/**
 * @file battery.h
 * @author Alexander Klein (alex@kleiax.de)
 * @brief Contains a class for battery monitoring
 * @version 0.1
 * @date 2022-02-05
 * 
 * @copyright Copyright (c) 2022
 * 
 */

#ifndef BATTERY_H
#define BATTERY_H

#include <stdint.h>
#include <iostream>
#include <math.h>
#include <Arduino.h>

#include "component.h"

/**
 * @brief A class for battery monitoring
 * 
 * This class reads the voltage from an analog pin to calculate the
 * charge level of a 3 Cell Li-Poly battery pack. The battery pack have
 * to be after a voltage diveder, so that maximum voltage for the
 * microcontroller is 3.3 Volt.
 */
class Battery : public Component {
    public:
        /**
         * @brief Construct a new Battery object
         * 
         * The voltage devider have to be calculated, so that the input
         * voltage from 3.3 Volt is never exceeded. It is assumed that
         * the microcontroller is connected to the second resistor.
         * 
         * @param pin The analog to read from.
         * @param r1 First resistor of the voltage devider.
         * @param r2 Second resistor of the voltage devider.
         */
        Battery(uint8_t pin, uint32_t r1, uint32_t r2);
        Battery(uint8_t pin);

        /**
         * @brief Get the battery voltage
         * 
         * @return double in Volt
         */
        double getBatteryVoltage() const;

        /**
         * @brief Get the charge level of the battery
         * 
         * @return uint8_t charge level in percent
         */
        uint8_t getBatteryPercent() const { return this->batteryPercent; }

        /**
         * @brief Checks if the battery is low.
         * 
         * The function will also return false if the battery voltage is
         * absurd low. This is for the case that the uController is powered
         * by usb and no battery is connected.
         * 
         * @param voltage the limit the battery have to
         * @return true if the battery is low
         * @return false if the battery is high
         */
        bool isBatteryLow(double voltage) const;

        bool isNewValue();

    private:
        void run() override;
        double calculateInputVoltage();
        void calculateBatteryVoltage();
        void calculateBatteryPercent();
        void readAdcToBuf();
        void initBuffer();
        uint16_t getBufAvg() const;

        static const uint8_t bufferSize = 30;

        uint8_t absurdLowVoltage = 5;
        uint8_t pin;
        uint8_t batteryPercent = 0;
        uint8_t batteryLowPercent = 10;
        uint8_t bufferPos = 0;
        uint8_t calulationDelayMultiplier = 5;
        uint8_t loopCounter = 0;
        uint16_t adcBuffer[bufferSize];
        uint32_t r1 = 0;
        uint32_t r2 = 0;
        bool calculatetNewValues = false;
        double batteryVoltage = 0;
        double batteryVoltageFactor;

        const float capacityVoltages[21] = {9.82, 10.83, 11.06, 11.12,  //  0  5 10 15
                                            11.18, 11.24, 11.3, 11.36,  // 20 25 30 35
                                            11.39, 11.45, 11.51, 11.56, // 40 45 50 55
                                            11.62, 11.74, 11.86, 11.95, // 60 65 70 75
                                            12.07, 12.25, 12.33, 12.45, // 80 85 90 95
                                            12.6 };

        const uint8_t rawAdcVoltagesCount = 60;
        const double startVoltage = 7;
        const double stepVoltage = 0.1;
        const uint16_t rawAdcVoltages[60] = // from 7.0V to 12.9V in 0.1V steps
                           {1820, 1851, 1880, 1910, 1937, 1967, 1992, 2020, 2048, 2080,
                            2109, 2136, 2163, 2189, 2218, 2244, 2273, 2302, 2334, 2363,
                            2391, 2415, 2441, 2471, 2499, 2531, 2557, 2587, 2617, 2646,
                            2674, 2699, 2730, 2761, 2791, 2816, 2843, 2872, 2900, 2930,
                            2958, 2991, 3017, 3049, 3080, 3115, 3144, 3178, 3208, 3242,
                            3276, 3313, 3346, 3389, 3433, 3470, 3509, 3548, 3590, 3636};
};

#endif // BATTERY_H