package st;

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

/**
 * Performs a bottom-up preliminary visit through the AST
 * initializing all Instances and placing them in the passed ST
 */
public class SymTableVars<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) {
        String id = n.f1.f0.tokenImage;
        symt.setActive(TypeEnum.classname, symt.getClass(id));
        id = n.f6.tokenImage;
        symt.setActive(TypeEnum.method, symt.getMethod(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);
        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.addMethod(id);
        symt.removeActive(TypeEnum.method);
        symt.removeActive(TypeEnum.classname);
        return null;
    }

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

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

    /**
     * f0 -> "class"
     * f1 -> Identifier()
     * f2 -> "extends"
     * f3 -> Identifier()
     * f4 -> "{"
     * f5 -> ( VarDeclaration() )*
     * f6 -> ( MethodDeclaration() )*
     * f7 -> "}"
     */
    public R visit(ClassExtendsDeclaration n, SymbolTable symt) {
        String id = n.f1.f0.tokenImage;
        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);
        n.f6.accept(this, symt);
        n.f7.accept(this, symt);

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

    /**
     * f0 -> Type()
     * f1 -> Identifier()
     * f2 -> ";"
     */
    public R visit(VarDeclaration n, SymbolTable symt) {
        n.f0.accept(this, symt);
        n.f1.accept(this, symt);
        n.f2.accept(this, symt);
        TokenKey id = new TokenKey(n.f1.f0.tokenImage,
                                   (ClassInstance) symt.getActive(TypeEnum.classname),
                                   (MethodInstance) symt.getActive(TypeEnum.method));
        TypeEnum rtrn = TypeEnum.ERROR;
        String cls = null;
        switch (n.f0.f0.which) {
        case 0:
            rtrn = TypeEnum.intarray; break;
        case 1:
            rtrn = TypeEnum.bool; break;
        case 2:
            rtrn = TypeEnum.integer; break;
        case 3:
            rtrn = TypeEnum.classname;
            cls = ((Identifier) n.f0.f0.choice).f0.tokenImage; break;
        default:
            MinimalLogger.severe("Unsupported case");
        }

        TypeInstance instance = new TypeInstance(id.getName(), rtrn, (MethodInstance) symt.getActive(TypeEnum.method),
                                                 (ClassInstance) symt.getActive(TypeEnum.classname));
        symt.put(id, instance);
        symt.addLocal(id.getName());
        symt.addClassInstance(instance, cls);
        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) {
        String id = n.f2.f0.tokenImage;
        symt.setActive(TypeEnum.method, symt.getMethod(id));
        symt.addMethod(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);
        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) {
        n.f0.accept(this, symt);
        n.f1.accept(this, symt);
        TokenKey id = new TokenKey(n.f1.f0.tokenImage,
                                   (ClassInstance) symt.getActive(TypeEnum.classname),
                                   (MethodInstance) symt.getActive(TypeEnum.method));

        TypeEnum rtrn = TypeEnum.ERROR;
        switch (n.f0.f0.which) {
        case 0:
            rtrn = TypeEnum.intarray; break;
        case 1:
            rtrn = TypeEnum.bool; break;
        case 2:
            rtrn = TypeEnum.integer; break;
        case 3:
            rtrn = TypeEnum.classname; break;
        default:
            MinimalLogger.severe("Unsupported case");
        }

        TypeInstance instance = new TypeInstance(id.getName(), rtrn, (MethodInstance) symt.getActive(TypeEnum.method),
                                                 (ClassInstance) symt.getActive(TypeEnum.classname));
        symt.put(id, instance);
        symt.addParameter(id.getName());


        return null;
    }

}