%{
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <stack>
#include <string>
#define INFILE_ERROR 1
#define OUTFILE_ERROR 2

    extern int yylineno;
    extern FILE *yyin;
    int yylex();

void yyerror(const char *msg, ...);

struct StackElement {
  std::string value;
  enum { INT, VAR } type;
};

std::stack<StackElement> expressionsStack;
FILE *tripletFile;
int tempVarCounter = 0;

std::string generateTempVar() {
  return "result" + std::to_string(tempVarCounter++);
}

void writeTriplet(const std::string& result, const std::string& arg1, const std::string& arg2, const std::string& op) {
  fprintf(tripletFile, "%s= %s %s %s \n", result.c_str(), arg1.c_str(), arg2.c_str(), op.c_str());

}

%}

%union {
    char *text;
    int ival;
}

%token <text> ID
%token <ival> INT_LIT
%token LET
%token INT_TYPE
%token SEMICOLON COLON

%left '+' '-'
%left '*' '/'

%start program

%%

program
    : statement_list { printf("koniec\n"); }
    ;

statement_list
    : statement
    | statement_list statement
    ;

statement
    : variable_declaration { printf("Deklaracja zmiennej\n"); }
    | expression SEMICOLON {
      printf("instrukcja\n");
    if (!expressionsStack.empty()) {
      expressionsStack.pop();
    }
    }
    ;

variable_declaration
    : LET ID COLON INT_TYPE '=' expression SEMICOLON
        {
          printf("Deklaracja zmiennej: %s\n", $2);
          if (!expressionsStack.empty()) {
            StackElement expression = expressionsStack.top();
            expressionsStack.pop();
            writeTriplet(std::string($2), expression.value, "", "=");
          }
        }
    ;

expression
    : expression '+' expression {
      printf("Wyrazenie z +\n");
      StackElement rhs = expressionsStack.top();
      expressionsStack.pop();
      StackElement lhs = expressionsStack.top();
      expressionsStack.pop();
      std::string temp = generateTempVar();
      writeTriplet(temp, lhs.value, rhs.value, "+");
    }
    | expression '-' expression {
        printf("Wyrazenie z -\n");
        StackElement rhs = expressionsStack.top();
        expressionsStack.pop();
        StackElement lhs = expressionsStack.top();
        expressionsStack.pop();
        std::string temp = generateTempVar();
        writeTriplet(temp, lhs.value, rhs.value, "-");
    }
    | expression '*' expression {
        printf("Wyrazenie z *\n");
        StackElement rhs = expressionsStack.top();
        expressionsStack.pop();
        StackElement lhs = expressionsStack.top();
        expressionsStack.pop();
        std::string temp = generateTempVar();
        writeTriplet(temp, lhs.value, rhs.value, "*");
    }
    | expression '/' expression {
        printf("Wyrazenie z /\n");
        StackElement rhs = expressionsStack.top();
        expressionsStack.pop();
        StackElement lhs = expressionsStack.top();
        expressionsStack.pop();
        std::string temp = generateTempVar();
        writeTriplet(temp, lhs.value, rhs.value, "/");
    }
    | '(' expression ')' { printf("Wyrazenie w nawiasach\n"); }
    | INT_LIT {
        printf("Literal calkowity: %d\n", $1);
        StackElement element;
        element.value = std::to_string($1);
        element.type = StackElement::INT;
        expressionsStack.push(element);
    }
    | ID {
        printf("Identyfikator: %s\n", $1);
        char buffer[128];
        snprintf(buffer, sizeof(buffer), "%s", $1);
        StackElement element;
        element.value = std::string(buffer);
        element.type = StackElement::VAR;
        expressionsStack.push(element);
    }
    ;

%%

int main(int argc, char *argv[]) {
  tripletFile = fopen("triplets.txt", "w");
  if (!tripletFile) {
      fprintf(stderr, "Blad\n");
      return OUTFILE_ERROR;
  }
  yyparse();
  fclose(tripletFile);
    return 0;
}