#ifndef VALUE_H
#define VALUE_H

#include <WiFi.h>
#include <patrix/log.h>
#include <patrix/mqtt.h>

class Value {

  const char *parent;

  const char *name;

  double threshold;

  unsigned long maxAgeMillis;

  unsigned long overdueSeconds;

  double currentValue = NAN;

  unsigned long currentMillis = 0;

  time_t currentEpoch = 0;

  double sentValue = NAN;

  time_t sentInterval = 0;

public:

  Value(
    const char *parent,
    const char *name,
    const double threshold,
    const unsigned long maxAgeSeconds,
    const unsigned long overdueSeconds
  ) : parent(parent),
      name(name),
      threshold(threshold),
      maxAgeMillis(maxAgeSeconds * 1000),
      overdueSeconds(overdueSeconds) {
    //
  }

  void update(const double value) {
    currentValue = value;
    currentMillis = millis();
    currentEpoch = time(nullptr);
  }

  void toJson(const JsonObject& json) const {
    json["value"] = currentValue;
    json["time"] = currentEpoch;
  }

  void send() {
    mqttPublish(String(parent) + "/" + name + "/plain", currentValue, true);

    JsonDocument json;
    toJson(json.to<JsonObject>());
    mqttPublish(String(parent) + "/" + name + "/json", json, true, false);

    markSent();
  }

  bool loop() {
    if (!isnan(currentValue) && millis() - currentMillis > maxAgeMillis) {
      warn("Value too old: %s/%s", parent, name);
      update(NAN);
    }

    const auto dueToNAN = isnan(currentValue) != isnan(sentValue);
    const auto dueToThreshold = abs(sentValue - currentValue) >= threshold;
    const auto dueToTime = sentInterval != 0 && sentInterval != time(nullptr) / overdueSeconds;
    const auto changed = dueToNAN || dueToThreshold || dueToTime;
    if (changed) {
      send();
    }
    return changed;
  }

  const char *getName() const {
    return name;
  }

  double getCurrentValue() const {
    return currentValue;
  }

  time_t getCurrentEpoch() const {
    return currentEpoch;
  }

private:

  void markSent() {
    sentValue = currentValue;
    sentInterval = time(nullptr) / overdueSeconds;
  }

};

#endif