/*
 * reptile_mqtt.ino — XIAO ESP32C6 Reptile Monitor
 * Publishes SHT31 x2 sensor data via MQTT every 5 s.
 * Subscribes reptile/fan/cmd ("ON"/"OFF") — web button takes full priority.
 */

#include <WiFi.h>
#include <PubSubClient.h>
#include <Wire.h>
#include <Adafruit_SHT31.h>
#include "Grove_Motor_Driver_TB6612FNG.h"

#define WIFI_SSID           "Omoshiro2G"
#define WIFI_PASSWORD       "qqqqqqqqqqqqq"
#define MQTT_SERVER         "192.168.11.201"
#define MQTT_PORT           1883
#define MQTT_CLIENT_ID      "reptile_monitor"
#define TOPIC_SENSOR        "reptile/sensor"
#define TOPIC_FAN_CMD       "reptile/fan/cmd"
#define TEMP_FAN_ON         27.0f
#define PUBLISH_INTERVAL_MS 5000UL

WiFiClient     wifiClient;
PubSubClient   mqttClient(wifiClient);
Adafruit_SHT31 sht31_bottom;
Adafruit_SHT31 sht31_top;
MotorDriver    motor;

bool          fanOn          = false;
bool          manualOverride = false;
unsigned long lastPublish    = 0;

void fanTurnOn()  { motor.dcMotorRun(MOTOR_CHA, 255); fanOn = true;  Serial.println("[Fan] ON");  }
void fanTurnOff() { motor.dcMotorStop(MOTOR_CHA);     fanOn = false; Serial.println("[Fan] OFF"); }

// Read one SHT31 sensor. Returns false (and zeroes output) on NaN.
bool readSensor(Adafruit_SHT31& sensor, const char* label, float& temp, float& hum) {
  temp = sensor.readTemperature();
  hum  = sensor.readHumidity();
  if (isnan(temp) || isnan(hum)) {
    Serial.print("[SHT31] "); Serial.print(label); Serial.println(" read error.");
    temp = hum = 0.0f;
    return false;
  }
  return true;
}

void initSensor(Adafruit_SHT31& sensor, uint8_t addr, const char* label) {
  if (!sensor.begin(addr)) { Serial.print("[SHT31] "); Serial.print(label); Serial.println(" not found!"); }
  else                     { Serial.print("[SHT31] "); Serial.print(label); Serial.println(" OK."); }
}

void mqttCallback(char* topic, byte* payload, unsigned int length) {
  char msg[16];
  unsigned int len = min(length, (unsigned int)(sizeof(msg) - 1));
  memcpy(msg, payload, len);
  msg[len] = '\0';
  Serial.print("[MQTT] cmd: "); Serial.println(msg);

  if      (strcmp(msg, "ON")  == 0) { manualOverride = true;  fanTurnOn();  }
  else if (strcmp(msg, "OFF") == 0) { manualOverride = false; fanTurnOff(); }
}

void connectWiFi() {
  Serial.print("[WiFi] Connecting");
  WiFi.mode(WIFI_STA);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  while (WiFi.status() != WL_CONNECTED) { delay(500); Serial.print("."); }
  Serial.print(" IP: "); Serial.println(WiFi.localIP());
}

void connectMQTT() {
  while (!mqttClient.connected()) {
    Serial.print("[MQTT] Connecting...");
    if (mqttClient.connect(MQTT_CLIENT_ID)) {
      mqttClient.subscribe(TOPIC_FAN_CMD);
      Serial.println(" connected.");
    } else {
      Serial.print(" failed rc="); Serial.print(mqttClient.state()); Serial.println(". Retry 5s.");
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);
  delay(500);
  Serial.println("=== Reptile Monitor MQTT ===");

  Wire.setPins(22, 23);
  Wire.begin();

  initSensor(sht31_bottom, 0x44, "Bottom");
  initSensor(sht31_top,    0x45, "Top");
  motor.init(0x14);

  mqttClient.setServer(MQTT_SERVER, MQTT_PORT);
  mqttClient.setCallback(mqttCallback);

  connectWiFi();
  connectMQTT();
}

void loop() {
  if (WiFi.status() != WL_CONNECTED) { Serial.println("[WiFi] Reconnecting..."); connectWiFi(); }
  if (!mqttClient.connected()) connectMQTT();
  mqttClient.loop();

  unsigned long now = millis();
  if (now - lastPublish < PUBLISH_INTERVAL_MS) return;
  lastPublish = now;

  float temp_b, hum_b, temp_t, hum_t;
  bool valid_b = readSensor(sht31_bottom, "Bottom", temp_b, hum_b);
  readSensor(sht31_top, "Top", temp_t, hum_t);

  if (!manualOverride && valid_b) {
    if      (temp_b > TEMP_FAN_ON && !fanOn) fanTurnOn();
    else if (temp_b <= TEMP_FAN_ON &&  fanOn) fanTurnOff();
  }

  char payload[160];
  snprintf(payload, sizeof(payload),
    "{\"temp_b\":%.1f,\"hum_b\":%.1f,\"temp_t\":%.1f,\"hum_t\":%.1f,\"fan\":\"%s\",\"manual\":%d}",
    temp_b, hum_b, temp_t, hum_t, fanOn ? "ON" : "OFF", manualOverride ? 1 : 0);

  Serial.print("[MQTT] "); Serial.print(payload);
  Serial.println(mqttClient.publish(TOPIC_SENSOR, payload) ? " [OK]" : " [FAIL]");
}