// -----------------------------------------------------------------------------
// ADS1X15-based Energy Monitor Sensor over I2C
// Copyright (C) 2017 by Xose Pérez <xose dot perez at gmail dot com>
// -----------------------------------------------------------------------------

#pragma once

#include "Arduino.h"
#include "BaseSensor.h"
#include "EmonSensor.h"

#if I2C_USE_BRZO
    #include <brzo_i2c.h>
#else
    #include <Wire.h>
#endif

#define ADS1X15_CHANNELS                (4)

#define ADS1X15_CHIP_ADS1015            (0)
#define ADS1X15_CHIP_ADS1115            (1)

#define ADS1X15_RESOLUTION              (16)

#define ADS1015_CONVERSIONDELAY         (1)
#define ADS1115_CONVERSIONDELAY         (8)

#define ADS1015_BIT_SHIFT               (4)
#define ADS1115_BIT_SHIFT               (0)

#define ADS1X15_REG_POINTER_MASK        (0x03)
#define ADS1X15_REG_POINTER_CONVERT     (0x00)
#define ADS1X15_REG_POINTER_CONFIG      (0x01)
#define ADS1X15_REG_POINTER_LOWTHRESH   (0x02)
#define ADS1X15_REG_POINTER_HITHRESH    (0x03)

#define ADS1X15_REG_CONFIG_OS_MASK      (0x8000)
#define ADS1X15_REG_CONFIG_OS_SINGLE    (0x8000)  // Write: Set to start a single-conversion
#define ADS1X15_REG_CONFIG_OS_BUSY      (0x0000)  // Read: Bit = 0 when conversion is in progress
#define ADS1X15_REG_CONFIG_OS_NOTBUSY   (0x8000)  // Read: Bit = 1 when device is not performing a conversion

#define ADS1X15_REG_CONFIG_MUX_MASK     (0x7000)
#define ADS1X15_REG_CONFIG_MUX_DIFF_0_1 (0x0000)  // Differential P = AIN0, N = AIN1 (default)
#define ADS1X15_REG_CONFIG_MUX_DIFF_0_3 (0x1000)  // Differential P = AIN0, N = AIN3
#define ADS1X15_REG_CONFIG_MUX_DIFF_1_3 (0x2000)  // Differential P = AIN1, N = AIN3
#define ADS1X15_REG_CONFIG_MUX_DIFF_2_3 (0x3000)  // Differential P = AIN2, N = AIN3
#define ADS1X15_REG_CONFIG_MUX_SINGLE_0 (0x4000)  // Single-ended AIN0
#define ADS1X15_REG_CONFIG_MUX_SINGLE_1 (0x5000)  // Single-ended AIN1
#define ADS1X15_REG_CONFIG_MUX_SINGLE_2 (0x6000)  // Single-ended AIN2
#define ADS1X15_REG_CONFIG_MUX_SINGLE_3 (0x7000)  // Single-ended AIN3

#define ADS1X15_REG_CONFIG_PGA_MASK     (0x0E00)
#define ADS1X15_REG_CONFIG_PGA_6_144V   (0x0000)  // +/-6.144V range = Gain 2/3
#define ADS1X15_REG_CONFIG_PGA_4_096V   (0x0200)  // +/-4.096V range = Gain 1
#define ADS1X15_REG_CONFIG_PGA_2_048V   (0x0400)  // +/-2.048V range = Gain 2 (default)
#define ADS1X15_REG_CONFIG_PGA_1_024V   (0x0600)  // +/-1.024V range = Gain 4
#define ADS1X15_REG_CONFIG_PGA_0_512V   (0x0800)  // +/-0.512V range = Gain 8
#define ADS1X15_REG_CONFIG_PGA_0_256V   (0x0A00)  // +/-0.256V range = Gain 16

#define ADS1X15_REG_CONFIG_MODE_MASK    (0x0100)
#define ADS1X15_REG_CONFIG_MODE_CONTIN  (0x0000)  // Continuous conversion mode
#define ADS1X15_REG_CONFIG_MODE_SINGLE  (0x0100)  // Power-down single-shot mode (default)

