#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include <driver/gpio.h>
#include <freertos/task.h>
#include <string.h>

typedef enum {
    Locked,
    Unlocked
} State;

typedef enum {
    Coin,
    Push
} Event;

typedef struct {
    State old_state;
    Event trigger;
    State new_state;
} Transition;

Transition transitions[] = {
    {Locked,Push,Locked},
    {Locked,Coin,Unlocked},
    {Unlocked,Push,Locked},
    {Unlocked,Coin,Unlocked},
};

void init_pins(){
    gpio_reset_pin(GPIO_NUM_26);
    gpio_set_direction(GPIO_NUM_26, GPIO_MODE_INPUT);
    gpio_reset_pin(GPIO_NUM_2);
    gpio_set_direction(GPIO_NUM_26, GPIO_MODE_INPUT);

}

const char * enum_to_string(State state){
  switch(state){
      case Locked: return "Locked";
      case Unlocked: return "Unlocked";
  }

}

void event_handler(Event current_event, State *current_state){
  //printf("reaching handler\n");
  for(int i = 0; i < 9; i++){
    if(*current_state == transitions[i].old_state && current_event == transitions[i].trigger){
      if(*current_state == Unlocked && transitions[i].trigger == Push){
          printf("Passing through!\n");
      }
      *current_state = transitions[i].new_state;
       printf("%s\n", enum_to_string(transitions[i].new_state));
    }
  }
}
void turnstile(void *(arg)){
  State current_state = Locked;
  while(1){
    //printf("%d\n", gpio_get_level(GPIO_NUM_2));
    if(gpio_get_level(GPIO_NUM_26) == 0){
        printf("Turnstile is Unlocked! Please move forward!\n");
        event_handler(Coin,&current_state);
    }
    if(gpio_get_level(GPIO_NUM_2) == 1){
        printf("Pushing....\n");
        event_handler(Push,&current_state);
    }
    vTaskDelay(1000/portTICK_PERIOD_MS);
  }
}
extern "C" void app_main(){
    init_pins();
    printf("Hello!\nWelcome to the turnstile simulator, to enter a coin please press the button.\n");
    printf("To simulate movement, a motion sensor has been added.\nPlease interact with the sensor to move through the turnstile!\n");
    xTaskCreate(&turnstile,"turnstile", 2048, NULL, 5, NULL);
}