%{
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void yyerror(const char *s);

typedef struct ASTNode {
    char *type;
    char *value;
    struct ASTNode *left;
    struct ASTNode *right;
} ASTNode;



ASTNode *createNode(const char *type, const char *value, ASTNode *left, ASTNode *right);
%}

%token SIMPLETYPE CLASS ENTRY IF WHILE WRITE READ RETURN
%token IDENTIFIER
%token CONSTANTEXP
%token LBRACE RBRACE LPAREN RPAREN LBRACKET RBRACKET ASSIGN EQ LT LE GT GE SEMICOLON DOT PLUS MINUS MULT DIV
%token COMMA

%start program

%left PLUS MINUS
%left MULT DIV
%left LT LE GT GE EQ

%%

program: 
    CLASS IDENTIFIER LBRACE entry_declaration class_body RBRACE
    ;


class_body:
    %empty
    | atrib_declaration class_body
    | method_declaration class_body
;
atrib_declaration:
    SIMPLETYPE IDENTIFIER SEMICOLON
    | SIMPLETYPE IDENTIFIER ASSIGN CONSTANTEXP SEMICOLON 
    ;

method_declaration:
    SIMPLETYPE IDENTIFIER LPAREN method_params RPAREN LBRACE method_body RBRACE
    ;

method_params:
    %empty
    | SIMPLETYPE IDENTIFIER
    | SIMPLETYPE IDENTIFIER COMMA method_params
    ;

method_body:
    %empty
    | statement_list
    ;

statement_list:
    %empty
    | statement statement_list
    ;

statement:
    atrib_statement
    | if_statement
    | while_statement
    | write_statement
    | read_statement
    | return_statement
    ;

atrib_statement:
    IDENTIFIER ASSIGN expression SEMICOLON
    ;

if_statement:
    IF LPAREN expression RPAREN LBRACE statement_list RBRACE
    ;

while_statement:
    WHILE LPAREN expression RPAREN LBRACE statement_list RBRACE
    ;

write_statement:
    WRITE LPAREN expression RPAREN SEMICOLON
    ;

read_statement:
    READ LPAREN IDENTIFIER RPAREN SEMICOLON
    ;

return_statement:
    RETURN expression SEMICOLON
    ;

expression:
    CONSTANTEXP
    | expression PLUS expression
    | expression MINUS expression
    | expression MULT expression
    | expression DIV expression
    | expression EQ expression
    | expression LT expression
    | expression LE expression
    | expression GT expression
    | expression GE expression
    | LPAREN expression RPAREN
    | IDENTIFIER
    | IDENTIFIER LBRACKET expression RBRACKET
    | LBRACKET array_list RBRACKET
    | class_method_call
    | class_expression
    ;

class_expression:
    IDENTIFIER
    | IDENTIFIER DOT class_expression
    ;

class_method_call:
    class_expression LPAREN array_list RPAREN

array_list:
    %empty
    | expression
    | expression COMMA array_list
    ;

entry_declaration:
    SIMPLETYPE ENTRY IDENTIFIER LPAREN RPAREN LBRACE statement_list RBRACE
    ;


%%

void yyerror(const char *s) {
    fprintf(stderr, "Error: %s\n", s);
}

ASTNode *createNode(const char *type, const char *value, ASTNode *left, ASTNode *right) {
    ASTNode *node = (ASTNode *)malloc(sizeof(ASTNode));
    node->type = strdup(type);
    node->value = value ? strdup(value) : NULL;
    node->left = left;
    node->right = right;
    return node;
}