#define ADS1X15_REG_CONFIG_DR_MASK      (0x00E0)
#define ADS1015_REG_CONFIG_DR_128SPS    (0x0000)  // 128 samples per second
#define ADS1015_REG_CONFIG_DR_250SPS    (0x0020)  // 250 samples per second
#define ADS1015_REG_CONFIG_DR_490SPS    (0x0040)  // 490 samples per second
#define ADS1015_REG_CONFIG_DR_920SPS    (0x0060)  // 920 samples per second
#define ADS1015_REG_CONFIG_DR_1600SPS   (0x0080)  // 1600 samples per second (default)
#define ADS1015_REG_CONFIG_DR_2400SPS   (0x00A0)  // 2400 samples per second
#define ADS1015_REG_CONFIG_DR_3300SPS   (0x00C0)  // 3300 samples per second
#define ADS1115_REG_CONFIG_DR_8SPS      (0x0000)  // 8 samples per second
#define ADS1115_REG_CONFIG_DR_16SPS     (0x0020)  // 16 samples per second
#define ADS1115_REG_CONFIG_DR_32SPS     (0x0040)  // 32 samples per second
#define ADS1115_REG_CONFIG_DR_64SPS     (0x0060)  // 64 samples per second
#define ADS1115_REG_CONFIG_DR_128SPS    (0x0080)  // 128 samples per second (default)
#define ADS1115_REG_CONFIG_DR_250SPS    (0x00A0)  // 250 samples per second
#define ADS1115_REG_CONFIG_DR_475SPS    (0x00C0)  // 475 samples per second
#define ADS1115_REG_CONFIG_DR_860SPS    (0x00E0)  // 860 samples per second

#define ADS1X15_REG_CONFIG_CMODE_MASK   (0x0010)
#define ADS1X15_REG_CONFIG_CMODE_TRAD   (0x0000)  // Traditional comparator with hysteresis (default)
#define ADS1X15_REG_CONFIG_CMODE_WINDOW (0x0010)  // Window comparator

#define ADS1X15_REG_CONFIG_CPOL_MASK    (0x0008)
#define ADS1X15_REG_CONFIG_CPOL_ACTVLOW (0x0000)  // ALERT/RDY pin is low when active (default)
#define ADS1X15_REG_CONFIG_CPOL_ACTVHI  (0x0008)  // ALERT/RDY pin is high when active

#define ADS1X15_REG_CONFIG_CLAT_MASK    (0x0004)  // Determines if ALERT/RDY pin latches once asserted
#define ADS1X15_REG_CONFIG_CLAT_NONLAT  (0x0000)  // Non-latching comparator (default)
#define ADS1X15_REG_CONFIG_CLAT_LATCH   (0x0004)  // Latching comparator

#define ADS1X15_REG_CONFIG_CQUE_MASK    (0x0003)
#define ADS1X15_REG_CONFIG_CQUE_1CONV   (0x0000)  // Assert ALERT/RDY after one conversions
#define ADS1X15_REG_CONFIG_CQUE_2CONV   (0x0001)  // Assert ALERT/RDY after two conversions
#define ADS1X15_REG_CONFIG_CQUE_4CONV   (0x0002)  // Assert ALERT/RDY after four conversions
#define ADS1X15_REG_CONFIG_CQUE_NONE    (0x0003)  // Disable the comparator and put ALERT/RDY in high state (default)


class EmonADS1X15Sensor : public EmonSensor {

    public:

        // ---------------------------------------------------------------------
        // Public
        // ---------------------------------------------------------------------

        EmonADS1X15Sensor(): EmonSensor() {
            _channels = ADS1X15_CHANNELS;
            init();
        }

        void setAddress(unsigned char address) {
            if (_address != address) _dirty = true;
            _address = address;
        }

        void setType(unsigned char type) {
            if (_type != type) _dirty = true;
            _type = type;
        }

        void setMask(unsigned char mask) {
            if (_mask != mask) _dirty = true;
            _mask = mask;
        }

        void setGain(unsigned int gain) {
            if (_gain != gain) _dirty = true;
            _gain = gain;
        }

        // ---------------------------------------------------------------------
        // Sensor API
        // ---------------------------------------------------------------------

        // Initialization method, must be idempotent
        void begin() {

            if (!_dirty) return;
            _dirty = false;

