package st;

import syntaxtree.*;
import visitor.*;
import java.util.*;
import misc.*;

/**
 * Performs a top-down final visit through the AST adding all local
 * methods, attributes, extension, and scoping information to the ST
 */
public class SymTableTopDown<R> extends GJDepthFirst<R,SymbolTable> {

    /**
     * f0 -> "class"
     * f1 -> Identifier()
     * f2 -> "{"
     * f3 -> "public"
     * f4 -> "static"
     * f5 -> "void"
     * f6 -> "main"
     * f7 -> "("
     * f8 -> "String"
     * f9 -> "["
     * f10 -> "]"
     * f11 -> Identifier()
     * f12 -> ")"
     * f13 -> "{"
     * f14 -> ( VarDeclaration() )*
     * f15 -> ( Statement() )*
     * f16 -> "}"
     * f17 -> "}"
     */
    public R visit(MainClass n, SymbolTable symt) {
        TokenKey id = new TokenKey(n.f1.f0.tokenImage, 0);
        symt.setActive(TypeEnum.classname, symt.getClass(id));
        TokenKey main = new TokenKey(n.f6.tokenImage, n.f6.beginLine);
        symt.setActive(TypeEnum.method, symt.getMethod(main));
        symt.addMethod(main);


        n.f0.accept(this, symt);
        n.f1.accept(this, symt);
        n.f2.accept(this, symt);
        n.f3.accept(this, symt);
        n.f4.accept(this, symt);
        n.f5.accept(this, symt);
        n.f6.accept(this, symt);
        n.f7.accept(this, symt);
        n.f8.accept(this, symt);
        n.f9.accept(this, symt);
        n.f10.accept(this, symt);
        n.f11.accept(this, symt);
        n.f12.accept(this, symt);
        n.f13.accept(this, symt);
        n.f14.accept(this, symt);
        n.f15.accept(this, symt);
        n.f16.accept(this, symt);
        n.f17.accept(this, symt);

        symt.removeActive(TypeEnum.method);
        return null;
    }

    /**
     * f0 -> "class"
     * f1 -> Identifier()
     * f2 -> "{"
     * f3 -> ( VarDeclaration() )*
     * f4 -> ( MethodDeclaration() )*
     * f5 -> "}"
     */
    public R visit(ClassDeclaration n, SymbolTable symt) {
        TokenKey id = new TokenKey(n.f1.f0.tokenImage, 0);
        symt.setActive(TypeEnum.classname, symt.getClass(id));


        n.f0.accept(this, symt);
        n.f1.accept(this, symt);
        n.f2.accept(this, symt);
        n.f3.accept(this, symt);
        n.f4.accept(this, symt);
        n.f5.accept(this, symt);
        return null;
    }

    /**
     * f0 -> "class"
     * f1 -> Identifier()
     * f2 -> "extends"
     * f3 -> Identifier()
     * f4 -> "{"
     * f5 -> ( VarDeclaration() )*
     * f6 -> ( MethodDeclaration() )*
     * f7 -> "}"
     */
    public R visit(ClassExtendsDeclaration n, SymbolTable symt) {
        TokenKey id = new TokenKey(n.f1.f0.tokenImage, 0);
        symt.setActive(TypeEnum.classname, symt.getClass(id));
        TokenKey ext = new TokenKey(n.f3.f0.tokenImage, 0);
        symt.setExtend(ext);


        n.f0.accept(this, symt);
        n.f1.accept(this, symt);
        n.f2.accept(this, symt);
        n.f3.accept(this, symt);
        n.f4.accept(this, symt);
        n.f5.accept(this, symt);
        n.f6.accept(this, symt);
        n.f7.accept(this, symt);
        return null;
    }

    /**
     * f0 -> Type()
     * f1 -> Identifier()
     * f2 -> ";"
     */
    public R visit(VarDeclaration n, SymbolTable symt) {
        String cls = (n.f0.f0.which == 3) ?
            ((Identifier) n.f0.f0.choice).f0.tokenImage :
            null;

        TokenKey id = new TokenKey(n.f1.f0.tokenImage, n.f1.f0.beginLine);
        TypeInstance me = symt.getType(id);
        symt.addLocal(id);
        symt.addClassInstance(me, cls);


        n.f0.accept(this, symt);
        n.f1.accept(this, symt);
        n.f2.accept(this, symt);
        return null;
    }

    /**
     * f0 -> "public"
     * f1 -> Type()
     * f2 -> Identifier()
     * f3 -> "("
     * f4 -> ( FormalParameterList() )?
     * f5 -> ")"
     * f6 -> "{"
     * f7 -> ( VarDeclaration() )*
     * f8 -> ( Statement() )*
     * f9 -> "return"
     * f10 -> Expression()
     * f11 -> ";"
     * f12 -> "}"
     */
    public R visit(MethodDeclaration n, SymbolTable symt) {
        ClassInstance cls = (ClassInstance) symt.getActive(TypeEnum.classname);

        TokenKey id = new TokenKey(n.f2.f0.tokenImage, n.f2.f0.beginLine);
        MethodInstance me = symt.getMethod(id);
        symt.setActive(TypeEnum.method, me);
        symt.addMethod(id);
        symt.addClassInstance(me, cls.getName());


        n.f0.accept(this, symt);
        n.f1.accept(this, symt);
        n.f2.accept(this, symt);
        n.f3.accept(this, symt);
        n.f4.accept(this, symt);
        n.f5.accept(this, symt);
        n.f6.accept(this, symt);
        n.f7.accept(this, symt);
        n.f8.accept(this, symt);
        n.f9.accept(this, symt);
        n.f10.accept(this, symt);
        n.f11.accept(this, symt);
        n.f12.accept(this, symt);
        symt.removeActive(TypeEnum.method);
        return null;
    }

    /**
     * f0 -> Type()
     * f1 -> Identifier()
     */
    public R visit(FormalParameter n, SymbolTable symt) {
        TokenKey id = new TokenKey(n.f1.f0.tokenImage, n.f1.f0.beginLine);
        symt.addParameter(id);


        n.f0.accept(this, symt);
        n.f1.accept(this, symt);
        return null;
    }

}