/* AFTER — the SAME pipeline, event-driven: a sensor DATA-READY interrupt defers each sample into
 * the pipeline (rawQ -> FILTER task -> filtQ -> ALERT task). Wokwi, ST Nucleo-C031C6.
 * When ALERT does heavy work it blocks ONLY ITSELF — the sensor keeps firing and samples BUFFER in
 * the queue, so nothing is missed. This is how you read a real MAX30102 (its data-ready INT pin),
 * instead of polling it in a loop.
 * LEDs (optional): yellow on a dropped glitch, red on an alert.
 */
#include <STM32FreeRTOS.h>
#include "sensor_contract.h"
#define LED_YELLOW PB1
#define LED_RED    PB14

QueueHandle_t rawQ, filtQ;

/* sensor DATA-READY ISR: capture the sample, defer to the pipeline, return fast. */
static void SensorDataReadyISR(const SensorSample_t *s) {
  BaseType_t xHigherPriorityTaskWoken = pdFALSE;
  xQueueSendFromISR(rawQ, s, &xHigherPriorityTaskWoken);
  portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
}

/* FAKE data-ready IRQ: fires every 250 ms regardless of how busy the downstream is. */
static void SensorSourceTask(void *pv) {
  (void)pv; uint32_t seq = 0;
  for (;;) {
    vTaskDelay(pdMS_TO_TICKS(250));
    seq++;
    SensorSample_t s = hh_make_sample(seq);
    SensorDataReadyISR(&s);                          // on real HW: the MAX30102 INT / EXTI handler
  }
}

static void FilterTask(void *pv) {
  (void)pv; SensorSample_t s;
  for (;;) if (xQueueReceive(rawQ, &s, portMAX_DELAY) == pdTRUE) {
    if (hh_valid(&s)) {
      xQueueSend(filtQ, &s, portMAX_DELAY);
    } else {
      digitalWrite(LED_YELLOW, HIGH);
      Serial.print("seq="); Serial.print(s.seq); Serial.println("  FILTER: drop glitch");
      vTaskDelay(pdMS_TO_TICKS(15)); digitalWrite(LED_YELLOW, LOW);
    }
  }
}

static void AlertTask(void *pv) {
  (void)pv; SensorSample_t f;
  for (;;) if (xQueueReceive(filtQ, &f, portMAX_DELAY) == pdTRUE) {
    const char *lvl = "OK";
    if (f.spo2_pct < 90.0f) lvl = "CRITICAL"; else if (f.temp_c >= 38.0f) lvl = "HIGH";
    bool a = (lvl[0] != 'O');
    digitalWrite(LED_RED, a ? HIGH : LOW);
    Serial.print("seq="); Serial.print(f.seq); Serial.print("  ALERT: "); Serial.println(lvl);
    if (a) {
      vTaskDelay(pdMS_TO_TICKS(500));                // heavy handling — blocks ONLY this task
      Serial.print("   (heavy alert done; "); Serial.print(uxQueueMessagesWaiting(filtQ));
      Serial.println(" sample(s) buffered while busy -- none missed)");
    }
  }
}

void setup() {
  Serial.begin(115200);
  pinMode(LED_YELLOW, OUTPUT); pinMode(LED_RED, OUTPUT);
  rawQ  = xQueueCreate(16, sizeof(SensorSample_t));
  filtQ = xQueueCreate(16, sizeof(SensorSample_t));
  Serial.println("AFTER: pipeline is EVENT-DRIVEN (data-ready IRQ -> tasks)");
  xTaskCreate(SensorSourceTask, "SENSOR", 256, NULL, 3, NULL);  // fires on time, always
  xTaskCreate(FilterTask,       "FILTER", 256, NULL, 2, NULL);
  xTaskCreate(AlertTask,        "ALERT",  256, NULL, 1, NULL);
  vTaskStartScheduler();
}
void loop() {}