            // Discover
            if (_address == 0) {
                unsigned char addresses[] = {0x48, 0x49, 0x4A, 0x4B};
                _address = i2cFindFirst(4, addresses);
            }
            if (_address == 0) {
                _error = SENSOR_ERROR_UNKNOWN_ID;
                return;
            }

            // Calculate ports
            _ports = 0;
            unsigned char mask = _mask;
            while (mask) {
                if (mask & 0x01) ++_ports;
                mask = mask >> 1;
            }
            _count = _ports * _magnitudes;

            // Bit depth
            _resolution = ADS1X15_RESOLUTION;

            // Reference based on gain
            if (_gain == ADS1X15_REG_CONFIG_PGA_6_144V) _reference = 12.288;
            if (_gain == ADS1X15_REG_CONFIG_PGA_4_096V) _reference = 8.192;
            if (_gain == ADS1X15_REG_CONFIG_PGA_2_048V) _reference = 4.096;
            if (_gain == ADS1X15_REG_CONFIG_PGA_1_024V) _reference = 2.048;
            if (_gain == ADS1X15_REG_CONFIG_PGA_0_512V) _reference = 1.024;
            if (_gain == ADS1X15_REG_CONFIG_PGA_0_256V) _reference = 0.512;

            // Call the parent class method
            EmonSensor::begin();

            // warmup all channels
            warmup();

        }

        // Descriptive name of the sensor
        String name() {
            char buffer[30];
            snprintf(buffer, sizeof(buffer), "EMON @ ADS1%d15 @ I2C (0x%02X)", _type == ADS1X15_CHIP_ADS1015 ? 0 : 1, _address);
            return String(buffer);
        }

        // Descriptive name of the slot # index
        String slot(unsigned char index) {
            char buffer[35];
            unsigned char channel = getChannel(index % _ports);
            snprintf(buffer, sizeof(buffer), "EMON @ ADS1%d15 (A%d) @ I2C (0x%02X)", _type == ADS1X15_CHIP_ADS1015 ? 0 : 1, channel, _address);
            return String(buffer);
        }

        // Type for slot # index
        magnitude_t type(unsigned char index) {
            if (index < _count) {
                _error = SENSOR_ERROR_OK;
                unsigned char magnitude = index / _ports;
                unsigned char i=0;
                #if EMON_REPORT_CURRENT
                    if (magnitude == i++) return MAGNITUDE_CURRENT;
                #endif
                #if EMON_REPORT_POWER
                    if (magnitude == i++) return MAGNITUDE_POWER_APPARENT;
                #endif
                #if EMON_REPORT_ENERGY
                    if (magnitude == i) return MAGNITUDE_ENERGY;
                #endif
            }
            _error = SENSOR_ERROR_OUT_OF_RANGE;
            return MAGNITUDE_NONE;
        }

        void pre() {
            static unsigned long last = 0;
            for (unsigned char port=0; port<_ports; port++) {
                unsigned char channel = getChannel(port);
                _current[port] = getCurrent(channel);
                #if EMON_REPORT_ENERGY
                    _energy[port] += (_current[port] * _voltage * (millis() - last) / 1000);
                #endif
            }
            last = millis();
        }

        // Current value for slot # index
        double value(unsigned char index) {

            if (index < _count) {

                _error = SENSOR_ERROR_OK;
                unsigned char port = index % _ports;
                unsigned char magnitude = index / _ports;

                unsigned char i=0;
                #if EMON_REPORT_CURRENT
                    if (magnitude == i++) return _current[port];
                #endif
                #if EMON_REPORT_POWER
                    if (magnitude == i++) return _current[port] * _voltage;
                #endif
                #if EMON_REPORT_ENERGY
                    if (magnitude == i) return _energy[port];
                #endif

            }

            _error = SENSOR_ERROR_OUT_OF_RANGE;
            return 0;

        }

    protected:

        //----------------------------------------------------------------------
        // Protected
        //----------------------------------------------------------------------

        unsigned char getChannel(unsigned char port) {
            unsigned char count = 0;
            unsigned char bit = 1;
            for (unsigned char channel=0; channel<ADS1X15_CHANNELS; channel++) {
                if ((_mask & bit) == bit) {
                    if (count == port) return channel;
                    ++count;
                }
                bit <<= 1;
            }
            return 0;
        }

        void warmup() {
            for (unsigned char port=0; port<_ports; port++) {
                unsigned char channel = getChannel(port);
                _pivot[channel] = _adc_counts >> 1;
                getCurrent(channel);
            }
        }

