// Filename: icte7.ino
// Author: Olivia Cady
// Date: 02/19/26
// Description: Uses a FreeRTOS scheduler to control a traffic light

// ==============================================
// Includes
// ==============================================
#include "freertos/FreeRTOS.h"     // FreeRTOS kernel API
#include "freertos/task.h"         // Task creation/management
#include "freertos/queue.h"        // Queue for inter-task communication

// ==============================================
// Pin Definitions
// ==============================================
#define RED_LED 2      // TODO: Connect Red LED
#define YELLOW_LED 5   // TODO: Connect Yellow LED
#define GREEN_LED 4    // TODO: Connect Green LED

// ==============================================
// Queue Handle
// ==============================================
// TODO: Define a global queue handle (QueueHandle_t)
// This queue will pass traffic light states between tasks.
QueueHandle_t queue;


// ==============================================
// Enum for Traffic Light States
// ==============================================
// TODO: Define an enum with RED, GREEN, and YELLOW
// This will make your code easier to read than using raw numbers.
enum states {RED, YELLOW, GREEN};
states red = RED;
states yellow = YELLOW;
states green = GREEN;

// ==============================================
// Traffic Controller Task
// ==============================================
// TODO: In a loop, send the current state to the queue
// Sequence: RED → GREEN → YELLOW → RED → ...
// Use vTaskDelay(pdMS_TO_TICKS(3000)) between state changes
void Task_TrafficController(void *pvParameters) {
  // Your code here
  while(1) {
    xQueueSend(queue, &red, 0);
    vTaskDelay(pdMS_TO_TICKS(3000));
    xQueueSend(queue, &green, 0);
    vTaskDelay(pdMS_TO_TICKS(3000));
    xQueueSend(queue, &yellow, 0);
    vTaskDelay(pdMS_TO_TICKS(3000));
  }
}


// ==============================================
// Traffic Light Task
// ==============================================
// TODO: Wait for a state from the queue.
// Turn OFF all LEDs first, then turn ON only the LED for that state.
// Print the current state to Serial (e.g., "Traffic Light: GREEN (Go)")
void Task_TrafficLight(void *pvParameters) {
    // Your code here
    while(1) {
      digitalWrite(RED_LED, LOW);
      digitalWrite(YELLOW_LED, LOW);
      digitalWrite(GREEN_LED, LOW);
      states next_state;
      xQueueReceive(queue, &next_state, 0);
      if (next_state == RED) {
        Serial.println("STOP");
        digitalWrite(RED_LED, HIGH);
      } else if (next_state == YELLOW) {
        Serial.println("SLOW DOWN");
        digitalWrite(YELLOW_LED, HIGH);         
      } else if (next_state == GREEN) {
        Serial.println("GO");
        digitalWrite(GREEN_LED, HIGH);
      }
    }
    
}


// ==============================================
// Setup
// ==============================================
void setup() {
    Serial.begin(115200);

    // TODO: Set all LED pins as OUTPUT
    pinMode(RED_LED, OUTPUT);
    pinMode(YELLOW_LED, OUTPUT);
    pinMode(GREEN_LED, OUTPUT);
    // TODO: Create the queue using xQueueCreate
    // Hint: Queue length can be 2, item size = sizeof(enum)
    queue = xQueueCreate(2, sizeof(states));
    // TODO: Create both tasks using xTaskCreate
    // Give both tasks the same priority for now
    xTaskCreate(Task_TrafficLight, "Traffic Light", 4096, NULL, 1, NULL);
    xTaskCreate(Task_TrafficController, "Traffic Controller", 4096, NULL, 1, NULL);
}


// ==============================================
// Loop
// ==============================================
void loop() {
    // Leave empty. FreeRTOS handles task scheduling.
}