parameter))
                new ErrorType(parameter.getLine(), parameter.getColumn(), "Variable \"" + parameter.getName() + "\" already defined");
        });
        return null;
    }

    // STATEMENTS

    @Override
    public Void visit(IfElse ast, Void param) {
        st.set();
        super.visit(ast, param);
        st.reset();

        return null;
    }

    @Override
    public Void visit(WhileLoop ast, Void param) {
        st.set();
        super.visit(ast, param);
        st.reset();

        return null;
    }

    @Override
    public Void visit(Variable ast, Void param) {
        Definition definition = st.find(ast.getName());
        if (definition != null)
            ast.setDefinition(definition);
        /*
        -- Error is assigned in the TypeCheckingVisitor (in order not to repeat the error), as the definition associated to the variable is null.
        else
            new ErrorType(ast.getLine(),ast.getColumn(),"Variable \"" + ast.getName() +"\" not defined");
         */
        return null;
    }


}