        //----------------------------------------------------------------------
        // I2C
        //----------------------------------------------------------------------

        void setConfigRegistry(unsigned char channel, bool continuous, bool start) {

            // Start with default values
            uint16_t config = 0;
            config |= _gain;                                // Set PGA/voltage range (0x0200)
            config |= ADS1X15_REG_CONFIG_DR_MASK;           // Always at max speed (0x00E0)
            //config |= ADS1X15_REG_CONFIG_CMODE_TRAD;        // Traditional comparator (default val) (0x0000)
            //config |= ADS1X15_REG_CONFIG_CPOL_ACTVLOW;      // Alert/Rdy active low   (default val) (0x0000)
            //config |= ADS1X15_REG_CONFIG_CLAT_NONLAT;       // Non-latching (default val) (0x0000)
            config |= ADS1X15_REG_CONFIG_CQUE_NONE;         // Disable the comparator (default val) (0x0003)
            if (start) {
                config |= ADS1X15_REG_CONFIG_OS_SINGLE;         // Start a single-conversion (0x8000)
            }
            if (continuous) {
                //config |= ADS1X15_REG_CONFIG_MODE_CONTIN;   // Continuous mode (default) (0x0000)
            } else {
                config |= ADS1X15_REG_CONFIG_MODE_SINGLE;   // Single-shot mode (0x0100)
            }
            config |= ((channel + 4) << 12);                // Set single-ended input channel (0x4000 - 0x7000)

            #if SENSOR_DEBUG
                //Serial.printf("[EMON] ADS1X115 Config Registry: %04X\n", config);
            #endif

            // Write config register to the ADC
            #if I2C_USE_BRZO
                uint8_t buffer[3];
                buffer[0] = ADS1X15_REG_POINTER_CONFIG;
                buffer[1] = config >> 8;
                buffer[2] = config & 0xFF;
                brzo_i2c_start_transaction(_address, I2C_SCL_FREQUENCY);
                brzo_i2c_write(buffer, 3, false);
                brzo_i2c_end_transaction();
            #else
                Wire.beginTransmission(_address);
                Wire.write((uint8_t) ADS1X15_REG_POINTER_CONFIG);
                Wire.write((uint8_t) (config >> 8));
                Wire.write((uint8_t) (config & 0xFF));
                Wire.endTransmission();
            #endif

        }

        double getCurrent(unsigned char channel) {

            // Force stop by setting single mode and back to continuous
            static unsigned char previous = 9;
            if (previous != channel) {
                setConfigRegistry(channel, true, false);
                setConfigRegistry(channel, false, false);
                setConfigRegistry(channel, false, true);
                delay(10);
                readADC(channel);
                previous = channel;
            }
            setConfigRegistry(channel, true, true);

            return read(channel);

        }

        unsigned int readADC(unsigned char channel) {

            (void) channel;

            unsigned int value = 0;

            #if I2C_USE_BRZO
                uint8_t buffer[3];
                buffer[0] = ADS1X15_REG_POINTER_CONVERT;
                brzo_i2c_start_transaction(_address, I2C_SCL_FREQUENCY);
                brzo_i2c_write(buffer, 1, false);
                brzo_i2c_read(buffer, 2, false);
                brzo_i2c_end_transaction();
                value |= buffer[0] << 8;
                value |= buffer[1];

            #else
                Wire.beginTransmission(_address);
                Wire.write(ADS1X15_REG_POINTER_CONVERT);
                Wire.endTransmission();
                Wire.requestFrom(_address, (unsigned char) 2);
                value |= Wire.read() << 8;
                value |= Wire.read();
            #endif

            if (_type = ADS1X15_CHIP_ADS1015) value >>= ADS1015_BIT_SHIFT;

            delayMicroseconds(500);

            return value;

        }

        unsigned char _address;
        unsigned char _type = ADS1X15_CHIP_ADS1115;
        unsigned char _mask = 0x0F;
        unsigned int _gain = ADS1X15_REG_CONFIG_PGA_4_096V;
        unsigned char _ports;


};