#include <Arduino.h>
#include "settings.h"
#include "Log.h"
#include "Battery.h"
#include "Mqtt.h"
#include "Led.h"
#include "System.h"

constexpr uint16_t maxAnalogValue = 4095u; // Highest value given by analogRead(); don't change!

float warningLowVoltage = s_warningLowVoltage;
uint8_t voltageCheckInterval = s_voltageCheckInterval;
float voltageIndicatorLow = s_voltageIndicatorLow;
float voltageIndicatorHigh = s_voltageIndicatorHigh;

void Battery_Init() {
    #ifdef MEASURE_BATTERY_VOLTAGE
        // Get voltages from NVS for Neopixel
        float vLowIndicator = gPrefsSettings.getFloat("vIndicatorLow", 999.99);
        if (vLowIndicator <= 999) {
            voltageIndicatorLow = vLowIndicator;
            snprintf(Log_Buffer, Log_BufferLength, "%s: %.2f V", (char *) FPSTR(voltageIndicatorLowFromNVS), vLowIndicator);
            Log_Println(Log_Buffer, LOGLEVEL_INFO);
        } else { // preseed if not set
            gPrefsSettings.putFloat("vIndicatorLow", voltageIndicatorLow);
        }

        float vHighIndicator = gPrefsSettings.getFloat("vIndicatorHigh", 999.99);
        if (vHighIndicator <= 999) {
            voltageIndicatorHigh = vHighIndicator;
            snprintf(Log_Buffer, Log_BufferLength, "%s: %.2f V", (char *) FPSTR(voltageIndicatorHighFromNVS), vHighIndicator);
            Log_Println(Log_Buffer, LOGLEVEL_INFO);
        } else {
            gPrefsSettings.putFloat("vIndicatorHigh", voltageIndicatorHigh);
        }

        float vLowWarning = gPrefsSettings.getFloat("wLowVoltage", 999.99);
        if (vLowWarning <= 999) {
            warningLowVoltage = vLowWarning;
            snprintf(Log_Buffer, Log_BufferLength, "%s: %.2f V", (char *) FPSTR(warningLowVoltageFromNVS), vLowWarning);
            Log_Println(Log_Buffer, LOGLEVEL_INFO);
        } else {
            gPrefsSettings.putFloat("wLowVoltage", warningLowVoltage);
        }

        uint32_t vInterval = gPrefsSettings.getUInt("vCheckIntv", 17777);
        if (vInterval != 17777) {
            voltageCheckInterval = vInterval;
            snprintf(Log_Buffer, Log_BufferLength, "%s: %u Minuten", (char *) FPSTR(voltageCheckIntervalFromNVS), vInterval);
            Log_Println(Log_Buffer, LOGLEVEL_INFO);
        } else {
            gPrefsSettings.putUInt("vCheckIntv", voltageCheckInterval);
        }
    #endif
}

// The average of several analog reads will be taken to reduce the noise (Note: One analog read takes ~10µs)
float Battery_GetVoltage(void) {
    #ifdef MEASURE_BATTERY_VOLTAGE
        float factor = 1 / ((float) rdiv2 / (rdiv2 + rdiv1));
        float averagedAnalogValue = 0;
        uint8_t i;
        for (i = 0; i <= 19; i++) {
            averagedAnalogValue += (float) analogRead(VOLTAGE_READ_PIN);
        }
        averagedAnalogValue /= 20.0;
        return (averagedAnalogValue / maxAnalogValue) * referenceVoltage * factor + offsetVoltage;
    #endif
}

// Measures voltage of a battery as per interval or after bootup (after allowing a few seconds to settle down)
void Battery_Cyclic(void) {
    #ifdef MEASURE_BATTERY_VOLTAGE
        static uint32_t lastVoltageCheckTimestamp = 0;

        if ((millis() - lastVoltageCheckTimestamp >= voltageCheckInterval * 60000) || (!lastVoltageCheckTimestamp && millis() >= 10000)) {
            float voltage = Battery_GetVoltage();

            if (voltage <= warningLowVoltage) {
                snprintf(Log_Buffer, Log_BufferLength, "%s: (%.2f V)", (char *) FPSTR(voltageTooLow), voltage);
                Log_Println(Log_Buffer, LOGLEVEL_ERROR);
                Led_Indicate(LedIndicatorType::VoltageWarning);
            }

            #ifdef MQTT_ENABLE
                char vstr[6];
                snprintf(vstr, 6, "%.2f", voltage);
                publishMqtt((char *) FPSTR(topicBatteryVoltage), vstr, false);
            #endif
            snprintf(Log_Buffer, Log_BufferLength, "%s: %.2f V", (char *) FPSTR(currentVoltageMsg), voltage);
            Log_Println(Log_Buffer, LOGLEVEL_INFO);
            lastVoltageCheckTimestamp = millis();
        }
    #endif
}